Hi, my son is 15 and was just diagnosed early spring with pars defect bilaterally in the L4 and on one side in the L5. He did not play school ball or summer ball. Towards the end of the summer season he did feel good enough to swing a bat and field some balls with minimal pain. He did nine weeks of physical therapy and was then released. Signed him up for fall ball and he began to practice and within three weeks he complained of being in severe pain again. Therapist thinks it’s his SI joint and not his spine issue. Does anybody have any experience with this and could all of this be associated with growing pains? We have been to a few different doctors and one thinks the pars defect was a very old injury so I’m wondering if the SI joint was the problem the whole time. Hard to get concrete answers :/