Practice considerations for the introduction and use of power mobility for children
The aim of the study was to support clinicians in recommending and justifying power mobility for children of different ages and abilities, and with different needs. The study comprised three distinct parts: a literature review; a Delphi consensus; and clinical practice considerations.
A scoping review of eight electronic databases and manual searches carried out in February 2011 identified 15 themes or transferable messages among 27 articles meeting initial inclusion criteria and these formed the basis of a draft paper. Informal consensus at two international conference presentations refined and modified the paper to include 10 messages supported by 24 articles. The literature review was updated in May 2012 and a modified Delphi process sought to formalize the consensus process with an international panel of 16 expert clinicians and researchers using a priori criteria of 80% agreement.
Evidence from studies was classified using the American Academy of Cerebral Palsy and Developmental Medicine guidelines, with evidence from most studies being classified as either level IV or level V, apart from one study each with evidence classified as level II and level III. Expert consensus on the content and wording of nine transferable messages may raise evidence overall to level III.
This paper suggests that power mobility may reasonably be considered as an effective and appropriate intervention for children lacking efficient, independent mobility from around 12 months of age including children who may never become competent drivers and children lacking independent mobility only in early childhood.
American Academy of Cerebral Palsy and Developmental Medicine
Randomized controlled trial
The onset of crawling has a widespread and significant effect on children's overall development.[1, 2] In a similar manner, using a power mobility device has been shown to trigger emotional and visual–perceptual development. Children typically take independent steps and freely explore their environment by 12 to 15 months of age, whereas children with physical disabilities may have limited opportunities to learn about the properties and principles of their own bodies in space. Lack of purposeful movement and a limited ability to affect the environment can result in passive, dependent behavior. Power mobility allows children with physical disabilities to move around more effectively and efficiently in their environment. Children may also use other mobility aids, such as walkers and manual wheelchairs, but these are considered functional only if they enable the child to keep up and participate with his or her peers.
Despite a developing body of research evidence, power mobility continues to be underutilized even though it is the most effective means of providing independent mobility to children with severe physical disabilities. Although clinicians may be motivated to incorporate research evidence into their practice, they often do not have the time or skills to evaluate the available research. Systematic reviews can be an effective means of identifying the best research evidence, but clinical practice guidelines may be more helpful for integrating such evidence into clinical practice.
In 2010, the authors were invited to participate in a best practice workshop on use of power mobility for children at the International Interdisciplinary Conference on Posture and Wheeled Mobility in Glasgow, Scotland. At that conference, current published opinion on the topic was discussed and workshop participants recommended development of a paper that would support clinical practice and clarify ‘appropriateness’ for power mobility. Specific recommendations included an up-to-date literature review with levels of evidence and inclusion of the child and family perspective.
Literature Review and Paper Development Methods
Since a standard systematic review protocol would be too restrictive a method to address the broad range of concerns and perspectives to be included in this paper, a scoping methodology was used. An electronic search of the following databases was completed in February 2011 and updated in May 2012: OT Seeker, Physiotherapy Evidence Database (PEDro), EBM Reviews, CINAHL, MEDLINE, EMBASE, PsycInfo, and ERIC. Key terms included power(ed) mobility, power(ed) wheelchair, and child(ren), as well as relevant medical subject headings for each database such as wheelchair/powered. Reference lists of articles were reviewed to identify additional studies, a hand search was undertaken to find known studies, and known researchers were contacted to identify or clarify details of unpublished studies.
Studies published in English were included if they involved at least one child with a disability who was below the age of 19 years and addressed the use of a power mobility device with regard to the age of introduction, impact on development, and influences on successful use. The term ‘power mobility device’ included power wheelchairs, powered ride-on toys or cars, powered scooter boards, and powered standers. All types of studies were included, from randomized controlled trials (RCTs) to single case studies. Qualitative or mixed methods designs were also included to ensure representation of the child and family perspective. No restrictions were placed on the date of publication or the publication status, as some important early research studies were known to have been published in conference proceedings or reports.
Titles and abstracts were read for all 107 articles or reports that met our initial wide-ranging criteria. Over 90% of these articles were also read in their full-text version. Descriptive or magazine articles, non-systematic review articles, or those that had a technology or equipment development focus were excluded. Surveys or cross-sectional designs were included if they addressed the child and family perspective or outcomes related to the child's use of power mobility devices. Those surveys reviewing service provision or provider perspectives were excluded.
Appraisal of initially included studies was completed using standard data extraction forms for quantitative and qualitative designs. Research on knowledge transfer suggests that take-home or actionable messages should be transferred from a body of research knowledge rather than from single studies and these are referred to as ‘transferable messages’. Some transferable messages had been previously identified by the first author and discussed at various conference presentations. Both authors then agreed on transferable messages or themes emerging from the literature review. Studies that provided the strongest support for these messages became the 27 initially included articles. Additional case studies, cross-sectional studies, and qualitative studies were identified, but were not included as they did not add to the level of evidence (see below and Appendix SI, online supporting information), increase the applicability of the transferable messages, or support the additional messages.[12-20]
The American Academy of Cerebral Palsy and Developmental Medicine (AACPDM) guidelines (see Appendix SI for a summary of levels I–V) were used to determine the levels of evidence for included studies, including group and single-participant designs. Two reviewers independently determined evidence levels; where differences occurred, they discussed scores until consensus was reached. Their consensus scores are reported throughout. The AACPDM systematic review protocol was not followed as it was developed for narrower intervention questions and quantitative studies only.
