TOTAL HIP ARTHROPLASTY AFFECTING BALANCING ABILITY AFTER SUDDEN PERTURBATION

摘要

The goal of this research was to analyze the effect of total hip arthroplasty (THA) on balancing ability among 20 healthy elderly people and 18 subjects operated on by a conventional direct-lateral approach during the early postoperative period. Balancing ability after sudden perturbation was modeled by the provocation test during double leg and single leg stance. The Lehr’s damping ratio characterized the balancing ability calculated from testing at double leg stance did not differ significantly from the results of testing at stance on the unaffected/healthy limb; however the results from testing during stance on the affected limb in patients differed significantly from the results of the other two tests in the early postoperative period. These results indicated that the healthy/unaffected side is always dominant. Furthermore, THA significantly decreased balancing ability on the affected side after sudden perturbation. Our results showed that the balancing ability sudden perturbation deteriorated 6 weeks after THA; however, 12 weeks after THA it improved compared to the results prior to surgery, although it did not return to normal. Deterioration in balancing ability after sudden perturbation can increase the risk of falling.