Shoulder Flexor muscles

Authors

Affiliations

Nathaniel Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

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Table 1: Glenohumeral Flexor muscles

Muscle	Origin	Insertion	Innervation	Action
Anterior deltoid	Lateral third of clavicle	Deltoid tuberosity of humerus	Axillary n. C5 - C6	GHJ: Flexion, IR, Adduction
Biceps brachii Long head	Supraglenoid tubercle of scapula Adjacent rim of Glenoid Labrum	Radial tuberosity Bicipital aponeurosis	Musculocutaneous n. C5 - C6	Elbow: Flexion, Supination GHJ: Flexion, Stabilization of humeral head during deltoid contraction, Abduction, IR
Biceps brachii Short head	Coracoid process	Radial tuberosity Bicipital aponeurosis	Musculocutaneous n. C5 - C6	Elbow: Flexion, Supination GHJ: Flexion, Stabilization of humeral head during deltoid contraction, Abduction, IR
Coracobrachialis	Coracoid process	Humerus (in line with crest of lesser tubercle)	Musculocutaneous n. C5 - C7	GHJ: Flexion, Adduction, IR
Pectoralis major	Clavicle (medial half) Sternum Costal cartilages 1-6 Rectus sheath (anterior layer)	Humerus (crest of greater tubercle)	Lateral pectoral n. Medial pectoral n. C5 - T1	Entire muscle: Adduction, IR Clavicular & Sternocostal parts: Flexion, Aids in respiration when shoulder is fixed

Note

When considering shoulder abduction, there is much more to the shoulder than just glenohumeral joint abduction. We must also consider the muscles that cause scapulothoracic posterior tilting.

Secondary

• Coracobrahialis is a secondary shoulder flexor¹.

References

1.

Biel A. Trail Guide to the Body: A Hands-on Guide to Locating Muscles, Bones, and More. 6th ed. Books of Discovery; 2019.