Measures of physical performance assessments: Self-Paced Walk Test (SPWT), Stair Climb Test (SCT), Six-Minute Walk Test (6MWT), Chair Stand Test (CST), Timed Up & Go (TUG), Sock Test, Lift and Carry Test (LCT), and Car Task

Authors


INTRODUCTION

In this review, clinical physical performance measures (PPMs) that relate directly to people with lower extremity osteoarthritis (OA) (1), yet are also relevant for other rheumatic conditions that affect the lower extremity, are evaluated. This information is complementary and an update to some of the measures of adult general performance presented in the special issue of Arthritis Care & Research in 2003 (2). In the current review, PPMs are defined as clinician-observed measures of physical function that assess a task that can be classified as “activities” using the World Health Organization International Classification of Functioning, Disability and Health (ICF) model (3). They do not include measures that are specific tests of body structure, body function, or impairments, e.g., specific measures of strength or balance. Physical function is related to “the ability to move around” (4) and “the ability to perform daily activities” (5) and is assessed directly by an observer while the activity is being performed by an individual, usually by timing, counting, or distance measures. PPMs measure what an individual can do rather than what the individual perceives they can do as in self-reported functional measures (5).

The selection of PPMs for this review was based on the following criteria: 1) clinical (field) tests: PPMs were selected if they were readily available, required portable or no equipment, and could be conducted within the clinical setting; 2) relevant to core activities commonly impaired in people with OA: a range of PPMs was selected to reflect the ICF activities most relevant to individuals with lower extremity OA, including walking and moving (ICF d450–69), changing and maintaining body position (ICF d410–29), climbing (ICF d4551), and carrying, moving, and handling objects (ICF d430–49); 3) current trends: PPMs that have been included in a performance battery for lower extremity OA were targeted to reflect current trends and recommendations in recent literature (a performance battery is a composite of a number of individual PPMs grouped together); and 4) most commonly cited: PPMs for individuals with OA that were most commonly cited in a literature search were given priority over those less frequently cited.

A computerized literature search using Medline, CINAHL, ISI Web of Science, Scopus, and Cochrane was performed. Key terms were mapped to medical subject headings terms: osteoarthritis (hip and knee), task performance and analysis, observation, physical examination, walking or mobility limitations, physical fitness, physical functioning or disability evaluation, and performance-based measures.

SELF-PACED WALK TEST (SPWT)

Description

Purpose.

The SPWT assesses the time it takes to walk short distances (typically less than 50 meters/150 feet). A number of different distances have been reported for the SPWT, e.g., 8 feet (6), 13 meters (7), 50 feet (8–10), or 40 meters (11–13). The SPWT is used in many population groups, including hip and knee osteoarthritis (OA), rheumatoid arthritis (RA), older adults, and children.

Content.

Individuals are asked to walk quickly and safely without overexerting themselves. The time it takes to cover a specified distance is recorded in seconds.

Domains covered.

Walking short distances.

International Classification of Functioning, Disability and Health categories.

d450: walking, d410–d429: changing and maintaining body position.

Number of items.

1.

Response options/scale.

Time (seconds). Measured on a continuous ratio scale.

Recall period for items.

Not applicable (N/A).

Endorsements.

Cibulka MT, White DM, Woehrle J, Harris-Hayes M, Enseki K, Fagerson TL, et al. Hip pain and mobility deficits. Hip osteoarthritis: clinical practice guidelines linked to the international classification of functioning, disability, and health from the orthopaedic section of the American Physical Therapy Association. J Orthop Sports Phys Ther 2009;39:A1–25 (14).

Examples of use.

Outcome measure following hip/knee arthroplasty: Kennedy DM, Stratford PW, Wessel J, Gollish JD, Penney D. Assessing stability and change of four performance measures: a longitudinal study evaluating outcome following total hip and knee arthroplasty. BMC Musculoskelet Disord 2005;6:3 (11).

Outcome measure following physical rehabilitation (exercise programs) for hip and knee OA: Galea MP, Levinger P, Lythgo N, Cimoli C, Weller R, Tully E, et al. A targeted home- and center-based exercise program for people after total hip replacement: a randomized clinical trial. Arch Phys Med Rehabil 2008;89:1442–7 (15).

Silva LE, Valim V, Pessanha AP, Oliveira LM, Myamoto S, Jones A, et al. Hydrotherapy versus conventional land-based exercise for the management of patients with osteoarthritis of the knee: a randomized clinical trial. Phys Ther 2008;88:12–21 (16).

Fisher NM, Gresham GE, Abrams M, Hicks J, Horrigan D, Pendergast DR. Quantitative effects of physical therapy on muscular and functional performance in subjects with osteoarthritis of the knees. Arch Phys Med Rehabil 1993;74:840–7 (17).

Outcomes following drug trials for OA: Altman RD, Moskowitz R. Intraarticular sodium hyaluronate (Hyalgan) in the treatment of patients with osteoarthritis of the knee: a randomized clinical trial. J Rheumatol 1998;25:2203–12 (18).

Altman RD, Rosen JE, Bloch DA, Hatoum HT, Korner P. A double-blind, randomized, saline-controlled study of the efficacy and safety of EUFLEXXA for treatment of painful osteoarthritis of the knee, with an open-label safety extension (the FLEXX trial). Semin Arthritis Rheum 2009;39:1–9 (19).

Predictive studies (risk/prevention) in hip and knee OA: Kauppila AM, Kyllonen E, Mikkonen P, Ohtonen P, Laine V, Siira P, et al. Disability in end-stage knee osteoarthritis. Disabil Rehabil 2009;31:370–80 (20).

Pua YH, Clark RA, Bryant AL. Physical function in hip osteoarthritis: relationship to isometric knee extensor steadiness. Arch Phys Med Rehabil 2010;91:1110–6 (21).

Thomas SG, Pagura SM, Kennedy D. Physical activity and its relationship to physical performance in patients with end stage knee osteoarthritis. J Orthop Sports Phys Ther 2003;33:745–54 (22).

Used in a number of different performance batteries: Lin YC, Davey RC, Cochrane T. Tests for physical function of the elderly with knee and hip osteoarthritis. Scand J Med Sci Sports 2001;11:280–6 (6).

Wright AA, Cook CE, Baxter GD, Garcia J, Abbott JH. Relationship between the Western Ontario and McMaster Universities Osteoarthritis Index Physical Function Subscale and physical performance measures in patients with hip osteoarthritis. Arch Phys Med Rehabil 2010;91:1558–64 (12).

Cecchi F, Molino-Lova R, Di Iorio A, Conti AA, Mannoni A, Lauretani F, et al. Measures of physical performance capture the excess disability associated with hip pain or knee pain in older persons. J Gerontol A Biol Sci Med Sci 2009;64:1316–24 (23).

McCarthy CJ, Oldham JA. The reliability, validity and responsiveness of an aggregated locomotor function (ALF) score in patients with osteoarthritis of the knee. Rheumatology (Oxford) 2004;43:514–7 (24).

Rejeski WJ, Ettinger WH Jr, Schumaker S, James P, Burns R, Elam JT. Assessing performance-related disability in patients with knee osteoarthritis. Osteoarthritis Cartilage 1995;3:157–67 (25).

Shields RK, Enloe LJ, Evans RE, Smith KB, Steckel SD. Reliability, validity, and responsiveness of functional tests in patients with total joint replacement. Phys Ther 1995;75:169–79 (26).

Stratford PW, Kennedy DM, Woodhouse LJ. Performance measures provide assessments of pain and function in people with advanced osteoarthritis of the hip or knee. Phys Ther 2006;86:1489–96 (27).

Steultjens MP, Roorda LD, Dekker J, Bijlsma JW. Responsiveness of observational and self-report methods for assessing disability in mobility in patients with osteoarthritis. Arthritis Rheum 2001;45:56–61 (28).

Juhakoski R, Tenhonen S, Anttonen T, Kauppinen T, Arokoski JP. Factors affecting self-reported pain and physical function in patients with hip osteoarthritis. Arch Phys Med Rehabil 2008;89:1066–73 (29) (Table 1).

Table 1. Physical performance battery membership for each physical performance measure*
Physical performance measureICF core activityPhysical performance battery
Shields et al, 1995 (26)Rejeski et al, 1995 (25)McCarthy and Oldham, 2004 (24)Steultjens et al, 2001 (28)Lin et al, 2001 (6)Stratford and Kennedy, 2006 (84)Juhakoski et al, 2008 (29)Cecchi et al, 2009 (23)Wright et al, 2010 (12)French et al, in press (85)
  • *

    ICF = International Classification of Functioning, Disability and Health; SPWT = Self-Paced Walk Test; SCT = Stair Climb Test; 6MWT = Six-Minute Walk Test; CST = Chair Stand Test; TUG = Timed Up & Go; LCT = Lift and Carry Test.

SPWT (time)d450: walking short distance d455: moving aroundX XXXXXXX 
SCT (time)d410: changing body position d455: moving around d4551: climbingXXX XX    
6MWT (distance)d450: walking long distance d455: moving around X X XXX X
CST (count)d410: changing body position  XXX  XXX
TUG (time)d450: walking short distance d455: moving around d410 changing body position     XX XX
LCT (time)d430: lift and carry objects d450: walking short distance X X      
Sock Test (0–3 grade)d540: dressing      X X 
Car Task (time)d410: changing body position X        
Transfer to/from lying down (time)d410: changing body positionX  X      
Step Test (count)d410: changing body position        X 
Standing balance (time)d415: maintaining body position       X  

Practical Application

How to obtain.

No formal instructions required.

Method of administration.

Performance based (assessed directly as test is performed). Equipment required: marked walkway, stopwatch, and tape measure. Assistive devices permissible (needs to be recorded and kept constant for comparisons).

Scoring.

Time (seconds) measured with a stopwatch. Lower values represent better performance. Time can be converted to a walking speed by dividing the distance covered by the time taken. Usually expressed as meters/second. Higher values represent better performance.

Score interpretation.

Mean ± SD normative speed reference values for healthy adults (30): woman age 50–59 years, 1.40 ± 0.15 meters/second (height normalized to 0.86); man age 50–59 years, 1.39 ± 0.23 meters/second (height normalized to 0.78); woman age 60–69 years, 1.28 ± 0.18 meters/second (height normalized to 0.81); man age 60–69 years, 1.36 ± 0.21 meters/second (height normalized to 0.78); woman age 70–79 years, 1.27 ± 0.21 meters/second (height normalized to 0.81); and man age 70–79 years, 1.33 ± 0.20 meters/second (height normalized to 0.76).

Gait speeds <1 meter/second identify a high risk of poor health-related outcomes in well-functioning older people (31). Older adults (ages ≥70 years) with slow gait speeds (≤0.7 meters/second) had a 1.5-fold increased risk of falls compared with those with normal speed (32).

Respondent burden.

Minimal; <5 minutes.

Administrative burden.

Minimal; <5 minutes. Time (seconds) is recorded on immediate completion of test. No training is required. Only 1 tester is required.

Translations/adaptations.

Easy translated/adapted into any language.

Psychometric Information

Acceptability.

Easy to use. Floor and ceiling effects have not been reported.

Reliability.

Evidence for internal consistency.

N/A.

Evidence for stability (test–retest).

50-feet SPWT: intrasession intraclass correlation coefficient (ICC1,1) 0.97 (95% confidence interval [95% CI] 0.95, 0.98) in 82 people with end-stage hip and knee OA (8). 40-meter SPWT: long interval (median 178 days) ICC2,1 0.91 (95% CI 0.81, 0.97) in 21 people with end-stage hip and knee OA (11). 8-meter SPWT: intrasession ICC2,1 0.93 (95% CI 0.88, 0.99) in 41 people with knee OA. Significant differences were found between the 5 trials, and reliability improved when the first trial was discarded: ICC2,1 0.96 (95% CI 0.93, 0.98) with no significant differences found between trials (9). 8-meter SPWT: 1-week interval ICC2,1 0.88 (95% CI 0.78, 0.93), which increased with subsequent testing a week later (ICC2,1 0.94; 95% CI 0.89, 0.97) (9).

Evidence for interrater reliability.

