When retracted, the claws are stored between his radius and ulna in the forearm. When extended, the claws slot between the metacarpals of the hand, and are not inside the wrist.

The claws have to go through the wrist during this process, so it would be a bad idea for Wolverine to extend his claws with a bent wrist or bend it during extension.

Fictional character anatomy lesson. You just got one.

because when they retract they go past his wrists

the x rays show that it stops at the wrist and lays against the bones so he would be able to bend his wrists as long as he doesn't try to extend the claws when his wrist is bent 90 degrees because that would cause them to come out of the wrist.

thats extended