Peter Attia· MD
for the thumb this joint right here the mCP joint uh where you have a skiers thumb for the ulnar collateral ligament and a radio collateral ligament tear though that's the most variable joint in the body in terms of varying among individuals so you have a minus 30 passively and you Flex nicely down to about 70 we look at my thumb I hyper extend a lot more but I only Flex down to about 40. and that's just everybody's different