The rotator cuff is located at the shoulder joint and is commonly mentioned by professionals during sports practice, but after all, what it is and how it can happen his injury?
It is a muscular group of four muscles, namely: Supra-thorny, Infra-thorny, lower Redondo and Subscapularis, whose main function is to keep the humeral head in the glenoid cavity when the humerus moves guaranteeing the stabilization of the shoulder joint (TORTORA & GRABOWSKI, 2002; HALL, 2000).
The Supra-thorny muscle prevents the upper displacement and pressing the humeral head into the Infra-thorny muscle and the lowest Redondo muscle function is to prevent from previous shifts and presses the humeral head medial way and down, and Subscapularis the muscle prevents the posterior displacement of the humeral head as well as pressing the same inside and down (CALAIS-GERMAIN, 2002).
Before it was thought that when conducting an overload by hand, the contraction of the deltoid, biceps and triceps were those who stabilized the
shoulder because of their vertical loads and kept the humeral head in the glenoid cavity. Later studies have shown that these muscles do not sketched any contraction when loading a weight.
The stabilization of the shoulder to the heavy lifting by hand is held with the horizontal rotator cuff muscles, especially the supraspinatus, infra-spinous and the lowest round.
For the upper limb performance with strength and dexterity is required to shoulder blade has a good stabilization against the trunk, this stabilization is basically done by the muscles: trapezius, rhomboids, scapula elevator and serratus anterior, these all the time are opposing the action gravity (MORELLI & VOLCANO, 1993).
As the injury occurs?
According Castiglia (2015), the lesion may result from an acute injury such as a fall or can be caused by chronic wear and tear with degeneration of the tendon. The impact with the anterior region of the shoulder blade, the acromion, is associated with rotator cuff injury in individuals over 40 years.
The author also reports that the injured subject is typical pain in the anterior shoulder that radiates to the lateral arm. May be present with the activities above shoulder level as picking up objects in the cabinet top or extend clothes on the line, or even the act of sleeping on the affected shoulder. The loss of strength and difficulties in routine activities like combing your hair or put the belt on his pants are also traditional symptoms.
If the injury occurs with trauma, you may feel a pop and immediate loss of strength.