Gait, lower extremity strength, and self-assessed mobility after hip arthroplasty.

BACKGROUND Rehabilitation services after hip arthroplasty (HA) usually occur in the first 6 months following surgery. Reports in the literature suggest that 9 months to several years after HA surgery, patients are generally satisfied with pain relief. However, many express dissatisfaction with their ability to perform domestic and social activities. Reduced walking ability and long-term lower extremity (LE) muscle weakness may contribute to decreased mobility. The purpose of this study was to compare the within-group LE muscle strength, gait, and self-assessed functional mobility in adults 9 months to 6 years after HA surgery to age- and gender-matched controls. METHODS Thirty subjects (15 HA and 15 control) were studied. LE muscle strength was assessed using the Spark handheld dynamometer. Gait parameters were measured using the GAITMAT II, and self-assessed mobility was evaluated using the hip-rating questionnaire. RESULTS The HA group walked significantly more slowly than the control group at maximum walking speed. The operative LE of the HA group had less muscle strength than the nonoperative LE, and the hip abductors were the most affected muscle group in that LE. The HA group scored lower in the domains of impact, pain, and function on the hip-rating questionnaire. CONCLUSION Because of long-term residual impairments and disabilities noted after HA surgery, intervention beyond the initial post-surgical rehabilitation is needed.