Walking on your knuckles is absolutely as odd as walking bipedally, a very peculiar way to get around. It doesn’t make sense, and it’s bothered anthropologists for years. Only chimps and gorillas do it. No one has come with the reason why—until now.~ from https://phys.org/news/2018-03-humans-knuckle-walkers.html
Having done quite a bit of walking on all-fours (aka “quadrapedie movement”, QM) I consider myself well-informed on this topic. Here’s my take:
Walking on knuckles sucks, but it is almost far superior to walking on the flat, open hands. Why does it suck? Because we humans are missing the fat pads (check the balls of your feet, and palm-side of your hand knuckles) that the Great Apes have on the back of their knuckles. When I walk on my knuckles in QM — and I do do that — I have to be very careful not to injure my knuckles. But in grass, it is delightfully more comfortable then flat, open hands. On your knuckles, the wrist is neutrally positioned and the wrist muscles are naturally activated, but not overly strained. The upper arm is easily kept inwardly rotated keeping elbows rotated/tucked rearward for a strong shoulder position. Meanwhile the forearm offers a nice range of rotation allowing comfortable hand placement.
Take a few steps on your knuckles and you cannot help but feel like a gorilla. rrr rrr RRR!