In order to address the original direction recommended by participants at the best practice workshop in Glasgow, a draft paper was developed, structured around four groups of children who were identified in the literature as being ‘appropriate’ for power mobility: children who will never walk; children with inefficient mobility; children who lose their ability to walk or to walk efficiently; and children who need mobility assistance in early childhood. Two additional sections – learning power mobility skills and supporting power mobility skills – were included to address the use of power mobility with more complex populations, as well as to address the child and family perspective.
Fifteen transferable messages, addressing common questions or concerns regarding topics such as the age of introduction, the impact on development, use with children who have more complex disabilities, and the environmental influences were developed. To assist clinicians in reflecting on the relevance of the evidence presented to their population and setting, case studies were included to illustrate examples of children from different age groups with a variety of needs who could benefit from the use of power mobility.
The paper was presented, for informal feedback and discussion, at the International Seating Symposium, Nashville, TN, USA in March 2011. More than 200 individuals participated in the first workshop and audience response technology was used to allow anonymous voting on the messages. Strong consensus was determined, a priori, to be above 70%. Any statements falling below this level of consensus were removed, modified, or combined according to feedback from workshop participants during the open discussion period. Further feedback was received from a workshop involving 50 participants from a wide range of countries at the European Seating Symposium, Dublin, in November 2011. Audience voting and discussion resulted in rewording and refinement of some transferable messages and further feedback on the clinical utility of the paper.
In the revised paper, 10 transferable messages supported by the literature were included. Two references were removed following this informal consensus and revision process[23, 24] as workshop participants voted to eliminate the associated messages. Much of the research evidence was of lower strength, with only one RCT identified. One level III single-participant design was identified, while four articles, achieving evidence level IV, described the results of two group[27-29] and one single-participant design. There were 14 level V studies representing a number of group[31-35] and single[36-41] case studies as well as cross-sectional designs.[42-44] In addition, five qualitative studies were included.[45-49]
Formal feedback on the format, layout, and content of the position paper was desired in order to ensure its suitability for use in a variety of international settings. A consensus of clinical experts is thought to be capable of verifying that the intervention in question may be reasonably supported, and equivalent to level III evidence. We, therefore, sought to combine expert opinion with the existing lower-level research evidence in a rigorous manner in order to assist in providing stronger guidance for clinicians, families, and funders regarding the use and benefits of power mobility for children.
The literature review was updated in May 2012 before the formal consensus process. Newly published studies were included and references updated for studies that had previously been included as theses or conference proceedings.[25, 29] The AGREE II checklist was used to reduce bias and ensure quality in the development of the clinical practice considerations. See Appendix SII, (online supporting information) for an evidence table of the studies that met the final inclusion criteria after the international consensus process.
International Consensus Process
This section of the article describes multiple rounds of expert reviews that were conducted to achieve consensus on the content and wording of several messages around which the paper was structured, as well as formal feedback on the scope, structure, content, and layout of the paper.
The Delphi technique is a method that uses sequential questionnaires or ‘rounds’ to gather information and establish consensus where there is uncertainty or a lack of empirical evidence, providing an efficient and economical method to communicate with a geographically diverse panel of experts. Participants remain unknown to other participants, allowing individuals to express their opinions openly, without peer pressure. Between each round, participants are provided with group level of agreement and their own individual ratings to allow the generation of knowledge and consensus building.
Individuals who had published research or opinion pieces in peer-reviewed journals in the last 15 years or who had provided education on the use of power mobility with children at national or international levels in the last 5 years were approached to participate in the expert panel. To ensure global representation, expert clinicians from internationally renowned centers were also approached. Twenty-one experts were approached; 19 consented to participate and 18 completed the first round. The expert panel comprised 11 occupational therapists, five physiotherapists, one psychologist, and one engineer. Ten participants were primarily academics or researchers and eight were primarily clinicians. Participants were recruited from Canada, the USA, the UK, Sweden, and Australia. Human participants ethics approval was obtained prior to the study from the University of British Columbia and Children's and Women's Health Centre of British Columbia Research Ethics Board.
This study involved a computer-based, online Delphi survey. Each participant was provided with a copy of the draft paper and invited to rate the content and relevance of the paper, as well as their level of agreement with 10 transferable messages. Agreement was represented by responses on a five-point Likert scale: 1, disagree strongly; 2, disagree; 3, neutral; 4, agree; 5, strongly agree. Narrative comments were solicited for each statement and on any section of the paper, as well as suggestions for additional references or messages.
Each expert was emailed an invitation to participate in the Delphi process. Experts who provided email consent for further contact were emailed the draft paper along with an individualized link to the survey tool. The draft paper included evidence levels to assist experts in making judgments about the quality of evidence supporting each statement. The first round survey was left open for 5 weeks.
In each of the three rounds, expert ratings were summarized in a report by the survey tool, with percentages of agreement calculated. Content analysis also determined common themes among participants’ responses to open-ended questions. These reports, along with the revised paper and participants’ individual responses, were included with the second and third round surveys. Expert-suggested wording changes for the transferable messages and suggestions of additional material or refinement of the paper were considered for incorporation into revised versions.
