Many patients experience shoulder pain, which is often thought of as “frozen shoulder” when communicating with friends. In fact, the concept of “frozen shoulder” encompasses many diseases, some of which are treated very differently, so the concept of “frozen shoulder” has been gradually abandoned internationally. Among the many diseases that cause shoulder pain, one of the most common is rotator cuff impingement or subacromial impingement syndrome. Shoulder injuries are more common in young people, athletes and the elderly. Especially in the elderly population, there are many causes of shoulder pain. Rotator cuff impingement or subacromial impingement syndrome occurs when the rotator cuff tendons and subacromial bursa are compressed in the narrow space under the acromion, which is often referred to as “frozen shoulder” in the elderly. This results in swelling and inflammation of the rotator cuff tendons and subacromial bursa. This compression is more severe when the arm is lifted off the torso and the symptoms are most pronounced. Minor rotator cuff injuries can develop over time into rotator cuff impingement, and repetitive motion of the shoulder joint can also lead to inflammation of the subacromial bursa. As we age and develop osteoarthritis, bone spurs can form in the acromion, further narrowing the subacromial space. Rotator cuff impingement due to acromion is more common in older adults who play sports or work in an overhead position. If calcium deposits occur in one of the rostro-capital ligaments, they can also lead to spur formation. ”Treatment of subacromial impingement syndrome generally consists of conservative treatment and surgery. Conservative treatment is mainly based on medication, short wave, magnetic therapy and laser to promote local blood circulation, accelerate the absorption of exudate and promote the repair of lesioned tissues. If conservative treatment fails, minimally invasive arthroscopic surgery can be used. Therefore, it is important to pay attention to rotator cuff impingement, a condition that causes shoulder pain, and to see a specialist in a timely manner. Patients with shoulder pain should not just put the “frozen shoulder” label on themselves or others, but should actively seek professional treatment and advice from a regular hospital specialist.