When tying two limbs together you can either bind the limbs in different positions and leave as is or tie the limbs off on a post or secure object.

When tying two limbs together you have a multitude of options:
two wrists together
two upper arms (above the elbows)
wrist to upper arm
wrist to ankle
wrist to thigh
ankle to thigh
ankle to ankle
thigh to thigh
etc….let your imagination go

All the knots show below can be used in different limb combinations.