Results for round 1
Agreement scores for each transferable message are summarized in Table 1. Only one message had less than 80% of ratings of 4 or 5 on the Likert scale. Message 9 generated some controversy over the definition of ‘competent’. The paper was revised and terms used in the paper such as ‘competent’, ‘proficient’, and ‘novice’ were defined based on research.
Table 1. Round 1 of Delphi results
|1. With access to a specialized PMD, it is possible for infants with disabilities to have augmented mobility experiences at 8mo of age, when their peers are beginning to move||0||0||0||7/18||11/18|
|2. Children can begin learning to steer a PMD around 14mo and those able to use a joystick can achieve competent control as young as 18–24mo||0||1/18||2/18||6/18||9/18|
|3. For children with minimal mobility experience, a PMD can promote psychosocial development, as well as functional mobility||0||0||1/18||0||17/18|
|4. For children with inefficient mobility, PM may enhance independence and participation in family, school, and community life||0||0||1/18||2/18||15/18|
|5. Using PM at a young age will not impede development of ambulation or other motor skills||0||0||0||7/18||11/18|
|6. PMDs for children with progressive neuromuscular disease should include specialized seating, powered seating functions, and be capable of accommodating alternate drive controls and additional assistive technology||0||0||1/18||6/18||11/18|
|7. Children with conditions that limit early functional mobility may benefit from PM to promote overall independence and psychosocial development||0||1/18||0||4/18||13/18|
|8. Children who have poorly established cause–effect may benefit from practice in a PMD||0||0||2/18||4/18||12/18|
|9. Children with severe intellectual and/or sensory impairments can learn to use a PMD competently||1/18||1/18||2/18||4/18||10/18|
|10. Time spent practicing and environmental support are very important, and can have more influence on successful learning of PM skills than differences in children's motor, cognitive, or sensory abilities||1/18||0||2/18||4/18||11/18|
Participants were asked whether they preferred having evidence levels presented with the statements or separately in a table. 12 out of 18 agreed or strongly agreed with keeping the evidence levels with the statements, while four were neutral, and two disagreed. However, five out of 18 agreed or strongly agreed with the idea of an evidence table, with seven neutral, and six disagreeing. As a compromise, an evidence table was created as an appendix.
Changes to the layout and organization of the paper were guided by narrative feedback provided by the experts. One participant suggested that the four groupings of children who can benefit from power mobility were too focused on physical limitations and diagnoses and, instead, suggested making them more functional.
Seventeen participants from round 1 continued to participate in round 2. Nine transferable messages were included, as consensus above 80% with strong agreement had been achieved for message 3 in round 1. Message 4 had also achieved strong agreement but wording changes had been suggested. The survey was left open for 6 weeks.
Results for round 2
Consensus above 80% agreement (rating of 4) and strong agreement (rating of 5) was achieved for all statements. Consensus above 80% with strong agreement was achieved for three messages (1, 2, and 8). Level of agreement on message 4 went down from round 1 owing to the change of wording (see Table 2).
Table 2. Round 2 of Delphi results
|1. With access to a specialized PMD, it is possible for infants with disabilities to have augmented mobility experiences as early as 8mo of age||0||0||0||3/17||14/17|
|2. Children can begin learning to maneuver a PMD as early as 14mo and those able to use a joystick may demonstrate competent control as young as 18–24mo||0||0||1/17||2/17||14/17|
|4. For children with inefficient mobility, PM may enhance independence in mobility and meaningful participation in family, school, and community life||1/17||3/17||1/17||2/17||10/17|
|5. Using PM at a young age has not been shown to impede development of ambulation or other motor skills||0||1/17||1/17||3/17||12/17|
|6. PMDs for children with progressive neuromuscular disease should include specialized seating, powered seating functions, and be capable of accommodating alternate drive controls and control of other assistive technology devices through the drive method||0||0||2/17||4/17||11/17|
|7. Children with conditions that limit early functional mobility may benefit from PM to promote overall independence and psychosocial development||0||1/17||1/17||3/17||12/17|
|8. Mobility experience in a PMD may support skill development for children learning cause–effect relationships||1/17||1/17||1/17||0||14/17|
|9. Children with severe intellectual and/or sensory impairments can learn to use a PMD competently with appropriate practice and environmental support||0||1/17||1/17||2/17||13/17|
|10. Successful learning of PM skills may depend at least as much on practice time and support within the child's environment as the child's motor, cognitive, or sensory abilities||0||1/17||0||3/17||13/17|
Wording changes were suggested for all messages and so all were included in the third round. Message 6 generated some controversy as some experts felt that it detracted from the main purpose and intent of the paper. As regards the organization and layout of the paper, the majority of participants (13 out of 17) preferred to retain the original four groupings of children. The functional descriptions were worked into the text to ensure that the diagnoses were seen as examples and not as limiters.
Eighteen experts were invited to participate, with 16 completing round 3. Since wording changes had been suggested, all transferable messages were included for rating in this round. Experts were asked to vote on whether or not they agreed with the removal of message 6 from the paper. The survey was left open for 7 weeks.
Results for round 3
The majority of participants (13 out of 16) agreed with the decision to remove message 6 from the paper. Some strongly felt that the content was important to include in the text but to relate it more broadly to all children with severe disabilities. Consensus above 80% with ratings of 5 was achieved on messages 2, 5, 7, and 8. Consensus above 80% with ratings of 4 and 5 was achieved on messages 1, 3, 4, 6, 9, and 10 (see Table 3).
