Arm muscle strain mostly occurs when the arm is strenuously active, or when the arm is overexerted, the following symptoms will occur when the strain occurs: 1. there will be severe local pain, showing tearing-like pain or stabbing pain, which is obviously aggravated when moving, and the pain can be slightly reduced when braking. 2. there will be local swelling, and the degree of swelling is positively correlated with the degree of muscle strain, the more serious the strain, the more powerful the swelling. 3. skin Petechiae, part of the strain bleeding, will appear after 2-3 days of strain extensive skin petechiae, and will spread along the tissue gap, and even lead to hand swelling and skin petechiae. 4, there will be obvious pressure pain, muscle strain site will appear obvious pressure pain points. 5, limited activity, because the muscle strain site in the activity, due to muscle contraction, will cause local intense pain, is tear-like pain, thus causing Activity is limited or afraid to move.