Just imagine this: Austin Mathews (yes, we’re leafs fans) is coming down the ice to score in the last minute of the Leafs game, you bring your arms up to cheer and- pain and weakness stop you from bringing your arm up to 90 degrees. Why is this happening? Why does the pain only happen just before 90 degrees but alleviate when you get past that point? Read along to find out. The shoulder is surrounded by 4 muscles to produce the movements of the shoulder which together are cal