Suprascapular Nerve Entrapment

What is Suprascapular Nerve Entrapment

Suprascapular nerve entrapment is pressure or squeezing (entrapment) of the nerve (suprascapular nerve) that provides feeling to the muscles near the shoulder blade (scapula) and shoulder joint. The suprascapular nerve begins in the spinal cord in the neck and passes down the front of the neck, behind the collarbone (clavicle), and over the back of the scapula. Nerve entrapment can happen anywhere along the nerve, but it commonly happens:

• In the neck, near where the nerve leaves the spinal cord.
• At the top of the scapula, under a band of tissue (ligament).
• Behind the scapula, where the nerve passes through a narrow area.

Suprascapular nerve entrapment is common among athletes who often raise their arms overhead and rotate their shoulders outward. This condition is sometimes called volleyball shoulder. Suprascapular nerve entrapment can lead to nerve damage in the shoulder (neuropathy).

Suprascapular nerve entrapment is an uncommon cause of shoulder pain that is being encountered more frequently in clinical practice with the increasing use of backpacks instead of briefcases. Suprascapular nerve entrapment syndrome is caused by compression of the suprascapular nerve as it passes through the suprascapular notch.

The most common causes of compression of the suprascapular nerve at this anatomical location include the prolonged wearing of heavy backpacks and direct blows to the nerve such as occur in football injuries and in falls from trampolines. Suprascapular nerve entrapment syndrome also is seen in baseball pitchers and quarterbacks.

This entrapment neuropathy manifests most commonly as a severe, deep, aching pain that radiates from the top of the scapula to the ipsilateral shoulder.

Tenderness over the suprascapular notch is usually present. Shoulder movement, especially reaching across the chest, may increase the pain. Untreated, weakness and atrophy of the supraspinatus and infraspinatus muscles occur.

What are the causes?

This condition is commonly caused by narrowing of the tissues around the suprascapular nerve. This may happen gradually from repeatedly making overhead arm motions, or it may result from a sudden (acute) injury.

Less commonly, this condition may be caused by a fluid-filled lump growing near the nerve (ganglion cyst) that causes the nerve to swell.

What increases the risk?

This condition is more likely to develop in young, male athletes, especially those who participate in sports that involve overhead arm movements. These sports include:

• Volleyball.
• Baseball.
• Tennis.
• Weight lifting.

What are the symptoms?

Symptoms of this condition may include:

• Pain. This may feel like a dull ache, and it may get worse with overhead arm movements.
• Weakness.
• Decreased range of motion.

The most important finding in patients with suprascapular nerve entrapment is weakness of the supraspinatus and infraspinatus muscles. This weakness manifests itself as weakness of abduction and external rotation of the ipsilateral shoulder. With significant compromise of the suprascapular nerve, atrophy of the infraspinatus muscle is apparent as it lies superficially.

The pain of suprascapular nerve entrapment can be exacerbated by abducting the ipsilateral scapula by reaching across the chest and simultaneously rotating the neck away from the involved shoulder. Tenderness to palpation of the suprascapular notch is often present.

How is this diagnosed?

This condition is diagnosed based on:

• Your symptoms.
• Your medical history, including your history of recent injuries.
• A physical exam to test your muscle strength and range of motion.
• Your body’s response to a shot (injection) of numbing medicine in your shoulder. This may be done to see if the medicine helps relieve your shoulder pain.
• Tests, such as:
  • Electromyogram (EMG). This is an electrical nerve study that is used to find out which nerve and muscles are affected.
  • X-rays.
  • MRI.
  • Ultrasound.

Electromyography helps distinguish cervical radiculopathy and Parsonage-Turner syndrome from suprascapular nerve entrapment syndrome. Plain radiographs are indicated in all patients who present with suprascapular nerve entrapment syndrome to rule out occult bony pathology. Ultrasound imaging may also aid in the identification of this uncommon cause of shoulder pain.

Based on the patient’s clinical presentation, additional testing, including complete blood cell count, uric acid level, erythrocyte sedimentation rate, and antinuclear antibody testing, may be indicated. Magnetic resonance imaging (MRI) of the shoulder is indicated if a primary joint pathological process or space-occupying lesion is suspected. The injection technique described here is a diagnostic and therapeutic maneuver.

Differential Diagnosis

Suprascapular nerve entrapment syndrome is often misdiagnosed as bursitis, tendinitis, or arthritis of the shoulder. Cervical radiculopathy of the C5 nerve root also may mimic the clinical presentation of suprascapular nerve entrapment syndrome.

Parsonage-Turner syndrome, also known as idiopathic brachial neuritis, may manifest as sudden onset of shoulder pain and can be confused with suprascapular nerve entrapment. Tumor involving the superior scapular nerve, shoulder, or both also should be considered in the differential diagnosis of suprascapular nerve entrapment syndrome.

How is this treated?

Treatment for this condition may include:

• Avoiding activities that cause pain.
• Medicines to help relieve pain.
• Physical therapy.
• One or more injections of numbing medicine (steroid) to help reduce inflammation and pain.
• Surgery to remove a cyst or enlarge a narrow area. Surgery may be needed if your condition does not improve after 6 months of trying other treatment methods.

