As explained in the video (02:50), shoulder problems are also closely affected by the core/body type. Please refer to the following for a detailed description of each condition.

1. Shoulder impingement / Rotator cuff lesions / Bursitis

Shoulder impingement refers to a phenomenon where the tendon of rotator cuff and/or bursa gets pinched between the acromion and humerus. This normally occurs when lifting the arm above 90 degrees and can cause inflammation to the RC or bursa, which are called 'rotator cuff tendonitis' or 'bursitis' respectively.

The most commonly affected muscle is the Supraspinatus and according to one study, many degenerative changes were observed on the underside of the supraspinatus tendon and not so much on the upper side. These changes are mainly due to scratches caused by the rough side of the upper arm bone and can be considered as scars through inflammatory reactions.

This means that impingement might not be the main issue. If it was impingement, degenerative changes might have been seen more on the upper surface of the supraspinatus tendon because that would be the area that actually collides with the acromion.

Therefore, the friction between the lower surface of the tendon and the bone itself is the real problem that we have to address. When the supraspinatus muscle gets tight, the attachment (tendon) is pulled, causing friction with the bone that touches the under surface of the tendon.

2. SLAP lesion

As shown in the image above, when the rotator cuff muscles become tight, the upper arm bone (Humerus) gets pulled towards the shoulder bone (Scapula). Then, the labrum between them can be compressed and possibly damaged. If any of the rotator cuffs (expressed in four colors in image above) get too tight or weak, the balance of the force will be shifted towards one side and the humerus will also be pulled towards that side. As a result, friction between the humerus and labrum worsen. In addition, if the biceps muscle tightens due to postural imbalance or possible overloading, it will pull the labrum down and forward as the biceps tendon is attached to the labrum. This will also increase the risk of developing SLAP lesions.

Eccentric exercises in this program will train the aforementioned muscles to elongate while holding the humerus stably in the center of the joint (Figure below). As you can see, the root cause of all major shoulder pain is related to the tightness in the surrounding muscles such as the biceps and rotator cuffs. Therefore, developing their capacity to control the humerus eccentrically is the key element in shoulder recovery. However at the same time, the workouts in this routine will not only address the shoulders but rather train the entire body holistically (breathing/core/body balance).