Shoulder discomfort is common, and the supraspinatus muscle often contributes to it. Understanding where pain from this muscle is typically felt provides valuable insight into the source of shoulder discomfort.
The Supraspinatus Muscle: Location and Role
The supraspinatus is a muscle located deep within the shoulder, nestled in the supraspinous fossa of the scapula. Its tendon passes under the acromion, a bony projection from the scapula, before attaching to the greater tubercle of the humerus. This muscle is one of the four muscles that comprise the rotator cuff, a group important for shoulder stability and movement.
The supraspinatus primarily initiates arm abduction (outward lifting) for the first 0 to 15 degrees of movement. Beyond this initial range, it works with the deltoid muscle to continue lifting the arm. It also plays an important role in stabilizing the glenohumeral joint by keeping the head of the humerus pressed firmly against the glenoid cavity of the scapula.
Direct Pain Location
When the supraspinatus muscle or its tendon is the source of discomfort, direct pain is most commonly felt in the top and outer shoulder. This sensation often localizes directly over the deltoid muscle. The area just below the acromion and over the greater tuberosity of the humerus can also be particularly tender to the touch. This tenderness results from inflammation or irritation of the supraspinatus tendon as it passes through a narrow space in the shoulder.
Referred Pain Patterns
Pain originating from the supraspinatus can extend beyond its immediate location, known as referred pain. This discomfort often radiates down the lateral (outer) aspect of the upper arm. The pain may even reach towards the elbow and into the forearm.
This referred pain is typically described as a dull ache rather than a sharp, tingling, or numb sensation, which helps differentiate it from nerve-related pain. It is a common pattern for muscle-related pain to be felt in areas distant from the actual muscle tissue involved. Identifying these referral patterns is important for accurately pinpointing the supraspinatus as the source of shoulder and arm discomfort.
Understanding the Pain: Characteristics and Triggers
Supraspinatus pain is often characterized as a persistent, dull ache in the shoulder region. However, it can become sharp with specific movements, particularly those involving lifting the arm. Activities that strain the shoulder, such as reaching overhead, reaching behind the back, or repetitive arm movements, commonly aggravate the pain.
Sleeping on the affected side can intensify discomfort, often disrupting sleep. Individuals may also experience weakness when attempting to lift their arm or perform certain motions. Clicking, grinding, or popping sensations within the shoulder joint can accompany supraspinatus issues, indicating altered mechanics or irritation within the joint.
When to Consult a Healthcare Professional
Consult a healthcare professional if shoulder pain persists for more than a few weeks despite rest and self-care measures. Seek medical attention if the pain progressively worsens over time. Significant weakness in the arm or an inability to lift the arm should prompt a professional evaluation.
Pain that develops after a specific injury, or if severe and difficult to move or use the shoulder, warrants medical assessment. If shoulder pain is accompanied by difficulty sleeping, a healthcare provider can help determine the underlying cause and appropriate course of action.