Rotator Cuff Injury, Causes, Signs and Symptoms, Diagnosis and Treatment. 

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Chapters
0:00 Introduction
1:30 Causes of Rotator Cuff Injury
2:21 Symptoms of Rotator Cuff Injury
2:39 Diagnosis of Rotator Cuff Injury
3:26 Treatment of Rotator Cuff Injury
In anatomy, the rotator cuff is a group of muscles and their tendons that act to stabilize the shoulder and allow for its extensive range of motion. Of the seven scapulohumeral muscles, four make up the rotator cuff. The four muscles are the supraspinatus muscle, the infraspinatus muscle, teres minor muscle, and the subscapularis muscle.
A rotator cuff tear is an injury where one or more of the tendons or muscles of the rotator cuff of the shoulder get torn.[4] Symptoms may include shoulder pain, which is often worse with movement, or weakness.[1] This may limit people’s ability to brush their hair or put on clothing.[4] Clicking may also occur with movement of the arm.[4]
Tears may occur as the result of a sudden force or gradually over time.[2] Risk factors include certain repetitive activities, smoking, and a family history of the condition.[1][2][5] Diagnosis is based on symptoms, examination, and medical imaging.[2] The rotator cuff is made up of the supraspinatus, infraspinatus, teres minor, and subscapularis.[1] The supraspinatus is the most commonly affected.[2]
Treatment may include pain medication such as NSAIDs and specific exercises.[1] It is recommended that people who are unable to raise their arm above 90 degrees after 2 weeks should be further assessed.[6] In severe cases surgery may be tried, however benefits of surgery are unclear as of 2019.[1][7] Rotator cuff tears are common.[2] Those over the age of 40 are most often affected.[2] The condition has been described since at least the early 1800s.[8]