SCAPULAR ROLE
· To provide STABILITY and MOBILITY at the glenohumeral joint (where the scapula / shoulder blade meets the humerus / arm bone)
· To transfer loads between the torso and the upper limbs and vice versa
· ‘Proper’ alignment produces ideal length-tension relationships for upper limb muscle function (NB: asymmetry or variations in alignment does not necessarily mean there is pain or pathology!)
Stability is dependent on 3 subsystems:
1. PASSIVE
Intrinsic stabilisers deep within the joint that include the capsule, labrum and ligaments
2. ACTIVE
Muscles of the rotator cuff, and other extrinsic muscles such as deltoids, serratus anterior, lats, levator scapula
3. MOTOR CONTROL
Neural, physical and behavioural aspects that underline human movement during a motor task
Muscles do not act in isolation! The shoulder relies on force coupling of surrounding muscles for stabilising and positioning, which is integrated by motor patterns.