A 38-year-old man presents to the physician for evaluation of a work-related injury. The patient reports that he was thrown from a forklift while on the job two weeks ago. He states that he now has difficulty lifting heavy objects with his left arm and complains of left shoulder pain. Past medical history is unremarkable. On physical examination, he has decreased range of motion in his left shoulder and has significant protrusion of the left scapula.
Which of the following nerves has most likely been injured in this patient?
A) Axillary nerve
B) Lateral anterior scapular nerve
C) Long thoracic nerve
D) Short thoracic nerve
E) Suprascapular nerve
C) Long thoracic nerve
This patient has most likely endured a long thoracic nerve injury, as he presents with signs and symptoms of a winged scapula. The long thoracic nerve innervates the serratus anterior muscle. In this case, the patient is most likely suffering from serratus anterior muscle paralysis. This prevents the muscle from anchoring the scapula to the rib cage, thus leading to a protruding scapula. Winging of scapula contributes to loss of power and limited flexion and abduction of the upper extremity and can cause considerable pain. This condition that can affect the ability to lift, pull, and push heavy objects, as well as to perform daily activities of living, such as brushing one’s hair and teeth and carrying grocery bags.
Key Learning Point
The long thoracic nerve innervates the serratus anterior muscle which anchors the scapula to the rib cage. Damage to the long thoracic nerve can result in winged scapula.
