Cammarata ML et al. – While both joint stiffness and proprioception were reduced in the osteoarthritis (OA) population, they were only weakly correlated. This suggests that other neurophysiologic factors play a larger role in the proprioceptive deficits in knee OA.Methods
- Participants were 13 patients with knee OA and 14 healthy age–matched subjects.
- Proprioceptive acuity was assessed in varus and valgus using the threshold to detection of passive movement (TDPM) test.
- Passive joint stiffness was estimated as the slope of the normalized torque–angle relationship at 0° joint rotation (neutral) and several rotations in varus and valgus.
- Analyses of variance were performed to determine the effect of OA and sex on each metric.
- Linear regression was used to assess the correlation between the TDPM and joint stiffness.
- The TDPM was significantly higher (P < 0.05) in the OA group compared to the control group for both varus and valgus, but significant sex differences were observed.
- Passive joint stiffness was significantly reduced (P < 0.05) in OA participants compared to the control group in neutral and valgus, but not varus, and significantly reduced in women compared to men.
- A weak negative correlation was observed between the TDPM and stiffness estimates, suggesting that poorer proprioception was associated with less joint stiffness.