Supraspinatus tendonitis sometimes referred to as "Shoulder Impingement Syndrome" or "Painful Arc Syndrome," is a common shoulder condition.
One in five persons has symptoms of shoulder impingement syndrome, making it the most widespread issue.
Supraspinatus symptoms might develop gradually over years or appear unexpectedly after an injury with no apparent explanation.
When the arm is moved between 60 and 120 degrees of abduction, the tendon is compressed against the bone, which is the typical symptom of supraspinatus tendonitis.
Painful arc syndrome symptoms often appear in middle life, most often between the ages of 45 and 65.
Supraspinatus tendonitis is often an overuse ailment brought on by constant friction on the tendon, however, it may also be brought on by a shoulder injury, instability, or impingement.
What Is Going On?
Shoulder discomfort is often brought on by supraspinatus tendonitis. The shoulder joint is made up of a ball and socket.
- the rounded tip of the upper arm bone known as the head of the humerus
- The shallow socket on the lateral angle of the scapula is called the Glenoid Fossa (shoulder blade).
The shoulder is the body's most flexible joint. The bone structure of most joints provides stability, but the shoulder trades mobility for bony rigidity.
Consider how much more mobility you have in your arms compared to your legs. But because of its enormous range of motion, the shoulder is far more vulnerable to damage.
The primary dynamic stabilizing muscles of the shoulder are the supraspinatus,1infraspinatus, teres minor, and subscapularis, which together make up the rotator cuff.
The acromion process, a bony protrusion at the top of the scapula that articulates with the clavicle, or collarbone, creates an arch above the head of the humerus, where the rotator cuff muscles and tendons connect.
Across the top of the shoulder blade is the supraspinatus muscle. The "subacromial space" a tiny passageway between the acromion and the head of the humerus is where the supraspinatus tendon travels.
The subacromial compartment is just 7–14 mm deep and is densely populated with the following:
- Spratus Spinatus Tendon
- A fluid-filled sac called the subacromial bursa helps the subacromial region move more smoothly.
- Joint Capsule: the top portion of the joint-encircling sac
- Long Biceps Head tendons of the thumb
When the arm is elevated to around shoulder height, especially when internally rotated, the subacromial space narrows significantly (thumb pointing down).
When the arm is elevated higher and turned externally, the gap then reopens (thumb pointing up).
What Causes Supraspinatus Tendonitis?
When the supraspinatus tendon is constantly rubbed against or "impeded" in the subacromial region, it may cause tendonitis.
As a result, the tendon becomes inflamed and gradually degenerates. Over time, rips might also form in the supraspinatus tendon, which could eventually result in a partial or full rotator cuff rupture.
Common causes of painful arc syndrome include:
Activities that need you to elevate your arm repeatedly, such as tennis and swimming, as well as gardening tasks like pruning or clipping hedges, are referred to as repetitive overhead activities.
Heavy lifting that must be done repeatedly, such as by labourers and builders
Posture: protracted forward slouching narrows the subacromial space.
Hereditary link: a genetic propensity
Injury, such as falling on a hand that is extended
Age: Due to wear and tear, the subacromial space tends to get smaller with time.
Bone spurs or an abnormally positioned or shaped acromion cause primary shoulder impingement, which narrows the subacromial space.
Dynamic shoulder instability causes friction due to weak rotator cuff muscles, which in turn causes secondary shoulder impingement.
Symptoms of Painful Arc Syndrome
Although mild supraspinatus tendonitis often goes unreported, discomfort in the shoulder and upper arm is usually what prompts individuals to seek medical attention.
Initially, only repeated or prolonged overhead or reaching actions cause supraspinatus discomfort. As the illness worsens over time, the function may start to be limited by weakness, stiffness, and shoulder and arm discomfort during rest.
Supraspinatus tendonitis symptoms may come on:
Suddenly: after a shoulder injury
Gradually: over time with no obvious or specific cause.
Shoulder Pain: A sharp, stabbing pain at the top and front of the shoulder and the outside of the arm that sometimes radiates to the elbow. Another potential symptom is a sudden, catching pain while twisting, reaching up or moving the arm out to the side.
Supraspinatus Tendonitis, also known as Painful Arc Syndrome, often manifests as a painful arc of movement during shoulder abduction.
Painful Arc: When raising the arm out to the side, a painful arc that generally extends between 80 and 120 degrees of shoulder abduction may be felt.
Outside of this range, movement often occurs pain-free. Movement in this range, including raising up and lowering down, is generally quite painful.
The term "Painful Arc Syndrome" refers to this characteristic supraspinatus tendonitis symptom.
Arm and Shoulder Weakness: A full-thickness rotator cuff tear, also known as a supraspinatus tendon full-thickness tear, is indicated by significant arm and shoulder weakness or by weakness without pain.
Functional Restriction: Reaching up to a cabinet, hanging laundry, and washing/brushing your hair at or above shoulder height may be unpleasant and limiting.
Sleep Disturbance: Supraspinatus tendinitis often causes sleep disturbances, particularly while sleeping on the afflicted side.
Full PROM: As long as there are no accompanying 2shoulder impingement issues, pure supraspinatus tendonitis usually results in full or almost full passive movement (where the arm is moved by someone else while your muscles are entirely relaxed). Pain may restrict active shoulder movement.
Diagnosing Supraspinatus Injuries
Your doctor or physical therapist can often determine whether you have supraspinatus tendonitis by asking you about your symptoms and looking at your shoulder.
You could also be given an MRI or ultrasound if a partial or full-thickness tear of the supraspinatus tendon is thought to be present.
Hawkins Kennedy Test
Steven Kennedy Test position: supported arm with 90-degree flexion at the shoulder and elbow
Test: Pushing the forearm downward causes the shoulder to internally rotate. Repeat the test while moving the arm into various body adduction positions.
Positive outcome: Shoulder pain
Jobe's Test or Empty Can Test
Thumbs pointed upward, both arms elevated 90 degrees abducted and 30 degrees flexed forward.
To test, turn your arms so that your thumbs are facing downward. The patient opposes the movement when the examiner presses down through the forearms.
Positive outcome: Shoulder pain
In the event that none of these tests reveals any discomfort, supraspinatus tendonitis is probably not the issue.
Conclusion:
Supraspinatus tendonitis is characterised by two of the most common symptoms: a painful arc with shoulder abduction and soreness when you push on the tendon.
Check out the shoulder pain diagnostic section for assistance determining the cause of your shoulder discomfort if you don't have these symptoms since it's likely not supraspinatus tendonitis.
Additional resources and citations
- 1infraspinatus
- 2shoulder impingement