Given names often turned into family names when people were identified by their father's name. For example, the first name Ahrend developed into the family name Ahrends by adding a genitive s-ending, as in Ahrend's son. Examples: Ahrends, Burkhard, Wulff, Friedrich, Benz.
OK the definition you have used for crouching associates it with stooping (which on Wikipedia redirects to bowing. Squatting essentially involves bending at the knees and hips. If there is any bending at the waist (and maybe lowering of the head) then that is considered stooping.
Sleepwalking is a disorder that causes people to get up and walk while they're asleep. It usually happens when a person is going from the deep stage of sleep to a lighter stage or into the awake state. The sleepwalker can't respond during the event and usually doesn't remember it. In some cases, he may talk and not make sense.