The long thoracic nerve supplies the serratus anterior — the muscle that holds the shoulder blade flat against the chest wall. When the nerve is damaged, the shoulder blade lifts away from the chest, producing the characteristic “winged scapula”. So what causes a long thoracic nerve injury, and how do we treat it?
What does the long thoracic nerve do?
The long thoracic nerve is a pure motor nerve — it carries no sensation. It runs from the neck down the side of the chest wall to supply the serratus anterior, a broad, flat muscle attaching the ribs to the inner border of the shoulder blade.
The serratus anterior stabilises the scapula against the chest and rotates it upwards. Without it, the shoulder blade can’t be held flat or rotated properly, which limits overhead movement — a significant problem for throwers, swimmers, and racquet-sport athletes.
Causes of long thoracic nerve injury
Damage can occur through:
- Traction or stretch injury — the nerve has a long, exposed course, making it vulnerable in overhead and contact sports. It’s commonly seen in weightlifters and volleyball players.
- Inflammation of the nerve (brachial neuritis), sometimes following a viral illness — this typically causes severe shoulder pain first, followed by weakness.
- Surgery or trauma — blunt or sharp injury to the chest wall, or an operation in the armpit region.
- Myopathy — occasionally a muscle disease causes similar weakness.
Symptoms of long thoracic nerve injury
People with a long thoracic nerve injury may report:
- Pain around the shoulder or shoulder blade, often vague in location
- Visible “winging” of the shoulder blade, particularly when pushing against a wall
- Fatigue or heaviness in the shoulder with prolonged activity
- Reduced performance in overhead sports such as swimming, tennis, and volleyball
Assessment and the wall push-up test
On examination, the hallmark is a winged scapula. This becomes far more obvious when you push forward against resistance — the wall push-up test — where the inner border of the shoulder blade lifts away from the chest.
Not all winging is the same.
An important part of the assessment is working out which nerve is involved, because the pattern differs:
- Medial winging — the inner border of the scapula lifts. This points to serratus anterior weakness from a long thoracic nerve injury.
- Lateral winging — the scapula shifts outwards, from trapezius weakness due to a spinal accessory nerve injury (sometimes described as a “flipped” shoulder blade).
- Rhomboid weakness — from a dorsal scapular nerve injury, a less common cause of winging with pain along the inner scapular border.
How is it diagnosed?
The diagnosis is primarily clinical, but investigations confirm it and exclude other causes:
- Nerve conduction studies and EMG — confirm the injury by demonstrating denervation of the serratus anterior. Repeat testing can also confirm recovery.
- MRI of the shoulder, cervical spine, and scapula — excludes structural causes such as cervical nerve compression or shoulder joint problems, and can show wasting of the serratus anterior.
- Ultrasound — assesses serratus anterior muscle bulk and can sometimes visualise the nerve.
It’s important to exclude a pinched nerve in the neck, thoracic outlet syndrome, and shoulder joint problems, all of which can cause overlapping symptoms.
Treatment of long thoracic nerve injury
Management is typically conservative, especially in athletes, because spontaneous recovery is common.
- Rest and activity modification — reducing overhead and repetitive pushing activities in the early phase.
- Maintaining range of movement — best achieved by moving the arm while lying on your back, so the scapula is supported and won’t wing, avoiding further traction on the nerve.
- Avoid stretching the serratus anterior — excessive retraction and downward rotation of the shoulder blade can aggravate the nerve.
- Progressive strengthening — once recovery begins, scapular stabilising exercises restore control and function.
- Time — nerve recovery is slow. Many cases improve over many months, and patience with a graded programme is essential.
Surgery is reserved for cases that fail to recover after a prolonged period. Options include nerve decompression or neurolysis, and in long-standing cases, tendon transfer to stabilise the scapula.
Frequently asked questions about long thoracic nerve injury
What is a winged scapula?
A winged scapula is when the shoulder blade lifts away from the chest wall instead of sitting flat. It happens when the muscles that hold it in place — most often the serratus anterior — are weak, usually because the nerve supplying them has been injured.
How long does a long thoracic nerve injury take to recover?
Nerve recovery is slow, and improvement typically takes many months. The good news is that spontaneous recovery is common with conservative treatment, so surgery is rarely the first option. Repeat nerve studies can track the recovery.
What is the wall push-up test?
It’s the simplest way to demonstrate scapular winging. You push against a wall with your arms extended, and the inner border of the shoulder blade lifts away from the chest if the serratus anterior is weak.
Can you exercise or lift weights with a winged scapula?
Overhead and heavy pushing movements should be reduced in the early phase, as they place traction on the nerve. Gentle movement — especially with the scapula supported (lying on your back) — is encouraged, and strengthening is added progressively as recovery begins.
What else causes a winged scapula?
Besides the long thoracic nerve, winging can come from a spinal accessory nerve injury (trapezius weakness, causing lateral winging) or a dorsal scapular nerve problem affecting the rhomboids. A pinched nerve in the neck and shoulder joint problems can also mimic it, which is why an accurate assessment matters.
Final word from Sport Doctor London about long thoracic nerve injury
Long thoracic nerve injury is an uncommon but important cause of shoulder pain and dysfunction, and the winged scapula is its hallmark. Most cases recover with conservative management, though it takes time. The key is an accurate diagnosis — identifying which nerve is involved and excluding other causes of scapular winging.
If you have shoulder weakness or a winged shoulder blade, Dr Masci can assess you in London, including ultrasound in clinic. Contact the team here or call +44 (0) 203 488 0350.
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