50-feet SPWT: baseline ICC1,1 0.94 (95% CI 0.90, 0.96) in 82 people with end-stage hip and knee OA. Reliability improved on subsequent testing occasions: ICC1,1 0.96 (95% CI 0.93, 0.98) (8). 40-meter SPWT: baseline ICC2,1 0.95 (95% CI 0.90, 0.98) in 29 people with hip OA (mean ± SD age 66.5 ± 9.4 years) when tested within a 7-day period (13).

Measurement error: minimum detectable change at 90% confidence (MDC90) and/or standard error of measurement (SEM).

40-meter SPWT: SEM 0.1 meter/second in 29 adults (mean ± SD age 66.5 ± 9.4 years) with hip OA (13). 50-feet SPWT: SEM 1.32 seconds (0.09 meter/second) and MDC90 3.08 seconds (0.2 meter/second) in 82 older people (mean ± SD age 70.3 ± 9.8 years) with end-stage hip and knee OA awaiting arthroplasty. This represents an 8.5% difference from trial to trial (8). 40-meter SPWT: SEM 1.73 seconds (95% CI 1.39–2.29; 0.14 meter/second) and MDC90 4.04 seconds (0.33 meter/second) in 21 people with end-stage hip and knee OA when tested over a long interval (median 178 days) (11).

Validity.

Evidence of content validity.

N/A.

Evidence of construct validity: function.

The 13-meter SPWT had a positive correlation with the Index of Severity for Knee (r = 0.66) in people with knee OA (7) and with the Lower Extremity Functional Scale (r = 0.59; 95% CI 0.44, 0.71) in people with knee and hip OA (33).

Evidence of construct validity: ROM.

A positive correlation was found between walking speed and flexion range of the hip and knee among 702 community-dwelling older people (r = 0.40 and 0.35, respectively) (34).

Evidence of criterion validity.

As baseline scores on the 8-feet SPWT decreased from 0.80 meter/second to 0.43 meter/second in community-dwelling older people, a greater percentage of people had disability in activities of daily living 4 years later (35). Adults ages ≥70 years with slow gait speeds (≤70 cm/second) had a 1.5-fold increased risk for falls (32).

Ability to detect change.

Evidence of responsiveness: standardized response means (SRMs) and effect sizes.

The 40-meter SPWT was responsive to detecting initial deterioration (n = 115; SRM −0.89 [95% CI −1.42, 0.68]) and then subsequent improvement (n = 89; SRM 0.79 [95% CI 0.66–1.45]) in the early postoperative period following hip or knee arthroplasty (11). Walking speed was not sensitive to change based on measures of disease activity in people with RA (36, 37).

Interpretability: minimum clinically important differences (MCIDs).

A small MCID of 0.05 meter/second and a substantial MCID of 0.10 meter/second were estimated for walking speed >10 meters in 492 community-dwelling elderly patients with mobility dysfunction, using both distribution- and anchor-based methods. Based on responsiveness indices, per-group sample size estimations when using gait velocity as an outcome measure were calculated as 142–161 subjects for small meaningful change and 37–42 subjects for substantial change (38).

In a sample of 65 patients with hip OA undergoing physiotherapy treatment, a comparison of 3 different anchor-based methods used to calculate MCIDs found that an increase greater than or equal to 0.2, 0.3, and 0.2 meter/second for the 40-meter SPWT was associated with a major improvement (defined as patient-reported change of greater than +5 on a −7 to +7 global rating of change scale) (13).

Critical Appraisal of Overall Value to the Rheumatology Community

Strengths.

A direct measure of walking speed over short distances, which is often limited in people with lower extremity OA. The test is quick and easy to perform and has minimal administrative or respondent burden. It appears to be relatively stable in people with lower extremity OA when tested over short durations (8) and appears to be a responsive outcome measure following rehabilitation and surgery (11). The SPWT has been used in 8 different performance batteries for people with lower extremity OA.

Caveats and cautions.

Baseline practice effects have been found; therefore, a practice trial is necessary prior to baseline testing and should be considered for followup testing (8). External factors such as age, sex, and ethnicity can affect results on the SPWT (39, 40). Depression and cognitive status are also associated with lower walking speeds (41). These external factors need to be considered when interpreting test results.

Clinical usability.

Easy to administer, analyze, and interpret; readily available; requires little equipment; takes <5 minutes to perform; and can be conducted in most settings. It is recommended that a practice trial be provided and patients be monitored over several occasions to improve reliability (8, 9).

The test–retest estimates of the SPWT met the requisite standards for making decisions at the individual patient level (11), whether tested by the same or different assessors (8). It is responsive to detecting deterioration and improvement in the early postoperative period (11).

The MDC90 of 0.2 meter/second found for the 50-feet SPWT provides information on the amount of change required to be confident that real change has occurred. In people with end-stage OA, this could represent up to 20% change (8).

Given that there is large variation in different methodologic approaches to define MCIDs, caution is needed when interpreting and using reported values to avoid misclassification of patient response to treatment (13).

Research usability.

The SPWT is a reliable measure in lower extremity OA. It is recommended that a practice trial be provided and patients be monitored over several occasions to improve reliability (8, 9).

Additional comparisons of methodologies used to calculate responsiveness and MCIDs are required in people with lower extremity OA (13).

STAIR CLIMB TEST (SCT)

Description

Purpose.

The SCT assesses the ability to ascend and descend a flight of stairs, as well as lower extremity strength, power, and balance.

A number of test variations have been developed for different populations (osteoarthritis [OA], rheumatoid arthritis, elderly, cardiopulmonary, cerebrovascular accident, and children). Test variations in people with lower extremity OA include the number of steps, the task requirement (ascent only or ascent/decent combined), or whether the test is timed over a set number of steps or the step count is recorded for a set period of time: 9-step ascend/descend (11, 25, 42–46), 4-step ascend/descend (6), 3-step ascent cycle duration (47), 30-second test (12 steps) (48, 49), 3-step measured on 0–6 scale of level of assistance (26), and 6-step fast and self-paced (21).

Content.

A 9-step SCT was developed for end-stage hip and knee OA (11, 42, 45, 46), which measures the time to ascend and descend a flight of 9 steps (step height 20 cm) in the usual manner at a safe and comfortable pace. Stepping pattern and use of aids are recorded. The use of a hand rail was not specified for this test.

A similar 5- or 9-step SCT was described for individuals with knee OA (25). The time required to ascend and descend an isolated set of 5 or 9 stairs (18 cm) using a single handrail is measured.

Domains covered.

Mobility and climbing.

International Classification of Functioning, Disability and Health categories.

d410–d429: changing and maintaining body position, d455: moving around, and d4551: climbing.

Number of items.

1.

Response options/scale.

Time (seconds) or number of steps negotiated measured on a continuous ratio scale.

Recall period for items.

Not applicable (N/A).

Endorsements.

Cibulka MT, White DM, Woehrle J, Harris-Hayes M, Enseki K, Fagerson TL, et al. Hip pain and mobility deficits. Hip osteoarthritis: clinical practice guidelines linked to the international classification of functioning, disability, and health from the orthopaedic section of the American Physical Therapy Association. J Orthop Sports Phys Ther 2009;39:A1–25 (14).

Logerstedt DS, Snyder-Mackler L, Ritter RC, Axe MJ. Knee pain and mobility impairments: meniscal and articular cartilage lesions. J Orthop Sports Phys Ther 2010;40:A1–35 (50).

Examples of use.

Outcome measure following hip/knee arthroplasty: Madsen OR, Brot C. Assessment of extensor and flexor strength in the individual gonarthrotic patient: interpretation of performance changes. Clin Rheumatol 1996;15:154–60 (49).

Farquhar S, Snyder-Mackler L. The Chitranjan Ranawat Award: the nonoperated knee predicts function 3 years after unilateral total knee arthroplasty. Clin Orthop Relat Res 2010;468:37–44 (51).

Floren M, Reichel H, Davis J, Laskin RS. The mini-incision mid-vastus approach for total knee arthroplasty. Oper Orthop Traumatol 2008;20:534–43 (52).

Zeni JA Jr, Snyder-Mackler L. Clinical outcomes after simultaneous bilateral total knee arthroplasty: comparison to unilateral total knee arthroplasty and healthy controls. J Arthroplasty 2010;25:541–6 (53).

Zeni JA Jr, Snyder-Mackler L. Early postoperative measures predict 1- and 2-year outcomes after unilateral total knee arthroplasty: importance of contralateral limb strength. Phys Ther 2010;90:43–54 (54).

Outcome measure following physical rehabilitation (exercise programs) in hip and knee OA: Galea MP, Levinger P, Lythgo N, Cimoli C, Weller R, Tully E, et al. A targeted home- and center-based exercise program for people after total hip replacement: a randomized clinical trial. Arch Phys Med Rehabil 2008;89:1442–7 (15).

Fisher NM, Gresham GE, Abrams M, Hicks J, Horrigan D, Pendergast DR. Quantitative effects of physical therapy on muscular and functional performance in subjects with osteoarthritis of the knees. Arch Phys Med Rehabil 1993;74:840–7 (17).

Ettinger WH Jr, Burns R, Messier SP, Applegate W, Rejeski WJ, Morgan T, et al. A randomized trial comparing aerobic exercise and resistance exercise with a health education program in older adults with knee osteoarthritis: the Fitness Arthritis and Seniors Trial (FAST). JAMA 1997;277:25–31 (55).

Fransen M, Nairn L, Winstanley J, Lam P, Edmonds J. Physical activity for osteoarthritis management: a randomized controlled clinical trial evaluating hydrotherapy or Tai Chi classes. Arthritis Rheum 2007;57:407–14 (56).

Bennell KL, Hunt MA, Wrigley TV, Hunter DJ, McManus FJ, Hodges PW, et al. Hip strengthening reduces symptoms but not knee load in people with medial knee osteoarthritis and varus malalignment: a randomised controlled trial. Osteoarthritis Cartilage 2010;18:621–8 (57).

McKnight PE, Kasle S, Going S, Villanueva I, Cornett M, Farr J, et al. A comparison of strength training, self-management, and the combination for early osteoarthritis of the knee. Arthritis Care Res (Hoboken) 2010;62:45–53 (58).

Talbot LA, Gaines JM, Huynh TN, Metter EJ. A home-based pedometer-driven walking program to increase physical activity in older adults with osteoarthritis of the knee: a preliminary study. J Am Geriatr Soc 2003;51:387–92 (59).

Outcomes following drug therapy trials: Clarke AK. A double-blind comparison of naproxen against indometacin in osteoarthrosis. Arzneimittelforschung 1975;25:302–4 (60).

Predictive studies (risk/prevention) in hip and knee OA: Pua YH, Clark RA, Bryant AL. Physical function in hip osteoarthritis: relationship to isometric knee extensor steadiness. Arch Phys Med Rehabil 2010;91:1110–6 (21).

Thomas SG, Pagura SM, Kennedy D. Physical activity and its relationship to physical performance in patients with end stage knee osteoarthritis. J Orthop Sports Phys Ther 2003;33:745–54 (22).

Singh JA, O'Byrne M, Harmsen S, Lewallen D. Predictors of moderate-severe functional limitation after primary total knee arthroplasty (TKA): 4701 TKAs at 2-years and 2935 TKAs at 5-years. Osteoarthritis Cartilage 2010;18:515–21 (61).

Zeni JA Jr, Axe MJ, Snyder-Mackler L. Clinical predictors of elective total joint replacement in persons with end-stage knee osteoarthritis. BMC Musculoskelet Disord 2010;11:86 (62).

Zeni JA Jr, Snyder-Mackler L. Preoperative predictors of persistent impairments during stair ascent and descent after total knee arthroplasty. J Bone Joint Surg Am 2010;92:1130–6 (63).

Cost-effectiveness: Sevick MA, Bradham DD, Muender M, Chen GJ, Enarson C, Dailey M, et al. Cost-effectiveness of aerobic and resistance exercise in seniors with knee osteoarthritis. Med Sci Sports Exerc 2000;32:1534–40 (64).

Used in a number of different performance batteries: Lin YC, Davey RC, Cochrane T. Tests for physical function of the elderly with knee and hip osteoarthritis. Scand J Med Sci Sports 2001;11:280–6 (6).

