Influence of weight bearing visual feedback on movement symmetry during sit to stand task

Weight-bearing asymmetry is common in individuals with hip osteoarthritis and after total hip arthroplasty. Including symmetry training to the rehabilitation programs may normalize movement strategies during dynamic tasks. The purpose of this study was to evaluate the immediate influences of real-time visual feedback of weight distribution on the interlimb movement symmetry during the sit-to-stand task, before and after total hip arthroplasty, and to determine whether physical impairments affect the response to visual feedback.

Subjects before and after total hip arthroplasty participated in three- dimensional motion analysis. Subjects completed 3 trials of sit-to-stand task in two conditions; "without visual feedback" and "with visual feedback". Outcome measures were the interlimb symmetry of vertical ground reaction force, and joint kinematics and kinetics. Pain and strength of lower limbs were assessed.

Compared to "without visual feedback" condition, subjects moved with greater symmetry of vertical ground reaction force and joint kinetics when visual feedback was received. However, subjects continued to demonstrate interlimb difference for joint kinetics and vertical ground reaction force in the visual feedback condition. The increase in symmetry was not strongly influenced by physical impairments and subjects before and after total hip arthroplasty responded similarly to the feedback.

We concluded that in a single session, the visual feedback of weight bearing distribution had a positive immediate effect on movement symmetry during the sit-to-stand task. Future studies that assess long-term retention and functional benefits are warranted before visual feedback is incorporated in rehabilitation for this patient population.