Sports Anatomy - Minor Pectoral Muscle (8)
Position and Structure:The subscapularis muscle is located in the upper part of the rib cage on the outer side, on the deep surface of the pectoralis major, completely covered by the pectoralis major. It is a triangular flat muscle, with dispersed muscle fibers originating from the 3.4.5 ribs in front. Near the rib cartilage and rib connection, the muscle fibers slope upwards, inside the coracobrachialis, terminating with a short tendon at the apex of the coracoid process. At this point, there is often a small bursa. The upper border between the collarbone and the pectoralis major is called the 'clavicular subscapular triangle.'The subscapularis muscleBelowto the third rib, usually at the connection between the ribs and rib cartilages of the second to fifth ribs.
Aboveto the top of the coracoid process.The subscapularis musclepulls the coracoid process forward and downward, rotates the coracoid process and pulls it down, elevating the ribs 3-5. When the coracoid process is fixed, it can elevate the ribs 3-5, assisting in inhalation.Weakness of the anterior serratus muscle can lead to winged scapula
Nerve innervation: Innervated by the inner and outer chest nerves, C7-T1Presentation: 1,
wood-like discomfort in front of the shoulder and radiating to the third to fifth fingers, difficulty lifting the shoulders forward, 2,
difficulty when extending the hand forward and lifting it to the same height as the shoulder, 3,
The associated area of the subscapularis muscle is similar to the coracoid process area of the pectoralis major area mainly in the front of the shoulder, sometimes it can affect the entire inner side of the arm, inner elbow, the radial side of the thumb and index finger, and the ring finger. 4,Injury or overuse of the subscapularis muscle causes muscle contraction, which often compresses important nerves and the manubrial channel entering the arm, which can be difficult to palpate the pulsation of the wrist even when it is restricted by the subscapularis muscle in this way. 5,
Tight subscapularis muscle squeezing the arm nerve causing discomfort in the forearm, hand or fingers,may be misdiagnosed as carpal tunnel syndrome. 6,
Due to the fatigue of the trapezoid muscle and the shortness of the subscapularis muscle leading to forced rounded shoulder posture, discomfort in the mid-back can occur. Excessive tension of the subscapularis muscle pulls the acromion process forward, when fatigued, the trapezoid muscle is weak and cannot resist the pull of the subscapularis muscle, the 'wing prominence' becomes more serious. ttttt
xm
z
“”
