[MEDIA]
Total gimmick imo If you want to improve your forearm do what your forearm is designed to do. Grip stuff.
I like the guy's channel, but it's definitely a gimmick. Click here to register a FREE forum account and REMOVE ADS
As long as your arms didn't wobble about under stress / load and potentially damage your rotator cuff (unlikely imo) I don't think it could hurt. I've seen the eastern Europeans doing something vaguely similar with Olympic rings....after a few years training is very boring so the more gear you have the better the variety.