The gleno-humeral joint (made up of the upper arm & shoulder socket) is the most mobile joint in the body. There are less bony constrictions around this joint compared with our other joints which allows for a larger range of movement but reduced stability. The stability is provided by various ligaments around the shoulder but principally by muscles along with the shoulder blade (scapula) that provides a base of support.
The muscles around the shoulder can be categorised into type depending on their role & position in relation to the joint.
Local Stabilisers are closest to the joint & provide feedback about the position of the joint & range of movement. Dysfunction of these muscles can be caused by pain or high load, too much or too little recruitment in a movement or delayed timing. To retrain these muscles you can challenge the balance, use low load closed kinetic chain exercises (where the hand is in a fixed space & cannot move i.e. in contact with the ground), or small range of movement exercises which are pain free. Examples of these muscles are the rotator cuff group.
Global Stabilisers are postural muscles which control the joint throughout the range of movement especially the inner & outer ranges & generate forces to control this range of movement. Dysfunction of these muscles causes lack of control of the movement of the joint, decreased force & potentially shaking when performing an exercise or movement. Again training for these muscles should involve closed kinetic chain exercises, low loads & proprioceptive (balance challenge). This can involve the use of props such as a BOSU or Swiss ball. Examples of these muscles are the deltoid group & the upper/middle trapezius.
Global Mobilisers normally span more than one joint (for example the biceps which works over the shoulder & elbow joints), are the prime mover muscles & produce rapid force. Tightness & over-activity (such as spasm) can cause issues with these muscles.To train these we need to use high speed & force, co-ordination & open kinetic chain (where the hand is free to move) exercises. Examples of these muscles are the biceps & pec major.
All of these muscles need to work together efficiently in order to perform movement pain free. Both Pilates & Sports Therapy sessions can help to maintain or improve flexibility, strength, balance of the muscles in relation to each other & general fitness. They can also rehabilitate you to normal daily or sporting activities & assess & correct any causative factors to decrease the likelihood of reccurrence of injury or reduced function.