We just found out our 14 year old daughter has a fused L5S1 . She was born this way evidently and is involved in several sports year round. Seeing Chiropractor now that helped my L5L4 herniated disk pain disappear. She is working on her and is telling us she should be fine long term and will be able to continue sports but will just need to be smarter in how she bends and lifts for the rest of her life and watch her posture when sitting. Anyone have this situation with one of their children who was an athlete?