Nonsteroidal antiinflammatory drugs (NSAIDs) or cyclooxygenase-2 (COX-2) inhibitors represent a reasonable first step in the treatment of suprascapular nerve entrapment syndrome.

The use of tricyclic antidepressants, such as nortriptyline, at a single bedtime dose of 25 mg titrating upward as side effects allow also is useful, especially if sleep disturbance also is present. Avoidance of repetitive trauma thought to be contributing to this entrapment neuropathy also is important, especially in professional athletes.

If these maneuvers fail to produce rapid symptomatic relief, injection of the suprascapular nerve with local anesthetic and steroid is a reasonable next step. Ultrasound guidance may improve the accuracy of needle placement and a decrease in needle-related complications. If symptoms persist, surgical exploration and release of the suprascapular nerve are indicated.

Follow these instructions at home:

• Ask your health care provider when it is safe for you to drive.
  • Do not drive or operate heavy machinery while taking prescription pain medicine.
• Return to your normal activities as told by your health care provider. Ask your health care provider what activities are safe for you.
• Do exercises as told by your health care provider.
• Do not use any tobacco products, such as cigarettes, chewing tobacco, or e-cigarettes. Tobacco can delay bone healing. If you need help quitting, ask your health care provider.
• Take over-the-counter and prescription medicines only as told by your health care provider.
• Keep all follow-up visits as told by your health care provider. This is important.

How is this prevented?

• Warm up and stretch before being active.
• Cool down and stretch after being active.
• Give your body time to rest between periods of activity.
• Make sure to use equipment that fits you.
• Be safe and responsible while being active to avoid falls.
• Do at least 150 minutes of moderate-intensity exercise each week, such as brisk walking or water aerobics.
• Maintain physical fitness, including:
  • Strength.
  • Flexibility.
  • Cardiovascular fitness.
  • Endurance.

Contact a health care provider if:

• You have pain that gets worse or does not get better with medicine.
• Your symptoms get worse or do not go away after 6 months of treatment.

Complications and Pitfalls

The proximity to the suprascapular artery and vein suggests the potential for inadvertent intravascular injection or local anesthetic toxicity from intravascular absorption or both. The clinician should carefully calculate the total milligram dosage of local anesthetic that may be given safely when performing this injection technique. Because of proximity of the lung, if the needle is advanced too deeply through the suprascapular notch, pneumothorax is possible. Care must be taken if surgical decompression of the suprascapular nerve is undertaken to avoid inadvertent trauma to the spinal accessory nerve as it runs along the ventral surface of the trapezius.

Clinical Pearls

Avoidance techniques of the repetitive movements responsible for suprascapular nerve entrapment are often forgotten in the rush to treatment.

The use of rolling briefcases instead of backpacks may help avoid continued trauma to the nerve. This injection technique renders the shoulder joint insensate.

It is important that the clinician ensures that the physical and occupational therapists caring for a patient who has undergone suprascapular nerve block understand that the shoulder girdle as well as the shoulder joint have been rendered insensate after this injection technique.

Deep heat modalities and range-of-motion exercises must be monitored carefully to avoid burns or damage to the shoulder.

Suprascapular Nerve Entrapment Rehabilitation

Ask your health care provider which exercises are safe for you. Do exercises exactly as told by your health care provider and adjust them as directed. It is normal to feel mild stretching, pulling, tightness, or discomfort as you do these exercises, but you should stop right away if you feel sudden pain or your pain gets worse. Do not begin these exercises until told by your health care provider.

Stretching and range of motion exercises

These exercises warm up your muscles and joints and improve the movement and flexibility of your shoulder. These exercises also help to relieve pain, numbness, and tingling.

Exercise A: Internal rotation, sleeper stretch

1. Lie on your left / right side on a firm surface.
2. Position your left / right upper arm straight out from your body. Bend your elbow to an “L” shape (90 degrees) so your fist or your fingers are aimed at the ceiling.
3. Use your other hand to gently push your left / right forearm down, toward the surface that you are lying on.
   1. You may place a folded towel under your left / right elbow to make this more comfortable.
4. Hold for __________ seconds.
5. Slowly return to the starting position.

Repeat __________ times. Complete this exercise __________ times a day.

Exercise B: Shoulder internal rotation I

1. Place your left / right hand behind your back, with your palm facing away from your back.
2. Use your other hand to dangle an exercise band, a towel, or a similar object over your healthy shoulder. Grasp the band with your left / right hand so you are holding onto both ends of the exercise band.
3. WIth your healthy hand, gently pull up on the exercise band until you feel a stretch in the front of your left / right shoulder.
   1. Avoid shrugging your shoulder while you raise your arm. Keep your shoulder blade tucked down toward the middle of your spine.
4. Hold for __________ seconds.
5. Release the stretch by letting go of the exercise band and lowering your hands.

Repeat __________ times. Complete this exercise __________ times a day.

Exercise C: Shoulder internal rotation II

1. Stand and hold a stick behind your back so your palms are facing behind you. Your arms should be straight.
2. Bend your elbows and slide the stick up your back until you feel a stretch in the front of your shoulders.
3. Hold for __________ seconds.
4. Slowly return to the starting position.

