THE ROTATOR CUFF – the stabilizer


Shoulder, is one of the most dynamic part of our body. Serving us with a lot of functions in our day-to-day life. Shoulder joint connects the arm with the axial body. The shoulder joint is an anatomical structure of our body, providing the human skeleton immense power to carry out lots and lots of functions, not only dynamically but statically as well. The muscles surrounding the shoulder joint not only functions while carrying out some action but also works at rest. There are many different structures that contributes in the formation and function of the shoulder joint. We are discussing about one of the most powerful muscles that helps the shoulder joint to play its part- “THE ROTATOR CUFF”. This muscle is like a team of four different muscles along with their tendon named as, SUPRASPINATUS, INFRASPINATUS, TERES MINOR AND SUBSCLAPULARIS, which play their individual parts in performing different movements at shoulder joint and also helps in the stabilization of the joint.
Before we start with the role of the rotator cuff as a whole let’s have a look on the location and the position of the muscles involved in the rotator cuff.

·       The SUPRASPINATUS, the muscle above the shoulder, lies in scapular plane (the upper border of the shoulder), is the location of one of the most important muscles, (origination from the supraspinous fossa and inserting in the superior facet of the greater tubercle),

·        The INFRASPINATUS (originated form the infraspinous fossa and inserting in the posterior facet of the greater tubercle),

·        The TERES MINOR (originating from the middle half of the lateral border of the scapula and inserting in the inferior facet of the greater tubercle),

·        The SUBSCAPULARIS (originating from the subscapular fossa and inserting in the lesser tubercle).



As the shoulder joint is the ball and socket joint, the rotator cuff muscle holds the ball called as the head of the humerus in the socket called as the glenoid cavity.
The 'rotator cuff' as the name suggests, rotates the shoulder joint (internal and external rotation) and enables the movement of abduction at the shoulder joint. The subscapularis and infraspinatus enables the movement of scaption i.e. the scapular plane shoulder abduction. The supraspinatus muscles play an important role in initiation of the movement of abduction at shoulder joint and provides 53% of the total strength to the cuff. The infraspinatus externally rotates the humerus and acts primarily when the arm is in neutral, the subscapularis internally rotates the humerus and the teres minor externally rotates the humerus and is more active in 90 degrees of abduction
The muscle most vulnerable to the injury is the supraspinatus muscle, the primary reason perhaps is the location of the muscle. The repetitive stress injury causes major damage to the supraspinatus muscle. Example can be given of someone carrying a bag on the shoulder. Rotator cuff muscle can also get injured by performing repeated overhead activities. The major damage caused to the rotator cuff can result in
·       Rotator cuff tear
·       Rotator cuff impingement
·       Rotator cuff tendinitis
If you are having any of the above conditions you may experience the following symptoms
ü Pain in and around the shoulder
ü Stiffness around the shoulder
ü Weakness of the muscles
ü Inability to perform movements of abduction (lifting the arm by the side) and external rotation (taking the arm outwards)
ü Arm feels heavy
ü Arm feels hanging
ü Soreness after exercise



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