Teres Minor - Muscle Overview

Teres Minor Muscle Overview

Anatomy & Location: The teres minor is nestled within the shoulder's rotator cuff muscles. It spans from the lateral border of the scapula, running diagonally and attaching itself to the humerus's upper region. Notably, its oblique orientation gives the muscle its characteristic narrow and elongated appearance.

Function: Teres minor has dual primary responsibilities:

1. External Rotation: Assists in the lateral rotation of the humerus.
2. Shoulder Stabilization: Alongside its rotator cuff counterparts, the teres minor stabilizes the humerus's head within the shoulder joint during various arm activities¹.

Origin and Insertion:

• Origin: It stems from the dorsal surface of the axillary border of the scapula.
• Insertion: Finds its attachment on the inferior facet of the greater tubercle of the humerus.

Neurovascular Supply: The axillary nerve innervates the teres minor, with its blood supply coming predominantly from the posterior circumflex humeral artery.

Trigger Points & Clinical Relevance: Trigger points, or hyperirritable nodules found in taut bands of muscle fibers, frequently develop in the teres minor due to:

1. Overuse: Repetitive shoulder activities, especially those that involve overhead movements, can overstress the muscle.
2. Direct Trauma: Injuries or impacts to the shoulder can instigate trigger point formation.
3. Postural Strains: Extended durations in poor postures, like rounded shoulders, can strain the teres minor.
4. Shoulder Instability: Instabilities can increase teres minor workload, possibly inducing trigger points².
5. Associated Muscular Imbalances: Dysfunctions in adjacent muscles can compromise the teres minor's optimal function, promoting trigger points³.

When these trigger points manifest, they can cause localized pain and even refer pain down the arm or into the shoulder blade region.

Therapeutic interventions, such as myofascial release, dry needling, and specific stretches, can address trigger points, offering relief from symptoms and restoring shoulder functionality⁴.

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