Marc Mora established relationship between the use of
pads and sports injuries in skating among adolescents in the
United States. He found that using a knee pad can effectively
protect the user from pain [6]. Powers et al. studied knee
joints using MRI and designed a series of studies to evaluate
the effect of knee joint curves. The results indicated that the
knee pad can correct the knee joint curve [7]. Sterett et al.
compared patients who used knee pads with those who did
not. They found that knee pads protect the anterior cruciate
ligament [8].