Common sporting shoulder injuries include dislocations, Acromioclavicular joint injuries, rotator cuff injuries, labral tears, thrower’s shoulder, biceps injuries, bursitis and fractures. Contact sports such as Rugby, AFL, Wrestling, Ice Hockey, Hockey and boxing to name a few, have a higher rate of dislocations and ACJ injuries. Rotator cuff tears and bicep lesions are more common in sports involving explosive heavy weight lifting or lifting weights above the head, laying sports requiring the arm to be moved over the head repeatedly as in tennis, baseball (particularly pitching), swimming and working with the arm overhead for many hours. . Fractures around the shoulder are seen with sports involving crashes and falls from heights. This article will highlight injuries to the rotator cuff muscles; how they are caused, diagnosed and what we can do for treatment and prevention.
The rotator cuff
Muscles involved
Infraspinatus, Teres Minor, Subscapularis and Supraspinatus
Muscular function:
The rotator cuff muscles balance the forces of the deltoids which act to raise the arm and in doing so forces the humeral head superiourly towards the acromion and coracoacromial arch. The rotator cuff muscles (especially supraspinatrus) counteract this action by preventing or limiting the head of the humerus moving superiourly when the arm is raised, which if not prevented will cause impingement of the subacromial structures.
Supraspinatus
Acts with deltoid to abduct the arms, assists in stabilising the shoulder joint and resisiting downward dislocation. It also assists in holding the head of the humerus in the glnoid fossa.
Infraspinatus and Teres Minor
These muscles outwardly rotate the head of humerus, they depress the head of humerus 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
Stabilisers the glenohumeral joint especially in preventing dislocation during forced lateral rotation of the abducted arm.
Rotator cuff strains:
The most injured rotator cuff muscle is the supraspinatus. Strains or tearing of the rotator cuff may be caused by overuse, falling on an out stretched arm and violent fast arm motions. E.g. Baseball pitching and outfield throwing.
Supraspinatus
Symptoms
Pain or weakness on resisted arm abduction
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
Infraspintus and Teres Minor
Symptoms
Pain and or weakness performing resisted outward rotation of the humerus compared to the non injured side. Also possibly resisted shoulder retraction and depression
Subscapularis
Symptoms
Pain and/or weakness performing resisted inward rotation of the humerus compared to the non injured side
Exercise rehab for the rotator cuff
Prior to commencing rotator cuff rehab, the scapula stabiliser muscles should be strengthened first then the rotator cuff.
Scapular stabilisation
Good scapula 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.
Exercises such as:
Single handed row over a bench
Wall push ups
Push ups
Behind the head lat-pull downs
Note: Hold the scapula in a retracted position during the action
- Consider NSAIDS, ultrasound, R.I.C.E where appropriate
- Light weights are required as these muscles are small
- Technique modifications
Stretching
- Incy wincy spider
- Codmans pendulum (small-larger circles)
- Posterior capsule
- Overhead towel side to side and shoulder depression hands behind hips
Infraspinatus/Teres minor
Stretching
- Horizontal arm flexion and adduction with gentle force
Subscapularis
- Focus on internal rotation (similar to infra and teres minor)
Prevention
All stretches and exercises should be incorporated into the training programme you have especially within the warm up to prevent injury and to maintain the rotator cuff in a healthy and fully functioning condition.
Biceps tendinosis
This injury is primarily caused by force being applied during repeated arm abduction movements. Take swimming for example, this injury can occur when the swimmer is using an excessively wide arm pull that results in medial rotation of the humerus as force is applied during the pull phase of the arm-stroke. This action results in the long head of the biceps tendon rubbing against the lateral side of the bicepital groove causing frictional stress on the tendon, abrading, inflammation and pain.
Poor technique in conjunction with repetitive action is the primary cause
Stretching
Arm in an adducted position elbow extension with shoulder hyperextension to gently stretch biceps tendon
Technique correction
Repeated incorrect technique will only result in re-occurence of the injury despite repeated treatment
