Stiff shoulder

Introduction

Stiff shoulder is a common musculoskeletal complaint that can significantly affect daily activities and overall quality of life. It may arise from various causes including injury, inflammation, or prolonged immobilization. Early recognition and management are important to prevent chronic disability and restore functional mobility.

Anatomy and Physiology of the Shoulder

Shoulder Joint Structure

The shoulder is a complex joint that allows a wide range of motion while maintaining stability through its muscles, tendons, and ligaments.

• Glenohumeral joint anatomy: A ball-and-socket joint formed between the humeral head and glenoid cavity, providing primary shoulder mobility.
• Acromioclavicular and sternoclavicular joints: These joints contribute to shoulder movement and connect the shoulder girdle to the axial skeleton.
• Rotator cuff muscles and tendons: A group of four muscles and their tendons that stabilize the glenohumeral joint and facilitate shoulder rotation and lifting.

Normal Shoulder Function

The shoulder’s normal function depends on coordinated movements of muscles, tendons, and ligaments to achieve smooth and pain-free motion.

• Range of motion and biomechanics: Includes flexion, extension, abduction, adduction, internal rotation, and external rotation of the arm.
• Role of muscles, tendons, and ligaments: Muscles provide power and control, tendons transmit force to bones, and ligaments maintain joint stability during movement.

Etiology of Shoulder Stiffness

Musculoskeletal Causes

Musculoskeletal conditions are a common source of shoulder stiffness, often resulting from injury, degeneration, or overuse.

• Rotator cuff injuries: Tendinopathy or tears can limit shoulder mobility and cause pain during movement.
• Osteoarthritis of the shoulder joint: Degenerative changes in cartilage lead to stiffness, reduced range of motion, and discomfort.
• Calcific tendinitis: Calcium deposits in tendons can produce pain and restrict shoulder movement.
• Post-traumatic stiffness: Fractures or dislocations may result in scar tissue formation and reduced mobility if not properly rehabilitated.

Inflammatory and Systemic Causes

Inflammatory and systemic disorders can contribute to stiffness by affecting the joint capsule or surrounding tissues.

• Adhesive capsulitis (frozen shoulder): Characterized by thickening and contraction of the joint capsule, leading to progressive pain and limited range of motion.
• Rheumatoid arthritis: Chronic autoimmune inflammation of the synovium can cause joint swelling, pain, and stiffness.
• Polymyalgia rheumatica: An inflammatory disorder that can produce bilateral shoulder stiffness and pain, particularly in older adults.

Neurological Causes

Neurological conditions can lead to shoulder stiffness through nerve injury or impaired muscle function.

• Stroke-related shoulder stiffness: Post-stroke spasticity or weakness can limit shoulder movement and contribute to pain and contractures.
• Brachial plexus injury: Trauma or compression of the brachial plexus may cause weakness, numbness, and restricted shoulder mobility.
• Peripheral nerve entrapment: Conditions such as cervical radiculopathy can affect nerve supply to shoulder muscles, resulting in stiffness and functional limitations.

Other Causes

Additional factors, including surgical interventions and prolonged immobilization, can also contribute to shoulder stiffness.

• Post-surgical stiffness: Following shoulder surgery, scar tissue formation and limited movement can lead to stiffness if not properly rehabilitated.
• Immobilization due to injury or illness: Extended periods of inactivity, such as after fractures or prolonged bed rest, can result in contractures and reduced joint mobility.

Risk Factors

Certain demographic, medical, and lifestyle factors increase the likelihood of developing shoulder stiffness.

• Age and gender: Stiff shoulder is more common in individuals over 40 years of age, with a slightly higher prevalence in females.
• Diabetes mellitus: People with diabetes are at increased risk of adhesive capsulitis and prolonged recovery from shoulder injuries.
• Previous shoulder injury or surgery: Trauma or surgical interventions can lead to scar tissue formation and restricted movement.
• Prolonged immobilization: Extended periods without shoulder movement, such as after fractures or illness, can result in stiffness and contractures.

Clinical Assessment

History Taking

A thorough history is essential to identify the underlying cause of shoulder stiffness and guide further evaluation.

