Action one
Reach out and touch the back of the head of the opposite side, such as touching the right ear with your left hand, indicating that the forward movement of the shoulder joint is unrestricted.
Action 2
Lift one arm to the side until it is directly above. If it can be done, it means that the shoulder abduction ability is no problem.
Action 3
Put your hands on your back to reach the center of the spine and the other scapula. If it can be done best, it means that there is no problem with the supination function of the shoulder.