Shoulder subluxation is a partial dislocation of the shoulder joint, where the ball of the humerus (upper arm bone) slips partially out of its socket in the scapula (shoulder blade) but does not fully dislocate. This injury can be painful and lead to instability in the shoulder, potentially causing damage to the surrounding muscles, ligaments, and nerves. Shoulder subluxations are often caused by trauma, overuse, or a weakened shoulder structure, and they may lead to recurrent dislocations or long-term instability if not addressed properly.

Shoulder Subluxation: Causes, Symptoms, and Treatment

What is Shoulder Subluxation?

In a shoulder subluxation, the ball of the upper arm bone (humerus) moves slightly out of its normal position in the glenoid (the socket in the shoulder blade), but it does not completely dislocate. This partial dislocation can happen during a fall, a direct blow to the shoulder, or any activity that puts excessive strain on the joint.

Subluxation differs from a complete dislocation in that the bone is not fully displaced, but the shoulder joint may still feel unstable or weak. Over time, repeated subluxations can increase the risk of full dislocations or long-term shoulder instability.

Causes of Shoulder Subluxation

Several factors can contribute to shoulder subluxation, including:

• Trauma or Injury: A sudden forceful movement, such as falling on an outstretched hand or a blow to the shoulder, can cause the humerus to slip partially out of the glenoid.

• Overuse or Repetitive Motion: Athletes or individuals who perform repetitive overhead movements, such as swimming, throwing, or weightlifting, are at higher risk.

• Weak or Injured Ligaments: People with lax or weak ligaments may experience joint instability, making the shoulder more prone to subluxation.

• Previous Shoulder Injury: A prior shoulder dislocation or subluxation can weaken the structures around the joint, increasing the likelihood of future episodes.

• Neurological Conditions: Certain neurological conditions, such as stroke or cerebral palsy, can affect muscle control and coordination, making the shoulder more prone to instability.

Symptoms of Shoulder Subluxation

The symptoms of shoulder subluxation can vary depending on the severity of the injury but typically include:

• Pain: While the pain is often less severe than in a complete dislocation, there may still be aching or sharp pain in the shoulder, particularly with certain movements.

• Instability: The shoulder may feel unstable, and you may have a sense that the joint is "loose" or might dislocate completely.

• Limited Range of Motion: Movements such as lifting the arm or rotating the shoulder may be painful or difficult due to the instability.

• Swelling: There may be mild swelling or bruising around the shoulder joint, especially if the injury is recent.

• Weakness: The muscles around the shoulder may feel weak, making it difficult to perform everyday tasks or activities that require shoulder strength.

• Clicking or Popping Sensation: Some people report feeling or hearing a clicking or popping sound when the shoulder is moved, especially when the joint moves out of alignment.

Diagnosing Shoulder Subluxation

Diagnosis of shoulder subluxation involves a combination of physical examination, medical history review, and imaging tests. During the physical exam, your healthcare provider will assess the shoulder's range of motion, stability, and any signs of deformity or weakness.

To confirm the diagnosis and rule out other injuries, such as fractures or full dislocations, additional tests may include:

• X-rays: X-rays can help detect any fractures or abnormalities in the bone structure and confirm whether there is any misalignment of the shoulder joint.

• MRI or Ultrasound: These imaging techniques can help evaluate soft tissue damage, such as injuries to the ligaments, rotator cuff, or labrum.

• CT Scan: In some cases, a CT scan may be used to get detailed images of the joint and assess for damage to the bone or soft tissue.

Treatment for Shoulder Subluxation

Treatment for shoulder subluxation focuses on reducing pain, improving stability, and preventing further injury. The course of treatment will depend on the severity of the subluxation, whether it is a recurrent issue, and if there is associated tissue damage.

Non-Surgical Treatment

For most people with a shoulder subluxation, non-surgical treatment is the first line of management. This typically includes:

• Rest and Ice: Initially, the shoulder should be rested, and ice should be applied to reduce swelling and inflammation.

• Immobilization: Wearing a sling or brace may help stabilize the shoulder and prevent further movement that could worsen the subluxation.

• Pain Relief: Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, can help relieve pain and reduce inflammation.

• Physical Therapy: A comprehensive rehabilitation program will be crucial for strengthening the muscles around the shoulder, improving joint stability, and restoring the range of motion. Therapy often includes strengthening exercises for the rotator cuff and scapular muscles, as well as proprioceptive training (balance and body awareness exercises).

• Activity Modification: Avoid activities that involve repetitive overhead motions or put undue strain on the shoulder joint until the injury has healed.

Surgical Treatment

In cases where the subluxation is recurrent or if there is significant damage to the shoulder's soft tissues (e.g., torn labrum or ligaments), surgery may be necessary. Surgical options include:

• Arthroscopic Surgery: A minimally invasive procedure where small incisions and a camera are used to repair or reattach damaged structures in the shoulder joint, such as the labrum or ligaments.

• Shoulder Stabilization Surgery: In cases of severe instability, a procedure may be performed to tighten the ligaments or reconstruct the labrum, restoring normal stability to the shoulder joint.

• Open Surgery: For more complex cases or when extensive tissue repair is needed, open surgery may be required to fully stabilize the shoulder joint.

Rehabilitation and Recovery

The recovery process for shoulder subluxation typically includes several stages:

• Phase 1: Acute Rest and Pain Management: The first stage of recovery involves managing pain and inflammation, and immobilizing the shoulder in a sling or brace for several days or weeks.

• Phase 2: Early Rehabilitation: Once the pain has subsided, gentle range-of-motion exercises will begin to restore flexibility to the joint. Active exercises may also start to strengthen the muscles around the shoulder.

• Phase 3: Strengthening and Stability: As healing progresses, more focused strengthening exercises will be added to improve the shoulder's stability and prevent future subluxations. This phase may also include proprioceptive exercises to improve coordination and control.

• Phase 4: Return to Activity: Gradually, activities and sports can be resumed once the shoulder has regained strength and stability. Full recovery may take several weeks to months, depending on the severity of the injury.

Prevention of Shoulder Subluxation

While not all cases of shoulder subluxation can be prevented, certain measures can help reduce the risk:

• Strengthen Shoulder Muscles: Regularly perform exercises to strengthen the rotator cuff and scapular muscles, which are crucial for shoulder stability.

• Improve Flexibility: Stretching exercises can help maintain flexibility in the shoulder joint and prevent strain on the ligaments and tendons.

• Avoid Overuse: Overhead activities or repetitive motions can increase the risk of subluxation, so be sure to take regular breaks and avoid overloading the shoulder.

• Proper Technique: Whether lifting, throwing, or engaging in sports, use proper technique to reduce the stress on the shoulder joint.

• Protective Gear: In contact sports, wear appropriate protective equipment to reduce the risk of shoulder injuries.

Australian Resources for Shoulder Subluxation

• Better Health Channel – Shoulder Injuries
  https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/shoulder-injuries

• Healthdirect Australia – Shoulder Subluxation
  https://www.healthdirect.gov.au/shoulder-subluxation

• Australian Physiotherapy Association – Shoulder Subluxation
  https://choose.physio/your-condition/shoulder-injuries/shoulder-subluxation

Important disclaimer: This webpage contains general information only and is not intended to be relied upon as personal clinical advice. While we aim to keep information accurate and up to date, it may not reflect the most current research or your individual circumstances. Palms Physiotherapy & Allied Health does not accept liability for decisions made based on this information without an individualised assessment by an appropriately qualified health professional. If you have concerns, please contact us to book an assessment or speak with your GP/medical team.