Hello Doctor, I have some problem in my collar muscles and my shoulder muscles because when i lift some weight the maximum part of weight is taken by collar muscles which then pains a lot. Few years back, before starting this problem, I used to work out very hard for collar and shoulder muscles. Now after so many years I have joined gym again, the shoulder exercises puts lot of stress on collar part also and it pains unbearably. I am afraid that by exercising hard in the previous years, I have damaged my collar and shoulder muscles. please tell me what this problem could be? and what should I do to make my muscle s weight carrying capacity as it used to be before first exercising??