The looseness is often a results of repetitive overhead movement when swimming and participating in tennis, for example.  This issue includes tearing the muscles or tendons while in the rotator cuff, resulting in pain and lessened arm mobility. Harm to the labrum, a cartilage ring surrounding the shoulder joint socket, https://www.theorthopaedicandpainpractice.com/what-are-shoulder-joint-dislocations/?_gl=1*164kc8h*_up*MQ..&gclid=Cj0KCQjwkt6aBhDKARIsAAyeLJ2krYJSOuy5mZksrNqH-VDjQwW1ScD49yD8BUWysDG6u6bJPCSbXVUaAuCPEALw_wcB