Supraspinatus tendinitis is often associated with Subacromial Impingement Syndrome6, Shoulder Impingement Syndrome3, or Rotator Cuff Tendinitis4. Inflammation of the tendon of the supraspinatus muscle leads to supraspinatus tendinitis. This is the most common cause of shoulder pain7.
There are four bones that make up the shoulder girdle: the humerus, clavicule, scapula, and sternum. These bones articulate as 4 functional joints: the scapulothoracic joint (ST joint), the glenohumeral joint (GH joint), the sternoclavicular joint (SC joint), and the acromioclavicular joint (AC joint).
Movements that occur at these joints are:
1. ST joint – elevation, depression, retraction, protraction, upward rotation, and downward rotation.
2. GH joint – flexion, extension, adduction, abduction, external rotation, and internal rotation.
3. SC joint - elevation, depression, retraction, protraction, and rotation.
4. AC joint – axial rotation and angulation.
The supraspinatus, infraspinatus, teres minor and subscapularis muscles comprise the rotator cuff muscle group. The main role of these muscles is stabilization of the humeral head in the glenoid fossa. Tendons of teres minor, supraspinatus, and infraspinatus insert on the greater tuberosity of the humerus, and subscapularis tendon inserts on lesser humeral tuberosity. Actions of these muscles are internal rotation (subscapularis), external rotation (teres minor and infraspinatus) and early abduction from 0˚ to 30˚ (supraspinatus)7. The subacromial bursa lies between supraspinatus tendon and the acromion.
Supraspinatus tendonitis can be caused by extrinsic and intrinsic factors. Extrinsic factors are divided into primary and secondary impingement. Increased subacromial loading, overhead activities, or trauma can cause primary impingement. Rotator cuff overload and muscle imbalance can cause secondary impingement. Supraspinatus tendonitis can also occur because of the decrease in the supraspinatus outlet space due to underlying instability of the glenohumeral joint3.
The supraspinatus outlet is a space formed by the acromion, acromioclavicular joint, and coracoacromial arch. The supraspinatus tendon runs through this outlet2. Any abnormalities of this outlet can cause impingement of the supraspinatus tendon.
In patients younger than 40 years of age, Supraspinatus Tendinitis occurs usually due to glenohumeral instability, acromioclavicular joint disease, or trauma. Patients older than 40 years of age, experience Supraspinatus Tendinitis mostly due to degenerative joint disease, glenohumeral impingement syndrome, or rotator cuff disease2. Most at risk for Supraspinatus Tendinitis are people whose job requires repetitive overhead motions and athletes who compete in sorts such as swimming, throwing sports, volleyball etc3.
Patients with Supraspinatus Tendinitis present with shoulder pain with movement and pain at night. They will also show weakness in the shoulder and arm. There is also possibility of tenderness and swelling in the upper front part of the shoulder and in some severe cases, difficulty to raise the arm to shoulder level4. Positive Neer’s, Hawkins-Kennedy, and Empty Can Test indicate Supraspinatus Tendinitis2.
Patients also present with painful arc between 60o and 120o of shoulder abduction.
The impingement syndrome is the most common cause of supraspinatus tendinitis. Weakness and dysfunction of the rotator cuff muscles leads to elevation of the humeral head during arm abduction which causes compression of the tissues under the acromion process. Edema and hemorrhage of the supraspinatus tendon occur which can eventually lead to the tendon degeneration and rupture5. Other causes of supraspinatus tendinitis include calcific tendinitis, trauma, crystal deposition, infection, or autoimmune conditions7.
X-rays of the shoulder can show calcifications in supraspinatus tendon, degenerative changes of the greater tuberosity, and decreased distance between head of the humerus and acromion process7. Another way quickly and easily diagnose the supraspinatus tendon disruption is ultrasonography 2. Magnetic resonance imaging (MRI) produces detailed soft-tissue images and it is most useful in determination of shoulder pathologies7. Arthroscopy is a surgical procedure in which a small fiberoptic tube is inserted into the shoulder for visual assessment of the joint4.
Evaluation/Special Orthopedic Tests
Neer’s, Hawkins-Kennedy, and Empty Can Test are used to determine if patient has Supraspinatus Tendinitis2.
Neer’s Test is performed with patient seated. Physical therapist passively elevates patients arm and then medially rotates the arm. Pain indicates a positive sign.
Hawkins-Kennedy Test is also performed with patient in seated position. Therapist passively moves patients arm to 90o of shoulder flexion and 90o of elbow flexion. Arm is the medially rotated and moved in different angles of flexion or horizontal abduction. Pain indicates a positive sign.
