text: Really weird but even i have this problem. I was asking same thing to many but i realised that while jogging i sometimes jerk my shoulder so it may be causing that. Also i am doing few yoga exercise to over come this and now it has reduced.\nI know other people will never understand that such thing cud happen but it does. You shund worry it isnt that serious thing. Observe your arm motionwhile jogging and do some yoga for strenthing your arm joints or physiotherapy will do.