Young competitive athletes are particularly at risk during puberty. Growth plates and apophyses are reduced in their stability by hormone influence. Epiphyses can slip, apophyses can tear out. Therefore, a regular examination of those athletes is important. The examination should focus on muscular asymmetries, or reduced range of motion of a joint. Shortened muscles have to be recon as a risk factor for apophysitis. Dysbalances of the musculature are mainly found in the trunk area. Training plans should be adapted to the increased vulnerability.