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Winged scapula

A winged scapula, also known as scapular winging, is a rare condition characterized by the abnormal protrusion or "winging" of the scapula (shoulder blade) from the posterior thoracic wall due to weakness or paralysis of the muscles responsible for its stabilization, leading to impaired upper extremity function and mobility.^[1] This dysfunction typically results from injury to the nerves innervating key scapular stabilizers, such as the serratus anterior, trapezius, or rhomboid muscles, and can manifest as medial or lateral winging depending on the affected muscle group.^[2] The primary causes of winged scapula include traumatic injuries (e.g., blunt trauma or sports-related impacts), iatrogenic damage from surgical procedures like lymph node biopsies or mastectomies, and less commonly, idiopathic or viral etiologies such as neuralgic amyotrophy.^[1] Nerve involvement is central: medial winging often stems from long thoracic nerve palsy affecting the serratus anterior muscle, while lateral winging arises from spinal accessory nerve injury paralyzing the trapezius or dorsal scapular nerve damage impacting the rhomboids.^[2] In rarer cases, it may be associated with neuromuscular disorders like facioscapulohumeral muscular dystrophy or Parsonage-Turner syndrome.^[1] The condition affects approximately 15 out of 7,000 individuals undergoing electromyography for shoulder complaints, with up to 71% of trapezius-related cases being iatrogenic.^[1] Clinically, patients present with shoulder or back pain, fatigue during overhead activities, weakness in arm elevation or pushing motions, and cosmetic concerns from the visible deformity, which becomes more pronounced when pressing against a wall or during arm flexion.^[2] Diagnosis relies on physical examination, including wall push tests to provoke winging, assessment of scapular alignment and muscle strength, supplemented by imaging like radiographs to rule out fractures and electromyography (EMG) or nerve conduction studies to confirm nerve dysfunction.^[1] Differential diagnoses include glenohumeral joint pathologies, cervical radiculopathy, or other neuropathies. Management begins conservatively with physical therapy focused on strengthening accessory muscles and improving scapular mechanics, often effective within 6-24 months for neuropraxic injuries, particularly those involving the long thoracic nerve.^[2] If conservative measures fail, surgical interventions such as nerve repair, neurolysis, tendon transfers (e.g., pectoralis major to serratus anterior), or scapulothoracic fusion may be pursued for chronic cases to restore function and alleviate pain.^[1] Early intervention is crucial to prevent long-term disability, though outcomes vary based on the underlying etiology and duration of symptoms.^[2]

Anatomy and Function

Scapular Anatomy

The scapula, commonly known as the shoulder blade, is a flat, triangular bone situated on the dorsal surface of the upper thoracic rib cage.^[3] It features three borders—superior, medial (vertebral), and lateral (axillary)—and three angles: superior, inferior, and lateral (glenoid).^[4] The posterior surface is divided by a prominent transverse ridge called the spine, which separates the supraspinous fossa above from the infraspinous fossa below; the spine extends laterally to form the acromion process.^[5] The acromion is an oblong projection that forms the summit of the shoulder and articulates with the clavicle at the acromioclavicular (AC) joint, a synovial plane joint stabilized by ligaments.^[3] On the anterior (costal) surface, the coracoid process projects as a hook-like structure superolaterally, serving as an attachment site for ligaments and structures.^[5] Laterally, the glenoid cavity—a shallow, pear-shaped articulation on the lateral angle—forms the glenohumeral (GH) joint with the head of the humerus, a ball-and-socket synovial joint.^[3] The scapulothoracic articulation represents a physiological joint rather than a true synovial one, consisting of a sliding interface between the anteromedial aspect of the scapula and the posterior thoracic wall.^[6] This arrangement allows for gliding motion of the scapula over the convex surface of the rib cage, facilitated by two major bursae (subscapular and superficial infraserratus) and four minor bursae that reduce friction during movement.^[4] The scapula overlies ribs 2 through 7, with its medial border positioned approximately 5 cm from the vertebral column.^[4] Anatomically, the scapula integrates with the posterior thoracic wall through its close apposition to the ribs and overlying soft tissues.^[3] The costal surface faces the thoracic cage, while the posterior surface relates to multiple muscles such as the trapezius, rhomboids, and levator scapulae, as well as nerves including the suprascapular and dorsal scapular nerves that course along its borders.^[3] The serratus anterior attaches along the medial border of the costal surface.^[5] In its normal resting position, the scapula exhibits an anterior tilt of 10–20°, internal rotation of 30–45° relative to the coronal plane, and a slight upward tilt of about 3°.^[6] Its mobility includes elevation and depression along the rib cage (approximately 10–15 cm of vertical translation), protraction and retraction (lateral and medial movements of 5–10 cm), as well as rotation and tilting to accommodate shoulder girdle dynamics.^[6]^[4]

