The rotator cuff comprises;
Supraspinatus, Infraspinatus, Teres Minor and Subscapularis.
The rotator cuff muscles balance the forces of the deltoids which act to raise the arm and in doing so forces the humeral head superiorly towards the acromion and coracoacromial arch. The rotator cuff muscles (especially supraspinatus) counteract this action by preventing or limiting the head of the humerus moving superiorly when the arm is raised, which if not prevented will cause impingement of the subacromial structures.
Supraspinatus: Acts with the deltoid to abduct the arms, assists in stabilizing the shoulder joint and resists downward dislocation. It also assists in holding the head of humerus in the glenoid fossa.
Infraspinatus and Teres Minor: These muscles outwardly rotate the head of humerus, they depress the head of humerus (with subscapularis) and prevent it from jamming against the acromion process during flexion and abduction of the arm. They also assist in prevention of dislocation of the shoulder especially when the humerus is in an abducted position.
Subscapularis: Stabilizes the glenohumeral joint especially in preventing dislocation during forced lateral rotation of the abducted arm.
Rotator cuff strains:
The supraspinatus muscle is the rotator cuff muscle most often injured. Strains or tearing of the rotator cuff may be caused by overuse, falling on an outstretched arm and violent fast arm motions.
e.g. fast throwing actions; baseball pitching, repeated outfield throwing, water polo ball throwing
- Simple tests and examinations can be taken to determine rotator cuff tendinitis, injury or weakness
Pain and/or weakness on resisted arm abduction or with “Incy wincy spider” (walking fingers up the wall).
Weakness can be indicated by the need to “hitch” the shoulder in resisted arm abduction compared to non-injured side.
Visual inspection may reveal muscle atrophy during resisted arm abduction compared to non-injured side.
Infraspinatus and Teres Minor:
Pain and or weakness performing resisted outward rotation of the humerus compared to the non-injured side. Also possibly resisted shoulder retraction and depression.
Pain and/or weakness performing resisted inward rotation of the humerus compared to the non-injured side.
Exercise rehab for the rotator cuff:
- Note Before commencing rotator cuff rehab and for successful rehab of the rotator cuff the scapular stabilizers should be strengthened first then the rotator cuff.
- Consider gradual pain free progression
Good scapular control is necessary to provide a stable base for arm movement to provide congruence with the head of humerus and correct positioning of the scapula.
- Single handed row over a bench
- Wall push-ups
- Behind the head lat-pull downs.
Note: Hold the scapula in a retracted position during the action (squeeze shoulder blades together and maintain a straight back, with shoulders back!)
- Consider adjunct treatment e.g. NSAIDS, ultrasound, RICE, intermittent pressure etc where appropriate.
- The rotator cuff muscles are small therefore only light weights are needed and good exercise form is needed
- Technique modifications
- Incy wincey spider 3 x 6 repeats
- Codman’s pendulum (small circles) 3 x 3 x30 secs
- As above but increase ROM
- Posterior capsule (but not anterior capsule) 3 x 3 x 30 sec plus as above with increased ROM
- Overhead towel side to side and shoulder depression hands behind hips, plus as above
Infraspinatus/Teres Minor Rehab;
Horizontal arm (shoulder) flexion and adduction with gentle force.
Rehab for Subscapularis:
Similar to that for Infraspinatus and Teres Minor but emphasis is on internal rotation.
Prevention and maintenance
For throwing sports and swimming some training of the rotator cuff musculature should occur daily to prevent injury and maintenance of the rotator cuff. These exercises could be included as part of the training program and more particularly as part of the warm-up.