10/26/2024
From my files for a colleague. Here you go Adam.
NECK, SHOULDER, CHEST, ARM OR HAND PAIN?
PROTRACTED/ROUNDED SHOULDERS?
THORACIC OUTLET SYNDROME?
⠀
PECTORALIS MINOR MUSCLE "THE KING OF COMPENSATION “
⠀
[ANATOMY, FUNCTION AND PATHOLOGY]
⠀
The pec minor attaches from the coracoid process of the scapula to ribs #3-5.
⠀
It is a muscle that becomes easily shortened and tight due to many factors, including rounded shoulder posture, glenohumeral joint dysfunction, breathing dysfunction and a variety of compensation patterns. It sits on top of the brachial plexus and can therefore contribute to Thoracic Outlet Syndrome.
⠀
The pec minor is located in an area of the shoulder with many other muscles, including the pec major, biceps, deltoids, coracobrachialis, subscapularis, serratus anterior and the latissimus dorsi.
⠀
Clusters of muscles like this often can become dysfunctional due to poor biomechanics. This can lead to adhesions, facilitation/inhibition, and synergistic dominance. The pec minor is often the overactive muscle in these compensation patterns.
⠀
Rounded shoulder posture and forward head posture will cause the pec minor to shorten. This action is called protraction and is opposed by the muscles of retraction.
These include the middle trapezius and the rhomboids. Commonly the pec minor becomes facilitated and the middle trapezius becomes inhibited. Release of the pec minor followed by strengthening of the middle trapezius can be very effective in these cases.
⠀
Because the pec minor rounds the shoulder, it is opposed by the latissimus dorsi which moves the shoulder back and down. Again, release of the pec minor followed by strengthening of the latissimus dorsi can be very effective.
⠀
The pec minor is a downward rotator of the scapula and oftentimes involved in glenohumeral dysfunction. If it is facilitated, it can inhibit the serratus anterior, which contributes to upward rotation of the scapula. This can lead to Impingement Syndrome and sometimes winging of the scapula. The resultant scapular instability greatly contributes to shoulder joint dysfunction.
