question: Hi, I am having difficulty with my shoulder. I was involved in an explosion in Afghanistan, and now I can t lift my arm to the side past 90 degrees and have no strength in it. This lack of ability isnt caused by pain but rather I just cant. Its kinda like when you try to bend your leg past straight your knee just doesnt let you. I have had MRI s and they show nothing really abnormal. I was wondering if this could be caused by a tbi. The doctors are running out of ideas