Increased Muscle Strength Limits Postural Sway During Daily Living Activities in Total Hip Arthroplasty Patients

OBJECTIVE: The aim of the study was to investigate the effect of maximal strength training on postural sway after total hip arthroplasty, performed before and after a battery of physical performance tests that resemble daily living activities. DESIGN: This study is an exploratory study based on data from a 3-mo randomized controlled trial involving 54 total hip arthroplasty patients performing maximal strength training or conventional rehabilitation. At 3, 6, and 12 mos postoperatively, postural sway was evaluated in two gait tests; ie, one test before and one test after conducting a battery of physical performance tests. RESULTS: At 3 mos postoperatively, postural sway in the test after was significantly higher for the conventional rehabilitation group than the maximal strength training group (P = 0.045); however, there was no between-group difference at the test before (P = 0.670). Postural sway was also significantly higher in the test after compared with the test before in the conventional rehabilitation group (P < 0.001). No difference was found between the test before and test after in the maximal strength training group (P = 0.713). At 6 and 12 mos postoperatively, there were no statistically significant within- or between-group differences in postural sway. CONCLUSIONS: Increased muscular strength limits postural sway 3 mos postoperatively in total hip arthroplasty patients after a demanding battery of physical performance tests simulating daily living activities.