McCarthy CJ, Oldham JA. The reliability, validity and responsiveness of an aggregated locomotor function (ALF) score in patients with osteoarthritis of the knee. Rheumatology (Oxford) 2004;43:514–7 (24).

Rejeski WJ, Ettinger WH Jr, Schumaker S, James P, Burns R, Elam JT. Assessing performance-related disability in patients with knee osteoarthritis. Osteoarthritis Cartilage 1995;3:157–67 (25).

Shields RK, Enloe LJ, Evans RE, Smith KB, Steckel SD. Reliability, validity, and responsiveness of functional tests in patients with total joint replacement. Phys Ther 1995;75:169–79 (26).

Stratford PW, Kennedy DM, Woodhouse LJ. Performance measures provide assessments of pain and function in people with advanced osteoarthritis of the hip or knee. Phys Ther 2006;86:1489–96 (27) (Table 1).

Practical Application

How to obtain.

No formal instructions are required. Descriptions are available from the literature (25, 42, 46).

Method of administration.

Performance based (assessed directly as test is performed). Equipment required: flight of 9–12 stairs and stopwatch to time in seconds to nearest tenth.

Scoring.

Time (seconds) taken to complete the task, where smaller values represent better performance, and number of steps negotiated in set time, where larger values represent better performance.

Score interpretation.

No formal normative values were found.

Respondent burden.

Less than 5 minutes.

Administrative burden.

Less than 5 minutes, including instructions. Time to score is upon completion of test where the time (seconds) or the number of steps negotiated is recorded. The step pattern (i.e., step-to-step, step-over-step) and use of gait aids and/or handrail can also be recorded. No training is required. Only 1 tester is required.

Translations/adaptations.

Easy to translate/adapt into any language.

Psychometric Information

Acceptability.

In a sample of 106 elderly people with symptomatic hip or knee OA, all were able to complete the SCT on 2 separate occasions (6).

Reliability.

Evidence for internal consistency.

N/A.

Evidence for stability (test–retest).

9-step SCT: long interval (median 178 days) intraclass correlation coefficient (ICC2,1) 0.90 (95% confidence interval [95% CI] 0.79, 0.96) in 21 people with end-stage hip and knee OA (11). 4-step SCT: intrasession ICC2,1 0.94–0.96 (95% CI 0.75, 0.99) in 106 older adults with symptomatic hip and/or knee OA (6). 5- or 9-step SCT: r = 0.93 in 25 people with knee OA over a 2-week period (25). When tested over a 3-month period test–retest reliability decreased (r = 0.75), reflecting the possibility of true change over this timeframe (25).

Evidence for interrater reliability.

Total interrater reliability between 3 clinicians: ICC2,1 0.94 (95% CI 0.55, 0.98) in 22 people 2–6 months following knee arthroplasty (65).

Measurement error: minimum detectable change at 90% confidence (MDC90) and/or standard error of measurement (SEM).

9-step SCT: an SEM of 2.35 seconds (95% CI 1.89, 3.10) and an MDC90 of 5.5 seconds were found in a sample of 21 people with end-stage hip and knee OA awaiting arthroplasty (mean ± SD age 63.7 ± 10.7 years) (11). 4-step SCT: an SEM of 0.25–0.28 seconds was found in 106 elderly people with symptomatic hip/knee OA (6). 11-step SCT: an SEM of 1.14 seconds and an MDC90 of 2.6 seconds was found in a sample of 22 people with lower extremity OA following knee arthroplasty (65).

Validity.

Evidence of content validity.

N/A.

Evidence of construct validity: function.

A positive correlation (r = 0.53) was found between the 4-step SCT and the Western Ontario and McMaster Universities Osteoarthritis Index physical functioning subscale in 106 elderly people with symptomatic hip/knee OA (6). A positive correlation (r = 0.44) was found between the 3-minute SCT (number of steps) and the Walking Impairment Questionnaire stair climbing subscale in 105 overweight patients with knee OA (66).

Evidence of construct validity: strength.

Negative correlations were found between the 9-step SCT and quadriceps/hamstring strength in knee OA (43, 67). Lower values (faster time) on the SCT indicated better performance, whereas higher values on the lower extremity strength test indicated better performance (r = −0.50 and −0.52, respectively).

Evidence of criterion validity.

The SCT correlated well (r = 0.59–0.68) with other physical performance measures (figure-8 walk test, gait speed, chair rise test) when tested following knee arthroplasty. The SCT was best associated with gait speed and least associated with the chair rise test (65).

Ability to detect change.

Evidence of responsiveness: standardized response means (SRMs) and effect sizes (ES).

The 9-step SCT was responsive to detecting initial deterioration (n = 87; SRM −1.74 [95% CI −2.13, −1.45]) and then subsequent improvement (n = 73; SRM 1.98 [95% CI 1.68, 2.42]) in 150 patients during the early postoperative period following hip or knee arthroplasty (11). The 12-step SCT was the most responsive physical performance measure during short-term recovery following knee arthroplasty, with an ES of −0.71 (worsening) 1 month postoperatively and an ES of 0.84 (improvement) at 12-month followup (67).

Interpretability: minimum clinically important differences (MCIDs).

No information on the MCID relevant to lower extremity OA could be found.

Critical Appraisal of Overall Value to the Rheumatology Community

Strengths.

The SCT is a direct measure of the ability to negotiate stairs, which is a common activity limitation and rehabilitation goal in people with lower extremity OA (68). The SCT appears to be stable in people with lower extremity OA and appears to be responsive to detect change (expected improvement and expected deterioration) following interventions such as physiotherapy and joint replacement surgery. The SCT correlates well with other physical performance measures and is best correlated with walking speed (6, 65).

The SCT has been used in 6 different performance batteries for people with lower extremity OA (6, 24–27, 29).

Caveats and cautions.

The SCT was dropped from 1 performance battery (27, 69), as it was thought to be measuring more complex constructs than just physical performance similar to some of the self-reported measures (70).

Direct comparisons of the SCT across studies and during multiple assessments require the utilization of consistent specifications used during testing. These specifications include the step number, step height, and depth; use of a hand rail; and use of assistive devices.

Clinical usability.

Easy to administer, analyze, and interpret; readily available; requires little equipment; takes <5 minutes to perform; and can be conducted in most settings provided access to stairs is available. There is a lack of information concerning the MCID for specific disease conditions, including OA.

Research usability.

The SCT is relatively stable across time provided standardized environment, instructions, and encouragement are supplied. The SCT is found to have greater responsiveness than the patient-report questionnaires during the acute stages after knee replacement surgery and was shown to be the most responsive physical performance measure in the early recovery period (67). Further knowledge is required on the MCID in different disease conditions such as lower extremity OA.

SIX-MINUTE WALK TEST (6MWT)

Description

Purpose.

The 6MWT assesses endurance and ability to walk over longer distances. The 6MWT was first described as a field test for physical fitness in 1963 (71) and then as a 12-minute walk test in people with chronic bronchitis (72). The 6MWT was found to perform as well as the 12-minute walk (73), and is now used to assess the submaximal level of functional performance at a similar level required for daily physical activities (74).

Used in many conditions, such as osteoarthritis (OA), cardiopulmonary disease, stroke, traumatic brain injury, patients who have undergone an amputation, Parkinson's disease, and Alzheimer's disease, as well as in elderly populations and children.

Content.

Measures the distance an individual is able to walk in 6 minutes on a hard, flat, indoor surface. Standardized verbal encouragement (e.g., “5 minutes to go–keep going you are doing really well”) can be provided at minute intervals and rest is allowed as required.

Domains covered.

Walking long distances.

International Classification of Functioning, Disability and Health categories.

d410–d429: changing and maintaining body position, d450: walking.

Number of items.

1.

Response options/scale.

Distance (meters) measured on a continuous ratio scale.

Recall period for items.

Not applicable (N/A).

Endorsements.

The American College of Rheumatology (http://www.rheumatology.org/practice/clinical/clinicianresearchers/outcomes-instrumentation/6MWT.asp).

Logerstedt DS, Snyder-Mackler L, Ritter RC, Axe MJ. Knee pain and mobility impairments: meniscal and articular cartilage lesions. J Orthop Sports Phys Ther 2010;40:A1–35 (50).

Examples of use.

Outcome measure following hip/knee arthroplasty: Kennedy DM, Stratford PW, Wessel J, Gollish JD, Penney D. Assessing stability and change of four performance measures: a longitudinal study evaluating outcome following total hip and knee arthroplasty. BMC Musculoskelet Disord 2005;6:3 (11).

Parent E, Moffet H. Comparative responsiveness of locomotor tests and questionnaires used to follow early recovery after total knee arthroplasty. Arch Phys Med Rehabil 2002;83:70–80 (47).

Mizner RL, Petterson SC, Clements KE, Zeni JA Jr, Irrgang JJ, Snyder-Mackler L. Measuring functional improvement after total knee arthroplasty requires both performance-based and patient-report assessments: a longitudinal analysis of outcomes. J Arthroplasty 2011;26:728–37 (67).

Stratford PW, Kennedy DM, Maly MR, Macintyre NJ. Quantifying self-report measures' overestimation of mobility scores postarthroplasty. Phys Ther 2010;90:1288–96 (75).

Outcome measure following physical rehabilitation in hip and knee OA: Ettinger WH Jr, Burns R, Messier SP, Applegate W, Rejeski WJ, Morgan T, et al. A randomized trial comparing aerobic exercise and resistance exercise with a health education program in older adults with knee osteoarthritis: the Fitness Arthritis and Seniors Trial (FAST). JAMA 1997;277:25–31 (55).

Foley A, Halbert J, Hewitt T, Crotty M. Does hydrotherapy improve strength and physical function in patients with osteoarthritis: a randomised controlled trial comparing a gym based and a hydrotherapy based strengthening programme. Ann Rheum Dis 2003;62:1162–7 (76).

Deyle GD, Henderson NE, Matekel RL, Ryder MG, Garber MB, Allison SC. Effectiveness of manual physical therapy and exercise in osteoarthritis of the knee: a randomized, controlled trial. Ann Intern Med 2000;132:173–81 (77).

Moffet H, Collet JP, Shapiro SH, Paradis G, Marquis F, Roy L. Effectiveness of intensive rehabilitation on functional ability and quality of life after first total knee arthroplasty: a single-blind randomized controlled trial. Arch Phys Med Rehabil 2004;85:546–56 (78).

Outcomes following drug therapy trials: Frestedt JL, Kuskowski MA, Zenk JL. A natural seaweed derived mineral supplement (Aquamin F) for knee osteoarthritis: a randomised, placebo controlled pilot study. Nutr J 2009;8:7 (79).

Predictive studies (risk/prevention) in hip and knee OA: Juhakoski R, Tenhonen S, Anttonen T, Kauppinen T, Arokoski JP. Factors affecting self-reported pain and physical function in patients with hip osteoarthritis. Arch Phys Med Rehabil 2008;89:1066–73 (29).

Farquhar S, Snyder-Mackler L. The Chitranjan Ranawat Award: the nonoperated knee predicts function 3 years after unilateral total knee arthroplasty. Clin Orthop Relat Res 2010;468:37–44 (51).

Maly MR, Costigan PA, Olney SJ. Role of knee kinematics and kinetics on performance and disability in people with medial compartment knee osteoarthritis. Clin Biomech (Bristol, Avon) 2006;21:1051–9 (80).

Crosbie J, Naylor J, Harmer A, Russell T. Predictors of functional ambulation and patient perception following total knee replacement and short-term rehabilitation. Disabil Rehabil 2010;32:1088–98 (81).

Parent E, Moffet H. Preoperative predictors of locomotor ability two months after total knee arthroplasty for severe osteoarthritis. Arthritis Rheum 2003;49:36–50 (82).

Predictive studies for hospitalization and mortality: Lord SR, Menz HB. Physiologic, psychologic, and health predictors of 6-minute walk performance in older people. Arch Phys Med Rehabil 2002;83:907–11 (83).

Used in a number of different performance batteries for people with lower extremity OA: Cecchi F, Molino-Lova R, Di Iorio A, Conti AA, Mannoni A, Lauretani F, et al. Measures of physical performance capture the excess disability associated with hip pain or knee pain in older persons. J Gerontol A Biol Sci Med Sci 2009;64:1316–24 (23).

