Scapular winging happens when one or both shoulder blades stick out from the back instead of lying flat against the ribcage, and the cause almost always traces to one of three categories: a damaged nerve that has stopped firing the muscles holding the blade in place, a structural problem like a bony growth wedged underneath the scapula, or a systemic muscle-wasting condition. By far the most common culprit is injury to the long thoracic nerve, which controls the serratus anterior muscle, but winging can also follow damage to the spinal accessory nerve, the dorsal scapular nerve, or even a fracture that healed in the wrong position.
Long Thoracic Nerve Injury and Medial Winging
The single most frequently reported cause of scapular winging is dysfunction of the serratus anterior muscle, almost always from an injury to the long thoracic nerve (LTN).1Journal of Hand Surgery. Anatomy, Etiology, and Management of Scapular Winging The serratus anterior wraps around the side of the chest and attaches along the inner border of the scapula. Its job is to pull the shoulder blade forward and hold it snug against the ribcage during arm movement. When the LTN is damaged and the serratus anterior goes slack, the medial (inner) edge of the scapula lifts away from the back, a pattern called medial winging.2PubMed Central. Scapular winging: anatomical review, diagnosis, and treatments
The long thoracic nerve is unusually vulnerable because of its anatomy. It runs a long, relatively unprotected course along the chest wall, making it susceptible to stretch injuries, direct blows, compression from heavy backpacks or shoulder straps, and even viral inflammation. Common scenarios include carrying heavy loads on the shoulder, repetitive overhead work, and blunt trauma to the lateral chest. Surgical procedures in the axillary region can also damage the nerve inadvertently. Sometimes the cause is never identified at all, and the winging just appears after what seemed like a routine illness or period of heavy exertion.
The serratus anterior does more than just pin the scapula to the ribs. Weakness or poor activation of this muscle is linked to several painful shoulder conditions because it plays a role in rotating the scapula upward when you raise your arm.3PubMed Central. Kinesiologic considerations for targeting activation of scapulothoracic muscles – part 1: serratus anterior Without it, the shoulder blade cannot tilt and rotate properly, and the shoulder joint loses mechanical leverage. People with LTN palsy often notice not just the visible winging but difficulty pushing objects, reaching overhead, and lifting even moderate weights.
Spinal Accessory Nerve Injury and Lateral Winging
The second major nerve-related cause produces a visually different pattern. When the spinal accessory nerve (SAN) is damaged, the trapezius muscle weakens or becomes paralyzed, and the scapula wings laterally rather than medially. Instead of the inner edge lifting, the shoulder drops and the outer edge flares, with the whole blade shifting outward.2PubMed Central. Scapular winging: anatomical review, diagnosis, and treatments This distinction matters clinically because the direction of winging points directly to which nerve is involved.
What makes SAN injury especially frustrating is that it is often iatrogenic, meaning it happens during a medical procedure. Lymph node biopsies in the posterior triangle of the neck are a classic cause, as the nerve passes through this region in a superficial and exposed position. Radical neck dissections for cancer and penetrating trauma to the neck also account for a significant share of cases.4PubMed Central. Patient outcome after surgical management of the spinal accessory nerve injury: a long-term follow-up study The resulting trapezius paralysis disrupts the entire muscular balance of the shoulder girdle, producing not just winging but pain, limited overhead reach, and sometimes nerve symptoms radiating down the arm.5Arthroscopy Techniques. The Modified Eden-Lange Tendon Transfer for Lateral Scapular Winging Secondary to Spinal Accessory Nerve Injury
Dorsal Scapular Nerve and the Rhomboids
A less commonly recognized cause of scapular winging is injury to the dorsal scapular nerve, which innervates the rhomboid muscles. The rhomboids retract the scapula, pulling it toward the spine. When they are paralyzed, the medial border of the scapula lifts away much as it does with serratus anterior weakness, but the inferior angle of the blade tends to rotate laterally, creating a subtly different appearance.6Journal of Shoulder and Elbow Surgery. Scapular winging due to rhomboid muscle paralysis: clinical assessment of 4 cases and anatomic study of the dorsal scapular nerve This is rare enough that it can easily be missed, and published cases are few.7PubMed. Dorsal scapular neuropathy causing rhomboids palsy and scapular winging
Motion analysis studies confirm that serratus anterior palsy and trapezius palsy produce distinct scapular movement patterns during arm elevation, including measurable differences in how much the scapula tilts and how far it protracts or rotates.8Clinical Biomechanics. Specific scapular kinematic patterns to differentiate two forms of dynamic scapular winging These differences are clinically useful for pinpointing the nerve at fault, especially when the visual distinction between medial and lateral winging is borderline.
