Ex-Polevaulter: Ongoing hamstring/buttock problems

I am looking for some help.
I finished polevaulting 6 years ago due to really bad back problems. Everytime I’d vault, the next day I would have pains going down my right side of my body into my legs. I have had physio for that complaint, with the back specialist concluding that there was slight dislocation of the lower vertebrae, and also that the bones were very dry. His suggestion was to take it easy for some time, and let everything go back into place.

I am now 4 years on. Back problem has gone. But I am experiencing right hamstring problems. basically it is flexible…touching my toes is easy, however what ever activity I do which involves running, I always feel that if I excert myself above 80% the hamstring will tear, and occasionally I get slight pulls.

when I massage the hamstring / buttock, the buttock has one huge knot, which could be muscle and may explain the problem.

Also this particular hamstring (right leg) I had problem when 14 /15 yrs old…the hamstring was pulling fragments of bone from my pelvic bone…which meant I needed 6 months of rest…… again this cleared up

I am just waundering what the problem is, and whether anyone has had anything similar…I’m just hoping that it is fixable….and I am not stuck with it…it gets really frustrating…..

any help or advise would be appreciated

Ian