Hypothesis :
- Impact of muscle weakness on activity limitations is greater in poor proprioception & laxity.
- Poor proprioception & laxity lead to instability of the knee, so aggravate impact of muscle weakness on activity limitations.
- Evidence is based on cross-sectional studies only.
Longitudinal association between change in muscle strength & change in activity limitations is moderated by poor proprioception and high laxity in pts with knee OA is unknown.