The IYTL exercise are very effective to stabilize the shoulder joint. That means they strengthen the muscles in the back of the shoulder, preventing the shoulder from rolling forward. This leads to less compression and grinding in the joint, less inflammation and pain.
Correct or incorrect alignment has a profound impact on alignment and physical pain. The healthiest sleep positions are (1) on your back with the legs straight but relaxed, arms down; (2) on your side with the knees together