Supraspinatus tendinosis is a common shoulder condition that often causes significant pain and limits arm movement. It frequently affects the rotator cuff, the group of muscles and tendons responsible for shoulder stability and range of motion. Understanding the nature, causes, and management strategies of this tendon problem is the first step toward recovery and restoring full shoulder function.
The Supraspinatus Tendon and Tendinosis Explained
The supraspinatus tendon is located at the top of the shoulder joint, connecting the supraspinatus muscle (on the shoulder blade) to the upper arm bone (humerus). It is part of the rotator cuff, which stabilizes the shoulder and allows for arm rotation. The primary function of the supraspinatus is to initiate lifting the arm away from the body, a movement known as abduction.
The term tendinosis describes chronic degeneration within the tendon tissue, involving the breakdown of collagen fibers. Unlike tendinitis, which implies acute inflammation, tendinosis is characterized by a failed healing response and disorganization of the tendon’s structure with little active inflammation present. This degenerative change occurs when tissue breakdown exceeds the body’s ability to repair the tendon. This imbalance weakens the tendon, making it susceptible to pain and further damage, and potentially leading to a rotator cuff tear.
Common Causes and Risk Factors
Supraspinatus tendinosis is often linked to the cumulative effects of repetitive mechanical stress on the tendon. Activities requiring the arm to be used repeatedly at or above shoulder height are a primary cause. This is frequently seen in athletes who play overhead sports (like tennis or swimming) or in occupations such as painting or carpentry. These repeated motions lead to micro-trauma, which, sustained without adequate recovery time, results in chronic tendon degeneration.
Age is a significant risk factor because tendons naturally lose strength and elasticity over time, making them more vulnerable to wear and tear, especially after age 40. Poor posture also contributes by causing the shoulder blade to slump forward, narrowing the space where the supraspinatus tendon passes. This mechanical compression, known as chronic impingement syndrome, irritates the tendon and accelerates the degenerative process. Systemic factors, such as diabetes, also increase susceptibility to this type of tendon issue.
Identifying the Symptoms
A person with supraspinatus tendinosis typically experiences a deep, aching pain within the shoulder joint. This discomfort often begins mildly and worsens progressively over weeks or months, sometimes radiating down the side of the arm toward the elbow. Pain is most noticeable during movement, particularly when lifting the arm out to the side or performing activities overhead.
Simple daily tasks become difficult, such as reaching across the body to put on a seatbelt or reaching behind the back to fasten clothing. Pain that disrupts sleep is another symptom, especially when lying directly on the affected shoulder. Although the tendon is degenerated, the shoulder usually retains a full passive range of motion, but moving against resistance provokes a sharp increase in pain.
Diagnosis and Treatment Approaches
A medical professional begins the diagnostic process by taking a detailed patient history and performing a focused physical examination of the shoulder. This includes specific tests to assess the strength of the rotator cuff muscles and determine the range of motion, often looking for a painful arc when the arm is lifted between 80 and 120 degrees. Specialized maneuvers, such as the “empty can test,” help isolate the supraspinatus tendon to confirm tenderness and weakness.
Imaging Studies
Imaging studies are utilized to confirm the diagnosis and rule out other conditions. X-rays can show bone spurs or structural abnormalities that may contribute to impingement, but they do not image soft tissues well. An ultrasound or Magnetic Resonance Imaging (MRI) scan is more effective for visualizing the tendon itself, revealing the extent of degeneration or confirming the presence of a partial or full tear.
Treatment for supraspinatus tendinosis is overwhelmingly conservative, focusing on reducing pain and restoring function. The initial approach involves rest and modification of activities that aggravate the tendon. Over-the-counter anti-inflammatory medications may be used to manage discomfort, though their role is primarily for pain relief rather than addressing chronic tendinosis.
Physical Therapy and Injections
Physical therapy is considered the cornerstone of effective rehabilitation, aiming to strengthen the rotator cuff muscles, improve shoulder mechanics, and correct muscle imbalances. A therapist designs a progressive program that includes exercises to stabilize the scapula and strengthen surrounding muscles, which helps to unload the compromised tendon. For persistent symptoms, a corticosteroid injection may provide short-term pain relief, but they are used sparingly due to potential adverse effects on tendon health. Surgery is reserved for severe cases that fail to improve after a dedicated course of conservative treatment, typically three to six months, especially if a significant tear is present.