Hello I am 13 years old, 5'8 145 pounds with an athletic build. Recently, I've been playing on my schools freshman football team and the other day while sprinting I got a sharp ache in my lower back right next to my right hip and above the tailbone, (near the ilium?) the pain gets worse with running. Ive tried to find a diagnosis and I haven't found any similar injuries with running being the cause. Any help is appreciated.