• Onset, duration, and progression: Determine whether stiffness developed gradually or suddenly and whether it is improving or worsening over time.
• Pain characteristics and aggravating factors: Assess the location, intensity, and triggers of pain, including activity-related or nocturnal pain.
• Impact on daily activities: Evaluate limitations in dressing, grooming, reaching overhead, or other functional tasks.
• Past medical and surgical history: Include prior injuries, surgeries, or systemic conditions that may contribute to stiffness.

Physical Examination

A comprehensive physical examination provides information on the severity and possible causes of shoulder stiffness.

• Inspection and palpation: Look for swelling, deformity, muscle atrophy, or tenderness around the shoulder joint.
• Range of motion assessment: Evaluate both active and passive movements including flexion, extension, abduction, adduction, internal rotation, and external rotation.
• Strength testing: Assess rotator cuff and surrounding muscle strength to identify weakness or imbalance.
• Special tests: Perform tests such as Neer, Hawkins-Kennedy, and Apley scratch test to identify impingement or rotator cuff pathology.

Investigations

Diagnostic tests help confirm the underlying cause of shoulder stiffness and guide appropriate management.

• Plain radiographs (X-rays): Evaluate joint space narrowing, osteophytes, or fractures.
• Ultrasound: Assess rotator cuff integrity and detect tendon tears or inflammation.
• MRI or CT scan: Provides detailed visualization of soft tissues, including tendons, muscles, and the joint capsule.
• Laboratory tests: May be indicated to identify inflammatory or systemic conditions such as rheumatoid arthritis or infection.

Management Strategies

Conservative Management

Conservative treatments are typically the first-line approach for shoulder stiffness and aim to reduce pain while restoring mobility.

• Physical therapy and range of motion exercises: Stretching, strengthening, and mobilization techniques help improve flexibility and prevent contractures.
• Analgesics and anti-inflammatory medications: Nonsteroidal anti-inflammatory drugs (NSAIDs) or acetaminophen can relieve pain and inflammation.
• Heat, cold therapy, and lifestyle modifications: Applying heat can relax muscles, cold can reduce inflammation, and activity modifications prevent aggravation.

Interventional Treatments

For patients not responding to conservative measures, interventional therapies may provide additional relief.

• Corticosteroid injections: Reduce inflammation in the joint or surrounding tissues, improving pain and range of motion.
• Hydrodilatation: Injection of fluid into the joint capsule to stretch it and restore mobility, particularly effective in adhesive capsulitis.

Surgical Management

Surgery is considered for patients with severe or refractory shoulder stiffness that does not improve with conservative or interventional treatments.

• Arthroscopic capsular release: Minimally invasive procedure to release contracted joint capsule in cases of adhesive capsulitis.
• Rotator cuff repair: Surgical repair of torn tendons to restore shoulder function and reduce stiffness.
• Joint replacement: Indicated in severe osteoarthritis where joint degeneration significantly limits movement and causes pain.

Rehabilitation and Recovery

Post-treatment rehabilitation is essential to regain full shoulder function and prevent recurrence of stiffness.

• Post-treatment physiotherapy: Structured exercise programs to restore range of motion, strength, and coordination.
• Gradual return to daily activities: Progressive activity to avoid overstressing the joint while maintaining mobility.
• Monitoring for recurrence or complications: Regular follow-up to assess recovery and detect any early signs of relapse or secondary issues.

Complications

If left untreated or inadequately managed, shoulder stiffness can lead to several complications affecting function and quality of life.

• Persistent pain and limited mobility: Chronic stiffness can restrict daily activities and reduce independence.
• Muscle atrophy: Prolonged immobility can lead to weakening and wasting of shoulder and surrounding muscles.
• Secondary joint degeneration: Altered biomechanics from stiffness can accelerate osteoarthritis or other degenerative changes.

Prevention Strategies

Preventive measures aim to reduce the risk of developing shoulder stiffness and promote long-term joint health.

• Regular shoulder exercises and stretching: Maintaining flexibility and strength helps prevent contractures and joint restriction.
• Avoiding prolonged immobilization: Early mobilization after injury or surgery reduces the risk of stiffness.
• Early intervention after injury or surgery: Prompt treatment and rehabilitation help maintain range of motion and prevent chronic stiffness.

References

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