HIP ABDUCTOR MUSCLE-ACTIVITY AS SUBJECTS WITH HIP PROSTHESES WALK WITH DIFFERENT METHODS OF USING A CANE

Background and Purpose. Using a cane held contralateral to a prostheti c hip is presumed to be an effective way to reduce the demands on the hip abductor (HA) muscles and, therefore, the forces on the implant. I n this study, surface electromyographic (EMG) activity was measured fr om the HA muscles to test this notion. Subjects. Twenty-four active su bjects (9 female, 15 male) with unilateral prosthetic hips were tested . The subjects, aged 40 to 86 years ((X) over bar=63.3, SD=10.7), were not regular cane users. Methods. Surface EMG activity and cane force were analyzed while the subjects walked with the cane held (1) contral ateral to the prosthesis (CL-CANE), (2) ipsilateral to the prosthesis (IL-CANE), and (3) contralateral to the prosthesis with instructions f or the subject to push with a ''near-maximal effort'' (CL-CANE+). Resu lts. Only the following conditions showed a change in HA muscle EMG ac tivity as compared with not using a cane: CL-CANE=-31.1%, CL-CANE+=-42 .3 %. Conclusion and Discussion. Holding the cane contralateral to the prosthetic hip appears to be an effective method of reducing demands on the HA muscles.