Ok the other day(friday) i was racing the 200m and on the back strech, i guess around the last 30m my shoulders began to burn pretty bad. I have recently over last year began to change my arm swing so as that my hands would not cross so much in front in of me. I am more efficient because of it, hence faster. I also noticed the burning today at practice(monday), i’m wondering if this burning is due to the change in my arm swing, if i will get use to it and it wont burn anymore, is it dangerous to my rotator cuff?