Nerve Injury (Long Thoracic Nerve, Roots C5-C7)

A long thoracic nerve injury affects a nerve that controls the serratus anterior muscle, which helps keep the shoulder blade stable and close to the chest wall. This nerve injury can cause the shoulder blade to stick out abnormally, a condition known as winged scapula. The injury usually involves the nerves from spinal roots C5 to C7 and can result from trauma, repetitive movements, or compression. When this nerve is damaged, it leads to weakness in lifting the arm and difficulty with overhead activities. The condition primarily impacts the musculoskeletal system and can cause pain, limited shoulder movement, and functional impairment. Early recognition is important to prevent long-term disability.

Long thoracic nerve injury involves damage to the long thoracic nerve, which arises from the ventral rami of spinal roots C5-C7 and innervates the serratus anterior muscle. The core pathology is nerve trauma or compression leading to denervation of the serratus anterior, resulting in winged scapula due to inability to stabilize the scapula against the thoracic wall. Common causes include blunt trauma, repetitive overhead activities, or iatrogenic injury during surgery. Clinically, patients present with scapular winging, shoulder pain, and weakness in arm elevation. This injury is significant because it impairs shoulder mechanics and can cause chronic disability if untreated. Diagnosis is based on clinical examination and confirmed by electrodiagnostic studies. Understanding this nerve's anatomy and function is essential for accurate diagnosis and management.