Poster 2: Postural control in elderly women with knee osteoarthritis

Objective: To examine the effect of painful knee osteoarthritis on baseline balance and the relationship between balance measures and clinical measures. Design: Cross-sectional, observational, and controlled study. Setting: Sports medicine laboratory. Participants: 22 healthy women and 26 women with unilateral knee pain (age range, 60-80y). Interventions: Not applicable. Main Outcome Measures: Outcome measures included 6 force platform measures, ambulatory and transfer knee-pain intensity score (visual analog scale [VAS]), and disease burden (Kellgren-Lawrence score). The force platform measures obtained using the Balance Master System, which included weight-bearing symmetry, sway, and movement time during performing 6 tasks: weight bearing and squat, unilateral stance with eyes open, rhythmic weight shift, sit to stand, tandem walk, and step up and over. Results: On-axis velocity (deg/s) and directional control (%) in front and back rhythmic weight shift, and rising index (% body weight) in sit to stand were lower in women with unilateral knee pain (P<.05). Center of gravity (COG) sway velocity (deg/s) during unilateral stance in painful legs was greater than that in subjects’ other legs. The weight of women with unilateral knee pain loaded less on the painful side during 30° and 60° squats and during sit to stand (P<.05). Movement time during step up and over on the painful side was longer than that on the pain-free side (P<.05). Ambulatory knee-pain intensity (VAS) had a linear relationship with the movement time during step up and over on the painful side (r=.42). Conclusion: Avoidance of pain associated with limb loading and decline in postural control ability were demonstrated in elderly women with unilateral knee pain. Based on these results, further studies should be carried out to correlate the avoidance and decline with the falls in patients with painful knee osteoarthritis.