A shoulder is a complex joint with many nerves that control the sensation and movement of the shoulder, hand, and arm. The brachial plexus is a bundle of nerves. It originates from the cervical spine’s nerve roots and extends from the shoulder down the arm. Shoulder nerves carry signals such as pain, touch, and temperature back to your brain. Injury or compression of the shoulder nerve may cause pain or weakness, thus affecting your day-to-day activities. Early diagnosis and treatment are always preferable.
Shoulder nerve injuries are relatively uncommon to other musculoskeletal injuries. It is estimated to occur in one or two babies out of every 1,000 births.
What Is The Anatomy Of The Shoulder Nerve?
The brachial plexus is a group of nerves that plays a major role in the movement and sensation of the upper arm. The common nerves of the brachial plexus include,
Axillary Nerve:
- The axillary nerve is formed from the C5 and C6 nerve roots of the brachial plexus. This nerve functions on three muscles: the deltoid, the teres minor, and the long head of the triceps muscle, which controls the shoulder or arm movement.
- It facilitates shoulder abduction (moving the arm away from the body) and external rotation.
Radial Nerve:
- The radial nerve is formed from the C5, C6, C7, C8, and T1 nerve roots of the brachial plexus. This nerve functions on triceps muscles to straighten the elbow.
- It controls the muscles of the forearm and hand that further extend up to the wrist and fingers.
- It also provides sensation to the back of the arm and hand.
Median Nerve:
- The median nerve is formed from the C5, C6, C7, C8, and T1 nerve roots of the brachial plexus. This nerve helps the wrist and fingers to bend and rotate the hand to face palm down.
- It facilitates sensation to the thumb side of the palm, the thumb, index, middle, and half of the ring finger.
Ulnar Nerve:
- The ulnar nerve is formed from the C8 and T1 nerve roots of the brachial plexus. This nerve helps the forearm muscles that bend the tips of the small and ring fingers (the flexor digitorum profundus) and also one of the muscles that bends the wrist.
- It provides sensation to the small finger side of the palm, the small finger, and the side of the ring finger next to the small finger.
Musculocutaneous Nerve:
- The musculocutaneous nerve is formed from the C5, C6, and C7 nerve roots of the brachial plexus. This nerve controls the shoulder muscles: the biceps brachii, brachialis, and coracobrachialis. It helps in flexing the elbow and turning the palm up in forearm supination (inward movement of palm).
- It provides sensation to the lateral (outside) forearm.
What Are The Causes Of The Shoulder Nerve Injury?
Below are the causes of the shoulder nerve injury.
- Accidents, falls, or sports injuries can lead to direct damage.
- Compression of the shoulder nerves by tight muscles, bone spurs, or other structures.
- Nerves can become trapped in narrow spaces, such as the carpal tunnel.
- Shoulder dislocation or fracture of the shoulder or arm.
Some of the medical conditions that may be also responsible for causing shoulder nerve injury.
- Parsonage-Turner syndrome (autoimmune inflammation)
- Herpes zoster
- Quadrilateral space syndrome, inflammation of the muscle, thus presses your nerve
- Cervical radiculopathy, pinched nerve in your arm
- Arthritis or tendinitis
What Are The Symptoms Related To Shoulder Nerve Injury?
Injuries of the shoulder nerves can cause various symptoms, depending on the affected nerve. Here are the symptoms of the different shoulder nerve injuries.
- Axillary nerve injury: Injury in the axillary nerve may cause,
- Weakness in the shoulder
- limited shoulder movement
- numbness on the outer upper arm
- Radial nerve injury: Damage in the radial nerve often leads to,
- Wrist drop
- Difficulty extending the wrist and fingers
- Weakness in the thumb
- Median nerve injury: Compression of the median nerve results in,
- Hand weakness
- Difficulty flexing the wrist and fingers
- Numbness or tingling in the palm and fingers
- Ulnar nerve injury: Injury to the ulnar nerve may cause,
- Pain, numbness, and tingling in the pinky and ring fingers
- Hand weakness
- In severe cases, a claw hand deformity.
- Musculocutaneous nerve injury: Damage to the musculocutaneous nerve may result in,
- Forearm weakness
- Difficulty bending the elbow
- Sensory loss on the outer forearm
How To Diagnose Shoulder Nerve Injury?
