By coincidence I have just been on an introductory course on kinetic lifting.
These belts were never mentioned, but since the UK is not as litigious as the US, I dare say, they have not really become an issue - yet.
What was interesting is the way the law can be used to transfer responsibility from the employer to the employee.
We were told in no uncertain terms that since we had been made aware of the most important points, that our employer was therefore only liable to incidence of back injury that fell outside the scope of the course, which actually pretty much covered the vast majority of possible situations at my workplace.
In other words, if one of us were to be injured lifting or moving a load and it could be demonstrated that it was contrary to the training we had recieved, well, tough.
I expect that in the US, those black belts are supposed to represent what we in the UK call Personal Protective Equipment(PPE) and that there are standards for use, maintenance and manufacture.
In the UK every task a person can reasonably be expected to carry out whilst at work has to be assessed for risks, from chemical, mechanical, environmental, lifting and many other possible risks.
Wherever possible tasks have to have a written document which states how the task is to be carried out, what safety equipment is to be used, where that is located, any other materials and any risks associated with those.
Employers might have literally thousands of these to produce, and if they are unlikely to be inspected, or very rarely, then it is a lot of effort for seemingly little result.
The result is that employers will take short cuts, a supervisor will perhaps see something on the tv, or maybe they see another company using some safety device, and then they will be copied.
This is, of course, wrong in a liability case - because you have to prove things, and compelling an employee to wear a so-called safety device for which there is no evidence of any benefit could be seen as part of a poor or incorrect assessment of the risks.
The only way the company, or employer can defray their liability, would be to send their employees on a course, possibly on the premises, that showed them and had practical demonstrations on how to move loads correctly, and this course would have to be delivered by a certified trainer, with a recorded lesson plan.
Attending such a course in itself would not alone completely defray liability, the empoyer would also have to demonstrate that safe working was part of company rules, in employment contracts, perhaps disciplinary records, risk assessment records and finally in day to day actual working practices, the latter can often be at odd with the records, we all take short cuts.
Those so called lifitng belts are no substitute for a proper company health and safety policy, and might actually reveal a lack of understanding of company liability by the company boss.