EVALUATION ON MUSCLE STRENGTH OF THE GLUTEUS MAXIMUS IN PATIENTS WITH UNILATERAL COXARTHROSIS

Abstract

Muscle strength of the gluteus maximus in patients with unilateral coxarthrosis was assessed by means of isokinetic dynamometry and electromyography before and after total hip replacement. Comparing with the mean value for age-matched healthy controls, the isokinetic muscle strength of the patients was 35% in peak torque, 29% in initial instantaneous power and 82% in endurance preoperatively. Muscle strength of the gluteus maximus postoperatively reached to 70% of controls even over one year. Electromyographic assessment was carried out on the gluteus maximus and the quadriceps femoris. Contractions of the gluteus maximus were noted little in the conventional quadriceps-setting exercise. However, the muscle strength increased significantly after one-week training in which the gluteus maximus was simultaneously contracted together with the quadriceps-setting. Besides, higher activities of the quadriceps femoris were recognized by such simultaneous training.