This do what they claim to do. Your calves might hurt more than normal when you walk in them.
I wouldn't recommend these for anyone that loses balance easily because they are a bit heavy and put you in a different balance (honestly they put you in a position where you need to stand correctly; it just feels funny at first.)
I feel these working so I give 4 stars for doing what they claim.
I leave one star empty because they are bulky and look funny. I'd like to be able to wear these without the planet knowing about it haha However, thats not a huge deal to me so I don't mind. In a way they're kind of like an updated version of those thick soled grandparent shoes (because of the obvious thick sole.)