Rejeski WJ, Ettinger WH Jr, Schumaker S, James P, Burns R, Elam JT. Assessing performance-related disability in patients with knee osteoarthritis. Osteoarthritis Cartilage 1995;3:157–67 (25).

Juhakoski R, Tenhonen S, Anttonen T, Kauppinen T, Arokoski JP. Factors affecting self-reported pain and physical function in patients with hip osteoarthritis. Arch Phys Med Rehabil 2008;89:1066–73 (29).

Stratford PW, Kennedy DM. Performance measures were necessary to obtain a complete picture of osteoarthritic patients. J Clin Epidemiol 2006;59:160–7 (84).

French HP, Fitzpatrick M, FitzGerald O. Responsiveness of physical function outcomes following physiotherapy intervention for osteoarthritis of the knee: an outcome comparison study. Physiotherapy. In press (85) (Table 1).

Used as a measure on the Senior's Fitness Test (Fullerton Functional Test), developed as part of the LifeSpan Wellness Program: Rikli RE, Jones CJ. The development and validation of a functional fitness test for community-residing older adults. J Aging Phys Act 1999;7:129–61 (86).

Rikli RE, Jones CJ. Functional fitness normative scores for community-residing older adults, ages 60–94. J Aging Phys Act 1999;7:162–81 (87).

Practical Application

How to obtain.

Descriptions are readily available online at: http://www.thoracic.org/statements/resources/pfet/sixminute.pdf and http://www.topendsports.com/testing/tests/walk-6min.htm.

Method of administration.

Performance based (assessed directly as test is performed). Ideally conducted in an enclosed quiet hallway by a single administrator. A standardized procedure is important as performance can vary depending on the instructions provided, number of turns in the course, frequency and type of encouragement given, and number of trials performed.

Equipment required: 30 meters, premeasured flat walking area with interval markings every 3 meters, cones or brightly colored tape to mark boundaries of the course, watch or timer, and a chair (for resting if required).

Scoring.

Distance (meters). Resting is allowed, but the time is not stopped. A greater distance represents better performance.

Score interpretation.

In a sample of 109 (61 women) healthy white subjects ages 45–85 years, the average distances were: men, 682 meters (range 549–900) and women, 643 meters (range 479–816).

For patients with advanced lung disease/chronic obstructive pulmonary disease or heart failure, a 6MWT distance of <300 meters was associated with increased morbidity and mortality (88).

6MWT distances were found to be associated with age, sex, and height, and in women, body mass index (BMI). Regression equations to predict 6MWT in middle-aged and elderly adults were calculated (89): men, 6MWT (meters) = 867 − (5.71 age, years) + (1.03 height, cm) and women, 6MWT (meters) = 525 − (2.86 age, years) + (2.71 height, cm) − (6.22 BMI, kg/m2).

Respondent burden.

Minimal; <10 minutes. Could be physically demanding for very frail people or those with respiratory disorders.

Administrative burden.

Less than 10 minutes, including instructions. Time to score is upon completion of the test where distance covered is calculated. It has been recommended that technicians who administer the 6MWT should be trained using a standard protocol, be supervised for several tests before administering them, and have cardiopulmonary resuscitation training (74).

Translations/adaptations.

Easily translated/adapted into any language.

Psychometric Information

Acceptability.

Possible ceiling effects for people with normal or high exercise capacities. Large baseline distances may limit the ability to detect performance improvements over time.

Reliability.

Evidence for internal consistency.

N/A.

Evidence for stability (test–retest).

Intrasession stability intraclass correlation coefficient (ICC2,1) 0.95–0.97 in 96 community-dwelling elderly people (ages 61–89 years) with independent functioning (40). Long interval (median 178 days) test–retest ICC2,1 0.94 (95% confidence interval [95% CI] 0.88, 0.98) in 21 people with end-stage hip and knee OA (11).

Measurement error: minimum detectable change at 90% confidence (MDC90) and/or standard error of measurement (SEM).

An SEM of 26.9 meters (95% CI 21.1, 34.8) and an MDC90 of 61.3 meters were found in 21 people with end-stage hip and knee OA awaiting arthroplasty (mean ± SD age 63.7 ± 10.7 years) (11).

Validity.

Evidence of content validity.

N/A.

Evidence of construct validity: endurance.

A positive correlation (r = 0.71) was found with maximum oxygen consumption following knee arthroplasty (90).

Evidence of construct validity: strength.

Positive correlations (r = 0.44–0.47) were found with quadriceps/hamstring strength in knee OA (43, 67) and (r = 0.58) with quadriceps strength 12 months post–knee arthroplasty (91).

Evidence of construct validity: function.

A positive correlation was found with the Walking Impairment Questionnaire distance subscale (r = 0.52) and speed subscale (r = 0.51) in 105 overweight people with knee OA (66).

A positive correlation was found with the Short Form 36 physical function scale (r = 0.62) (91). The 6MWT was less well correlated with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function subscale (r = −0.27; a negative value was expected as greater values on the 6MWT indicated better performance, whereas lower values on the WOMAC indicated better function) in people with hip OA (29).

Evidence of criterion validity.

Preoperative 6MWT scores, along with knee pain and knee flexion range, were significant predictors (adjusted R2 = 0.66) of locomotor ability 2 months after knee arthroplasty (82).

Ability to detect change.

Evidence of responsiveness: standardized response means (SRMs) and effect sizes (ES).

The 6MWT was responsive to detecting initial deterioration (n = 82; SRM −1.74 [95% CI −1.97, −1.60]) and then subsequent improvement (n = 61; SRM 1.90 [95% CI 1.46, 2.39]) in the early postoperative period following hip or knee arthroplasty in 150 subjects (11). It was found to be the most responsive physical performance measure in 39 patients with knee OA following physiotherapy intervention (ES 0.43, SRM 0.54) (85).

Interpretability: minimum clinically important differences (MCIDs).

A small MCID of 20 meters and a substantial MCID of 50 meters have been estimated for the 6MWT in a sample of 492 community-dwelling elderly people with mobility dysfunction when using both distribution- and anchor-based methods. Based on responsiveness indices, per-group sample size estimations for the 6MWT were calculated as 71–115 subjects for a small meaningful change and 13–20 subjects for a substantial meaningful change (38).

The smallest difference that was associated with a noticeable clinical difference in patients' perceptions of exercise performance (i.e., “a little bit better”) was 54 meters (37, 71) in a study of 112 patients (50% women) with stable severe chronic obstructive pulmonary disease (92).

Critical Appraisal of Overall Value to the Rheumatology Community

Strengths.

The 6MWT measures submaximal functional performance, which is a common problem found in people with lower extremity OA (68). It appears to be sensitive to detect change following interventions such as physical therapy and joint replacement surgery. The measure appears to be appropriate for both early and end-stage OA as well as postarthroplasty.

The 6MWT has been used in a number of different performance batteries for people with lower extremity OA (23, 25, 29, 84, 85). It is also used in the Senior's Fitness Test (Fullerton Functional Test) developed as part of the LifeSpan Wellness Program (86, 87).

Caveats and cautions.

The 6MWT is a single measure that evaluates the global and integrated responses of the systems (cardiovascular, cardiopulmonary, and neuromuscular) involved during exercise. As such, a single distance score may not provide specific information on the function or contribution of each of the systems involved in the test. This may limit its use as an outcome measure for some populations, such as in systemic sclerosis (93).

A number of factors can cause variations in performance and therefore need to be documented. Encouragement has been shown to increase the distance walked (94). The number of trials performed can also vary the walk distance (95). It has been suggested that a practice test is not needed in most clinical settings but should be considered. If a practice test is performed, then at least 1-hour rest should be allowed before the second test. The greatest distance is then recorded (74).

Contraindications.

Absolute: unstable coronary disease. Relative: resting heart rate >120 beats/minute, systolic blood pressure (BP) >180 mm Hg, diastolic BP >100 mm Hg; exertional angina without availability of antiangina medications; resting tachycardia >120 beats/minute; and syncope during exercise (especially in pulmonary hypertension) (74, 88).

Clinical usability.

Easy to administer, analyze, and interpret; readily available; requires little equipment; takes <10 minutes to perform; and can be conducted in most settings provided enough space is available.

There is a lack of information concerning the MCID for specific disease conditions, including OA. Current knowledge of MCIDs for the 6MWT in elderly people with mobility dysfunction suggests this value is smaller than the minimum detectable change (MDC) in people with lower extremity OA (38).

Research usability.

The 6MWT is relatively stable across time provided standardized environment, instructions, and encouragement are supplied. Further knowledge is required on the MDC and MCID in different disease conditions such as lower extremity OA. Administrative and respondent burden does not limit research use.

CHAIR STAND TEST (CST)

Description

Purpose.

The CST assesses the ability to rise from a chair and sit back down, as well as lower body strength and power.

Measured by either the time it takes to complete a specified number of chair stand repetitions (e.g., 10 repetitions [96], once [41], or 5 repetitions [35, 97]) or the number of chair stand repetitions possible in a 30-second period (8, 48, 98).

The 10-repetition CST was originally developed for people with polymyositis and lower extremity weakness (96). A 30-second CST was later developed for community-dwelling older adults (ages 66–97 years) (98). It is also used in hip and knee osteoarthritis (OA), older adults, and children.

Content.

For the 30-second CST, individuals are required to stand up from a standard chair (∼43 cm) to a fully extended standing position as many times as possible with their arms folded across their chest. The number of completed repetitions achieved in 30 seconds is recorded (98).

Domains covered.

Sitting and getting in/out of a seated position.

International Classification of Functioning, Disability and Health categories.

d410: changing basic body position.

Number of items.

1.

Response options/scale.

The total number of stand repetitions completed in 30 seconds or the time it takes to complete a specified number of repetitions measured on a continuous ratio scale.

Recall period for items.

Not applicable (N/A).

Endorsements.

None known.

Examples of use.

Outcome measure following hip/knee arthroplasty: Boonstra MC, De Waal Malefijt MC, Verdonschot N. How to quantify knee function after total knee arthroplasty? Knee 2008;15:390–5 (99).

Catani F, Innocenti B, Belvedere C, Labey L, Ensini A, Leardini A. The Mark Coventry Award: articular contact estimation in TKA using in vivo kinematics and finite element analysis. Clin Orthop Relat Res 2010;468:19–28 (100).

Outcome measure following physical rehabilitation (exercise programs) in hip and knee OA: Talbot LA, Gaines JM, Huynh TN, Metter EJ. A home-based pedometer-driven walking program to increase physical activity in older adults with osteoarthritis of the knee: a preliminary study. J Am Geriatr Soc 2003;51:387–92 (59).

French HP, Fitzpatrick M, FitzGerald O. Responsiveness of physical function outcomes following physiotherapy intervention for osteoarthritis of the knee: an outcome comparison study. Physiotherapy. In press (85).

Arnold CM, Faulkner RA. The effect of aquatic exercise and education on lowering fall risk in older adults with hip osteoarthritis. J Aging Phys Act 2010;18:245–60 (101).

Piva SR, Gil AB, Almeida GJ, DiGioia AM 3rd, Levison TJ, Fitzgerald GK. A balance exercise program appears to improve function for patients with total knee arthroplasty: a randomized clinical trial. Phys Ther 2010;90:880–94 (102).

Wang C, Schmid CH, Hibberd PL, Kalish R, Roubenoff R, Rones R, et al. Tai Chi is effective in treating knee osteoarthritis: a randomized controlled trial. Arthritis Rheum 2009;61:1545–53 (103).

Outcomes following drug trials for OA: Fujita T, Fujii Y, Munezane H, Ohue M, Takagi Y. Analgesic effect of raloxifene on back and knee pain in postmenopausal women with osteoporosis and/or osteoarthritis. J Bone Miner Metab 2010;28:477–84 (104).

Predictive studies (risk/prevention) in hip and knee OA: Guralnik JM, Ferrucci L, Simonsick EM, Salive ME, Wallace RB. Lower-extremity function in persons over the age of 70 years as a predictor of subsequent disability. N Engl J Med 1995;332:556–61 (35).

The CST has been used in a number of different performance batteries: Lin YC, Davey RC, Cochrane T. Tests for physical function of the elderly with knee and hip osteoarthritis. Scand J Med Sci Sports 2001;11:280–6 (6).

