4.5 Shoulder abductor stretch
Part B. Direction and range of movement
This technique involves full shoulder adduction, full shoulder internal rotation, partial shoulder extension, partial scapular retraction and downwards rotation. Adduction of the arm behind the back is about 10 degrees but varies between individuals; ranging from 5 to 25 degrees.
During adduction there is about there is about 4 cm retraction or medial movement of the scapula along the rib cage and towards the spine. Shoulder internal rotation is about 95 degrees, while shoulder extension is about 50 degrees.
This is primarily a stretch for the shoulder abductors supraspinatus and middle deltoid. Other muscles that may be stretched include serratus anterior, teres minor and the long head of triceps brachii.
Cervical sidebending can be introduced into the technique to stretch upper trapezius, anterior, middle and posterior scalene, sternocleidomastoid and levator scapulae.
Grasp your wrist with the other hand and pull your arm down and across your back to depress the shoulder, then actively sidebend your head and cervical spine away from the side of the depressed shoulder.
This is a safe stretch that is unlikely to cause problems. This is an especially good stretch for lengthening supraspinatus, which is the muscle most commonly torn in rotator cuff injuries. By stretching supraspinatus and middle deltoid regularly this will reduce the probability of a rotator cuff strain. This is also a mild stretch for the upper part of the shoulder joint capsule and ligaments, hence may be used when there is a frozen shoulder.