>how many degrees of freedom do the knee and elbow joints have?
Those of Quaismodo after a traffic accident
In case you mean how far one can move them
(for invented example <170 o )
here they have thingies like that: D .
Usually plastic discs with degrees on them. Then one might measure it
of a child, oneself, some fossil and a skeleton. Not sure if that was
what you were referring to.