Journal article

Moment arms of the muscles crossing the anatomical shoulder

David C Ackland, Ponnaren Pak, Martin Richardson, Marcus G Pandy

Journal of Anatomy | WILEY | Published : 2008


The objective of the present study was to determine the instantaneous moment arms of 18 major muscle sub-regions crossing the glenohumeral joint during coronal-plane abduction and sagittal-plane flexion. Muscle moment-arm data for sub-regions of the shoulder musculature during humeral elevation are currently not available. The tendon-excursion method was used to measure instantaneous muscle moment arms in eight entire upper-extremity cadaver specimens. Significant differences in moment arms were reported across sub-regions of the deltoid, pectoralis major, latissimus dorsi, subscapularis, infraspinatus and supraspinatus (P < 0.01). The most effective abductors were the middle and anterior de..

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Funding Acknowledgements

This work was supported by a fellowship from the Victorian Endowment for Science, Knowledge, and Innovation (VESKI) to M. G. P. and a Melbourne School of Engineering Scholarship to D. C. A. Funding provided by Encore Medical Inc., Austin, Texas, USA, is also gratefully acknowledged.