Role of Key Muscles and Nerves

The serratus anterior muscle is a critical stabilizer of the scapula, originating from the external surfaces of ribs 1 through 8 or 9 via a series of digitations and inserting along the anterior aspect of the medial border of the scapula from the superior angle to the inferior angle.^[7] This muscle primarily functions to protract the scapula (pulling it forward around the thoracic wall) and to upwardly rotate the glenoid fossa during arm elevation, enabling full overhead motion of the upper limb.^[8] Its innervation is provided by the long thoracic nerve, which derives from the anterior rami of spinal nerves C5 through C7.^[7] The trapezius muscle, a broad superficial muscle of the upper back, is divided into upper, middle, and lower fibers with distinct roles in scapular control. The upper fibers originate from the occipital bone, ligamentum nuchae, and spinous processes of C7-T3, inserting on the lateral clavicle and acromion; they elevate the scapula. The middle fibers arise from the spinous processes of T1-T4 and insert on the medial aspect of the acromion and scapular spine, retracting the scapula. The lower fibers originate from the spinous processes of T4-T12 and insert on the medial end of the scapular spine, depressing and upwardly rotating the scapula.^[9] Innervation to the trapezius comes primarily from the spinal accessory nerve (cranial nerve XI) for motor supply to all fibers, supplemented by proprioceptive branches from C3 and C4 via the cervical plexus.^[10] The rhomboid major and minor muscles act synergistically to stabilize the medial border of the scapula against the thoracic wall. The rhomboid minor originates from the nuchal ligament and spinous processes of C7-T1, inserting on the medial border of the scapula at the base of the spine. The rhomboid major arises from the spinous processes of T2-T5 and inserts inferior to the rhomboid minor on the medial scapular border. Together, these muscles retract the scapula and produce downward rotation of the glenoid fossa, countering upward rotation during certain movements.^[11] Both are innervated by the dorsal scapular nerve, branching from the C5 spinal root (with contributions from C4 in some cases).^[12] The levator scapulae muscle contributes to scapular elevation and stability, originating from the transverse processes of cervical vertebrae C1 through C4 and inserting on the superior angle and medial border of the scapula, just superior to the rhomboid minor.^[13] Its primary function is to elevate the scapula and assist in ipsilateral neck rotation and lateral flexion when the scapula is fixed.^[14] Innervation is supplied by branches of the dorsal scapular nerve (C5) and anterior rami of C3 and C4.^[13] These muscles exhibit biomechanical interdependence to ensure scapular stability, particularly during arm elevation, where coordinated force couples—such as the upper and lower trapezius with the serratus anterior for upward rotation, and the rhomboids with the levator scapulae for retraction and elevation—maintain optimal glenohumeral positioning and prevent excessive translation or tilting of the scapula along the thorax.^[15] This integrated action distributes forces across the shoulder girdle, supporting efficient upper limb function without compromising the dynamic stability of the glenoid fossa.^[16]

Pathophysiology

Mechanisms of Scapular Winging

Scapular winging is characterized by the abnormal protrusion of the medial border of the scapula away from the thoracic wall, resulting from unopposed forces due to dysfunction in the stabilizing muscles of the scapulothoracic articulation.^[2] This displacement disrupts the normal scapulohumeral rhythm, where coordinated muscle actions maintain scapular positioning during upper extremity motion.^[1] The serratus anterior muscle plays a key role in protracting the scapula and rotating its inferior angle upward and laterally around the thoracic cage.^[2] The primary mechanism of scapular winging involves paralysis or weakness of the serratus anterior, leading to medial winging that becomes prominent during arm protraction, such as in maneuvers like the wall push test.^[1] In this scenario, the unopposed pull of antagonist muscles, including the rhomboids and trapezius, causes the medial scapular border to lift away from the thorax, often with superior translation of the entire scapula and medial rotation of its inferior angle.^[17] Secondary mechanisms include trapezius weakness, which produces lateral winging visible at rest due to drooping of the shoulder and lateral displacement of the scapular inferior angle.^[1] Similarly, rhomboid weakness results in lateral winging during arm abduction, as the loss of scapular retraction allows downward and lateral drift of the inferior angle under gravitational forces.^[2] These processes arise from fundamental force imbalances in the scapulothoracic stabilizers, where the absence of protraction and upward rotation permits antagonist muscles or gravity to dominate, forcing the scapula into an abnormal position.^[17] Winging manifests in two stages: dynamic, where protrusion occurs or worsens with specific movements like forward flexion or abduction, reflecting active muscle dysfunction; and static, where the abnormality persists at rest due to chronic imbalance or severe impairment.^[1]

Classification of Winging Types

Winged scapula is classified into medial and lateral types based on the direction of scapular protrusion and the underlying muscle dysfunction. Medial winging occurs when the medial border of the scapula protrudes posteriorly, typically due to weakness or paralysis of the serratus anterior muscle, which is innervated by the long thoracic nerve; this is most evident during forward arm flexion or pushing against resistance.^[1] In contrast, lateral winging involves posterior protrusion of the medial scapular border with lateral displacement of the scapula, resulting from dysfunction of the trapezius (innervated by the spinal accessory nerve) or rhomboid muscles (innervated by the dorsal scapular nerve), and is often noticeable at rest or during arm abduction.^[7] These distinctions guide targeted evaluation, as medial winging commonly presents with greater functional impairment in overhead activities, while lateral winging may lead to shoulder drooping and subtle instability.^[18] Further classification differentiates primary from secondary winging according to etiology. Primary winging arises from isolated neuromuscular deficits, such as direct nerve injuries or muscular pathologies affecting scapular stabilizers.^[1] Secondary winging, however, develops as a compensatory response to glenohumeral joint instability, rotator cuff tears, or mass effects that disrupt normal scapulothoracic rhythm.^[7] Clinically, primary types often allow for more straightforward rehabilitation focused on the affected muscle, whereas secondary forms require addressing the underlying joint pathology to prevent progression.^[18] Winging is also categorized as acute or chronic based on onset and duration. Acute winging manifests suddenly, often following trauma or iatrogenic injury, with potential for spontaneous resolution within 6 to 9 months in cases of neuropraxia.^[1] Chronic winging persists beyond 2 years, typically involving irreversible nerve damage or longstanding muscle atrophy, necessitating advanced interventions like nerve grafting or muscle transfers.^[7] Prognostically, acute serratus anterior-related winging carries a favorable outlook with conservative management, achieving up to 80% recovery, compared to chronic trapezius palsy, which has poorer nonoperative outcomes and may require surgical reconstruction within 18 to 24 months for optimal function.^[18] Rare variants include bilateral winging, which occurs in systemic neuromuscular disorders like facioscapulohumeral muscular dystrophy, and isolated dorsal scapular nerve involvement leading to rhomboid-specific lateral winging.^[1] These uncommon presentations imply a broader diagnostic workup for genetic or multifocal etiologies, with implications for reduced reversibility and the need for multidisciplinary management, such as scapulothoracic fusion in progressive cases yielding approximately 88% symptom resolution at one year.^[7]