Empty Can Test is performed with patient seated. Arms are abducted to 90o, internally rotated, thumbs are pointed down, and arms are moved about 30o forward. Therapist then applies resistance to abduction. Weakness or pain is positive sign.
There are three phases during the treatment of Supraspinatus Tendinitis: Acute, Recovery, and Maintenance phase2.
Goals of this phase are to decrease and inflammation, increase pain free ROM, and stop Supraspinatus muscle atrophy. During this phase patient should eliminate any overhead activities and activities that cause an increase in sympthoms1. During this phase Codman’s pendulum exercises and active assisted ROM exercises should be done for increase in ROM7. Mobilizations of glenohumeral joint have showed to be successful in decreasing the pain and increasing ROM in patients with Supraspinatus Tendinitis6. These mobilizations include inferior, anterior, and posterior glides. Isometric exercises for strengthening rotator cuff muscles should be introduced in this phase2. Nonsteroidal anti-inflammatory drugs (NSAIDs) could help in reducing the pain for mild to moderate symptoms and in severe cases local subacromial corticosteroid injection might be given to decrease pain7. In addition, modalities such as cryotherapy and electrical nerve stimulation can be used.
Goals of recovery phase are to achieve normal ROM, improve muscle strength and neuromuscular control, and achieve normal shoulder arthrokinematics. ROM exercises should be done actively and in all planes of motion3. Strengthening should include isotonic resistance exercises (external, internal rotations, extension, flexion, abduction, and stabilizing exercises for the scapula). In this phase patient should reach full ROM and 70% strength compared to uninvolved side. Patients should return to their regular activity level, ADLs, and their occupation. If the patient is an athlete, during this phase treatment should also focus on sport specific exercises, plyometric exercises, PNF, and isokinetic exercises2. Get athletes back to their sport.
Goal of this phase is to maintain full ROM, strength, and prevent recurrence of the injury. During this phase exercises should increase in time (focus on muscle endurance)2. Proper arthrokinematics should be emphasized and patient should regularly perform home exercises program which includes strengthening and stretching. Patient should be educated on understanding early signs of Supraspinatus Tendinitis2.
Surgery and Post-op Treatment
If the patient doesn’t show any improvement and stays significantly disabled after 6 months of conservative treatment then patient can be referred for surgical evaluation2. 90% of patients with Supraspinatus Tendinitis show improvement and get better with conservative treatment because of this surgery for this condition is very rare3. In rare cases arthroscopic surgery may be necessary to make more room for the Supraspinatus tendon. During this procedure, surgeon removes the coracoacromial ligament, trim off calcifications of the acromion and excise the nearby bursa. It is possible that there can be a small tear in the tendon, which can be repaired during this procedure5. During this surgery, between 2 and 4 small incisions are made at the shoulder joint. One incision is used for instruments, other for camera, and the rest of them are used to enable fluid drainage. During arthroscopy, sterile fluid is pumped into the shoulder to keep the joint free of debris and large enough so the camera and instruments can fit5. After the surgery, the patient is placed in a sling.
After the surgery, treatment should start with active and passive ROM exercises as soon as possible. After the decrease of pain and increase of ROM patient should start with strengthening program which is the same as for conservative treatment. Patients are advised not to start with their sport until they have full active ROM and normal strength in operated shoulder. This generally takes around 3 to 4 months2.
Additional Web Based Resources
1. Benjamin B. Shoulder series #2: Supraspinatus Tendinitis. Massage & Bodywork. June/July 2004.
2. Chang W. Shoulder impingement syndrome. Physical Medicine and Rehabilitation Clinics of North America. 15 (2004) 493–510.
3. DeBerardino T. Supraspinatus Tendinitis. Medscape. January 2010.
4. McLaughlin E. Supraspinatus Tendinitis: Rotator Cuff Tendinitis. Medicine on Line. http://www.medicineonline.com/articles/s/2/supraspinatus-tendinitis/rotator-cuff-tendinitis.html
5. Neer C. Anterior acromioplasty for the chronic impingement syndrome in the shoulder. The Journal of Bone and Joint Surgery. 1972; 54(1):41-50.
6. Senbursa G, Baltaci G, Atay A. The effectiveness of manual therapy in supraspinatus tendinopathy. ACTA Orthopaedica et Traumatologica Turcica. 2011;45(3):162-167.
7. Starr M, Kang H. Recognition and management of common forms tendinitis and bursitis. The Canadian Journal of CME. 2001; 155-163.