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Shoulder Instability & Dislocation – The difference
With an amazing range of motion, the shoulder is the most mobile joint in your body. There is a constant necessity for the shoulder joint to maintain a balancing act between mobility and stability. When this balancing act goes wrong, in both directions the shoulders begin to lose their mobility and turns stiff. The shoulder joint is a ball-and-socket joint in which the humerus bone fits into a cup-shaped glenoid socket of the shoulder blade. When it is not possible to maintain the humeral head within the centre of the glenoid when the arm is being mobilized, it can lead to shoulder instability.
With a shoulder instability condition the shoulder may dislocate repeatedly during active movement or exercise. When the joint moves more than it should do normally without coming out of the joint then this could mean shoulder hypermobility. In a shoulder instability condition the muscles, ligaments, tendons that surround the shoulder joint also loosen up adding to the inability of keeping the ball in the socket. This is often confused with shoulder dislocation. An unstable shoulder can cause it to dislocate. During dislocation, unlike in shoulder instability there will be complete separation of the ball of the shoulder which is the humerus from the glenoid socket. Shoulder dislocation can hence happen multiple times and especially during activities like lifting, reaching up and back, swimming, or moving the arm suddenly.
The shoulder is the most frequently dislocated major joint in the body. In a shoulder dislocation the muscles, ligaments or shoulder capsule gets torn and damage can happen to the labrum or the bony socket too. When the dislocation of the shoulder joint is partial or temporary then it is termed as Subluxation. When an unstable shoulder gives a feeling of instability without any actual physical separation of the joint it is called Apprehension.
A shoulder dislocation often happens because of injury or trauma from an accident or fall. If the initial dislocation is quite severe then this can lead to chronic instability which consequently means continued dislocations. A shoulder instability is a possibility if there has been a prior shoulder dislocation, or in the case of athletes involved in sports such as volleyball, swimming that involve overhead motions, or if the person has certain connective tissue disorders that contribute to joint laxity, or double-jointedness when the joints seem loose.
There are two major types of dislocation. The most common type of dislocation is forward and downward dislocation. This happens as a result of falling on an outstretched hand or on the shoulder itself. Backward dislocation is be caused by a blow to the front of the shoulder, or if the upper arm is violently twisted. Whereas in the case of shoulder instability the two basic forms are dislocation and subluxation. Once a shoulder gets dislocated the shoulder joint may become unstable proving to be at a higher risk of repeated dislocations. Atraumatic shoulder instability is a condition that is usually related to a genetic predisposition.
For enquiry related to Shoulder Injuries, Sports Injuries and their treatment options, send a message to www.BangaloreShoulderInstitute.com/contact
Visit the youtube channel to watch videos by Dr Ayyappan V Nair on different shoulder, sports and other orthopaedic conditions and their treatment options – https://www.youtube.com/channel/UCJldz_Osg88qFYM99IEsjew
