Journal article

Lines of action and stabilizing potential of the shoulder musculature

David C Ackland, Marcus G Pandy

JOURNAL OF ANATOMY | WILEY | Published : 2009

Abstract

The objective of the present study was to measure the lines of action of 18 major muscles and muscle sub-regions crossing the glenohumeral joint of the human shoulder, and to compute the potential contribution of these muscles to joint shear and compression during scapular-plane abduction and sagittal-plane flexion. The stabilizing potential of a muscle was found by assessing its contribution to superior/inferior and anterior/posterior joint shear in the scapular and transverse planes, respectively. A muscle with stabilizing potential was oriented to apply more compression than shear at the glenohumeral joint, whereas a muscle with destabilizing potential was oriented to apply more shear. Si..

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