Diagnosis of the injured nerve of the shoulder requires a comprehensive assessment and a detailed physical examination. In most cases, imaging tests may be recommended by the doctor. A shoulder-nerve imaging test includes:
- Neuromuscular ultrasound is used to identify damage to nerves and muscles in the body.
- Nerve conduction study/Electromyography helps detect neuromuscular abnormalities.
- An X-ray helps to assess the integrity of your shoulder joint and bones.
- MRI (Magnetic Resonance Imaging).
How Can Shoulder Nerve Injury Be Treated?
Shoulder fractures can be treated with both non-surgical and surgical methods.
Non-surgical Treatments:
- Rest and immobilization: By taking rest, you can also get relief from pain. Your doctor may also recommend using slings to immobilize your shoulder, arm, or hand to reduce pain and inflammation in the affected shoulder nerve.
- Physical therapy: Rehabilitation exercises may be provided by your physiotherapist to restore the range of motion and flexibility of the shoulder, arm, and hand.
- Pain management: NSAIDs like ibuprofen are also advised to relieve pain and inflammation.
- Corticosteroid injections: Injections of corticosteroids can help to reduce inflammation and pain.
Surgical Treatment
- Nerve decompression: Nerve decompression is a surgical procedure, typically performed to relieve pressure and restore normal function of the shoulder nerve. It usually occurs in the axillary nerve, radial nerve, and musculocutaneous nerve. This is usually performed when physical and non-surgical methods are not effective.
- Nerve grafting: Nerve grafting or nerve transplant, in which a healthy nerve is taken from another part of the body to replace the damaged section. Thus, it helps to restore the shoulder nerve’s function. It is usually performed when the radial nerve is severely affected.
- Carpal tunnel release: Carpal tunnel syndrome (compression of the median nerve) is the cause of shoulder or arm-related nerve pain. Carpal tunnel release involves the cutting of the ligament that is compressing the median nerve. This helps to relieve pressure on the shoulder nerve.
- Nerve transposition: Nerve transposition is a surgical method to move the ulnar nerve in different locations to prevent its further compression. Thus, it helps protect and restore the function of the shoulder nerve.
Also Read:- Shoulder Replacement Surgery Cost in India
How Can Shoulder Nerve Injury Be Prevented?
Steps you can take to avoid a shoulder nerve injury include:
- Maintaining proper body posture
- Make an ergonomic workstation setup to maintain the natural ‘S’ shape of the spine.
- Do regular exercises.
- Take frequent breaks.
- Wear appropriate protective gear for sports and activities.
- Avoid lifting heavy objects with excessive force.
Helpful:- Top 10 Orthopedic Surgeons in Gurgaon
A Note From Dr. N.K. Magu
A shoulder nerve injury can greatly affect your daily activities. If you are feeling any pain, numbness, or weakness in the shoulder or arm, it is important to get medical advice. Non-surgical treatments such as rest, immobilization, and physical therapy are effective for minor shoulder nerve injuries. However, for severe cases, your doctor may recommend surgical treatment based on the type of nerve injury. Early diagnosis and treatment can prevent further complications.
FAQ’s
Q: What is the main nerve of the shoulder?
A: The axillary nerve is considered the main nerve of the shoulder. It provides function to three muscles: the deltoid, the teres minor, and the long head of the triceps muscle, which is responsible for the shoulder and arm movement.
Q: What nerve referred to shoulder pain?
A: The axillary nerve is often implicated in shoulder pain, especially when injured or compressed, affecting shoulder movement and sensation.
Q: What is the test for the shoulder nerve?
A: Shoulder nerve issues are typically diagnosed using physical exams and imaging tests like MRI, CT scans, or nerve conduction.
Q: What causes damage to the nerve?
A: Shoulder nerve damage can result from trauma, such as fractures or dislocations, compression from crutches or pressure, or surgical complications, leading to impaired nerve function.
Q: What is the nerve supply of the shoulder nerve?
A: The shoulder nerve supply includes the axillary nerve, radial nerve, median nerve, ulnar nerve, and musculocutaneous nerve, each responsible for specific motor and sensory functions in the shoulder and arm.
References:
https://www.shoulderdoc.co.uk/article/1181
https://my.clevelandclinic.org/health/body/22264-axillary-nerve
