The ReBuilder®
I have searched their websites, I did not find any hard research evidence for anything they said the device will do. They have a long monologue on the site and trying to prove this thing really should work. But, "should work" is a long way from it actually works.
About the FDA approved statement, I have found the following sentences on their website: "It is registered under the 510K basis as both a TENS and an EMS, (which is the only two categories that the FDA offers). The FDA does not approve any medical device, the FDA only 'approves' pharmaceuticals." Well, I wonder what they meant when they typed the words "FDA Approved" on the front page of their website.
The company is conducting an "ReBuilder Evaluation Study". I have found the "Enrollment Form" on their page. But be aware if you want to enroll yourself in the study. You need to sign the form and declared that "I have not been promised any particular clinical outcome". And also be aware that any credible clinical study should randomly enrolled and conducted with a double blind experiment design. I cannot find any approval for human subject protection, which is federal mandate for research involves human subjects.