Inverted crunches using a chin-up bar?
I did some for a while but recently I have noticed that whenever I hang upside down for a while, I feel the chin-up bar digging into the back of my knees and it sort of hurts in an irritating way.
Since then, I have padded the back of my knees but I'm sure there's a better way around this problem. Suggestions, please?
I also have another question here if you could answer it as well - this question is about press-ups (also known as push-ups).