This includes both rotator cuff tears and impingement syndrome. Fine adjustments of the humeral head within the glenoid is achieved by coordinated activity of four interrelated muscles arising from the scapula and is called rotator cuff.
|Rotator Cuff Tear|
Role of Rotator Cuffs
In the movement of abduction, supraspinatus steadies the head from above, infraspinatus depresses the head, and subscapularis steadies the head in front paralleling the action of the infraspinatus. This combined action allows the deltoid muscle to swing up the arm from a steady fulcrum irrespective of the position of the scapula.
Rotator cuff tear which is commonly associated with supraspinatus tendon. Other causes like bicipital tendonitis, and intraspinatus tendonitis, subacromial bursitis, etc. may give rise to rotator cuff problems, but they are not that common.
|Rotator Cuff Syndrome|
Causes of impingement syndrome
• Complete or partial rupture of rotator cuff.
• Supraspinatus tendonitis.
• Calcific deposits.
• Subacromial bursitis.
• Subdeltoid bursitis.
• Bicipital tenosynovitis.
|Shoulder Motion With Rotator Cuff|
Neer’s stages of impingement syndrome
Types of Impingement Syndrome
Primary: Here impingement occurs beneath the coracoacromial arch and is due to subacromial overloading.
Secondary: This is due to relative decrease in the subacromial arch and is due to microinstability of the glenohumeral joint or scapulothoracic instability.
Posterior (Internal): Seen in overhead athletes like throwers, swimmers and tennis players. Here the supra- and infraspinatus tendons are pinched between the posterior and superior aspects of the glenoid when the arm is in elevated and externally rotated position. Among the three, primary impingement is more common.