Force analysis of individual muscles acting simultaneously on the shoulder joint during isometric abduction

摘要: Abstract A technique was developed for calculating the force generated by individual muscles that contribute to isometric abduction of upper limb in coronal plane with humerus medially rotated. The instantaneous center rotation located and used indicate had a component which contributed abduction. Mathematical relationships were obtained forces as function their respective ‘effective’ or physiological cross-sectional areas. effective area expressed maximum thickness middle fibers deltoid muscle — parameter could be measured easily on an X-ray film. static equilibrium equation about solved. Any involved In process applying this technique, certain functions clarified.