Clinical Presentation

Signs and Symptoms

A winged scapula is characterized by the visible protrusion of the medial border of the scapula from the thoracic wall, creating an abnormal "wing-like" appearance that becomes more pronounced during arm movements such as pushing against a wall or door.^[19] This protrusion often occurs unilaterally, resulting in noticeable shoulder asymmetry and potential postural imbalance as the affected scapula shifts abnormally relative to the unaffected side.^[1] Patients commonly report a dull ache or discomfort in the shoulder, upper back, or neck, which may intensify during overhead activities, prolonged driving, or repetitive arm use, though pain is absent in some isolated cases and primarily arises from muscle fatigue rather than direct injury.^[20] Muscle fatigue in the periscapular region frequently accompanies these sensations, leading to a sense of tiredness during sustained efforts.^[21] Functional limitations manifest as weakness in pushing, throwing, or reaching overhead, often accompanied by scapular dyskinesis that impairs daily activities like lifting groceries or brushing hair.^[19] These deficits stem from disrupted scapulothoracic mechanics, reducing overall upper extremity strength and endurance.^[1] Sensory changes, such as numbness, are typically absent unless an associated neuropathy is present.^[22]

Physical Examination Findings

The physical examination for winged scapula begins with visual observation of the patient from a posterior view, both at rest and during active shoulder movements, to assess scapular alignment, tilt, and asymmetry in protraction or retraction. At rest, medial winging due to serratus anterior dysfunction may present as superior translation of the scapula with medial rotation of the inferior angle, while lateral winging from trapezius or rhomboid weakness shows inferior translation and lateral rotation of the inferior angle. During motion, such as forward flexion or abduction, asymmetry becomes more apparent, with the affected scapula demonstrating excessive medial border elevation or protrusion away from the thoracic wall.^[1]^[7]^[23] Specific provocative tests help confirm and differentiate the underlying muscle involvement. The wall push test, commonly used to evaluate serratus anterior function, involves the patient facing a wall with arms extended forward at shoulder height and pushing against it as if performing a push-up; winging is evident if the medial scapular border protrudes noticeably during this maneuver. For assessing trapezius and rhomboid function, the shoulder abduction and external rotation test requires the patient to abduct the arm to 90 degrees while resisting external rotation; winging is observed if the scapula shifts laterally or the inferior angle rotates outward, often limiting abduction to 90 degrees or less. These tests accentuate dynamic instability and are positive when the affected scapula fails to stabilize properly compared to the contralateral side.^[20]^[23]^[7] Palpation during the examination focuses on the medial scapular border, periscapular muscles, and potential nerve pathways to identify tenderness, which may indicate inflammation or entrapment, and to evaluate for muscle atrophy suggestive of chronic denervation. Atrophy is particularly notable in the trapezius for lateral winging or serratus anterior for medial winging, presenting as visible wasting or reduced bulk when compared bilaterally.^[1]^[7] Range of motion assessment reveals characteristic limitations due to scapular instability, such as reduced active forward flexion beyond 120 degrees in cases of serratus anterior palsy, where the scapula cannot glide superiorly to support humeral elevation. Similarly, trapezius dysfunction impairs shoulder abduction and elevation, often resulting in drooping of the affected shoulder girdle and measurable asymmetry in overall mobility. These findings underscore the mechanical role of scapular stabilizers in shoulder function.^[1]^[7]

Etiology

Traumatic Causes

Traumatic causes of winged scapula primarily involve injury to the long thoracic nerve, leading to serratus anterior muscle dysfunction and medial scapular winging, or less commonly to the spinal accessory or dorsal scapular nerves affecting trapezius or rhomboid function. These injuries often result from direct or indirect forces that compress, stretch, or lacerate the nerves during acute events or repetitive activities.^[1] Direct blunt trauma, such as blows to the shoulder or axilla, can stretch or compress the long thoracic nerve, commonly occurring in sports like football tackles, wrestling, or motor vehicle accidents with arm traction. For instance, contact sports and falls may cause neuropraxia or axonotmesis, with symptoms appearing gradually over days to weeks. In athletes, sports-related activities account for approximately 12.7% of long thoracic nerve injuries leading to winging, with weightlifting being a prominent example due to repetitive overhead motions.^[1]^[24] Iatrogenic trauma arises from surgical interventions, particularly those involving the axilla or neck, where inadvertent damage to the long thoracic nerve occurs during procedures like mastectomy or axillary lymph node dissection for breast cancer. Studies report an incidence of up to 8% for winged scapula 15 days post-axillary dissection in such patients, often resolving with time but occasionally persisting. Other examples include complications from chest tube insertion or axillary nerve blocks during anesthesia.^[25]^[1] Penetrating injuries, such as stab wounds or gunshots, can directly lacerate the long thoracic or spinal accessory nerves, resulting in immediate winging. Additionally, fractures of the clavicle, scapula, or associated structures may impinge on these nerves or cause avulsion of muscle attachments, as seen in inferior scapular angle fractures leading to pseudowinging. Overuse trauma from repetitive strain in athletes, such as swimmers or rowers performing overhead strokes, induces microtears in the serratus anterior or chronic nerve compression, contributing to progressive winging without acute insult.^[1]^[26]^[24]

