I am 18 years old, and since my last growth spurt in high school (when Iwas 16) I have recurring lower back pain after sports, ( Basketball, Football, Track). For example, I will be perfectly fine in normal daily routines, no pain sitting or walking.. and then I will go to play basketball. I will stretch, but after I'm done I develop a terrible pain on the right side of my lower back, if I stretch it, it seems to only hurt more. Once the pain has started it hurts when I sit walk, stand up.. and basically do any motion requiring my back to move. The pain is a shooting pain when I move or stretch. I had gone to a doctor when I was 17 during track season because it got so bad I could barely walk, I have missed multiple practices and such due to the pain as well, all the doctor could say is stretch more, and I've also tried strengthening exercises. In my senior track season the pain was bearable, but I have no explanation as to why, this is also true when I played club basketball and intramural basketball, the pain was still there but much less. I hadn't exercised much over the summer, but the first time I played basketball and football the pain returned with a vengeance, and now I'm sitting, typing in pain, also knowing that when I stand up it will hurt to straighten my back and walk.
Please help, I don't think its a skeletal disorder because it isn't chronic, its only triggered by rigorous activity, mainly running and jumping. If it matters I'm 6,4 160 lbs, and have few back problems in my family, but nothing like this.