Parsonage-Turner Syndrome
Not every nerve injury behind scapular winging comes from a blow, a stretch, or a surgical nick. Parsonage-Turner syndrome (PTS), also called neuralgic amyotrophy, is an inflammatory condition of the brachial plexus that can strike seemingly out of nowhere. It typically begins with severe, sudden-onset pain in one shoulder, followed within days or weeks by profound weakness and muscle wasting.9PubMed. Parsonage-Turner Syndrome and Hereditary Brachial Plexus Neuropathy When the long thoracic nerve is affected, which it often is, the result is a winged scapula that appears after the initial pain begins to subside.10PubMed Central. Winged Scapula Caused by Parsonage-Turner Syndrome After BNT162b2 mRNA COVID-19 Vaccination
PTS has been reported following viral infections, vaccinations, surgery, and intense physical stress, though in many cases no clear trigger is found. A hereditary form, hereditary brachial plexus neuropathy, produces attacks that are clinically indistinguishable from the sporadic version but tend to recur. Because PTS can affect multiple nerves simultaneously, patients sometimes present with a more complex pattern of weakness than isolated LTN or SAN palsy would produce. The early phase of PTS is frequently misdiagnosed as a rotator cuff tear or cervical disc problem because the initial pain is so prominent and the winging has not yet appeared.
Bony Growths and Pseudo-Winging
Scapular winging is not always a nerve problem. Sometimes the scapula is being pushed away from the ribcage by a physical mass underneath it. Osteochondromas, benign bony tumors capped with cartilage, are the best-documented structural cause. When one of these growths develops on the undersurface (ventral aspect) of the scapula, it creates a mechanical block between the scapula and the chest wall. The shoulder blade rides up and away from the ribs, producing what looks like winging but is actually “pseudo-winging” because the serratus anterior and other periscapular muscles are neurologically intact.11PubMed Central. Painful Snapping and Pseudo-winging Scapula due to a large Scapular Osteochondroma
A subscapular osteochondroma typically causes pain and a grinding or snapping sensation when the shoulder moves, along with the visible prominence of the shoulder blade.12PubMed Central. Painful Pseudowinging and Snapping of Scapula due to Subscapular Osteochondroma In one reported case, a large osteochondroma on the scapula even pushed into the axilla and displaced the brachial plexus and nearby blood vessels, yet the long thoracic nerve was intact and the serratus anterior contracted normally when tested. The winging resolved completely after surgical removal of the growth.13PubMed Central. Pseudo-winging of the scapula caused by scapular osteochondroma: review of literature and case report That pattern, winging that disappears once the mass is taken out, is the hallmark of pseudo-winging and the reason imaging is important whenever the clinical picture does not fit a straightforward nerve palsy.
Fractures, Malunion, and Congenital Deformities
Scapula fractures are uncommon because the bone sits in a well-padded muscular envelope, but when they do occur and heal in a poor position, the resulting bony malunion can produce visible winging and limited shoulder motion. In these cases, clinical testing shows that the trapezius, rhomboids, and serratus anterior all function normally, and there are no signs of nerve damage. The mechanical problem is entirely structural: the misshapen bone no longer glides smoothly against the chest wall.14JSES Reviews, Reports, and Techniques. Treatment of extra-articular scapula fracture malunion using pre-operative three-dimensional printing: a case report and overview of the literature
On the congenital side, Sprengel’s deformity is a condition present from birth in which one scapula sits abnormally high on the back. This happens because the scapula fails to descend fully during fetal development. It produces both a cosmetic deformity and functional limitations in shoulder movement, and the appearance can mimic or overlap with scapular winging.15PubMed Central. Sprengel’s deformity of the shoulder: Current perspectives in management Sprengel’s deformity is rare and usually identified in childhood, but mild cases occasionally go undiagnosed until adult life.
Muscular Dystrophy and Systemic Muscle Disease
When winging affects both shoulder blades or progresses gradually over months to years, a systemic muscle disease may be the underlying cause. Facioscapulohumeral muscular dystrophy (FSHD) is the most relevant example. FSHD is a common inherited form of muscular dystrophy that selectively wastes the muscles around the face, shoulder blade, and upper arm. The periscapular muscles weaken and atrophy, causing progressive bilateral winging that worsens over time.16PubMed Central. Management of scapular dysfunction in facioscapulohumeral muscular dystrophy: the biomechanics of winging, arthrodesis indications, techniques and outcomes Unlike nerve-based winging, which is usually one-sided and sudden, FSHD winging tends to be bilateral and insidious. The distinction is important because the treatment pathway is entirely different: nerve repair and tendon transfers do not help a muscle that is degenerating from within.
How Doctors Spot and Confirm Scapular Winging
Winging is often visible to the naked eye, especially during arm movement, but confirming the cause takes more effort. The classic bedside test is the wall push-up, where you lean into a wall with arms extended and push. If the serratus anterior is weak, the scapula wings prominently. This test is widely taught, but research suggests it may not be the best option. One study found that the wall push-up was perfectly sensitive for detecting serratus anterior deficiency but had zero specificity, meaning it flagged every patient regardless of cause. A shoulder flexion resistance test, where the examiner pushes down on the raised arm while watching the scapula, was both perfectly sensitive and perfectly specific in the same study.17JSES International. Serratus anterior dysfunction examination: wall push-up or shoulder flexion resistance test?