Cecchi F, Molino-Lova R, Di Iorio A, Conti AA, Mannoni A, Lauretani F, et al. Measures of physical performance capture the excess disability associated with hip pain or knee pain in older persons. J Gerontol A Biol Sci Med Sci 2009;64:1316–24 (23).

McCarthy CJ, Oldham JA. The reliability, validity and responsiveness of an aggregated locomotor function (ALF) score in patients with osteoarthritis of the knee. Rheumatology (Oxford) 2004;43:514–7 (24).

Steultjens MP, Roorda LD, Dekker J, Bijlsma JW. Responsiveness of observational and self-report methods for assessing disability in mobility in patients with osteoarthritis. Arthritis Rheum 2001;45:56–61 (28).

French HP, Fitzpatrick M, FitzGerald O. Responsiveness of physical function outcomes following physiotherapy intervention for osteoarthritis of the knee: an outcome comparison study. Physiotherapy. In press (85).

Wright AA, Hegedus EJ, David Baxter G, Abbott JH. Measurement of function in hip osteoarthritis: developing a standardized approach for physical performance measures. Physiother Theory Pract 2011;27:253–62 (105) (Table 1).

Also used in the Senior's Fitness Test (Fullerton Functional Test) developed as part of the LifeSpan Wellness Program: Rikli RE, Jones CJ. The development and validation of a functional fitness test for community-residing older adults. J Aging Phys Act 1999;7:129–61 (86).

Rikli RE, Jones CJ. Functional fitness normative scores for community-residing older adults, ages 60–94. J Aging Phys Act 1999;7:162–81 (87).

Practical Application

How to obtain.

Descriptions are readily available online at: http://www.topendsports.com/testing/tests/chair-stand.htm.

Method of administration.

Performance based (assessed directly as test is performed). Equipment required: a straight back chair without arm rests (seat 43 cm high) and a stopwatch or timer (30 seconds).

Scoring.

Number of repetitions (count), where higher values represent better performance, and time (seconds) taken to complete set number or repetitions, where smaller values (faster time) represent better performance.

Score interpretation.

Normative scores for the 30-second CST in community-dwelling older people (87): age range 60–64 years, average count for women 12–17, average count for men 14–19; age range 65–69 years, average count for women 11–16, average count for men 12–18; age range 70–74 years, average count for women 10–15, average count for men 12–17; age range 75–79 years, average count for women 10–15, average count for men 11–17; age range 80–84 years, average count for women 9–14, average count for men 10–15; age range 85–89 years, average count for women 8–13, average count for men 8–14; age range 90–94 years, average count for women 4–11, average count for men 7–12.

The score interpretation calculator is available online at: http://www.exrx.net/Calculators/SeniorChairStand.html.

Respondent burden.

Less than 3 minutes.

Administrative burden.

Less than 3 minutes to administer, including instructions. Time to score is upon completion of test where the number of stands/time taken is recorded. The use of arms to assist in standing/sitting can also be recorded. No training is required. Only 1 tester is required.

Translations/adaptations.

Easy to translate/adapt into any language.

Psychometric Information

Acceptability.

Possible floor effects have been found for the repetition CST. In a sample of 106 older adults with symptomatic hip or knee OA, 24% were unable to complete the 5-repetition chair rise test due to pain (6).

Similarly, in a sample of 5,000 community-dwelling residents, 22% of people age >71 years could not complete the 5-repetition chair rise test (106).

Reliability.

Evidence for internal consistency.

N/A.

Evidence for stability (test–retest).

30-second CST: intrasession intraclass correlation coefficient (ICC1,1) 0.95 (95% confidence interval [95% CI] 0.93, 0.97) in 82 older people with end-stage hip or knee OA (8). 5-repetition CST: intrasession ICC2,1 0.94–0.96 (95% CI 0.75, 0.99) in 106 elderly people with symptomatic hip and/or knee OA (6). 30-second CST: 2–5 days test–retest ICC 0.89 (95% CI 0.79, 0.936) in 76 community-dwelling older person (98).

Evidence of interrater reliability.

30-second CST: ICC1,1 0.93 (95% CI 0.87, 0.96) when tested at baseline, which improved on subsequent testing occasions (ICC1,1 0.98; 95% CI 0.96, 0.99) (8); and ICC2,1 0.81 (95% CI 0.63, 0.91) in 29 people with hip OA when tested within a 7-day period (13).

Measurement error: minimum detectable change at 90% confidence (MDC90) and/or standard error of measurement (SEM).

30-second CST: an SEM of 1.3 repetitions was found in 29 people with hip OA (mean ± SD age 66.5 ± 9.4 years) (13); and an SEM of 0.7 repetitions (11% difference from trial to trial) and an MDC90 of 1.64 repetitions was found in 82 older people with end-stage hip and knee OA awaiting arthroplasty (mean ± SD age 70.3 ± 9.8 years) (8).

Validity.

Evidence of content validity.

N/A.

Evidence of construct validity: function.

A positive correlation was found with walking speed (r = 0.66) in frail older adults (107) and a positive correlation was found with the Stair Climb Test (r = 0.59) when tested following knee arthroplasty (65).

Evidence of construct validity: strength.

A moderate correlation was found with the weight-adjusted leg-press test of lower extremity strength in both community-dwelling older men (r = 0.78; 95% CI 0.63, 0.88) and women (r = 0.71; 95% CI 0.53, 0.84) (98).

Evidence of predictive validity.

A 1-repetition CST >3.5 seconds was found to be a significant predictor of falls in the ambulatory frail older people, with an adjusted odds ratio of 3.4 (95% CI 1.2, 9.4) (108).

Ability to detect change.

Evidence of responsiveness: standardized response means (SRMs) and effect sizes (ES).

A small ES (0.36, SRM 0.39; mean change score 2.2 [95% CI 0.4, 4.1]) was found for the 5-repetition CST in 39 people with knee OA following outpatient exercised-based physiotherapy (85).

Interpretability: minimum clinically important differences (MCIDs).

In a sample of 65 patients with hip OA undergoing physiotherapy treatment, a comparison of 3 different anchor-based methods used to calculate MCIDs found that an increase greater than or equal to 2.0, 2.6, and 2.1 repetitions on the 30-second CST was associated with a major improvement (defined as patient-reported change of greater than +5 on a −7 to +7 global rating of change scale) (13).

Critical Appraisal of Overall Value to the Rheumatology Community

Strengths.

A direct measure of the ability to rise from a chair, which is an activity that is commonly limited in people with lower extremity OA (4, 42, 68). The test is quick and easy to perform and has minimal administrative or respondent burden. The CST appears to be relatively stable in people with lower extremity OA when tested over short durations. The CST has been used in 6 different performance batteries for people with lower extremity OA.

Caveats and cautions.

It is important to consider the CST version (i.e., 30 seconds or repetitions) being used, as psychometric information will be specific to the method. Baseline practice effects have been found; therefore, a practice trial is recommended prior to baseline testing and should be considered for followup testing (8). Floor effects have been noted for the repetition CST, and use of the 30-second CST may help overcome this (98). Other factors such as age, sex, and ethnicity can affect the results of the CST and need to be considered when interpreting test results (39, 98).

Clinical usability.

Easy to administer, analyze, and interpret. The CST requires little equipment, can be conducted in most settings, and takes <3 minutes to perform.

Available evidence of measurement error associated with the CST indicates that a change of at least 2 repetitions in a 30-second period is required to determine real change. In some age groups, this could require that up to 22% change is required to indicate real improvement or deterioration.

Given that there is large variation in different methodologic approaches to define MCIDs, caution is needed when interpreting and using reported values to avoid misclassification of patient response to treatment (13).

Research usability.

Repeated intrasession testing may be limited, as repeated sit-to-stand activity may aggravate pain in people with OA (8). Limited information on ES limits the ability to estimate adequate sample sizes when using this measure as a primary outcome measure in clinical studies. Additional comparisons of methodologies used to calculate responsiveness and MCIDs are required in people with lower extremity OA (13).

TIMED UP & GO (TUG)

Description

Purpose.

The TUG assesses basic mobility skill as well as strength, balance, and agility. Originally developed for frail elderly people as the “Get-Up and Go Test” in 1986 (109), it was adapted in 1991 to include the “time” component (110). The TUG is used in a range of populations from children to the elderly and for many conditions, including osteoarthritis (OA), joint arthroplasty, rheumatoid arthritis (RA), hip fractures, stroke, vertigo, and cerebral palsy.

Content.

Time (seconds) taken to rise from sitting in an armchair, walk 3 meters, turn, walk back to the chair, then sit down using regular footwear and a walking aid if required.

Domains covered.

Mobility and short distances (walking, turning, rising from a chair, sitting down into a chair).

International Classification of Functioning, Disability and Health categories.

d410: changing basic body position, d450: walking, and d455: moving around.

Number of items.

1 (with 4 subcomponents: rising from sitting, walking, turning, and sitting back down).

Response options/scale.

Timed (seconds) measured on a continuous ratio scale.

Recall period for items.

Not applicable (N/A).

Endorsements.

The American College of Rheumatology (http://www.rheumatology.org/practice/clinical/clinician researchers/outcomes-instrumentation/TUG.asp).

Cibulka MT, White DM, Woehrle J, Harris-Hayes M, Enseki K, Fagerson TL, et al. Hip pain and mobility deficits. Hip osteoarthritis: clinical practice guidelines linked to the international classification of functioning, disability, and health from the orthopaedic section of the American Physical Therapy Association. J Orthop Sports Phys Ther 2009;39:A1–25 (14).

Examples of use.

Outcome measure following rehabilitation in hip and knee OA: Galea MP, Levinger P, Lythgo N, Cimoli C, Weller R, Tully E, et al. A targeted home- and center-based exercise program for people after total hip replacement: a randomized clinical trial. Arch Phys Med Rehabil 2008;89:1442–7 (15).

Fransen M, Nairn L, Winstanley J, Lam P, Edmonds J. Physical activity for osteoarthritis management: a randomized controlled clinical trial evaluating hydrotherapy or Tai Chi classes. Arthritis Rheum 2007;57:407–14 (56).

French HP, Fitzpatrick M, FitzGerald O. Responsiveness of physical function outcomes following physiotherapy intervention for osteoarthritis of the knee: an outcome comparison study. Physiotherapy. In press (85).

Hinman RS, Bennell KL, Crossley KM, McConnell J. Immediate effects of adhesive tape on pain and disability in individuals with knee osteoarthritis. Rheumatology (Oxford) 2003;42:865–9 (111).

Outcome measure following hip and knee arthroplasty: Zeni JA Jr, Axe MJ, Snyder-Mackler L. Clinical predictors of elective total joint replacement in persons with end-stage knee osteoarthritis. BMC Musculoskelet Disord 2010;11:86 (62).

Mizner RL, Petterson SC, Clements KE, Zeni JA Jr, Irrgang JJ, Snyder-Mackler L. Measuring functional improvement after total knee arthroplasty requires both performance-based and patient-report assessments: a longitudinal analysis of outcomes. J Arthroplasty 2011;26:728–37 (67).

Boonstra MC, De Waal Malefijt MC, Verdonschot N. How to quantify knee function after total knee arthroplasty? Knee 2008;15:390–5 (99).

Kennedy DM, Hanna SE, Stratford PW, Wessel J, Gollish JD. Preoperative function and gender predict pattern of functional recovery after hip and knee arthroplasty. J Arthroplasty 2006;21:559–66 (112).

Outcomes of drug therapy trials in knee OA: Kraemer WJ, Ratamess NA, Anderson JM, Maresh CM, Tiberio DP, Joyce ME, et al. Effect of a cetylated fatty acid topical cream on functional mobility and quality of life of patients with osteoarthritis. J Rheumatol 2004;31:767–74 (113).

Predictive studies (risk/prevention) in hip and knee OA: Kennedy DM, Hanna SE, Stratford PW, Wessel J, Gollish JD. Preoperative function and gender predict pattern of functional recovery after hip and knee arthroplasty. J Arthroplasty 2006;21:559–66 (112).

Arnold CM, Faulkner RA. The history of falls and the association of the timed up and go test to falls and near-falls in older adults with hip osteoarthritis. BMC Geriatr 2007;7:17 (114).