Non-Traumatic Causes

Non-traumatic causes of winged scapula arise from diverse etiologies that impair the function of scapular stabilizers, such as the serratus anterior, trapezius, or rhomboid muscles, without acute mechanical injury to the shoulder girdle. These include neuropathies, infections, systemic disorders, congenital anomalies, neoplastic conditions, and iatrogenic factors, often leading to progressive or insidious onset of medial or lateral winging due to nerve compression, inflammation, or direct muscle pathology.^[1] Neuropathies, particularly those affecting the long thoracic nerve, are prominent non-traumatic contributors. Idiopathic long thoracic neuritis, characterized by spontaneous inflammation or demyelination of the nerve, results in isolated serratus anterior palsy and medial scapular winging, typically presenting with shoulder pain and weakness without identifiable triggers.^[27] Parsonage-Turner syndrome, an acute brachial plexitis of presumed immune-mediated origin, frequently involves the long thoracic nerve, leading to winged scapula in 30% to 70% of affected individuals, often following a viral prodrome or vaccination.^[28] This condition manifests as severe pain followed by rapid muscle atrophy and winging, distinguishing it from other neuropathies by its multifocal brachial plexus involvement.^[27] Infectious processes can indirectly cause winging through neural invasion or secondary inflammation. Viral infections, such as herpes zoster (varicella-zoster virus), rarely affect peripheral nerves like the long thoracic or accessory nerves, resulting in scapular winging as part of cranial or brachial neuropathies, as seen in cases of jugular foramen involvement.^[29] Bacterial infections, notably Lyme disease (Borrelia burgdorferi-induced neuroborreliosis), lead to mononeuritis or radiculoneuritis affecting the long thoracic nerve, causing unilateral medial winging and arm weakness, particularly in endemic regions.^[30] Systemic diseases involving muscle or connective tissue often produce bilateral or progressive winging. Muscular dystrophies, exemplified by facioscapulohumeral muscular dystrophy (FSHD), cause early and characteristic scapular winging due to selective atrophy of scapulothoracic stabilizers like the serratus anterior and trapezius, linked to D4Z4 repeat contractions on chromosome 4q35.^[31] Inflammatory myopathies, including immune-mediated necrotizing myopathies with anti-HMGCR antibodies, can present with scapular winging mimicking FSHD through proximal muscle inflammation and fibrosis, often accompanied by elevated creatine kinase levels.^[32] Neoplastic causes, including benign tumors like scapular osteochondromas, can result in static winging by altering scapular mechanics or compressing adjacent structures.^[33] Congenital etiologies are uncommon and typically stem from developmental anomalies affecting muscle development or nerve innervation. These can lead to inherent serratus anterior weakness and stable winging from birth or early childhood. Rare genetic conditions, like CHD7 mutations associated with CHARGE syndrome, may cause prominent scapulae and winging due to abnormal muscle patterning or innervation, presenting with dysmorphic features and non-progressive asymmetry.^[34] Iatrogenic non-surgical causes include radiation therapy to the axilla or supraclavicular region, which induces fibrosis, vascular damage, or direct neuropathy of the long thoracic nerve, resulting in delayed-onset winged scapula, as observed in breast cancer survivors receiving adjuvant radiotherapy.^[35] This complication arises from cumulative radiation doses affecting neural structures, leading to progressive serratus anterior dysfunction months to years post-treatment.^[36]

Diagnosis

Diagnostic Approach

The diagnostic approach to winged scapula begins with a thorough history taking to establish the onset, which may be acute following trauma or insidious in chronic cases, alongside any history of injury, surgery, or repetitive activities involving the shoulder girdle.^[1] Patients often report associated symptoms such as shoulder pain, upper back discomfort exacerbated by pressure against surfaces, muscle weakness particularly during overhead activities, fatigue, or subjective instability.^[7] Inquiry into hand dominance, occupation, hobbies, recent illnesses, or immunizations helps identify potential iatrogenic or idiopathic etiologies.^[2] Differential diagnosis is essential to distinguish winged scapula from other shoulder pathologies, including rotator cuff tears, glenohumeral instability, brachial plexopathy, cervical spine disorders, thoracic outlet syndrome, and acromioclavicular joint issues.^[1] Medial winging due to serratus anterior dysfunction may mimic rotator cuff pathology or instability, while lateral winging from trapezius or rhomboid weakness can resemble scoliosis, neurosis, or cervical spondylosis.^[2] This step involves correlating historical details with potential neurologic or mechanical causes to narrow possibilities.^[7] Initial assessment integrates physical examination findings with symptom correlation to localize the affected muscle or nerve, observing for scapular asymmetry at rest and during motion to classify winging as medial or lateral.^[1] Specific physical tests, such as the wall push test to provoke medial winging in serratus anterior dysfunction, resisted shoulder shrug or elevation for trapezius weakness, and scapular retraction or resisted adduction for rhomboid involvement, aid in identifying weakness patterns consistent with long thoracic, spinal accessory, or dorsal scapular nerve involvement.^[7]^[2] This combined evaluation helps differentiate primary scapular dysfunction from compensatory mechanisms in broader shoulder disorders.^[2] A decision tree guides progression to advanced testing: plain radiographs of the cervical spine, chest, scapula, and shoulder are obtained initially to exclude structural abnormalities like fractures or masses.^[1] If a structural cause is suspected based on history and exam, targeted imaging such as MRI or CT follows; conversely, electromyography (EMG) and nerve conduction studies are pursued for suspected neural etiologies to confirm denervation and guide localization.^[7] This stepwise rationale ensures efficient confirmation while minimizing unnecessary interventions.^[2] For complex cases involving multifocal neurologic involvement or unclear etiology, multidisciplinary input from neurologists, orthopedic specialists, and physical therapists is recommended to refine the diagnosis and coordinate care.^[1] This collaborative approach enhances accuracy in challenging presentations, such as post-traumatic or iatrogenic winging.^[7]

