Hello Sir, my name is Ahmed Abdelhakeem, I'm a medical student currently studying in Egypt, and I'm suffering from locking of my right shoulder, my shoulder gets locked up when i do certain movements like internal rotation of the arm and I have to make it click with popping sound and severe pain to be able to move it again. It started 6 years ago when i was playing table tennis and after that when i was play fighting with my friend trying to push him. From 2 months, i was playing a football game when i came into contact with another player while my arm was extended and abducted and the contact came from behind making something inside my shoulder to move and it locked, so i popped it with a click, followed by severe pain. After that, it locked more than usual, so I did an MRI and the results were a minimally swollen and slightly edematous supraspinatus tendon near it's insertion and significant amount of fluid collection in the gleno-humeral articulation and in the subcoracoid bursa, however the right gleno-humeral is maintaining normal joint spaces and fairly smooth articulating surfaces. Currently I saw a physician who told me to put it in an arm-sling and shoulder support and take NSAIDs, but still I did not know the diagnosis of my case. I want to know what causes my shoulder to lock with certain movements, thanks in advance.