GENERAL INFORMATION
The teres major is a muscle located in the shoulder region. It is a thick and triangular muscle that lies inferior to the teres minor muscle. The teres major assists in various movements of the shoulder joint and is involved in actions such as adduction, extension, as well as internal rotation.
ORIGIN
This muscle originates from the inferior angle and lower part of the lateral border of the scapula.
INSERTION POINT
The muscle inserts into the medial lip of the intertubercular groove (bicipital groove) of the humerus.
MAJOR ARTERIES
It receives its blood supply primarily from the circumflex scapular artery and the subscapular artery, which are branches of the axillary artery.
NEURAL INNERVATION
The teres major is innervated by the lower subscapular nerve, which arises from the posterior cord of the brachial plexus (C5-C7).
TRIGGER POINT
Trigger points can develop in this muscle, causing localised pain as well as tenderness. These trigger points can be associated with muscle overuse, poor posture, or trauma.
CONCENTRIC FUNCTION
Contraction of the teres major muscle results in shoulder adduction (bringing the arm toward the body), extension (moving the arm backwards), as well as internal rotation (rotating the arm inward).
ECCENTRIC FUNCTION
This muscle has a limited eccentric function during controlled movements, aiding in the controlled release of tension during shoulder abduction, flexion, and external rotation.
ISOMETRIC FUNCTION
Isometric contraction of the teres major provides stability and support to the shoulder joint during activities that require static holding or resisting external forces.
RELATED MUSCLE SCIENTIFIC NAMES
- Teres major: This thick, triangular muscle located in the shoulder region assists in adduction, extension, and internal rotation of the shoulder joint.
ANTAGONIST
- Deltoid: This muscle is responsible for shoulder abduction and works opposite to the muscle during arm movements.
- Infraspinatus: Located on the posterior scapula, this muscle externally rotates the arm and opposes the internal rotation function of the teres major.
- Teres minor: This muscle aids in the external rotation of the arm and counteracts the internal rotation action of the teres major.
COMMON INJURIES
- Strains or tears: Overuse, improper lifting techniques, or trauma can cause strain or tear in the tire’s major muscle.
- Rotator cuff injuries: In some cases, teres major injuries can occur alongside rotator cuff injuries or impingement syndrome.
EXERCISES
- Bent-over rows: Compound exercise that targets the back muscles, including the teres major, by rowing a barbell or dumbbells.
- Lat pulldowns: Exercise that targets the latissimus dorsi muscles but also engages the teres major.
- Pull-ups: Bodyweight exercise that primarily targets the latissimus dorsi but also involves the teres major.
- Single-arm dumbbell rows: Focuses on the back and shoulder muscles, engaging the teres major during the rowing motion.
- Cable straight-arm pulldowns: Exercise that engages the latissimus dorsi and teres major by pulling a cable bar straight down with extended arms.
STRETCHES
- Cross-body stretch: Bring the affected arm across the chest and use the opposite hand to gently pull it closer to the body, stretching the teres major.
- Wall stretches: Place the hand on a wall at shoulder height and lean the body away, stretching the teres major as well as other shoulder muscles.
- Child’s pose: Kneel on the floor, extend the arms forward, and sit back on the heels to stretch the back as well as shoulder muscles, including the teres major.
- Overhead triceps stretch: Reach one arm overhead, bend the elbow, and use the opposite hand to gently push the arm further down the back, stretching the muscle.
- Doorway stretch: Stand in a doorway, place the hands on the frame at shoulder height, and lean forward to stretch the chest as well as shoulder muscles, including the teres major.