Imaging and Electrophysiological Tests

Imaging modalities play a crucial role in evaluating winged scapula by visualizing structural abnormalities and soft tissue involvement, while electrophysiological tests confirm neural and muscular pathology. X-rays serve as the initial imaging tool to assess bony alignment of the scapula, cervical spine, chest, and shoulder, helping to rule out fractures, tumors, or other skeletal issues that could contribute to winging.^[1] Magnetic resonance imaging (MRI) is employed to evaluate soft tissues, particularly for detecting muscle atrophy, such as in the serratus anterior, and signs of denervation like edema or fatty infiltration, which indicate chronic nerve injury.^[1]^[37] MRI can also identify nerve compression or mass lesions affecting the long thoracic or accessory nerves, though it is rarely the first-line test unless clinical suspicion points to these issues.^[2] Ultrasound provides a cost-effective, dynamic assessment of scapular winging during arm motion, allowing real-time visualization of abnormal scapular movement and muscle evaluation, particularly the serratus anterior, trapezius, and rhomboids.^[38] It uses standard and ancillary views to detect muscle atrophy, structural changes, or nerve abnormalities without radiation exposure, complementing other diagnostics.^[38] Electromyography (EMG) is the definitive electrophysiological test for confirming denervation in muscles like the serratus anterior (for long thoracic nerve involvement) or trapezius (for accessory nerve issues), revealing findings such as fibrillation potentials, positive sharp waves, reduced motor unit recruitment, and polyphasic potentials.^[2]^[1] Needle EMG helps differentiate axonal injury from other causes and assesses the degree of muscle involvement.^[2] Nerve conduction studies (NCS), often paired with EMG, measure latency and amplitude in the long thoracic or accessory nerves to quantify lesion severity, distinguishing between axonal loss and demyelination while supporting the diagnosis of peripheral nerve injury.^[2]^[1] These studies are particularly useful 3-6 weeks post-injury when denervation changes become evident.^[2]

Management

Conservative Treatments

Conservative treatments for winged scapula primarily involve non-invasive approaches to alleviate symptoms, strengthen affected muscles, and promote nerve recovery, particularly in cases due to long thoracic nerve injury affecting the serratus anterior. These interventions are recommended as the initial management strategy for most patients, with observation periods allowing spontaneous resolution in many instances.^[1]^[7] Physical therapy forms the cornerstone of conservative management, focusing on strengthening the serratus anterior and other scapular stabilizers while incorporating postural training to improve scapulothoracic mechanics. Exercises such as wall slides, where the patient stands against a wall and slides the arms upward while protracting the scapula, and scapular punches using resistance bands to simulate punching motions that emphasize serratus anterior activation, are commonly prescribed to enhance muscle recruitment and endurance. These are typically performed in a progressive manner, starting with isometric holds and advancing to dynamic movements, over an initial intensive phase of 6-12 weeks, followed by ongoing maintenance to support long-term recovery. Postural training includes cues for scapular retraction and depression to counteract winging during daily activities.^[1]^[39]^[40] Bracing with scapular stabilization devices, such as a winger's brace or modified thoracolumbar orthosis, can help maintain the scapula flush against the thoracic wall during activities, reducing strain on the serratus anterior and preventing further muscle stretching. These braces are particularly useful for isolated serratus anterior palsy, with studies showing resolution of winging in approximately 64% of patients during use, though pain may persist in over two-thirds of cases despite improved range of motion. Bracing is often recommended for support during recovery, with usage around 12 hours per day for several months alongside therapy, but compliance can be limited due to discomfort.^[41]^[23] Pain management strategies include nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen to reduce inflammation and discomfort, along with ice or heat applications for acute symptom relief. Modalities such as transcutaneous electrical nerve stimulation (TENS) may be incorporated to modulate pain signals and facilitate muscle relaxation, particularly in cases with associated scapular dyskinesis. These approaches are used adjunctively to enable participation in physical therapy without exacerbating symptoms.^[20]^[1]^[42] Activity modification is essential to avoid aggravating motions, such as overhead reaching or heavy lifting, which can worsen winging and pain. For desk workers, ergonomic adjustments like raising monitors to eye level and using supportive chairs to promote neutral shoulder posture help minimize scapular stress throughout the day. Patients are advised to limit arm elevation above shoulder height initially, gradually reintroducing activities as strength improves.^[7]^[20] Approximately 75% of medial winging cases resolve with conservative treatments over 1-2 years, with full resolution of winging and restoration of function occurring in the majority through nerve regeneration and muscle adaptation. Overall recovery timelines vary, with neuropraxic injuries often resolving in 6-9 months on average, though persistent mild deficits may remain in some.^[1]^[43]^[7]

