**4.6. Summary**

We therapists realize after all that, at the present time, WBV effectiveness against SCI, PD, MS, and knee OA has not been established. There are reasons for that: disease mechanisms have not been clarified, and optimum conditions such as stimulation frequency are not definitely set yet. And in intervention studies, one cannot completely eliminate the influence of other factors. It is unfortunate that not enough high-level evidence-based research has been done or published.

Though rather limited in scope, we therapists can help people with disabilities, or even people without disabilities, by suppressing the muscle tone of a given muscle through the spinal cord loop.
