I tried to lift a portable microphone PA system. I felt something pull the minute I moved the thing. I put some ice on it and then heat and tried not to use it so much. A friend warned me that I shouldn’t wait too long before going to the doctor but I did. My shoulder got worse band I could barely raise my arm without pain. Finally I went to an orthopedic doctor who xrayed it and said I had a frozen shoulder. This led to shots and physical therapy. Took almos two years for my shoulder to heal. Don’t wait too long!