Table 3. Round 3 of Delphi results
|1. With access to a specialized PMD, it is possible for infants with disabilities to have augmented mobility experiences below 8mo of age||0||2/16||1/16||5/16||8/16|
|2. Children can begin learning to maneuver a PMD below 14mo of age and those able to use a joystick have demonstrated competent control as young as 18–24mo||0||1/16||0||0||15/16|
|3. For children with minimal mobility experience, a PMD can support overall development as well as functional mobility||0||0||3/16||3/16||10/16|
|4. For children with inefficient mobility, PM may enhance independence and meaningful participation in family, school, and community life||0||0||2/16||2/16||12/16|
|5. There is no evidence that using PM at a young age impedes development of ambulation or other motor skills||0||0||1/16||1/16||14/16|
|6. PMDs for children with progressive neuromuscular disease should include specialized seating, powered seating functions, and be capable of accommodating alternate drive controls and control of other assistive technology devices through the drive method. REMOVAL||0||2/16||1/16||7/16||6/16|
|7. Children with conditions that limit early functional mobility may benefit from PM to promote independence and support overall development||0||0||0||1/16||15/16|
|8. Mobility experience in a PMD may support development of self-initiated behavior and learning||0||0||1/16||0||15/16|
|9. Many children with severe intellectual and/or sensory impairments can learn to use a PMD competently with appropriate practice and environmental support||0||1/16||1/16||2/16||12/16|
|10. Successful learning of PM skills may depend at least as much on practice time and quality of learning support within the child's environment as the child's motor, cognitive, or sensory abilities||0||1/16||0||3/16||12/16|
Discussion and final versions of transferable messages
Expert feedback on overall flow, readability, relevance, and usefulness improved steadily over each round as the paper was revised and suggestions from participants were incorporated. The evidence table was revised to reflect only the studies that were used to support the transferable messages. The transferable messages shown below are the final versions that were selected to be included in the practice considerations paper. These are not necessarily the version included in round 3, but the version for which there was highest consensus.
With access to a specialized power mobility device, it is possible for infants with disabilities to have augmented mobility experiences as early as 8 months of age
For this message, the strongest consensus occurred in round 2: 14 out of 17 experts strongly agreed and the remaining three agreed. Some participants suggested that 8 months of age was not early enough for some types of disability, but consensus was not as high following a change to ‘below 8 months of age’. Concerns were expressed that power mobility may be detrimental to infants below 8 months of age (R Kermoian, personal communication 2012). This message is supported by level V case study evidence.[39, 40]
Children can begin learning to maneuver a power mobility device below 14 months of age and those able to use a joystick have demonstrated competent control as young as 18 to 24 months
Consensus was strongest in round 3 for this message, with 15 out of 16 experts strongly agreeing. This message reflects the majority of early power mobility research that focused on age of use and included only children able to use joysticks.[31, 32, 37, 38] One early case study described a child with no limbs learning to use a power mobility device using body movement and switches. A recent RCT also included children with cognitive and communication limitations, as well as children using head controls and switches.
For children with minimal mobility experience, a power mobility device can promote overall development as well as functional mobility
In round 1, 17 out of 18 experts strongly agreed with this message, so it was not included in round 2. However, participants suggested wording changes of ‘psychosocial’ to ‘overall’ and ‘promote’ to ‘support’. In round 3, only 10 out of 16 strongly agreed and three agreed. Of six experts who voted neutral or ‘agree’ in round 3 instead of ‘strongly agree’ as they had in round one, two comments favored changing back to the word ‘promote’ and one commented against ‘overall’ with preference for ‘psychosocial’. Generally, comments were in favor of having the more inclusive term ‘overall’, rather than the term ‘psychosocial’. Consequently, ‘overall’ was retained in the final version. A recent theoretical paper provides support for this decision. This message is supported by one level II study, one level III study, three level IV studies,[27-30] two level V studies,[35, 40] and two qualitative studies.[45, 46]
For children with inefficient mobility, power mobility may enhance independence and participation in family, school, and community life
This is the version used in round 1, where it had the highest consensus, with 15 out of 18 experts strongly agreeing, two agreeing and one person voting neutral. One participant suggested adding the words ‘in mobility’ to ‘independence’ but other participants disagreed and consensus was not as high in round 2. Only 12 out of 16 experts strongly agreed with the addition of the word ‘meaningful’ before ‘participation’ in round 3. This message is supported by level V and qualitative evidence.[47, 48]
There is no evidence that using power mobility at a young age impedes development of ambulation or other motor skills
Consensus was highest for this version in round 3, with 14 out of 16 experts agreeing strongly, one person agreeing, and one person voting neutral. In previous rounds, other versions of this message were felt to be too strong in relation to the level of evidence. This message is supported by one RCT, one level IV, and one level V study.
The following statement was removed: ‘power mobility devices for children with progressive neuromuscular disease should include specialized seating, powered seating functions and be capable of accommodating alternate drive controls and control of other assistive technology devices through the drive method’. This was removed because it was supported by weak level V evidence and related to only one population, whereas the statement itself was relevant to children with a wide variety of complex disabilities. Participants felt that this message detracted from the main flow and purpose of this paper, but the content was included in paragraph relating to all children with complex disabilities.
