Shoulder Bursitis: Understanding Causes, Symptoms, and Treatment

What is Shoulder Bursitis?

Shoulder bursitis is an inflammatory condition affecting one of the small, fluid-filled sacs (bursae) located within the shoulder joint, most commonly the subacromial bursa, leading to pain, swelling, and restricted movement, often due to overuse or mechanical irritation.

Understanding Shoulder Bursitis

Bursitis is the inflammation of a bursa. Bursae (plural of bursa) are small, gelatinous sacs located throughout the body, acting as cushions between bones, tendons, muscles, and skin. Their primary function is to reduce friction and allow for smooth, pain-free movement of these structures over one another.

In the shoulder, several bursae exist, but the subacromial bursa is by far the most commonly affected in cases of shoulder bursitis. This bursa is strategically positioned beneath the acromion (a bony projection of the shoulder blade) and above the rotator cuff tendons. When this bursa becomes inflamed, it swells, causing pain and limiting the smooth gliding of the rotator cuff tendons, often leading to a condition known as shoulder impingement syndrome.

Anatomy of the Shoulder and Bursae

The shoulder is a complex ball-and-socket joint, renowned for its extensive range of motion. Key anatomical components include:

• Humerus: The upper arm bone.
• Scapula: The shoulder blade, which includes the acromion (the bony top part of the shoulder).
• Clavicle: The collarbone.
• Rotator Cuff: A group of four muscles (supraspinatus, infraspinatus, teres minor, subscapularis) and their tendons that surround the head of the humerus, providing stability and enabling a wide range of arm movements.

The subacromial/subdeltoid bursa is critical to shoulder function. It lies between the deltoid muscle and the rotator cuff tendons below, and the acromion and coracoacromial ligament above. Its role is to facilitate frictionless movement of the rotator cuff tendons as the arm is lifted and rotated. When this bursa becomes inflamed, the space for the tendons to glide through diminishes, leading to pain and potential impingement.

Causes and Risk Factors

Shoulder bursitis typically arises from repetitive stress, injury, or underlying conditions. Common causes and risk factors include:

• Repetitive Overhead Activities: Sports like swimming, tennis, baseball, or occupations requiring frequent overhead reaching (e.g., painting, construction, carpentry).
• Shoulder Impingement Syndrome: This is a very common cause where the rotator cuff tendons and the bursa become compressed between the acromion and the humeral head during arm elevation.
• Acute Trauma: A direct fall or blow to the shoulder can inflame the barsa.
• Poor Posture: Forward head posture and rounded shoulders can alter shoulder mechanics, reducing the subacromial space and increasing friction.
• Incorrect Lifting Techniques: Using improper form when lifting heavy objects can put excessive strain on the shoulder.
• Muscle Imbalances: Weakness in the rotator cuff muscles or scapular stabilizers can lead to abnormal shoulder movement patterns and increased stress on the bursa.
• Bone Spurs: Bony growths on the acromion can narrow the subacromial space, irritating the bursa and tendons.
• Underlying Medical Conditions: While less common, inflammatory conditions such as rheumatoid arthritis, gout, or psoriasis can sometimes cause bursitis. Diabetes may also increase susceptibility.
• Age: The risk of bursitis tends to increase with age due to cumulative wear and tear on the joint structures.

Symptoms of Shoulder Bursitis

The symptoms of shoulder bursitis can vary in intensity but typically include:

• Localized Pain: A dull ache or sharp pain on the outside or top of the shoulder, often radiating down the arm.
• Pain with Movement: The pain usually worsens with specific movements, particularly lifting the arm overhead, reaching behind the back, or reaching across the body.
• Painful Arc: A characteristic symptom is pain experienced within a specific range of motion (typically between 60 and 120 degrees of arm abduction), which lessens once the arm is fully raised.
• Tenderness: The area around the shoulder, especially over the bursa, may be tender to the touch.
• Swelling: While not always visibly apparent, inflammation within the bursa can cause internal swelling.
• Restricted Range of Motion: Pain can limit the ability to move the arm fully, especially in overhead positions.
• Weakness: Due to pain, the shoulder may feel weak, making it difficult to perform daily activities.
• Night Pain: Pain often worsens at night, especially when lying on the affected side, disrupting sleep.

