Motor vehicle Mishaps: A unexpected, strong effects from the motor vehicle accident can dislocate the shoulder. Causes of Shoulder Instability / Dislocation Shoulder instability and dislocation can occur as a consequence of various causes, together with: Trauma: A sudden and forceful impact or injury on the shoulder, like a slide https://www.theorthopaedicandpainpractice.com/what-are-shoulder-joint-dislocations/?_gl=1*164kc8h*_up*MQ..&gclid=Cj0KCQjwkt6aBhDKARIsAAyeLJ2krYJSOuy5mZksrNqH-VDjQwW1ScD49yD8BUWysDG6u6bJPCSbXVUaAuCPEALw_wcB