Muscle Energy Techniques, Second Edition by John Gibbons

Author:John Gibbons
Language: eng
Format: epub
Publisher: North Atlantic Books

Subscapularis

Origin: Subscapular fossa (anterior surface of scapula).

Insertion: Lesser tubercle at the top of humerus. Capsule of shoulder joint.

Nerve: Upper and lower subscapular nerves (C5–C7), from the posterior cord of the brachial plexus.

Action: As a rotator cuff, subscapularis stabilizes the GHJ; mainly prevents the head of the humerus being pulled upward by the deltoid, biceps brachii, and long head of triceps brachii. Medially rotates the humerus.

The subscapularis is responsible for internal rotation of the GHJ as well as being able to depress, stabilize, and adduct the humeral head within the glenoid fossa during overhead movements.

The subscapularis in one way is antagonistic (opposite) as well synergistic (helper or assister) to the muscles of the infraspinatus, teres minor, and posterior deltoid because it provides a posterior pull on the humerus while the other muscles provide an anterior pull. However, they all work collectively or synergistically to centralize the humeral head within the glenoid fossa.

Weakness or inhibition of the subscapularis potentially allows the humeral head to displace anteriorly because the other larger internal rotators, latissimus dorsi, and teres major, take over the role of internal rotation and subsequently this can cause the humerus to be forced into an anterior glide position because the subscapularis has lost its ability to control the posterior glide motion of the humeral head.

If this situation arises then an impingement type of syndrome or even a bicipital tendinopathy of the long head of the biceps brachii muscle can follow.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.