Children with conditions that limit early functional mobility may benefit from power mobility to promote independence and support overall development
Round 3 had the highest consensus for this version, with 15 out of 16 experts strongly agreeing, and one agreeing. This message is supported by one level V case study.
Mobility experience in a power mobility device may support development of self-initiated behavior and learning
This message was changed significantly in each round and consensus steadily rose, with round 3 having the highest consensus: 15 out of 16 experts strongly agreed and one person was neutral. This message is supported by both qualitative and case study evidence.[34, 35, 45, 49]
Many children with severe intellectual and/or sensory impairments can learn to use a power mobility device competently with appropriate practice and environmental support
This message was definitely more controversial, but consensus rose from 10 out of 18 strongly agreeing in round 1 to 12 out of 16 strongly agreeing and another two agreeing in round 3. One expert was neutral and another disagreed. This statement is supported by level IV, level V, and qualitative evidence.[45, 49]
Successful learning of power mobility skills may depend at least as much on practice time and quality of learning support within the child's environment as the child's motor, cognitive, or sensory abilities
Again, this was controversial, but consensus rose from 11 out of 18 experts strongly agreeing in round 1, to 12 out of 16 strongly agreeing and another three agreeing in round 3, with only one person disagreeing. This statement is supported by level IV, level V, and qualitative evidence.
Development of this paper was limited by the size and diversity of the international panel. Unfortunately, we were unable to secure more participants from some European countries owing to language barriers and we did not secure any participants from Asia. A limitation common to Delphi surveys is the subjective process used to identify the participants. To attempt to reduce bias, we endeavored to contact all individuals who had published research or opinion pieces in peer-reviewed journals in the last 15 years and gave them the option to participate.
By including participants biased toward a particular viewpoint, our results may have been skewed. However, the clinicians and researchers who participated had a minimum of 5 years’ experience of working with children using power mobility. They came from a variety of different disciplines, backgrounds, and clinical settings, as well as from different countries. They had definite opinions and the Delphi process provided them with opportunities to contribute their ideas and to modify their opinions as they worked through the group process.
The resulting international consensus practice considerations paper is intended to provide guidance for clinicians, families, and funders regarding the use and benefits of power mobility for children. It describes different groups of children who can benefit from the use of power mobility and provides guidance on the use and expectations for children at different ages and with different needs and abilities. The paper also provides some guidance on environmental influences that can affect the successful introduction and use of power mobility with children.
The aim of the development of these practice considerations was to combine evidence-based literature with expert opinion in order to make recommendations on decision-making and justification for power mobility use with infants, children, and adolescents. It has been structured in three sections. The first describes different groups of children who benefit from the use of power mobility, and includes six transferable messages. The second section discusses issues of ‘readiness’ and the process of learning power mobility skills for children with complex developmental needs. The benefit of power mobility experience for children who may never develop competent driving skills is included in this section, along with two transferable messages. The final section discusses the environmental influences on the development of power mobility skill and includes one transferable message.
For the purposes of this paper, the term ‘power mobility skills’ describes the development of skills from the exploratory behavior of the novice through to learning to control the functions of the power mobility device, to competent use in daily life. The term ‘competent’ is used to describe a child who has learned to operate the power mobility device, i.e. they can avoid obstacles and maneuver in a safe environment. Proficient use, defined as the ability to use judgment and focus on the activity rather than on controlling the device, can take many years.
The field of rehabilitation is undergoing a paradigm shift from considering power mobility as a final option, reserved for older children once all other forms of mobility have been tried and found ineffective, to a therapeutic modality that can be used to support development, exploration, and participation for a wide range of infants and children with disabilities. Children and their families may use a variety of mobility solutions depending on the environment or activity. Although not all children will become competent or proficient power wheelchair users, clinicians should consider power mobility as an accepted intervention even for very young children who do not have the ability to move and explore independently. The aim of this intervention is to address the secondary effects of lack of mobility on other areas of development such as socialization, cognition, visual–perception, and language.
Children's use of power mobility should be commensurate with age-appropriate and developmental expectations. An infant using a power mobility device should be in a safe environment or have adult supervision and assistance. Older children with cognitive or sensory limitations may need adult supervision or assistance in the community (as they would if able to walk) but may learn to use a power wheelchair to meet their independent mobility needs.
General considerations for all children when introducing power mobility
The child's postural abilities and needs for support when using the proposed device need to be identified. Remember that the child is likely to need more support when in a mobile system than when in a stationary seat. Postural supports should enhance the child's abilities to use his or her hands (or other body parts) to activate the power mobility device.[55, 56]
Any limitations within the child's visual, perceptual, or sensory system need to be identified. Visual, perceptual, or sensory limitations do not preclude the consideration of power mobility, but may require an alternative approach to training, compensatory strategies, and/or technology.
The child's developmental level needs to be considered. Children functioning at around a 2-year-old cognitive level may start by driving the power mobility device in circles, but would quickly move on to attempt to purposefully drive to a toy or person and are expected to become proficient drivers in time. Some children with more complex physical, cognitive, or sensory limitations move relatively quickly from the exploratory behaviors of the novice to attempting to move toward a goal, but may require a longer training period and more supervision to develop competent driving skills. Other children functioning at very early developmental levels may never move beyond the exploratory behaviors of the novice but power mobility experience can stimulate overall development in areas such as initiation, head and hand control, visual attention, and child-directed exploration that are also important outcomes. Knowing the child's developmental level guides clinicians as to the most appropriate device, approach, or expectations for power mobility.
