Ah yes, I see what you mean. Joint 2 would set the 90 degree position as zero degrees in your example.
Ok what about this (using your example above), create the worm in it's starting position (but NOT in the saved location - maybe high up in the air?). Then once the joints have been attached, set the position/rotation of the bodies to the saved location (the end position).
Ok what about this (using your example above), create the worm in it's starting position (but NOT in the saved location - maybe high up in the air?). Then once the joints have been attached, set the position/rotation of the bodies to the saved location (the end position).