I pulled my ham a year ago and literally every time i try to sprint it pulls. i tried massaging it. tried rehabbing/prehabbing. I don't know whats wrong. i do mobility work to warm up and dynamic stretching. I've only pulled it once in the gym and it was soon after the first pull (the worst one). i can jog and walk with no problems. as soon as i try to sprint it feels like someone is clenching their fist around my hamstrings in my right leg.
i know this isn't powerlifting, but i am a powerlifter and need my hamstrings to be as strong/healthy as possible. i can feel the tightness in my deadliest but other than that it hasn't been an issue. I often worry about it though