Which children need power mobility?
Four different groups of children can benefit from power mobility: (1) children who will never walk; (2) children with inefficient mobility; (3) children who lose the ability to walk or to walk efficiently; and (4) children who need mobility assistance in early childhood.
Children who will never walk and need functional mobility
Children in this group have a poor prognosis for functional mobility without the use of power mobility. The group includes, but is not limited to, children with the following diagnoses: cerebral palsy (CP), Gross Motor Function Classification System (GMFCS) levels IV and V; spinal muscular atrophy types I and II or congenital muscular dystrophy; multiple limb deficiencies or severe arthrogryposis; congenital high-level spinal cord lesions; and osteogenesis imperfecta types II, III, and VIII.
‘Lisa’ is a 2-year-old female with congenital muscular dystrophy. The joystick on her power wheelchair was modified to increase sensitivity and was positioned in the middle to allow her to use both hands. She became competent in power mobility skills within 6 hours and her parents felt confident that she would be able to use a power wheelchair in their home and community with age-appropriate supervision. A pediatric, international standard-compliant power wheelchair with tilt was ordered to allow the family to transport the device in a wheelchair-accessible vehicle.
Children who have inefficient mobility
Children in this group have a limited ability to walk or maneuver a manual wheelchair but need more effective mobility through the use of power mobility for energy conservation and efficiency. This group includes, but is not limited to, children with the following diagnoses: CP (GMFCS levels III and IV, and some adolescents at level II); C6 or C7 spinal cord injuries; thoracic myelomeningocele; and osteogenesis imperfecta types IV–VII. Children with arthritis or medical conditions may also have inefficient mobility at times.
In children with a disability, walking ability peaks well before adolescence and gait often worsens and requires more energy as these children age. Very small numbers of children with CP are able to propel manual wheelchairs efficiently and power mobility may enhance participation at school, outdoors, and in the community. To achieve efficient mobility and meaningful participation, a child must be able to maintain the same speed (without undue effort) and access the same activities and environments as his or her peers.
‘Chase’ is a 12-year-old boy with thoracic-level myelomeningocele. He has been an efficient manual wheelchair user for a number of years and plays wheelchair basketball and sledge hockey. However, his kyphoscoliosis has progressed rapidly and Chase is experiencing chest pain when seated in an upright position for long periods.
Chase is on a waiting list for spinal instrumentation surgery and, after this, will not be allowed to manually maneuver his chair for at least 6 months. A power wheelchair with tilt has been prescribed for his use at school and outdoors, while he continues to use his manual wheelchair in the home. Following surgery, Chase will be a full-time power wheelchair user for at least 6 months and long term may use power mobility outdoors and in the community to enhance participation with peers.
Children who lose the ability to walk or to walk efficiently
These children may have a prognosis for increasing disability or have lost the ability to walk as a result of illness or injury. This group includes, but is not limited to, children with the following diagnoses: neuromuscular diseases (e.g. Duchenne muscular dystrophy, limb girdle dystrophy, type III spinal muscular atrophy, Friedreich ataxia), acquired brain injury, and spinal cord injuries. These children have already experienced independent mobility at a young age and, therefore, power mobility is used to maintain participation in family, school, and community life.
With progressive neuromuscular diseases, children can usually operate a standard joystick initially and learn power mobility skills quickly. Children with acquired brain injury often have more complex learning needs. Children with high-level spinal cord injuries are usually unable to access a standard joystick. Access options for these children typically involve movements of the head or face and include a chin joystick, mouth switches or a mouth joystick, sip and puff, or proximity head array. An assessment by a clinician specialized in alternative access methods for power mobility may be helpful.
Clients with muscular dystrophy gradually lose the ability to use a standard joystick but can regain full independence by using alternative driving methods. It is important to select a power wheelchair that will meet the client's needs for speed and outdoor performance and electronics that can accommodate changing needs, as well as integrating power seating functions, medical equipment (ventilator, suction, G-tube pumps, etc.), electronic aids to daily living, and computer access.
‘Nikki’ was diagnosed with limb girdle dystrophy at 8 years of age. Although she was able to walk independently and to maneuver a manual wheelchair, her muscle disease progressed rapidly and an indoor/outdoor power wheelchair with tilt-in-space and expandable electronics was recommended. The funder declined the expandable electronics and reluctantly agreed to include tilt.
Three years later, Nikki is completely wheelchair dependent. She has a rapidly progressive scoliosis and uses contoured seating. She constantly uses her tilt system to change position and increase comfort. Recline and lateral tilt options are being considered to address respiratory and pain issues. Nikki is also having difficulty exerting enough pressure to operate the standard joystick. The funder will now have to pay for an expensive upgrade to the electronics in order to accommodate the provision of a more sensitive joystick and integration of seating functions through the driver control.
Children who require mobility assistance in early childhood
These children need efficient, effortless, functional mobility early in childhood even if they will later use other means of mobility. This group includes, but is not limited to, children with the following diagnoses: arthrogryposis (surgical intervention may allow walking at older ages); lumbar-level myelomeningocele (ambulation and efficient manual wheelchair use may be achieved in later childhood); osteogenesis imperfecta (interventions such as intra-medullary rodding may allow walking at older ages); and CP (GMFCS level III).
