JointOffset: where the leg is attached (hip joint)
ExtendedOffset: where the foot joint should be in relation to the hip joint when the leg is fully extended.
ContractedOffset: where the foot joint should be in relation to the hip joint when the leg is fully contracted (you should sprite it so this can be quite a small vector)
IdleOffset: not used due to walkpaths always being active.
MaxLength: Used to limit the radius the foot can move inside.
the foot should have the same jointoffset as the atomgroups and be ~the same size.
Your limbpaths will need a lot of editing, otherwise he'll do a crazy foothop. you might also need to up or down the movespeed to get it looking acceptable graphically.