Although these injuries are very real, the incidence of such injuries is low. To many physicians, the repeated "micro-traumas" that occur over a period of time to a young athlete’s whole body are just as important as the Cumulative Trauma Disorders. These "micro-traumas" are experienced by footballers for example, who put their bodies through the rigors of a full contact sport from a very young age - resulting in such problems as stress fractures. All of these conditions may lead to problems in later life, and these problems need to be addressed.
The aftermath of epiphyseal plate damage and osteochondrosis can have marked effects on the child’s physical growth and development as he or she enters adulthood and old age. In rare cases, repetitive activities such as the tennis and baseball pitching have brought about a stretching of the epiphyseal growth center. Hence, the active arm can actually become longer than the untrained arm. The stretching of the arm is a characteristic common with professional adult baseball players and tennis players. Even though this bone hypertrophy (bone enlargement) has never been documented as being detrimental to the athlete, it is still important to note that the "normal" growth and development of the child has been impaired through intense, repetitive activity.
This bone hypertrophy is often combined with excessive muscle hypertrophy. Professional tennis players can regularly be seen with larger forearms and biceps on their dominant arm compared to their untrained arm. Rowers, for example, participate in an activity that is very repetitive and can cause a strain on such muscle groups as the pectorals located on the front of the chest. This continued loading on the pectorals leads them to undergo hypertrophy and they become larger and stronger.