Knee joint stiffness during walking in knee osteoarthritis
Article first published online: 28 DEC 2009
Copyright © 2010 by the American College of Rheumatology
Arthritis Care & Research
Volume 62, Issue 1, pages 38–44, 15 January 2010
How to Cite
Dixon, S. J., Hinman, R. S., Creaby, M. W., Kemp, G. and Crossley, K. M. (2010), Knee joint stiffness during walking in knee osteoarthritis. Arthritis Care Res, 62: 38–44. doi: 10.1002/acr.20012
- Issue published online: 28 DEC 2009
- Article first published online: 28 DEC 2009
- Manuscript Accepted: 27 AUG 2009
- Manuscript Received: 23 MAY 2008
- Early Career Researcher Grants Scheme from the University of Melbourne
- Arthritis Foundation of Australia
To investigate the construct validity of walking knee stiffness as a measure to differentiate between individuals with and without knee osteoarthritis (OA) and the construct validity of walking knee stiffness as related to self-reported knee stiffness. The contributors to walking stiffness and its relationship with loading rate and adduction moment are also investigated.
Thirty-seven individuals with knee OA and 11 asymptomatic controls participated. Knee stiffness was calculated during walking as the change in knee flexion-extension moment divided by the change in knee flexion angle. Forward-stepwise regression models and Pearson's correlation coefficients were used to evaluate the relationships between variables.
Knee stiffness in walking was significantly greater in the OA group (mean ± SD 10.1 ± 4.4 Nm/°/kg × 100) compared with the controls (mean ± SD 5.6 ± 1.5 Nm/°/kg × 100) (P < 0.001). Knee excursion range explained 39% of the variance in walking knee stiffness (B = −0.736, P < 0.001) and knee extensor moment a further 7% (B = 6.974, P = 0.045). In the OA group, walking knee stiffness was not associated with self-reported stiffness (r = 0.029; P = 0.863). For the OA group, greater self-reported stiffness was associated with lower peak knee adduction moment (B = −0.354, P < 0.001).
The construct validity of walking knee stiffness is supported. The poor correlation between walking stiffness and self-reported stiffness suggests the 2 measures evaluate different aspects of knee stiffness. Since a measure of walking stiffness is likely to provide valuable information, future research evaluating its clinical significance is merited.