The rotator cuff include the supraspinatus muscle/tendon, infraspinatus muscle/tendon, teres muscles/tendon, and the subscapularis muscle/tendon. The supraspinatus is most often the muscle that causes pain. Ths is because of wear and tear that causes degeneration due to its close anatomical relationship with the acromian process. The small space between the humeral head and the acromian process houses the supraspinatus tendon, subacromial bursa and biceps tendon. If anything reduces that subacromial space, then the chances of something being pinched and worn down increases greatly.
I have seen an increase in patients with shoulder impingment syndrome. There are many causes of the impingement: 1) can be from an osteophyte (spurs or bone growth) growing down from the underside of the acromian; 2) previous shoulder trauma that either disrupts the stabilising mechanism of the shoulder joint (as in shoulder dislocation) or 3) from a past injury or poor posture that causes a change in the firing patterns of the stabilising rotator cuff muscles that allow the humeral head to bounce around or shear too much within the ‘socket’ and this increases the chance for impingement. By far the most common cause of rotator cuff problems is altered scapula position due to muscle tightness or poor muscle firing. This can influence the position of the acromian as the arm is lifted above the head. The key muscle to influence a poor scapula position is the pec minor. This muscle causes the scapula to sit in a downwardly rotated position at rest, bringing the acromian process closer to the humeral head.
The way I treat this problem is by teaching clients the proper exercises to influence the firing patterns of the dynamic stabilisers of the shoulder – the rotator cuff. For example the simplest way to activate a subscapularis muscle is grab a 1-2 kg dumbbell and lie on the floor on your back. Place the arm up into 90 degrees abduction so the elbow supports the arm on the floor and the hand holding the weight is directly over the elbow. Slowly lower the dumbbell towards the floor moving towards the head (this is eccentric external rotation – controlled by subscapularis). Only lower to about 45 degrees and then return to the start (concentric internal rotation – again subscapularis). As an activation drill this can be done with a light weight and non fatiguing repetitions.
The easiest way to loosen an infraspinatus is to self massage it. Stand against a wall, place the hand behind the head and with the other hand, reach around and place a tennis ball in the back of the shoulder (between the shoulder blade and the wall). If it hurts then press on it. Hold the trigger point for about 1 minute and then move on to a different spot.
Furthermore, the pec minor and levator scapulae need to be loosened and stretched. And the muscles which work to upwardly rotate the scapula need to be strengthened (the trapezius and the serratus anterior).
I always recommend the foam roll to improve poor thoracic spine mobilty and extension. Lack of motion in the thoracic spine influences the scapula. I have also used the warm laser on most of these cases with very good results.