Kinesiology 2241A/B Lecture Notes - Lecture 12: Subscapularis Muscle, Anatomical Terms Of Motion, Infraspinatus Muscle

• School: Western University
• Department: Kinesiology
• Course: Kinesiology 2241A/B
• Professor: Thomas Richard Jenkyn

Document Summary

The upper extremeties: the upper extremity is also known as "the arm, there are 5 joints that we will consider, shoulder, shoulder "girdle, elbow, radial- ulnar joint, wrist. The glenoid: the glenoid fossa is a shallow depression in the lateral scapula. The rotator cuff: the joint capsule of the glenohumeral joint combines with the tendons of the supraspinatus, subscapularis, infraspinatus, and teres minor to form the rotator cuff. Stabilization by the rotator cuff: each of the 4 muscles of the rotator cuff has significant force components that stabilize the humeral head in the glenoid fossa (i. e. push in into the depression) Same muscles are working together to do one thing and opposing each other to enable motion in certain planes: muscles cooperate to create internal- external rotation. Image image image: the deltoid muscle group sit on top of the 4 rotator cuff muscles and acts to ab-duct the arm, deltoid has a tiny lever arm (rotary component)