A separate comparative analysis of multiple arm maneuvers in patients with neuromuscular disorders found that slowly lowering the arms forward from a raised position was the most sensitive method for bringing out winging when it was not apparent at rest, catching it in all tested patients. The wall push-up, despite its popularity, ranked fourth with roughly 60% sensitivity.18PubMed. Is pushing the wall, the best known method for scapular winging, really the best? A Comparative analysis of various methods in neuromuscular disorders The practical takeaway: if your clinician only asks you to push against a wall and sees nothing alarming, the winging could still be there. Asking you to raise your arms and slowly lower them forward may be more revealing.
Beyond the physical exam, electromyography and nerve conduction studies are the standard tools for confirming which nerve is affected. These tests measure the electrical activity in the muscles and the speed at which signals travel along the nerves. A thorough electrodiagnostic workup should test both the long thoracic nerve and the spinal accessory nerve on both sides, along with needle examination of their target muscles.19PubMed. Unilateral winged scapula: Clinical and electrodiagnostic experience with 128 cases, with special attention to long thoracic nerve palsy Imaging with MRI or CT is added when a bony growth, mass, or fracture is suspected, or when the clinical picture does not match a straightforward nerve palsy.20Journal of Bone and Joint Surgery. Scapular Winging: A Great Masquerader of Shoulder Disorders
Treatment and the Question of Recovery
For nerve-related scapular winging, the initial approach is almost always conservative: physical therapy aimed at strengthening the remaining functional muscles, avoiding activities that aggravate the nerve, and giving the nerve time to regenerate. The recovery window, however, is long and unpredictable. A systematic review found that spontaneous recovery with nonsurgical management ranged from about 21% to 78% across studies, with a median follow-up of six years.21PubMed. Treatment of neurogenic scapular winging: a systematic review on outcomes after nonsurgical management and tendon transfer surgery That wide range reflects genuine uncertainty: some patients recover fully within months, while others are still symptomatic years later.
When conservative treatment fails, surgery becomes an option. For LTN palsy, the pectoralis major tendon transfer is a well-described procedure in which the pectoralis muscle insertion is detached and reattached to the inferior edge of the scapula, essentially substituting one muscle’s pull for the absent serratus anterior.22PubMed Central. Pectoralis Major Transfer for Treatment of Serratus Anterior Dysfunction in the Setting of Long Thoracic Nerve Palsy For SAN palsy causing lateral winging, the modified Eden-Lange transfer reroutes other muscles to take over the trapezius’s role.5Arthroscopy Techniques. The Modified Eden-Lange Tendon Transfer for Lateral Scapular Winging Secondary to Spinal Accessory Nerve Injury In FSHD, where the muscles themselves are degenerating, a scapulothoracic arthrodesis (fusing the scapula to the ribcage) is used for patients with severe winging who still have a functioning deltoid. Studies report improved shoulder elevation and quality of life after the procedure regardless of the specific surgical technique used.16PubMed Central. Management of scapular dysfunction in facioscapulohumeral muscular dystrophy: the biomechanics of winging, arthrodesis indications, techniques and outcomes
For osteochondroma-related pseudo-winging, the fix is more straightforward: surgical excision of the bony growth. Case reports consistently describe complete resolution of winging, pain, and snapping after the mass is removed, with rapid recovery when a muscle-sparing surgical approach is used.23PubMed Central. Surgical treatment of rare case of scapula osteochondroma in a resource limited setting Removing the osteochondroma also eliminates the small risk of malignant transformation that comes with leaving a growing bony lesion in place.
Athletes and Thoracic Outlet Syndrome
Overhead athletes, including swimmers, tennis players, and baseball pitchers, are at heightened risk for nerve injuries around the shoulder, including those affecting the long thoracic and spinal accessory nerves.24PubMed Central. Neurologic Injuries in the Athlete’s Shoulder Repetitive overhead motion can stretch, compress, or inflame these nerves over time, producing winging that develops gradually rather than appearing after a single incident. The challenge in athletes is that the early symptoms of nerve irritation, including vague shoulder pain, fatigue, and a subtle loss of power, overlap heavily with more common diagnoses like rotator cuff tendinitis and impingement.
An especially tricky scenario involves adolescent athletes who develop chronic shoulder-girdle pain and scapular winging or dyskinesis with normal electrodiagnostic studies. A case series described a group of young athletes fitting this profile who later turned out to have neurogenic thoracic outlet syndrome, a compression problem at the thoracic outlet where nerves and blood vessels pass between the collarbone and first rib. These patients showed rapid functional improvement after thoracic outlet decompression surgery, despite earlier testing that suggested no nerve abnormality.25PubMed. Rapid Functional Recovery After Thoracic Outlet Decompression in a Series of Adolescent Athletes With Chronic Atraumatic Shoulder-Girdle Pain, Scapular Winging/Dyskinesis, and Normal Electrodiagnostic Studies The lesson here is that a clean nerve conduction study does not always rule out a compressive nerve problem, and persistent winging in a young athlete warrants a broader diagnostic workup than standard tests alone provide.