‘Maya’ is a 3-year-old female with type IV osteogenesis imperfecta. She has had intramedullary rodding of her femurs and professionals in her specialized clinic anticipated that she would stand and walk by this age. However, she has not progressed beyond independent sitting as a result of frequent upper limb fractures. Maya learned to steer a power wheelchair within a few minutes of practice and a pediatric international standard compliant power wheelchair with seat elevator was prescribed to give her a means of effortless, independent mobility and increased access to activities in her environment. Maya's joystick was modified to allow it to be easily transferred from the left to the right side of her wheelchair owing to her frequent fractures, and a custom foot box was provided for protection while she develops proficiency.
Transferable messages related to children who can benefit from power mobility
With access to a specialized power mobility device, it is possible for infants with disabilities to have augmented mobility experiences as early as 8 months of age (level V evidence[39, 40])
This research challenges the lower age limit for considering power mobility. In order to limit the impact of physical disability on overall development, clinicians should consider augmenting independent mobility opportunities around the same age as children typically begin to crawl. In these case reports, the specialized power mobility device was fitted with a supportive infant seat and could be remotely controlled by an adult to ensure safety.
Children can begin learning to maneuver a power mobility device below 14 months of age and those able to use a joystick have demonstrated competent control as young as 18 to 24 months (evidence levels II and V[31, 32, 36-38])
The majority of power mobility research addresses the age of successful use with most studies having focused on children using joysticks. Children who are unable to use a joystick efficiently may benefit from an assessment to identify a more appropriate access method. Children who use alternate access methods (that are more cognitively challenging than a joystick), or who have additional visual, perceptual, cognitive, or communication disabilities, may require a longer time to learn power mobility skills or may require more specialized training.
For children with minimal mobility experience, a power mobility device can promote overall development as well as functional mobility
Power mobility experience appears to have a broad impact on development. The supporting evidence is divided into different domains for ease of understanding but it should be recognized that these areas are interwoven and all emerge from and have intellectual underpinnings. Evidence for cognition is supported by level V evidence; receptive language is supported by levels II and V; social and play skills are supported by levels IV[28, 29] and V; independence is supported by level IV; cause–effect is supported by level V; and self-initiated movement is supported by levels III and IV, and qualitative evidence.[45, 46]
For children with inefficient mobility, power mobility may enhance independence and facilitate participation in family, school and community life (level V evidence and qualitative evidence[47, 48])
Children need an efficient means of mobility to move around the classroom and playground and to keep up with friends in the community. Using a power wheelchair can help save energy for learning and playing with others. Adolescents need safe and efficient mobility choices and some who can walk or use a manual wheelchair also use power mobility to enhance participation in school and community life. The need for exercise should be addressed at other times and by other more effective means.
There is no evidence that using power mobility at a young age impedes development of ambulation or other motor skills (evidence levels II, IV, and V)
Power mobility does not appear to negatively affect motor development and it has been suggested that children may be more motivated to use their motor skills and participate in therapy once they have experienced the independence that power mobility can provide.
Children with conditions that limit early functional mobility may benefit from power mobility to promote independence and support overall development (evidence level V)
Learning power mobility skills
Children begin power mobility by exploring movement and learning to control direction. Gradually, they start to develop functional mobility skills. Competence in using the chair in daily life emerges first, but proficiency occurs only over time and with experience. Readiness assessments such as the Pediatric Power Wheelchair Screening Test have been used to identify children who will quickly and easily learn to use a joystick-operated power wheelchair. This screening is not appropriate for children with multiple and complex disabilities who may use switches or other access methods. Instead of focusing on readiness skills or passing a ‘driving test’, clinicians should consider augmenting mobility at an early age for children who are unlikely to walk, in order to promote overall development and help lessen the secondary effects of immobility.
Transferable messages related to learning power mobility skills
Mobility experience in a power mobility device may support development of self-initiated behavior and learning (level V evidence[34, 35] and qualitative evidence[45, 49])
For children with delayed cognitive and physical development, the use of a power mobility device may facilitate overall learning. Movement of the device provides immediate feedback, as well as vestibular and visual stimulation, when the child activates the joystick or switch. Some of these children may never develop competent use of a power mobility device but still benefit from the independent mobility experience.
Many children with severe intellectual and/or sensory impairments can learn to use a power mobility device competently with appropriate practice and environmental support (level IV and V evidence and qualitative evidence[1, 45, 49])
These children may need extensive experience and training to be successful. Some children will always require adult supervision to ensure safety, but a power mobility device can allow spontaneous exploration in a safe environment which will promote overall development. For young children, learning power mobility skills is not like an adolescent with typical mobility learning to drive a car, but is similar to a child learning to walk or to use a tricycle. The adult needs to be a ‘responsive partner’ and to help elicit children's learning through play rather than interfering with their concentration by talking and directing. The amount and type of training will vary between individuals and will depend on their needs, deficits, motivations, and learning styles. Even those with severe visual impairment can use power mobility with adaptations such as use of a cane or a specialized wheelchair with sensors.
