In the treatment of periarthritis of the shoulder, there is a method called "arm-swinging". The main technique of arm-swinging involves swinging the shoulder joint inward, outward, forward, and backward, forming a circle with the shoulder joint. This circle is actually two circles: one from the front to the back, and another from the back to the front. The arm-swinging method should be very effective for treating periarthritis of the shoulder, but the following issues need to be noted: First, it is crucial to exclude any rotator cuff injuries, especially tears in the supraspinatus or infraspinatus muscles. If tears in the supraspinatus or infraspinatus muscles occur, the arm-swinging method is not recommended due to its "zipper effect." This refers to a small initial tear that could further enlarge through improper exercise, eventually becoming a large tear. Thus, the first point is to rule out rotator cuff injuries. Second, when performing the arm-swinging method, one should not rush and should progress gradually. Initially, the range may be very small or the movement may not be possible to perform, but with consistent and persistent practice, the range of motion will gradually increase, making arm-swinging easier. However, rushing may lead to muscle tears around the shoulder joint or tear injuries to the joint capsule. Third, although the arm-swinging method can have a beneficial effect in treating periarthritis of the shoulder, starting the exercise can be very painful. Therefore, it may be necessary to use other methods initially, such as taking non-steroidal anti-inflammatory drugs orally, or undergoing massage or physiotherapy, to relax the muscles and ligaments around the shoulder joint. This can reduce pain during the arm-swinging exercises and enhance effectiveness.