Walking Quarduped with physics

I'm trying to make a quadruped that moves with in-game physics. At the moment my plan is to use legs on joints, which work by lifting up, rotating towards the destination, extending and returning to original position. Rear legs would do the same without sideways movement, so the creature would automatically turn to face the direction its moving.

Apparently the customizable joints should be best for the wobbly movement I'm looking for, but I have no idea how to make them rotate. I have...

Walking Quarduped with physics