[Medical Q&A] What are the symptoms if the "sleeve" of the shoulder is damaged?

Planner: Chinese Medical Association

Reviewer: Shao Zengwu, Chief Physician and Professor of Union Hospital affiliated to Tongji Medical College, Huazhong University of Science and Technology

The rotator cuff is a group of sleeve-like structures composed of the tendons of the supraspinatus, infraspinatus, subscapularis and teres minor wrapped around the front, top and back of the humeral head. Partial or full-thickness tearing of the rotator cuff tissue caused by trauma, chronic impact wear, degeneration and other factors is collectively referred to as rotator cuff injury. It is more common in middle-aged people over 40 years old, heavy manual laborers and those who have been engaged in sports that mainly rely on upper limb strength for a long time.

Common symptoms are shoulder pain and weakness. Pain often occurs on the side and front of the upper arm and shoulder. Tenderness is mostly located at the greater tuberosity of the humerus or under the acromion. Patients often avoid using the affected arm due to pain, which further aggravates shoulder weakness, stiffness and even muscle atrophy. The pain worsens during daily activities such as combing hair and raising the arm above the head, and may even be impossible to complete. Night pain is common, and patients often have difficulty falling asleep due to pain on the affected side, or suddenly wake up during sleep, which seriously affects their quality of life. Patients with rotator cuff injuries usually have obvious active motion limitations, with shoulder abduction and forward ranges both <45°, but the passive range of motion may not be significantly limited. If combined with periarthritis of the shoulder, both active and passive motions are limited, which is not uncommon in clinical practice. There are also a few patients with complete rotator cuff tears, whose functional limitations and pain levels are not obvious, only weakness. Typical signs include positive arm drop test, positive shoulder impact test, positive pain arc, etc., and friction in the joint during active or passive movement of the glenohumeral joint.