I’ve read that this exercise is bad for the knees, and I’ve also read that it can help strengthen the knees. I suppose it depends on the quality of form and also the individual. This one’s a bit different than other squats because of the momentum involved and raising of the heel. Regardless, I personally feel it’s better to make use of the shrimp squat and pistol squat instead if your primary goal here is strength development. Even at its difficulty level I don’t think the Hindu squat is worth any potential risk because there are comparable variations (tuck jumps, box jumps, Bulgarian split squats, etc) that are probably safer. Of course some people won’t have any issues with it and can do it indefinitely.