Halket A, Stratford PW, Kennedy DM, Woodhouse LJ. Using hierarchical linear modeling to explore predictors of pain after total hip and knee arthroplasty as a consequence of osteoarthritis. J Arthroplasty 2010;25:254–62 (115).

Used in a number of different performance batteries: Wright AA, Cook CE, Baxter GD, Garcia J, Abbott JH. Relationship between the Western Ontario and McMaster Universities Osteoarthritis Index Physical Function Subscale and physical performance measures in patients with hip osteoarthritis. Arch Phys Med Rehabil 2010;91:1558–64 (12).

Cecchi F, Molino-Lova R, Di Iorio A, Conti AA, Mannoni A, Lauretani F, et al. Measures of physical performance capture the excess disability associated with hip pain or knee pain in older persons. J Gerontol A Biol Sci Med Sci 2009;64:1316–24 (23).

Juhakoski R, Tenhonen S, Anttonen T, Kauppinen T, Arokoski JP. Factors affecting self-reported pain and physical function in patients with hip osteoarthritis. Arch Phys Med Rehabil 2008;89:1066–73 (29).

Stratford PW, Kennedy DM. Performance measures were necessary to obtain a complete picture of osteoarthritic patients. J Clin Epidemiol 2006;59:160–7 (84) (Table 1).

Practical Application

How to obtain.

Descriptions are readily available online at: http://www.unmc.edu/media/intmed/geriatrics/nebgec/pdf/frailelderlyjuly09/toolkits/timedupandgo_w_norms.pdf.

Method of administration.

Performance based (assessed directly as test is performed). Simple test with minimal equipment: standard arm chair (seat height ∼46 cm, arm height ∼65 cm), 3-meter walkway with floor mark, and stopwatch or watch with time in seconds. It is recommended that 2 trials are performed and the best result is used.

Scoring.

Time (seconds). Smaller values (faster time) represent better performance.

Score interpretation.

Normative age group reference (116): age 60–69 years, time 8.1 seconds (95% confidence interval [95% CI] 7.1, 9.0); age 70–79 years, time 9.2 seconds (95% CI 8.2, 10.2); and age 80–99 years, time 11.3 seconds (95% CI 10.0, 12.7).

In frail elderly people, scores <10 seconds = normal; 10–19 seconds = good mobility, can go out alone, mobile without a gait aid; 20–29 seconds = problems, cannot go outside alone, requires a gait aid; and ≥30 seconds = with increased functional dependence (110). Older adults who take >14 seconds to complete the TUG have a high risk for falls (117).

Respondent burden.

Minimal; <3 minutes.

Administrative burden.

Minimal; <3 minutes. Score is immediate. No training is required. Only 1 tester is required.

Translations/adaptations.

Easy to translate/adapt into any language. Adaptations: TUG extended (117), i.e., 1) TUG Cognitive: TUG test while counting backward from a randomly selected number between 20 and 100 and 2) TUG manual: TUG while carrying a full cup of water, and i-TUG (118), i.e., uses portable inertial sensors to automatically detect and separate the subcomponents of the TUG.

Psychometric Information

Acceptability.

In 1,200 community-dwelling older people with varying cognitive and functional ability (including fallers), 6% refused to complete the test and none were unable to complete the test (119). All but 1 was able to complete the test in a study of 65 older people with RA (120).

A floor effect has been found in short-term hospitalized older people, with ∼25% unable to complete the test (121). Ceiling effects after knee replacement have been found where improvements reach a plateau earlier than other physical performance measures (11).

Reliability.

Evidence for internal consistency.

N/A.

Evidence for stability (test–retest).

Intrasession stability in 96 community-dwelling older people (ages 61–89 years) with independent functioning was high (intraclass correlation coefficient [ICC2,1] 0.95–0.97) (40). Test–retest reliability in frail older people over longer periods (up to 132 days) was less reliable (ICC 0.74) (107). Test–test reliability in 21 people with end-stage hip and knee OA when tested over a long interval (median 178 days) was not sufficient for individual patient use (ICC2,1 0.75; 95% CI 0.51, 0.98) Testing over this time period was likely to have captured true change in this population (11).

Evidence for interrater reliability.

ICC2,1 0.87 (95% CI 0.63, 0.91) in 29 people with hip OA (mean ± SD age 66.5 ± 9.4 years) when tested within a 7-day period (13). In the frail older people, interrater reliability was high within the same day (ICC 0.99) and on a consecutive visit (ICC 0.99) when measured by a physical therapist, physician, and patient attendant (110). In 22 people with RA, interrater reliability among 3 physical therapists was also high (r = 0.97) (122).

Measurement error: minimum detectable change at 90% confidence (MDC90) and/or standard error of measurement (SEM).

An SEM of 0.84 seconds was found in a sample of 29 people with hip OA (mean ± SD age 66.5 ± 9.4 years) (13). An SEM of 1.07 seconds (95% CI 0.86, 1.41) and an MDC90 of 2.49 seconds was found in a sample of 21 people with end-stage hip and knee OA awaiting arthroplasty (mean ± SD age 63.7 ± 10.7 years) (11). An SEM of 1 second was found in 22 people with RA (mean 60 years, range 18–80 years) when tested over a 2–7-day period (122).

Validity.

Evidence of content validity.

N/A.

Evidence of construct validity: balance.

Negative correlations were found with the Berg Balance Scale in frail older people (r = −0.81) (110) and with the Tinetti Performance-Oriented Mobility Assessment balance in community dwelling older people (r = −0.55) (119).

Evidence of construct validity: gait speed.

A negative correlation with gait speed has been found in frail older people (r = −0.61) (110).

Evidence of construct validity: strength.

A negative correlation with quadriceps strength (r = −0.49) and hamstring strength (r = −0.51) has been found in people with knee OA (123).

Evidence of construct validity: function.

A negative correlation with the Bartel Index of Activity has been found in older people (r = −0.78) (110). Not well correlated with the Western Ontario and McMaster Universities Osteoarthritis Index physical function subscale (r = 0.282) in patients with hip OA, as they are measuring different constructs (29, 84). Selective in discriminating between 28 knee patients following total knee arthroplasty for OA and 31 healthy controls (99).

Evidence of criterion validity.

A TUG >10 seconds was predictive of near falls in older people with hip OA (odds ratio [OR] 3.1; 95% CI 1.0, 9.9) (114). A preoperative TUG ≥15.3 seconds was sensitive (83.3%) and specific (61.1%) to predict a deep vein thrombosis in a sample of 38 patients with hip OA following a total hip arthroplasty (OR 7.0; 95% CI 1.6, 30.8) (124).

Ability to detect change.

Evidence of responsiveness: standardized response means (SRMs) and effect sizes (ES).

Responsive in detecting initial deterioration (n= 116; SRM −1.08 [95% CI −1.38, 0.92]) and then subsequent improvement (n = 89; SRM 1.04 [95% CI 0.84, 1.61]) in the early postoperative period following hip or knee arthroplasty in 150 subjects (11).

Improvement in TUG time (P = 0.01) was found following a quadriceps and hamstrings strengthening program in a 36 people with RA (125).

A small ES (0.33, SRM 0.35) was found in 39 patients with knee OA following physiotherapy intervention. Median change score for this knee OA population was 1 second (95% CI 0.1, 1.9) (85).

Sensitivity of the TUG to detect change where change has occurred has been questioned in the less severe OA patients (126).

Interpretability: minimum clinically important differences (MCIDs).

In a sample of 65 patients with hip OA undergoing physiotherapy treatment, a comparison of 3 different anchor-based methods used to calculate MCIDs found that a reduction greater than or equal to 0.8, 1.4, and 1.2 seconds on the TUG was associated with a major improvement (defined as patient-reported change of greater than +5 on a −7 to +7 global rating of change scale) (13).

Critical Appraisal of Overall Value to the Rheumatology Community

Strengths.

Easy to administer and can be used in most environmental contexts. Requires minimal equipment and interpretation. The TUG assesses common problems found in people with lower extremity OA and can be used for a variety of other populations. Appears to be a responsive outcome measure following rehabilitation and surgery. Has been used a in a number of different performance batteries (12, 23, 29, 84).

Caveats and cautions.

The stability of the TUG over longer intervals would not meet the standards for individual patient use (11). The TUG is limited for cognitively impaired frail older people, as up to 35.5% of this subpopulation is unable to physically perform the test (127).

As the TUG incorporates 4 different subcomponents that represent different functioning constructs, the total score (time in seconds) limits interpretation about the proportional contribution of these subcomponents on activity limitation.

Clinical usability.

Easy to administer, analyze, and interpret; readily available; requires little equipment; takes <5 minutes to perform; and can be conducted in most settings. Research provided about MDC and SRM provides information on outcomes following intervention and true change over time (11).

Given that there is large variation in different methodologic approaches to define MCIDs, caution is needed when interpreting and using reported values to avoid misclassification of patient response to treatment (13).

Floor and ceiling effects may limit the use of the TUG directly following surgery such as joint replacement arthroplasty (24, 25).

Research usability.

Results may be affected by floor and ceiling effects in some subgroups. Interpretation may be limited by the multiple constructs contained in the measure. Administrative burden or respondent burden does not limit research use.

Additional comparisons of methodologies used to calculate responsiveness and MCIDs are required in people with lower extremity OA (13).

SOCK TEST

Description

Purpose.

The Sock Test assesses the ability to put on a sock or footwear. Originally developed for people with musculoskeletal pain. Also used as an outcome measure in people with back pain (128) and hip osteoarthritis (OA) (12, 29, 105).

Content.

Starting from sitting on a high bench, with feet off the floor, the person is instructed to lift up 1 leg at a time in the sagittal plane and simultaneously reach down toward the lifted foot with both hands, one on each side, grabbing the toes with the fingertips of both hands. The foot must not touch the bench and should be in the air at all times during the test. After testing each leg once, the patient is given a score on the most limited performance. Scores are given as ordinal values from 0 (can grab the toes with fingertips and perform the action with ease) to 3 (can hardly, if at all, reach as far as the malleoli).

Domains covered.

Flexibility and putting on/taking off socks.

International Classification of Functioning, Disability and Health categories.

d540: dressing.

Number of items.

1.

Response options/scale.

The test is measured using a 4-point ordinal scale (0–3) reflecting the ability and ease of the performance.

Recall period for items.

Not applicable (N/A).

Endorsements.

None found.

Examples of use.

Physical performance measure in a back pain performance battery: Strand LI, Moe-Nilssen R, Ljunggren AE. Back Performance Scale for the assessment of mobility-related activities in people with back pain. Phys Ther 2002;82:1213–23 (128).

Physical performance measure in OA performance batteries: Wright AA, Cook CE, Baxter GD, Garcia J, Abbott JH. Relationship between the Western Ontario and McMaster Universities Osteoarthritis Index Physical Function Subscale and physical performance measures in patients with hip osteoarthritis. Arch Phys Med Rehabil 2010;91:1558– 64 (12).

Wright AA, Hegedus EJ, David Baxter G, Abbott JH. Measurement of function in hip osteoarthritis: developing a standardized approach for physical performance measures. Physiother Theory Pract 2011;27:253–62 (105).

Practical Application

How to obtain.

Descriptions are available from the literature (129).

Method of administration.

Performance based (assessed directly as test is performed). Equipment required: high bench.

Scoring.

4-point ordinal grading (0–3). Smaller values represent better performance: 0 = can grab toes with fingertips, perform the action with ease; 1 = can grab toes with fingertips, but performs action with effort; 2 = can reach beyond the malleoli, but cannot reach toes; and 3 = can hardly, if at all, reach as far as the malleoli.

Score interpretation.

No formal normative values are available.

Respondent burden.

Less than 5 minutes.

Administrative burden.

Less than 5 minutes, including instructions. Time to score is upon completion of test where the test is graded on a 4-point ordinal scale.

Translations/adaptations.

Easy to translate/adapt into any language.

Psychometric Information

Acceptability.

In a study of 93 people with hip OA (mean age 66.4 years, range 41–85 years, and mean body mass index [BMI] 28.97 kg/m2, range 20.37–48.72), all participants were able to participate in the Sock Test (12).

