Common Causes of Shoulder Pain
Eight Conditions Related to Acute or Chronic Discomfort
Shoulder pain is a common complaint, with a myriad of causes. The eight most common abnormalities resulting in shoulder pain are discussed.
Shoulder pain is a very common joint complaint. There are many causes of shoulder pain, and diagnosing the underlying problem can be a challenge. The most common causes of shoulder pain include:
- Shoulder Impingement
- Rotator cuff tendinitis
- Bursitis
- Rotator cuff tear
- Labral tear
- Biceps tendon tear
- Frozen shoulder (adhesive capsulitis)
- Arthritis
Impingement Syndrome/Rotator Cuff Tendinitis/Shoulder Bursitis
Impingement syndrome includes subcategories of shoulder disease such as rotator cuff tendinitis, and shoulder bursitis. Impingement is usually secondary to degeneration of the acromioclavicular (AC) joint of the shoulder. The AC joint is formed by the acromion (a part of the shoulder blade) and the end of the clavicle (the collarbone). The AC joint acts as a bony roof, which protects the muscles and tendons of the rotator cuff. When AC joint degeneration occurs, bony spurs form, which can press on the rotator cuff, causing irritation. Over time, this can lead to tendinitis of the rotator cuff, and/or bursitis of the shoulder. Tendinitis refers to inflammation of the tendons of the rotator cuff. Bursitis of the shoulder refers to irritation of the fluid sac that protects the upper surface of the rotator cuff. Both entities have similar symptoms of non-specific shoulder pain, and are treated similarly, with rest, anti-inflammatory medication, and physical therapy.
Rotator Cuff Tear
Rotator cuff tear refers to focal disruption of one or more of the tendons that comprise the rotator cuff. Not all tears are painful – many older individuals may have rotator cuff tears without symptoms. Tears can have different shapes – some tears are small holes, while others are large gaps in the in the rotator cuff. Rotator cuff tears can be the result of acute injury, or may be chronic, from repetitive motion.
Labral Tear
The labrum is a rim of cartilage that lines the socket of the shoulder joint. Its function is to deepen the socket, providing better stability for the joint. The labrum can tear from acute injury, or from chronic degeneration over time. Symptoms of labrum tear include constant aching sensation of the shoulder, pain with certain specific movements, or a “catching” sensation with motion. Tears can affect any portion of the labrum, but are most common in the upper, or superior, portion.
Biceps Tendon Rupture
The biceps muscle is the major muscle of the front of the upper arm, and is responsible for flexion of the elbow. The biceps has one tendon attachment near the elbow, and two near the shoulder. The longer of these two shoulder attachments is vulnerable to tear, especially in older individuals. Tear of the tendon of the long head of the biceps may occur without symptoms, or may cause pain and mild weakness of the upper arm.
Frozen Shoulder
Known clinically as Adhesive Capsulitis, frozen shoulder is a painful restriction of movement of the shoulder joint. Sometimes, frozen shoulder occurs for no identifiable reason. Other times, it is associated with long term shoulder immobilization. Adhesive capsulitis is a poorly understood condition, and is thought to be due to contraction of the connective tissue capsule of the shoulder. It is usually a diagnosis of exclusion, with no abnormalities demonstrated on x-ray or MRI imaging.
Arthritis
Arthritis of the shoulder is similar to arthritis of other joints. The most common type is degenerative arthritis, or osteoarthritis. In this condition, chronic “wear and tear” of the joint causes loss of the cushioning cartilage, leading to pain with movement. Shoulder arthritis is somewhat less common than arthritis of weight bearing joints, such as the hip or knee.