Surgical Options

Surgical intervention for winged scapula is typically considered when conservative treatments fail after 6-12 months, particularly in cases of persistent serratus anterior paralysis due to long thoracic nerve injury.^[7] Indications include significant functional impairment, pain, or scapular instability confirmed by electromyography (EMG) showing denervation without recovery.^[44] Procedures aim to restore nerve function, augment muscle power, or stabilize the scapula, with selection based on injury chronicity, patient age, and comorbidities; outcomes vary by technique, with recent studies (as of 2025) reporting 36.8-87% success for nerve transfers depending on the method.^[45]^[46] Neurolysis involves surgical release of the long thoracic nerve from compressive structures, such as the middle scalene muscle, in cases of entrapment without complete transection. This procedure, often performed via a supraclavicular approach with microneurolysis, has demonstrated high efficacy, with 98% of patients achieving resolution of winging and pain relief.^[44] Postoperative recovery emphasizes early mobilization, allowing full range of motion within days, though long-term monitoring for recurrence is essential.^[45] For irreparable nerve injuries, such as those from trauma or avulsion, nerve grafting or transfer offers potential reinnervation of the serratus anterior. Techniques include intercostal nerve transfer to the long thoracic nerve or grafting using sural nerve segments, typically indicated within 1-2 years of onset to optimize outcomes. Success varies, with full serratus anterior recovery reported in small series and up to 87% achieving excellent or good improvement in larger cohorts, alongside mild residual winging in some cases; sling immobilization for 3 weeks postoperatively followed by gradual strengthening.^[44]^[46] Muscle transfer procedures reconstruct serratus anterior function by rerouting adjacent muscles, commonly used for chronic paralysis. The latissimus dorsi transfer, often split and anchored to the scapular inferior angle, improves scapular stabilization and abduction, with studies reporting significant functional gains and pain relief, though clinical failure rates up to 41% have been noted in some series.^[7]^[47] Rhomboid transfer, as in the modified Eden-Lange procedure, involves attaching the rhomboid major and minor to the scapular medial border and supraspinatus fossa, eliminating winging in small cohorts without residual deformity.^[44] Postoperative care includes 4-6 weeks of immobilization in a brace, transitioning to physical therapy focused on range of motion and strengthening to prevent adhesions.^[45] Scapulopexy, a salvage option for severe, static winging unresponsive to other interventions (e.g., in neuromuscular disorders), fixes the scapula to the thoracic wall using wires, sutures, or plates without full arthrodesis. This stabilizes the scapulothoracic articulation, with reports of 100% satisfaction and complete resolution of winging in small series of 26 cases, though it limits mobility.^[44] It is rarely first-line due to complications like pneumothorax or hardware failure, with postoperative immobilization lasting 6-12 weeks before progressive rehabilitation.^[44] Overall surgical success rates vary from 60-90% depending on the technique and etiology, emphasizing multidisciplinary evaluation prior to proceeding.^[45]

Epidemiology and Prognosis

Incidence and Risk Factors

Winged scapula is a relatively rare condition in the general population, with estimates suggesting an incidence of approximately 0.2% to 0.5% based on electromyography referrals and neurological examinations.^[1] For instance, one study identified serratus anterior palsy in 15 out of 7,000 electromyography cases, while another reported only 3 cases in 12,000 neurological evaluations.^[1] The true prevalence may be underestimated due to frequent misdiagnosis as nonspecific shoulder strain or pain, leading to incomplete epidemiological data and underreporting in clinical settings.^[48] Certain populations exhibit higher rates, particularly among athletes engaged in overhead or contact sports such as baseball, volleyball, or football, where repetitive motions or blunt trauma increase vulnerability to nerve injuries causing winging.^[1] Winged scapula is more common among athletes in overhead or contact sports due to trauma or repetitive strain, though exact incidence is unclear and often conflated with the more prevalent scapular dyskinesis.^[1] Demographic risk factors include a male predominance with a ratio of approximately 2:1, often linked to greater participation in physically demanding or trauma-prone activities.^[49] The condition most commonly affects individuals aged 20 to 40 years, aligning with peak years for athletic involvement and occupational exposures.^[50] Occupational risks are prominent in professions involving heavy lifting or repetitive overhead work, such as construction or manufacturing, where stretch or compression injuries to the long thoracic or spinal accessory nerves are more frequent.^[1] Iatrogenic causes have risen notably following breast cancer surgeries, with nerve injury rates leading to winged scapula ranging from 3.6% to 16.8% depending on the procedure, such as axillary lymph node dissection.^[51]^[52]

Long-Term Outcomes

In idiopathic cases of winged scapula due to long thoracic nerve palsy, spontaneous recovery occurs in approximately 50-80% of patients within 1-2 years, primarily through natural nerve regeneration and conservative management.^[53]^[1] This recovery rate is higher in less severe cases, with up to 78% achieving symptom resolution by 2 years, though evidence is derived from limited studies emphasizing the benign natural course for non-traumatic etiologies.^[53] In chronic cases persisting beyond 2 years, about 20-25% of patients experience ongoing weakness, with risks of secondary complications such as adhesive capsulitis, chronic shoulder pain, and muscle atrophy leading to permanent scapular asymmetry.^[1] These sequelae can result in reduced shoulder endurance and stiffness, particularly if untreated, contributing to long-term functional limitations.^[1] Visible asymmetry may also impose psychological burdens, including body image concerns in cases where winging is prominent.^[20] Following treatment, physical therapy yields functional improvements in approximately 70% of patients, enhancing shoulder range of motion and strength through targeted exercises.^[18] Surgical interventions, such as nerve decompression or tendon transfers, demonstrate high efficacy with functional score improvements and pain reduction in over 90% of cases, alongside low recurrence rates under 10%.^[54]^[55] Prognostic factors favoring better long-term outcomes include early intervention within the first year and non-traumatic (idiopathic) etiology, which correlate with higher rates of full recovery and minimal sequelae compared to iatrogenic or postoperative causes.^[22]^[56]

