Asymmetry of posture and truncal musculature following unilateral arm amputation--a clinical, electromyographic, posture analytical and photogrammetric study

Abstract

Unilateral upper limb amputation causes changes in statics of the spine. As a result asymmetrical posture of the spine, muscular asymmetries follow. In this study a population of upper limb amputees (above and below elbow amputees) is examined by clinical, electromyographical analysis and gait analysis. Upper limb amputations cause in correlation to weight loss a shift of the trunk to the side of the amputation, a scoliosis with a bowing to the side of the amputation, an elevation of the shoulder on the amputation side and a torsion of the trunk. Muscular asymmetries result from loss of function (muscles of the arm, M. latissimus, M. trapezius) and by shifting of the center of gravity. In order to get the center of gravity over the legs, the amputee compensates the loss of weight by shifting the upper trunk to the side of the amputation. As a result the shift of the segmental center of gravity at the lumber height to the side of the normal arm with muscular asymmetry in the erector trunci lumbalis results. As well we saw an overactivity of musculus glutaeus medius and resulting stress of the amputation sided hip joint. There was a remarkable difference between above and below elbow amputees caused by differences in weight loss. Muscular and static asymmetries in amputees who lost their arm only a short period before could be reduced by compensating the weight loss. Results for technical orthopaedic fitting and stress on gymnastic procedures to compensate these statistical problems are discussed.