In order to acquire consistent power and skill, elite athletes
who aim at performance improvement spend a significant
amount of time training. In the training and similar
repeated processes, athletes are exposed to fatigue and the
danger of injury, which may result in sports injury1). Sports
injury is defined as injury to the body occurring in relation
to sports, causing disability in daily life or reducing enthusiasm
for exercise, and is the major factor behind declines
in athletes’ performance. Most professional athletes have
chronic injury, resulting in performance decline, so that
early retirement occurs repeatedly2). Accordingly, not only
is supervision of athletes needed, but prevention of chronic
sports injury in general persons, and allowing subjects to
continue exercise consistently without losing interest in
sports is also needed. Prevention of injury is most important,
and when injury occurs, it is very important to allow a
return to sports activities through rehabilitation.