Repeat __________ times. Complete this exercise __________ times a day.

Exercise D: Chin tuck (axial extension)

1. Using good posture, sit on a stable surface or stand up. If you have trouble keeping good posture, rest your back and head against a stable wall during this exercise.
2. Look straight ahead and slowly move your chin back, toward your neck, until you feel a stretch in the back of your head.
   1. Your head should slide back.
   1. Your chin should be slightly lowered.
3. Hold for __________ seconds.
4. Return to the starting position.

Repeat __________ times. Complete this exercise __________ times a day.

Exercise E: Cervical side bend

1. Using good posture, sit on a stable surface or stand up.
2. Without moving your shoulders, slowly tilt your ear toward your uninjured shoulder until your feel a stretch in your neck muscles on your left / right side. You should be looking straight ahead.
3. Hold for __________ seconds.
4. Slowly return to the starting position.

Repeat __________ times. Complete this exercise __________ times a day.

Exercise F: Cervical rotation

1. Using good posture, sit on a stable surface or stand up.
2. Keeping your eyes level with the ground, slowly turn your head to one side as if you are looking over your shoulder. Stop when you feel a stretch along the side and back of your neck.
3. Hold for __________ seconds.
4. Slowly return to the starting position and repeat on the other side.

Repeat __________ times. Complete this exercise __________ times a day.

Strengthening exercises

These exercises build strength and endurance in your shoulder. Endurance is the ability to use your muscles for a long time, even after they get tired.

Exercise G: Scapular depression and adduction

1. Sit on a stable chair. Support your arms in front of you with pillows, armrests, or a tabletop. Keep your elbows near the sides of your body.
2. Gently move your shoulder blades down and back toward the middle of your spine. Relax the muscles on the tops of your shoulders and in the back of your neck.
3. Hold for __________ seconds.
4. Slowly release the tension, and relax your muscles completely before you repeat the exercise.

Repeat __________ times. Complete this exercise __________ times a day. After you have practiced this exercise, try doing it without the arm support. Then, try doing it while standing instead of sitting.

Exercise H: External rotation, isometric

1. Stand or sit in a doorway, facing the door frame.
2. Bend your left / right elbow and place the back of your wrist against the door frame. Only your wrist should be touching the frame. Keep your upper arm against your side.
3. Gently press your wrist against the door frame, as if you are trying to push your arm away from your abdomen.
   1. Avoid shrugging your shoulder while you do this. Keep your shoulder blade tucked down toward the middle of your back.
4. Hold for __________ seconds.
5. Slowly release the tension, and relax your muscles completely before you repeat the exercise.

Repeat __________ times. Complete this exercise __________ times a day.

Exercise I: Cervical flexion, isometric

1. Face a wall and stand about 6 inches (15 cm) away from it. Place a soft object, about 6–8 inches (15–20 cm) in diameter, between your forehead and the wall. A soft object could be a small pillow, a ball, or a folded towel.
2. Tuck your chin and gently push your forehead into the soft object. Keep your jaw and forehead relaxed.
3. Hold for __________ seconds.
4. Release the tension slowly. Relax your neck muscles completely before you repeat the exercise.

Repeat __________ times. Complete this exercise __________ times a day.

Exercise J: Cervical lateral flexion, isometric

1. Stand about 6 inches (15 cm) away from a wall. Stand so one of your shoulders faces the wall, and look straight ahead. Place a soft object, about 6–8 inches (15–20 cm) in diameter, between the side of your head and the wall. A soft object could be a small pillow, a ball, or a folded towel.
2. Tuck your chin and gently tilt your head into the object. Keep your jaw and forehead relaxed.
3. Hold for __________ seconds.
4. Release the tension slowly. Relax your neck muscles completely before you repeat the exercise. Do this exercise on both sides of your neck.

Repeat __________ times. Complete this exercise __________ times a day.

Exercise K: Cervical extension, isometric

1. Stand about 6 inches (15 cm) away from a wall, with your back facing the wall. Place a soft object, about 6–8 inches (15–20 cm) in diameter, between your head and the wall. A soft object could be a small pillow, a ball, or a folded towel.
2. Tuck your chin and gently tilt your head back into the soft object. Keep your jaw and forehead relaxed.
3. Hold for __________ seconds.
4. Release the tension slowly. Relax your neck muscles completely before you repeat the exercise.

Repeat __________ times. Complete this exercise __________ times a day.

Exercise L: External rotation

1. Sit in a stable chair without armrests, or stand.
2. Secure an exercise band at elbow height on your left / right side.
3. Place a soft object, such as a folded towel or a small pillow, between your left / right upper arm and your body to move your elbow a few inches (about 10 cm) away from your side.
4. Hold the end of the band so it stretches slightly.
5. Keeping your elbow pressed against the soft object under your arm, move your forearm out, away from your body. Keep your body steady so that only your forearm moves.
6. Hold for __________ seconds.
7. Slowly return to the starting position.

Repeat __________ times. Complete this exercise __________ times a day.