Reliability.

Evidence for internal consistency.

N/A.

Evidence for stability (test–retest).

No evidence found.

Evidence of interrater reliability.

14-day interval: weighted κ = 0.79 (95% confidence interval 0.5, 1.0) in 21 people with musculoskeletal pain (129).

Measurement error: minimum detectable change and/or standard error of measurement.

No evidence found.

Validity.

Evidence of content validity.

N/A.

Evidence of construct validity: function.

A positive correlation was found with the Disability Rating Index (rs = 0.45) in people with musculoskeletal pain (129). A weak correlation was found with the Western Ontario and McMaster Universities Osteoarthritis Index physical functioning subscale (r = 0.243) (29).

Evidence of criterion validity.

An increased likelihood of patient-perceived functional difficulty (measured using yes/no answers to a set of 3 questions) at 1-year followup was found with higher pretest Sock Test scores (129). Using a score of 0 as a reference, a score of 2 on the Sock Test increased the likelihood of perceived functional difficulties after 1 year by 6 times, and a score of 3 increased this by 12 times (129).

The sensitivity and specificity of the Sock Test to patient-reported (yes/no) activity limitation in 237 adults with musculoskeletal pain (129) were reported as: Sock Test = 1, sensitivity 0.77, specificity 0.91; Sock Test = 2, sensitivity 0.99, specificity 0.31; Sock Test = 3, sensitivity 1.00, specificity 0.25.

Ability to detect change.

Evidence of responsiveness: standardized response means and effect sizes.

Changes in Sock Test scores between baseline testing and 1-year followup testing correlated best with changes in the dressing items on the Disability Rating Index, but the correlation was low (dressing items = 0.36, overall = 0.35) (129).

Interpretability: minimum clinically important differences (MCIDs).

No relevant evidence for MCID was found.

Critical Appraisal of Overall Value to the Rheumatology Community

Strengths.

A direct measure of putting on and taking off socks and footwear, which is a commonly reported problem in people with lower extremity OA (1). The test is quick and easy to perform and has minimal administrative or respondent burden.

The Sock Test has been used in 2 different performance batteries for people with lower extremity OA (12, 29) (Table 1).

Caveats and cautions.

Stability of this measure has not been determined and evidence to the responsiveness to change is limited. There is an increased likelihood (P < 0.05) of scoring 1 or higher on the Sock Test with increases in age and BMI. Patients between ages 51 and 65 years were almost 3 times more likely to score >0 on the Sock Test than patients between ages 21 and 35 years. Patients with BMI values >27.1 kg/m2 were almost 10 times more likely to score >0 on the Sock Test than patients with BMI <22.1 kg/m2 (129).

Clinical usability.

Easy to administer, analyze, and interpret; readily available; requires little equipment; takes <3 minutes to perform; and can be conducted in most settings provided a sufficiently high enough bench is available.

There is a lack of information concerning the stability, measurement error, and MCID for specific disease conditions, including lower extremity OA, limiting the interpretability in the clinical setting.

Research usability.

Further evaluation of the Sock Test is required to determine the stability, measurement error, and MCID for disease-specific populations, including people with OA.

LIFT AND CARRY TEST (LCT)

Description

Purpose.

The LCT assesses how quickly and how easily a person can lift up and carry an object over a short distance. It was developed in 1995 for people with knee osteoarthritis (OA) (25). Variations on the LCT have been used in other study populations such as lower back pain (128).

Content.

The test requires the person to walk ∼2.7 meters to a set of shelves, pick up a 4.5 kg weight (reported in error as 22 kg in the original article; correct weight of 4.5 kg [10 lbs] was confirmed with the corresponding author) from the lower shelf (approximately knee height), turn and carry the weight for ∼4.35 meters around a cone, return to the shelves, and place the weight on a high shelf (approximately shoulder height) as quickly as possible.

Domains covered.

Lifting and carrying objects and walking short distances.

International Classification of Functioning, Disability and Health categories.

d430: lift and carry objects and d450: walking short distances.

Number of items.

1.

Response options/scale.

Time (seconds). Measured on a continuous ratio scale. The task is also rated on a self-perceived difficulty 0–10 ordinal scale.

Recall period for items.

Not applicable (N/A).

Endorsements.

None found.

Examples of use.

Outcome measure following physical rehabilitation (exercise programs) in knee OA: Ettinger WH Jr, Burns R, Messier SP, Applegate W, Rejeski WJ, Morgan T, et al. A randomized trial comparing aerobic exercise and resistance exercise with a health education program in older adults with knee osteoarthritis: the Fitness Arthritis and Seniors Trial (FAST). JAMA 1997;277:25–31 (55).

Predictive studies (risk/prevention) in hip and knee OA: Bieleman HJ, Reneman MF, van Ittersum MW, van der Schans CP, Groothoff JW, Oosterveld FG. Self-reported functional status as predictor of observed functional capacity in subjects with early osteoarthritis of the hip and knee: a diagnostic study in the CHECK cohort. J Occup Rehabil 2009;19:345–53 (130).

Physical performance measure in a performance battery for lower extremity OA: Rejeski WJ, Ettinger WH Jr, Schumaker S, James P, Burns R, Elam JT. Assessing performance-related disability in patients with knee osteoarthritis. Osteoarthritis Cartilage 1995;3:157–67 (25) (Table 1).

Practical Application

How to obtain.

Full instructions, including script and equipment, are available from the original publication (25).

Method of administration.

Performance based (assessed directly as test is performed). Equipment required: shelves (low set to knee height and high set at shoulder height), weighted object, stopwatch, marked floor, and cone.

Scoring.

Time (seconds). Timing stops when the weight first touches the high shelf. Faster (lower) times represent better performance. The person then rates the self-perceived demand of the task on a 0–10-point difficulty scale, where 0 = easy and 10 = very difficult.

Score interpretation.

No information found.

Respondent burden.

Less than 5 minutes.

Administrative burden.

Less than 5 minutes, including instructions. Time to score is upon completion of test where the time (seconds) is recorded and the self-reported demand of the task is recorded on a 0–10-point difficulty scale.

Translations/adaptations.

None found.

Psychometric Information

Method of development.

Single item that evaluates the ability to lift and carry a weight over short distances as well as rate the self-perceived demand of the task.

Acceptability.

It is unknown whether there are any floor or ceiling effects.

Reliability.

Evidence for internal consistency.

N/A.

Evidence for stability (test–retest).

Stability of over a 14-day period: r = 0.92 in 25 people with knee OA (25). Stability over a 3-month period: r = 0.77 in 72 people with hip and knee OA. Stability may have been compromised by real change following a health education intervention that occurred in the interim period (25).

Measurement error: minimum detectable change (MDC) and/or standard error of measurement (SEM).

An SEM of 0.49–0.50 second in a sample of 25 people with knee OA and 0.27–0.30 second in a sample of 78 people with knee OA can be calculated from the data reported by Rejeski et al (25).

Validity.

Evidence of content validity.

N/A.

Evidence of construct validity.

Significant correlation with the Fitness and Arthritis Trial Functional Activities Inventory ambulation and climbing subscale (r = 0.34) (25).

Evidence of criterion validity.

As hypothesized, lower values (faster times) on the LCT were correlated (negative correlations were expected as lower values [faster time] on the LCT indicate better performance, whereas higher values on the treadmill, peak oxygen consumption [VO2max], and knee strength tests indicated better performance) concurrently with higher values on the treadmill time (r = −0.40), VO2max (r = −0.38), and knee strength (r = −0.58) in 104–437 people with knee OA (25).

Ability to detect change.

Evidence of responsiveness: standardized response means and effect sizes (ES).

Responsive to the effects of an aerobic exercise intervention (mean ± standard error of the mean 9.0 ± 0.2 seconds versus 10.0 ± 0.1 seconds; P < 0.001) and a resistance exercise intervention (mean ± standard error of the mean 9.3 ± 0.1 seconds versus 10.0 ± 0.1 seconds; P = 0.003) (55). (Note: only ± standard error of the mean was used, not SD, and ES cannot be calculated).

Interpretability: minimum clinically important differences (MCIDs).

No relevant evidence was found.

Critical Appraisal of Overall Value to the Rheumatology Community

Strengths.

A direct measure of lifting and carrying activities (such as carrying groceries or washing), which are reported to be limited in people with lower extremity OA (68). Quick and easy to perform, minimal administrative or respondent burden, but requires a contextual setup. Appears to be stable over shorter durations (2 weeks); however, may be influenced by external factors and true change over longer periods (3 months). The LCT has been used in 1 performance battery for people with lower extremity OA.

Caveats and cautions.

Small systematic improvements across time have been noted, which may reflect motivational or learning effects (25).

Clinical usability.

Easy to administer, analyze, and interpret; takes <5 minutes to perform; and can be conducted in most settings provided access to the appropriate equipment is available. There is a lack of information concerning the MDC, SEM, and MCID for specific disease conditions, including OA.

Research usability.

More research is required to determine the responsiveness to change, MDCs, and MCIDs in people with OA and other populations.

CAR TASK

Description

Purpose.

The Car Task assesses how quickly and easily a person can get in and out of the car. It was originally developed for people with knee osteoarthritis (OA) (25).

Content.

Starting ∼27 cm away from the car door with the hip aligned with the edge of the door, participants are instructed to open the door, sit down in the car, close the door, reopen the door, and then step out to resume a fully erect standing position.

Domains covered.

Getting in/out of a car.

International Classification of Functioning, Disability and Health categories.

d410: changing basic body position and d475: driving.

Number of items.

1.

Response options/scale.

Time (seconds) measured on a continuous ratio scale. The task is also rated on a self-perceived difficulty 0–10 ordinal scale.

Recall period for items.

Not applicable (N/A).

Endorsements.

None found.

Examples of use.

Outcome measure following physical rehabilitation (exercise programs) in knee OA: Ettinger WH Jr, Burns R, Messier SP, Applegate W, Rejeski WJ, Morgan T, et al. A randomized trial comparing aerobic exercise and resistance exercise with a health education program in older adults with knee osteoarthritis: the Fitness Arthritis and Seniors Trial (FAST). JAMA 1997;277:25–31 (55).

Predictive studies (risk/prevention) in hip and knee OA: Bieleman HJ, Reneman MF, van Ittersum MW, van der Schans CP, Groothoff JW, Oosterveld FG. Self-reported functional status as predictor of observed functional capacity in subjects with early osteoarthritis of the hip and knee: a diagnostic study in the CHECK cohort. J Occup Rehabil 2009;19:345–53 (130).

Physical performance measure in a performance battery for lower extremity OA: Rejeski WJ, Ettinger WH Jr, Schumaker S, James P, Burns R, Elam JT. Assessing performance-related disability in patients with knee osteoarthritis. Osteoarthritis Cartilage 1995;3:157–67 (25) (Table 1).

Practical Application

How to obtain.

Full instructions, including script and equipment, are available from the original publication (25).

Method of administration.

Performance based (assessed directly as test is performed). Equipment required: car, marker, and stopwatch.

Scoring.

Time (seconds) starts at the command “Go” and stops when the person is standing fully erect. Smaller values (faster time) represent better performance. The person then rates the self-perceived demand of the task on a 0–10-point difficulty scale, where 0 = easy and 10 = very difficult.

Score interpretation.

No information found.

Respondent burden.

Less than 10 minutes.

Administrative burden.

Less than 10 minutes, including instructions. Time to score is upon completion of the test where the time (seconds) is recorded and the self-reported demand of the task is recorded on a 0–10-point difficulty scale.

Translations/adaptations.

None found.

Psychometric Information

Acceptability.

It is unknown whether there are any floor or ceiling effects.

Reliability.

Evidence for internal consistency.

N/A.

Evidence for stability (test–retest).

14-day test–retest: r = 0.88 in 25 people with knee OA (25). 3-month test–retest: r = 0.86 (25).

Measurement error: minimum detectable change (MDC) and/or standard error of measurement (SEM).

An SEM of 0.88–0.97 second in a sample of 25 people with knee OA can be calculated by data reported by Rejeski et al (25).

Validity.

Evidence of content validity.

N/A.

Evidence of construct validity.