Diagnosis

Diagnosing shoulder bursitis involves a combination of medical history, physical examination, and imaging studies:

• Medical History: The doctor will ask about your symptoms, the onset of pain, aggravating activities, and any relevant medical conditions or past injuries.
• Physical Examination: This is crucial. The clinician will assess your range of motion, observe your posture, palpate (feel) the shoulder for tenderness, and perform specific orthopedic tests (e.g., Neer's test, Hawkins-Kennedy test) to provoke impingement symptoms and differentiate bursitis from other conditions like rotator cuff tears.
• Imaging Tests:
  • X-rays: Primarily used to rule out bony abnormalities like bone spurs, arthritis, or fractures. They do not show bursitis directly.
  • Ultrasound: Can effectively visualize fluid accumulation within the bursa and soft tissue inflammation. It's also useful for guiding injections.
  • Magnetic Resonance Imaging (MRI): Provides detailed images of soft tissues, including the bursa and rotator cuff tendons. An MRI can help confirm bursitis and rule out or identify associated conditions like rotator cuff tears or tendinopathy.
• Aspiration (Fluid Removal): In rare cases, if an infection is suspected, fluid may be withdrawn from the bursa with a needle and sent for laboratory analysis.

Treatment Approaches

The primary goal of shoulder bursitis treatment is to reduce inflammation, alleviate pain, and restore normal shoulder function. Most cases respond well to conservative management.

Conservative Management

• Rest and Activity Modification: Avoiding activities that aggravate the shoulder is paramount. This may involve temporary cessation of sports or modifying work tasks.
• Ice Application: Applying ice packs to the affected area for 15-20 minutes several times a day can help reduce inflammation and pain.
• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Over-the-counter NSAIDs like ibuprofen or naproxen can help manage pain and inflammation.
• Physical Therapy: A cornerstone of treatment, physical therapy aims to:
  • Reduce pain and inflammation through modalities like ultrasound or manual therapy.
  • Restore full, pain-free range of motion through stretching and mobilization exercises.
  • Strengthen the rotator cuff muscles, scapular stabilizers, and deltoid to improve shoulder mechanics and stability.
  • Address postural imbalances and educate on proper movement patterns for daily activities and sports.
  • Gradually return to activity.

Injections

• Corticosteroid Injections: If conservative measures are insufficient, a corticosteroid injection directly into the subacromial bursa can provide significant, albeit temporary, pain relief by reducing inflammation. These are often performed under ultrasound guidance for accuracy.

Surgical Intervention

• Bursectomy: Surgery to remove the inflamed bursa (bursectomy) is rarely necessary. It is typically considered only in chronic cases where all conservative treatments have failed and symptoms persist for an extended period. This procedure is often performed arthroscopically (minimally invasive).

Prevention Strategies

Preventing shoulder bursitis largely involves managing risk factors and maintaining optimal shoulder health:

• Proper Warm-up and Cool-down: Always warm up before exercise and cool down afterward to prepare muscles and tendons for activity and aid recovery.
• Gradual Progression: Avoid sudden increases in the intensity, duration, or frequency of activities, especially those involving overhead movements.
• Correct Form and Technique: Learn and practice proper biomechanics for sports, lifting, and everyday tasks. Seek guidance from a qualified coach or physical therapist.
• Strength and Flexibility Training: Regularly strengthen the rotator cuff and scapular stabilizer muscles to maintain shoulder stability. Incorporate stretches to maintain shoulder mobility and flexibility, especially for the posterior capsule and pectoral muscles.
• Ergonomics: Adjust your workspace and daily habits to minimize stress on the shoulders. Ensure your computer screen is at eye level and your chair provides good support.
• Listen to Your Body: Do not push through pain. If an activity causes shoulder discomfort, modify it or take a break.
• Address Postural Imbalances: Work on correcting poor posture, such as rounded shoulders or a forward head posture, which can contribute to shoulder impingement.

When to Seek Medical Attention

While many cases of shoulder bursitis improve with self-care, it's important to consult a healthcare professional if you experience:

• Severe, sudden shoulder pain.
• Inability to move your arm or perform daily tasks.
• Pain that does not improve with rest, ice, and over-the-counter pain relievers within a few days.
• Signs of infection, such as fever, redness, warmth, or pus around the shoulder.
• Persistent weakness, numbness, or tingling in your arm or hand.

Early diagnosis and appropriate management are key to preventing chronic shoulder pain and dysfunction.