References

[1]
Winging of the Scapula - StatPearls - NCBI Bookshelf - NIH
Jun 2, 2025 · Scapular winging is characterized by abnormal scapula motion due to dysfunction of its stabilizing muscles.Etiology · History and Physical · Treatment / Management · Differential Diagnosis
[2]
Scapular winging: anatomical review, diagnosis, and treatments - NIH
Scapular winging is a rare debilitating condition that leads to limited functional activity of the upper extremity. It is the result of numerous causes, ...Missing: definition | Show results with:definition
[3]
Scapular Winging - Shoulder & Elbow - Orthobullets
Feb 27, 2025 · Scapular Winging ; originates from ribs 1-8 and inserts on anteromedial border of scapula. total 7-10 slips ; innervated by long thoracic nerve.
[4]
Scapular Winging - Radsource
The trapezius, rhomboids, and serratus anterior muscles are the primary medial stabilizing muscles of the scapula. Anatomy and Function. The scapula is the ...
[5]
Trapezius muscle: Anatomy, origins, insertions, actions - Kenhub
Function. The main function of the trapezius is stabilizing the scapula in its anatomical place, as well as controlling it during movements of the shoulder and ...
[6]
Trapezius | Department of Radiology
... scapula; superior and inferior fibers act together in superior rotation of scapula. Innervation: Spinal root of accessory nerve (CN XI) (motor) and cervical ...
[7]
Anatomy, Back, Rhomboid Muscles - StatPearls - NCBI Bookshelf
May 16, 2023 · The rhomboids are a collective group of muscles formed by the rhomboid major and minor. The rhomboids are important in upper limb movement and stability.
[8]
Rhomboid Major and Minor - UW Radiology - University of Washington
Action: Retract scapula and rotate it to depress glenoid cavity; fix scapula to thoracic wall. Innervation: Dorsal scapular nerve ( C4 and C5) Arterial ...
[9]
Anatomy, Head and Neck, Levator Scapulae Muscles - NCBI - NIH
The levator scapulae muscles primarily elevate the scapulae, and also assist in neck extension, ipsilateral rotation, and lateral flexion.Introduction · Structure and Function · Embryology · Blood Supply and Lymphatics
[10]
Levator scapulae muscle - Kenhub
Innervation. The levator scapulae muscle is innervated by the anterior rami of spinal nerves C3 and C4 and the dorsal scapular nerve (C5), a branch of the ...Origin And Insertion · Relations · Function
[11]
Scapular Stabilization for Shoulder Pain: Putting the Cart Before the ...
Feb 1, 2025 · Motion of the scapula along the thorax during arm elevation is the result of a muscular force couple consisting of the upper and lower portions ...
[12]
Shoulder Instability Biomechanics - Shoulderdoc
The scapular muscles provide a stable base for shoulder movement. The key force couples in scapular mobility and stability are the lower trapezius and ...Static Stabilisers · Dynamic Stabilisers · 2. Muscles
[13]
Scapular Winging - PMC - NIH
Jul 15, 2013 · Scapula winging most commonly presents in association with isolated injury to the long thoracic nerve and resultant serratus anterior paralysis.
[14]
Scapular Winging - Physiopedia
As a result, the medial or lateral borders of the scapula protrudes from back, like wings. ... There is primary, secondary, and dynamic scapular winging. Primary ...
[15]
Scapular (Shoulder Blade) Disorders - OrthoInfo - AAOS
The most common symptoms of scapular dyskinesis include: Pain and/or tenderness around the scapula, especially on the top and medial (inner) border; Weakness in ...
[16]
Winged Scapula: Causes, Symptoms, Tests & Treatment
Jul 5, 2024 · The most obvious winged scapula symptom is one shoulder blade looking noticeably out of place compared to the other. You might feel symptoms in ...
[17]
Scapular Winging: Symptoms, Causes, and Treatment - Healthline
Sep 25, 2017 · What are the symptoms of scapular winging? · pain or discomfort in your neck, shoulders, and back · fatigue · a drooping shoulder ...Symptoms · Causes · Diagnosis · Treatment
[18]
Scapular winging: Symptoms, treatments, and exercises
Feb 28, 2025 · If there is nerve damage, it can also cause weakness in the arms, shoulders, and neck. Some other symptoms include:
[19]
https://orthoinfo.aaos.org/en/diseases--conditions/scapular-shoulder-blade-disorders
[20]
Incidence, Etiology, and Management of Long Thoracic ... - PubMed
Nov 11, 2021 · The most affected patients (12.7%) were involved in sports and related activities, with 20 different sports and related activities reported in ...Missing: trauma | Show results with:trauma
[21]
Winged scapula incidence and upper limb morbidity after surgery for breast cancer with axillary dissection - Supportive Care in Cancer
### Summary of Winged Scapula Statistic After Axillary Dissection in Breast Cancer Patients
[22]
Inferior scapula avulsion fracture: an unusual presentation of winged ...
Aug 10, 2023 · Scapular winging can also be caused by avulsion of muscle away from the scapula, sometimes with an associated fracture of the inferior pole of ...
[23]
WINGED SCAPULA CAUSED BY PARSONAGE-TURNER ... - NIH
Feb 15, 2023 · Non-traumatic induced injury to the long thoracic nerve includes causes such as viral illness, vaccination, allergic drug reactions, drug ...
[24]
Understanding Parsonage-Turner syndrome and hereditary brachial ...
Jun 5, 2025 · A winged scapula (left) is reported in 30% to 70% of attacks. Weakness of the serratus anterior muscle can result from a long thoracic nerve ...
[25]
Vernet Syndrome by Varicella-Zoster Virus - PMC - NIH
The winged scapula became more prominent with shoulder flexion, and manual muscle tests showed decreased muscular strength of Medical Research Council (MRC) ...
[26]
Winged Scapula Secondary to Neuroborreliosis - PMC