Significant correlation with the Fitness and Arthritis Trial Functional Activities Inventory: ambulation and climbing subscale (r = 0.38) and complex activities subscale (r = 0.35) (25).

Evidence of criterion validity.

When tested concurrently, lower values (faster times) on the Car Task were significantly correlated (negative correlations were expected as lower values [faster time] on the Car Task indicate better performance, whereas higher values on the treadmill, peak oxygen consumption [VO2peak], and knee strength tests indicated better performance) with higher values on treadmill time (r = −0.45), VO2peak (r = −0.40), and knee strength (r = −0.46) when tested in 104–209 people with knee OA (25).

Ability to detect change.

Evidence of responsiveness: standardized response mean and effect sizes (ES).

Responsive to the effects of an aerobic exercise intervention (mean ± standard error of the mean 8.7 ± 0.4 seconds versus 10.6 ± 0.3 seconds; P < 0.001) and a resistance exercise intervention (mean ± standard error of the mean 9.0 ± 0.3 seconds versus 10.6 ± 0.3 seconds; P = 0.003) (Note: only ± standard error of the mean was used, not SD, and ES cannot be calculated).

Interpretability: minimum clinically important differences (MCIDs).

No relevant evidence was found.

Critical Appraisal of Overall Value to the Rheumatology Community

Strengths.

Direct measure of the ability to get into and out of a car, which is reported to be limited in people with lower extremity OA (25). The test is quick to perform and has minimal administrative or respondent burden, but requires a contextual setup (i.e., access to a car). Initial testing appears to be stable over shorter durations (2 weeks); however, it may be influenced by external factors, such as learning effects over longer periods (3 months). The Car Task has been used in 1 performance battery for people with lower extremity OA (25) (Table 1).

Caveats and cautions.

Small systematic improvements across time have been noted, which may reflect motivational or learning effects (25).

Clinical usability.

Easy to administer, analyze, and interpret and takes <10 minutes to perform, but requires outdoor access to a car. There is a lack of information concerning the measurement error, responsiveness to change, and MCID-specific disease conditions, including OA.

Research usability.

More research is required to determine the responsiveness to change, MDCs, and MCIDs in people with lower extremity OA and other populations. Administrative and respondent burden does not limit research use.

Table  . Summary Table for Clinical Physical Performance Measures of Activity*
ScalePurpose/contentMethod of administrationRespondent burdenAdministrative burdenScore interpretationReliability evidenceValidity evidenceAbility to detect changeStrengthsCautions
  • *

    SPWT = Self-Paced Walk Test; ICC = intraclass correlation coefficient; 95% CI = 95% confidence interval; SEM = standard error of measurement; MCD90 = minimal detectable change at 90% confidence; r = Pearson's correlation coefficient; SRM = standardized response mean; THR = total hip replacement; TKR = total knee replacement; MCID = minimum clinically important difference; OA = osteoarthritis; SCT = Stair Climb Test; WOMAC-PF = Western Ontario and McMaster Universities Osteoarthritis Index physical functioning subscale; ES = effect size; 6MWT = Six-Minute Walk Test; BMI = body mass index; VO2max = maximum oxygen consumption; SF-36 = Short Form 36; CST = Chair Stand Test; OR = odds ratio; TUG = Timed Up & Go; DVT = deep vein thrombosis; DRI = Disability Rating Index; LCT = Lift and Carry Test; FAST = Fitness and Activity Seniors Trial.

SPWTAssesses lower extremity function through timed walking over short distances (usually <50 meters)Performance basedMinimal; <5 min
  • Minimal; <5 min

  • Easy to set up with minimal equipment

  • Hand score at completion of test

  • Usually converted to speed (e.g., meters/min, meters/sec)

  • Gait speeds <1 meter/sec associated with high risk of dysfunction in older people (31)

  • Normative values available (30)

  • Test–retest ICC2,1 0.91 (95% CI 0.81, 0.97) (11)

  • Intertester ICC1,1 0.96 (95% CI 0.93, 0.98) (8)

  • 40-meter SPWT: SEM 1.32 sec (11)

  • 40-meter SPWT: MCD90 4.04 sec (11)

Construct: r = 0.66 with Index of Severity for Knee (7), r = 0.59 with Lower Extremity Functional Scale (33)
  • SRM 0.79 (95% CI 0.66, 1.45; n = 89) after THR or TKR (11)

  • 40-meter SPWT: MCID 0.2–0.3 meter/sec (13)

  • Measures a core activity limitation in lower extremity OA

  • Stable over short periods

  • Responsive following rehabilitation and surgery

  • Easy to conduct Acceptable

Can be affected by practice effects, depression, and cognitive status
SCT
  • Assesses lower extremity strength, power, and times (sec)

  • Ability to negotiate a defined number of stairs

Performance basedMinimal; <5 min
  • Minimal; <5 min

  • Easy to set up provided access to stairs

  • Hand score on completion of test

No relevant information found
  • Test–retest ICC2,1 0.90 (95% CI 0.79, 0.96) (11)

  • Intertester ICC2,1 0.94 (95% CI 0.55, 0.98) post-TKR (65)

  • 9-step SCT: MCD90 5.5 sec (11)

  • Construct function: r = −0.53 with WOMAC-PF (6)

  • Construct strength: r = −0.50 to 0.52 with quadriceps and hamstrings (43)

  • SRM 1.98 (95% CI 1.68, 2.42; n = 89) after THR or TKR (11)

  • ES 0.84 12 months after TKR (67)

  • Measures a core activity limitation in lower extremity OA

  • Stable over short periods

  • Responsive following rehabilitation and surgery

  • Easy to conduct

  • Acceptable

Step number, step height, and use of hand rail can vary performance and need to be kept consistent on multiple assessments
6MWT
  • Assesses endurance and the ability to walk over longer distances

  • Measures distance covered in 6 min

Performance based<10 min
  • <10 min

  • Easy to set up, provided sufficient space, with minimal equipment

  • Hand score on completion of test

  • Distances associated with age, sex, height, and in women, BMI

  • Predictive regression equations available for older adults (89)

  • Test–retest ICC2,1 0.94 (95% CI 0.88, 0.98) (11)

  • SEM 26.9 meters (95% CI 21.1, 34.8) (11)

  • MCD90 61.3 meters (11)

  • Construct endurance: r = 0.71 with VO2max (90)

  • Construct function: R = 0.62 with SF-36 function (91)

  • Predictive: R2 = 0.66 for walking ability after TKR (47)

  • SRM 1.90 (95% CI 1.46, 2.39; n = 61) after THR or TKR (11)

  • ES 0.43, SRM 0.54 following physical therapy (85)

  • MCID 50–54 meters (38, 92)

  • Measures a common limitation in lower extremity OA

  • Stable over short periods

  • Responsive following rehabilitation and surgery

  • Appropriate for early and end-stage OA

  • Use of encouragement and the number of trials performed can vary performance

  • Contraindicated in unstable coronary disease

  • Precautions available

CSTAssesses lower extremity strength and power and the ability (number) to rise and sit in a chair over 30 sec or the time taken to do a set number of repetitionsPerformance basedMinimal; <3 min
  • <3 min

  • Easy to set up with minimal equipment and score on completion of test

  • Inability to rise without using arms is a predictor of falls in elderly (OR 3.4; 95% CI 1.2, 9.4) (108)

  • Age and sex normative values available (86, 131)

  • Test–retest intrasession ICC1,1 0.95 (95% CI 0.93, 0.97) (8)

  • 2–5-day ICC 0.95 (95% CI 0.93, 0.97) (98)

  • Intertester ICC1,1 0.93 (95% CI 0.87, 0.96) (8)

  • SEM 0.7 stands (8)

  • MCD90 1.6 stands (8)

  • Construct function: r = 0.66 with walking speed (107)

  • Construct strength: r = 0.71–0.78 with the leg press test for elderly (98)

  • ES 0.36, SRM 0.39 following physical therapy (85)

  • 30-sec CST: MCID 2–2.6 reps (13)

  • Measures a common activity limitation for lower extremity OA

  • Easy to conduct

  • A practice trial is necessary to minimize baseline practice effects

  • Pain may limit acceptability and result in potential floor effects

TUG
  • Assesses lower extremity strength and power and basic mobility skills

  • Measures time (sec) to rise from a chair, walk 3 meters, turn, and walk back to sit in chair

Performance basedMinimal; <3 min
  • <3 min

  • Easy to set up with minimal equipment Hand score on completion of test

  • TUG >10 sec is a predictor of near falls in hip OA (OR 3.1) (114)

  • Older adults with TUG >14 sec have higher risk for falls (117)

  • Normative values available (116)

  • Test–retest intrasession ICC2,1 0.95 (95% CI 0.95, 0.97) in elderly (40)

  • 3–6 month ICC2,1 0.75 (95% CI 0.51, 0.98) (11)

  • SEM 1.07 sec (95% CI 0.86, 1.41) (8)

  • MCD90 2.49 sec (8)

  • Construct function: r = −0.51 with Bartel Index (110)

  • Construct strength: r = 0.49–0.51 with quadriceps and hamstrings (123)

  • Predictive: TUG ≥5.3 83% sensitivity, 61% specificity to predict DVT post-THR (124)

  • SRM 1.04 (95% CI 0.89, 1.61) after THR or TKR (11)

  • ES 0.33, SRM 0.35 after physical therapy (85)

  • MCID reduction of 0.8–1.4 sec (13)

  • Measures a core activity for lower extremity OA

  • Responsive following rehabilitation and surgery

  • Easy to conduct Acceptable

  • Lack of stability when reassessed over longer (>6 mos) intervals

  • Can be affected by ceiling and floor effects

  • Multiple subcomponents may limit interpretation

Sock Test
  • Assesses lower extremity flexibility and ability to put on footwear

  • Measured on 0–3 ordinal scale of ability and ease

Performance basedMinimal; <5 min
  • Minimal; <5 min

  • Easy to set up with minimal equipment

  • Hand score (grade) on completion of test

No relevant information foundIntertester weighted κ = 0.79 (95% CI 0.5, 1.0) (129)
  • Construct function: ρ = 0.45 with DRI (130)

  • Predictive: 6–12 times increased likelihood of dysfunction with scores of 2 and 3 (129)

No relevant evidence found
  • Direct measure of a common activity limitation in lower extremity OA

  • Easy to conduct Acceptable

Scores can be influenced by age and BMI and need to be considered when interpreting results
LCT
  • Assesses the ability to lift up, carry, and replace a weight over a short distance

  • Measures the time (sec) taken and ease

Performance basedMinimal; <5 min
  • Minimal; <5 min

  • Hand score on completion of test

No relevant information found
  • 14-day test–retest: r = 0.92 (25)

  • 3-month test–retest: r = 0.77 (25)

  • SEM 0.49–0.50 sec in knee OA (25)

Construct function: r = −0.40 with treadmill time (25), r = −0.38 with VO2peak (25), r = 0.34 with FAST Functional Activities Inventory (25)
  • P < 0.001 following aerobic exercise in knee OA (55)

  • P = 0.003 following resistive exercise program in knee OA (55)

  • Direct measure of a common activity limitation in lower extremity OA

  • Appears stable over short periods

  • Small systematic improvements over time may reflect motivational or learning effects

  • Stability may be influenced by external factors over longer periods Requires a contextual setup

Car Task
  • Assesses the ability to get in and out of a car

  • Measures the time (sec) taken and ease

Performance based<10 min
  • <10 min

  • Hand score on completion of test

No relevant information found
  • 14-day test–retest: r = 0.88 (25)

  • 3-month test–retest: r = 0.86 (25)

  • SEM 0.88–0.97 sec in knee OA (25)

  • Construct function: r = −0.45 with treadmill time (25), r = 0.35–0.38 with FAST Functional Activities Inventory (25)

  • Construct strength: r = −0.46 with knee strength (25)

  • P < 0.001 following aerobic exercise in knee OA (55)

  • P = 0.003 following resistive exercise program in knee OA (55)

  • Direct measure of a common activity limitation in lower extremity OA

  • Appears stable over short periods

  • May be influenced by learning effects on repeat testing occasions

  • Requires access to a car for testing

AUTHOR CONTRIBUTIONS

All authors were involved in drafting the article or revising it critically for important intellectual content, and all authors approved the final version to be published.

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