Of course I'm only 25, and I can say this is bullshit now, but who knows in 20 years or so. Maybe I'll get arthritis anyway. I still do pushups on my knuckles because it strengthens my wrists, and I happen to enjoy the calloused knuckles. Also, I get a wider range of motion by doing them on my knuckles because I'm up higher. I've been doing them since high school, and I've never had any pain or aches in my hands from doing them alone. You're 21 right Ramzee? You got time before you need to worry about arthritis, even from doing something as simple as pushups on your knuckles. Think of the shaolin monks. They do some of the craziest stuff like poking their fingers at stone to 'strengthen' their fingers. Not only do these guys live for 300 years, they have three-foot fu-man-chus! Ok, that was a joke, but there are some pretty damn old monks out there who can still kick some serious ass and function perfectly well. I don't suggest you try to strengthen your fingers or anything else like that, but I definitely don't believe push-ups on your knuckles are going to hurt you, even in the long-term.