PROPERTIES OF MUSCULUS GLUTEUS MAXIMUS IN ABOVE-KNEE AMPUTEES

The present study aimed at evaluating possible changes of the gluteus maximus muscle bulk size and in the contracting properties of gluteus maximus in the amputated above-knee limb. Seven male above-knee ampute es, with a mean age of 47.4 years volunteered to participate in the pr esent study. Twenty-one healthy subjects with a mean age of 34.0 years served as the control group. Muscle belly displacement was measured b y means of a precision electromagnetic sensor dc-dc displacement trans ducer while performing maximal voluntary isometric contractions; The m uscle twitch contraction has been quantified by the latency period (ii ), time to peak tension (T2) and the slope of the record. A statistica lly significant decrease in muscle belly displacement on the amputated side has been observed in comparison with controls and non-amputated side. The latency period on the amputated side was significantly longe r and the slope less steep than in the control group. These results in dicated atrophied and slower gluteus maximus on the amputated side of above-knee amputees. Revelance-Gluteus maximus is an important hip ext ensor and its good function is necessary to control above-knee prosthe tic limb. Atrophy of gluteus maximus proved by decrease of muscle bell y displacement of the amputated limb of above-knee amputees requires p rogrammes of physical therapy directed at strengthening the muscle in order to improve the quality of their gait.