Examination showed medial winging of the right scapula on arm flexion (Figure 2), most likely due to unilateral long thoracic nerve palsy from Borrelia ...
[27]
Facioscapulohumeral Muscular Dystrophy - GeneReviews - NCBI
Jul 10, 2025 · Scapular winging is the most common initial finding; preferential weakness of the lower trapezius muscle results in characteristic upward ...Summary · Diagnosis · Clinical Characteristics · Management
[28]
Anti-HMGCR myopathy mimicking facioscapulohumeral muscular ...
Neurological examination showed slight facial weakness, bilateral winged scapula, muscle atrophies of the proximal arms, abdominal paresis, proximal and arm- ...1. Case Report · Figure 2 · Figure 3<|separator|>
[29]
Scapular winging (Concept Id: C0240953) - NCBI
Scapulohumeroperoneal myopathy is an autosomal dominant muscle disorder characterized by slowly progressive muscle weakness and atrophy affecting both proximal ...
[30]
Prominent scapulae mimicking an inherited myopathy expands the ...
Jan 27, 2016 · An alternative explanation is that the abnormalities may result from abnormal patterning, migration and differentiation of muscle progenitor ...
[31]
Nerves Around the Shoulder: What the Radiologist Should Know?
... radiation to the neck or lateral arm. Weakness, loss of function ... long thoracic nerve damage leading to serratus anterior impairment and winged scapula.
[32]
Scapula alata in early breast cancer patients enrolled in a ...
May 16, 2012 · We argue that scapular winging is not an innocuous sign, that it should be actively evaluated in order to identify patients who might be most at ...
[33]
Scapular Winging following Sports-Related Injury in a Rugby Player
Oct 26, 2021 · T1-weighted magnetic resonance image showing slight atrophy of the serratus anterior muscle (dotted line) on the right side compared with ...
[34]
Neuromuscular ultrasound for evaluation of scapular winging
Conclusion: Ultrasound is a non-invasive, painless, and radiation-free technology that can be used to evaluate scapular winging. Muscle Nerve 56: 7-14, 2017.Missing: MRI X- ray conduction
[35]
Rehabilitation of scapular muscle balance: which exercises to ...
The exercises side-lying external rotation, side-lying forward flexion, prone horizontal abduction with external rotation, and prone extension were found to be ...
[36]
Learn The Best Serratus Anterior Exercises - [P]rehab
Keeping your elbows straight and reach overhead, focus on the extra scapula push-out when you are overhead, this will help with Serratus Anterior Activation!
[37]
Scapular Bracing is Effective in Some Patients but Symptoms Persist ...
A scapular-protecting brace is one option for treating patients with a winging scapula in isolated serratus palsy.
[38]
THE EFFECT OF ELECTRICAL STIMULATION VERSUS SHAM ...
Electrical stimulation with exercises for scapular dyskinesis showed improvements in spine to scapula distance at 120 degrees of shoulder abduction.
[39]
Long thoracic nerve injury: the shortest route to recovery!
With conservative treatment, most LTN injuries resolve on average within nine months, however, recovery can take anywhere from six to 24 months(1,7). Some ...
[40]
https://theprehabguys.com/serratus-anterior-exercises/
[41]
Winged Scapula: A Comprehensive Review of Surgical Treatment
Dec 7, 2017 · Winged scapula is caused by paralysis of the serratus anterior or trapezius muscles due to damage to the long thoracic or accessory nerves.Missing: options | Show results with:options
[42]
Scapular Winging: A Great Masquerader of Shoulder Disorders
Jul 16, 2014 · Abstract. Background: The incidence of scapular winging is unclear, but it may be more common than previously thought. It can be difficult to ...Missing: winged | Show results with:winged
[43]
Scapular winging secondary to serratus anterior dysfunction
There were 34 females and 62 males, with a mean age of 38 years (range, 15-77 years). Winging affected the right scapulae in 69 patients, the left scapulae in ...
[44]
REVIEW OF NEUROPHYSIOLOGY DATA IN PATIENTS ...
Findings Patient demographics: Male –66 % (n 27); female –34 % (n14), Age< 18 yrs –7.3 % (n 3), 18–40 yrs –44 % (n 18), 41–60 yrs –31.7 % (n 13), >60 yrs –17% ...Missing: gender | Show results with:gender
[45]
Diagnosis and epidemiology of winged scapula in breast cancer ...
Dec 16, 2021 · The global incidence of WS after BCS is 16.79%. Additionally, the anterior flexion test and the push-up test are the most commonly performed ...Missing: prevalence | Show results with:prevalence
[46]
Scapular winging in surgical treatment of breast cancer, prospective ...
Apr 8, 2021 · Results: The cumulative incidence of scapular winging was 3.6% and seven cases of winged scapula were diagnosed. All the cases were diagnosed ...Missing: prevalence | Show results with:prevalence
[47]
The Natural Course of Serratus Palsy at 2 to 31 Years - PMC - NIH
We believe the natural course of serratus palsy in clinically less severe cases is benign with symptoms recovering in 78% of patients by 2 years. However, our ...
[48]
Microneurolysis and decompression of long thoracic nerve injury are ...
Mar 7, 2007 · Long thoracic nerve injury leading to scapular winging is common, often caused by closed trauma through compression, stretching, traction, ...
[49]
Treatment of neurogenic scapular winging: a systematic review on ...
Most patients with a functional deficit due to scapular winging are thought to recover spontaneously within 24 months, but this is based on only a few studies. ...Missing: timeline | Show results with:timeline
[50]
Isolated serratus palsy etiology influences its long-term outcome
Postoperative isolated serratus palsies may recover more poorly than other palsies, but palsies caused by infection presumably show a better outcome. Serratus ...