<Ul> <Li> The racquet - holding arm bones of tennis players become much stronger than those of the other arm . Their bodies have strengthened the bones in their racquet - holding arm since it is routinely placed under higher than normal stresses . The most critical loads on a tennis player's arms occur during the serve . There are four main phases of a tennis serve and the highest loads occur during external shoulder rotation and ball impact . The combination of high load and arm rotation result in a twisted bone density profile . </Li> <Li> Weightlifters often display increases in bone density in response to their training . </Li> <Li> The deforming effects of torticollis on craniofacial development in children . </Li> <Li> An Anterior - Posterior Pelvic X-ray of an amputee . The right hip is much more dense with bone than the left . </Li> </Ul> <Li> The racquet - holding arm bones of tennis players become much stronger than those of the other arm . Their bodies have strengthened the bones in their racquet - holding arm since it is routinely placed under higher than normal stresses . The most critical loads on a tennis player's arms occur during the serve . There are four main phases of a tennis serve and the highest loads occur during external shoulder rotation and ball impact . The combination of high load and arm rotation result in a twisted bone density profile . </Li> <Li> Weightlifters often display increases in bone density in response to their training . </Li> <Li> The deforming effects of torticollis on craniofacial development in children . </Li>

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