Pectoral nerves lesions

Causes

• Usually result from brachial plexus damage.
• Seat belt injury.
• Body-builders occasionally develop medial pectoral neuropathy, either isolated or in combination with thoracodorsal neuropathy.

Symptoms & signs

• Weakness in adduction and medial rotation of the upper arm.
• Difficulty using arm when climbing.
• Pectoral muscle atrophy.

Examination

• Test adduction strength: Have the patient in supine position, with the shoulder flexed (90o for testing upper fibers, 45o for testing lower fibers) with elbow flexed. Hold patient’s arm above elbow with one hand and stabilize opposite shoulder with your other hand. Ask them to try to reach opposite shoulder while you resist the adduction.