*2.5.3.2 Musculocutaneous nerve compression neuropathy*

**Anatomy:** The musculocutaneous nerve originates from the lateral cord of the brachial plexus (C5–7), opposite the lower border of pectoralis minor. As the name suggests, it is a complex nerve. It innervates the biceps, coracobrachialis and brachialis muscles. It superficializes near the lateral edge of the bicipital aponeurosis and continues in the distal part of the forearm under the name of lateral antebrachial cutaneous nerve. It receives the sensation of the lateral part of the forearm [16, 36–42]. It contains only motor fibers above the elbow and only sensory fibers below the elbow (**Figure 7**) [16, 42].

**Description:** It is characterized by compression of the musculocutaneous nerve while travelling within the coracobrachialis muscle or at the point-where the lateral antebrachial cutaneous branch separating from the nerve is superficialized [9, 17, 38].

**Causes:** Musculocutaneous nerve entrapment is less common than others. Impingement usually occurs after trauma. Factors such as weightlifting, ball sport (throwing etc.), football, sleep, rowing, remote control sports (such as model airplane flying), prolonged repetitive forceful contracture of the elbow flexors such as following prolonged windsurfing, playing recreational basketball, humeral fractures, osteochondroma of the humerus, shoulder surgery, anterior shoulder subluxation, vigorous upper extremity exercise, coracoid process transfer are recommended foretiology of musculocutaneous nerve compression [7, 9, 36, 37, 39–41].

**Clinical features:** Compression of the musculocutaneous nerve causes wasting and weakness in the muscles innervated by the nerve. Patients may have dysesthesia on the lateral aspect of the forearm. Lateral cutaneous nerve (LACN) may be injured in situations such as venipuncture, cut-down procedure, compression. LACN is a purely sensory nerve. However, patients affected by LACN complain of pain rather than paresthesia. Symptoms caused by compression of the LACN may mimic other syndromes that cause elbow pain, such as lateral epicondylitis and radial tunnel [9, 36, 41].
