The teres minor muscle is one of the muscles of the shoulder, a joint connecting the upper limbs to the trunk (1).

Position. The teres minor is one of four rotator cuff muscles (supraspinatus, infraspinatus, scapularis, and teres minor) (1) located at the shoulder.

Structure. The teres minor muscle is a skeletal muscle, that is to say a muscle placed under the voluntary control of the central nervous system and made up of muscle fibers. Small and elongated in shape, the teres minor muscle is located below the infraspinatus and works synergistically with the latter (2).

Origin. The teres minor muscle inserts on the lateral border of the dorsal aspect of the scapula, or scapula (2).

Termination. The teres minor muscle is inserted below the insertion of the infraspinatus, at the level of the greater tubercle of the humerus (2).

Innervation. The teres minor muscle is innervated by the axillary nerve originating from the C5 and C6 cervical vertebrae (2).

Upper limb and shoulder movement. The teres minor muscle is involved in the various movements of the upper limb and the shoulder, which are (2):

• lateral rotation of the humerus,
• abduction of the arm,
• stabilization of the shoulder joint, by keeping the head of the humerus in the joint cavity of the scapula, or scapula.

Pain in the shoulder, as well as pain in the arm are frequently felt. The causes of these pains are varied and may be of muscular origin.

Muscle pain without lesions. (5)

• Cramp. Sometimes occurring at the level of the teres minor, it corresponds to an involuntary, painful and temporary contraction of a muscle.
• Contracture. Sometimes manifesting in the teres minor, it is an involuntary, painful and permanent contraction of a muscle.

Muscle injury. The teres minor muscle can be damaged with pain.

• Elongation. First stage of muscle damage, elongation corresponds to a stretching of the muscle caused by micro tears and resulting in muscle disorganization.
• Breakdown. Second stage of muscle damage, the breakdown corresponds to a rupture of muscle fibers.
• Rupture. The last stage of muscle damage, it corresponds to a total rupture of a muscle.

Rotator cuff tendinopathies. They designate all the pathologies that can occur in the tendons of the muscles of the rotator cuff, in particular those associated with the teres minor.6 The causes of these pathologies can be varied. The origin can be intrinsic as well with genetic predispositions, as extrinsic, with for example bad positions during the practice of sport.

• Tendinitis: It is an inflammation of the tendons.

Drug treatments. Depending on the pathology diagnosed, different treatments may be prescribed to reduce pain and inflammation in the teres minor muscle.

Surgical treatment. Depending on the type of pathology diagnosed, surgery may be performed.

Physical treatment. Physical therapies, through specific exercise programs, can be prescribed such as physiotherapy or physiotherapy.

Physical examination. First, a clinical examination is performed in order to observe and assess the symptoms perceived by the patient.

Medical imaging exam. X-ray, CT, or MRI exams can be used to confirm or further the diagnosis.

The teres minor muscle is said to have been described for the first time by the physician Gabriel Fallope, best known for his work on the reproductive system and his description of the fallopian tubes, which now bear his name. He then described the teres minor as the eighth muscle of the arm (7).