613 - Lateral Scapular Winging Caused By Spinal Accessory Nerve Entrapment

Friday, February 20, 2026

5:00 PM - 6:30 PM AST

Presenting Author(s)

CH

Carla Hanna, MD

Resident Physician
Burke Rehabilitation Hospital
New Hyde Park, New York, United States

Co-Author(s)

AS

Anju Sanchala, DO

Resident
Burke Rehabilitation Hospital
Ardsley, New York, United States
AA

Amru Al-Rifai, MD

Resident Physician
Burke Rehabilitation Hospital
White Plains, New York, United States
BN

Bram Newman, MD, FAAPMR, CAQSM, DipABLM

Program Director - Sports Medicine Fellowship
Burke Rehabilitation
Hillsdale, New Jersey, United States

Submitter(s)

CH

Carla Hanna, MD

Burke Rehabilitation Hospital
New Hyde Park, New York, United States

Case Diagnosis: Left lateral scapular winging due to left-sided spinal accessory nerve entrapment

Case Description: A 26-year-old male presented to a primary care provider for evaluation of left upper back pain that began three months earlier, associated with weightlifting and rock climbing. Symptoms were managed conservatively. The pain persisted and he was ultimately referred to Sports Medicine. On initial evaluation, he described the pain as stabbing over the posterior aspect of the left shoulder. Physical exam revealed left lateral scapular winging, preserved motor strength, and negative impingement tests. Cervical spine and left shoulder radiographs were normal. Nerve conduction studies of the long thoracic and spinal accessory nerve were normal, but electromyography of the left trapezius muscle demonstrated polyphasic potentials and incomplete interference pattern consistent with spinal accessory nerve (SAN) entrapment. He was referred for targeted physical therapy focused on scapular stabilization.

Discussions: Scapular winging is characterized by abnormal scapular motion due to dysfunction of its stabilizing muscles. Medial winging is caused by weakness of the serratus anterior muscle due to long thoracic nerve injury, whereas lateral winging is caused by trapezius or rhomboid dysfunction from spinal accessory or dorsal nerve impairment. The SAN travels superficially in the posterior triangle of the neck which leaves the nerve susceptible to injury. Surgical procedures are the most common cause of injury, followed by non-iatrogenic causes such as blunt trauma and gunshot wounds. Sports-related injuries are less common with only a few cases highlighting palsy due to weightlifting, volleyball, or carrying heavy climbing gear. This case demonstrates that any activity with repetitive over-head motion may predispose to SAN entrapment.

Conclusions: Although iatrogenic injury remains the most common cause, providers should consider SAN involvement in athletes presenting with acute shoulder pain and scapular winging. Early recognition and targeted therapy may help prevent long-term dysfunction.