Case example of a child with more complex developmental needs
‘Oliver’ has dyskinetic CP (GMFCS level V). He is non-verbal and cognitive testing is unreliable; however, he makes choices through eye gaze. Oliver gains some independent mobility through a supportive gait trainer, but this can only be used indoors on smooth surfaces.
At age 6, Oliver's ability to target switches with his hands was erratic and effortful. He was lent an old power wheelchair with a proportional head control to develop the initial skill of learning to keep his head up to activate the chair and dropping his head to stop. After 6 months’ training, he tried different types of head control devices and was most successful with small mechanical switches. One was positioned behind his head with right and left turn switches by his cheeks.
After 5 years, Oliver is a proficient driver. His switches were recently changed to a proximity style and are arranged close to the back of his head. He is able to drive through doorways and in crowded corridors, showing good judgment and safety awareness. His family has a wheelchair-accessible van and a new, more powerful power wheelchair has been ordered in preparation for high school.
Supporting power mobility skills
Initially, parents may view power mobility negatively but, once their child has power mobility experience, most describe positive feelings related to seeing their child experiencing independence and control.[27, 47] Families report that power mobility leads to increased participation and integration with other children, but they note that appropriate training and support are major factors in successful use. Aspects of the physical, social, and cultural environment can have a great influence on power mobility use, as well as personal factors such as motivation, goals, and priorities.
At this time, power wheelchairs are often large and difficult to transport. This can be a major barrier to families incorporating one into a child's life. The development of less expensive and more child- and family-friendly options, such as ride-on toy cars, may help to reduce this barrier. Standard power wheelchairs do not appear to facilitate reach and interaction with toys. Development of inexpensive, lightweight, child- and family-friendly power mobility devices to facilitate participation in play in both the home and the preschool environment is needed.
To enhance power wheelchair use without contributing to problems of posture and pain, supportive seating, powered seating functions, and adequate suspension are important features to consider. For children with progressive or severe and complex disabilities, power wheelchairs should be ordered with electronics capable of accommodating alternative access technologies, integration of powered seating functions, and control of other assistive technologies, such as communication, computer, or electronic aids to daily living through the drive controls. These features are often needed to promote optimal participation and independence through the power wheelchair.
Clinicians may have difficulty accessing power mobility devices for extended trial and training for children who do not immediately demonstrate the ability to maneuver and control the device safely. Developing relationships with wheelchair providers in order to borrow power wheelchairs for longer periods may help address this barrier. Power mobility experience can also be provided with powered toys, cars, standers, and recycled or shared wheelchairs during therapy sessions.
Transferable message related to supporting power mobility skills
Successful development of power mobility skills may depend at least as much on practice time and quality of learning support within the child's environment as the child's motor, cognitive, or sensory abilities (level IV and V evidence and qualitative evidence)
To learn any new skill, all children need extensive practice. Identifying where the child is in the learning process, providing a suitable environment (including an appropriately programmed power mobility device), and providing learning strategies is critical to success. Children who are given more time and experience using a power mobility device, and who are supported in their learning by those around them, are more likely to be successful in developing power mobility skills.
Use of power mobility enhances independence and overall development in young children who do not walk.[25, 27-29] In children who have inefficient mobility or lose the ability to walk, power mobility enhances activity and participation.[47, 48] Without efficient, independent mobility, young children are at risk of developing passive, dependent behaviour and older children are at risk of decreased participation and isolation. Mobility should be effortless and allow children and adolescents the opportunity to participate fully in age-appropriate and meaningful activities. All children who lack efficient independent mobility should be considered for power mobility and not excluded on the basis of age, limited vision, early developmental level, physical access limitations, or the ability to use other means of mobility for short distances.
The authors thank Debra A Field for acting as second reviewer in determining the levels of evidence for included studies. We thank the 16 members of the international review panel who took part in the Delphi process: Jacqueline Casey (School of Health Sciences, University of Ulster, Northern Ireland, UK), Stephanie Chapman (Chailey Heritage Clinical Services, UK), Josephine Durkin (Independent consultant Occupational Therapist in Neurodisability, UK), Debra A Field (University of British Columbia, Graduate Programs in Rehabilitation Science and Sunny Hill Health Centre for Children, British Columbia, Canada), Jan Furumasu (Rancho Los Amigos National Rehabilitation Center, CA, USA), James C (Cole) Galloway (Department of Physical Therapy, University of Delaware, Newartk, DE, USA), Marlene Holder (Holland Bloorview Kids Rehabilitation Hospital, Ontario, Canada), Maria Jones (University of Oklahoma Health Sciences Center, Department of Rehabilitation Sciences, OK, USA), Karen Kangas (Clinical Educator and Adjunct Faculty, Misercordia University, Dallas, PA, USA), Rosanne Kermoian (Stanford University, CA, USA), Michelle Lange (Access to Independence Inc., USA), Sarah McGarry (Princess Margaret Hospital for Children and Edith Cowan University, Western Australia), Lisbeth Nilsson (Lund University, Sweden), Paul Nisbet (Communication, Access, Literacy and Learning, Scotland, University of Edinburgh), Elisabet Rodby-Bousquet (Centre for Clinical Research, Uppsala University, Västeräs, Sweden), Tylie Stokes (Chailey Heritage Clinical Services, UK). Finally, we acknowledge Dr Susan R Harris for her editorial expertise in preparing this manuscript for publication.