The teres minor muscle has the same role as the infraspinatus, laterally rotating and depressing the head of the humerus.  Shortness or greater stiffness of the lateral rotators relative to the stiffness of the axioscapular muscle (serratus anterior) is common and can contribute to excessive anterior and superior glide of the humeral head.  Restricted posterior glide and excessive anterior glide are factors in shoulder impingement syndromes.

The lateral rotators often become short or stiff and can interfere with the posterior glide of the humeral head.  It is therefore extremely important to monitor their length and strength characteristics.

Actions

• Laterally rotates the shoulder (glenohumeral joint)
• Adducts the shoulder (g/h joint)
• Extends the shoulder (g/h joint)
• Horizontally abducts the shoulder (g/h joint)
• Stabilizes the head of the humerus in the glenoid cavity

Origin

• Superior half of the lateral border of the scapula

Insertion

• Greater tubercle of the humerus

Nerve Innervation

• Axillary