I don't know about sensory... I believe you're referring to the plantar reflex test (I don't think this reflex occurs in the hands). I don't think it would really be comparable to the whole "which toe am I grabbing?" game because it's just testing for a reflex, so you don't have to consciously feel the stimulus for the reflex to happen. If anything it would be more of a motor test.
The plantar reflex tests the integrity of the spinal cord from L4 to S2 and the corticospinal tract (essentially the bundle of nerve fibers that connect the brain and spinal cord). Normally if you draw an object down the side of the sole of the foot, a person's toes will curl downwards in plantar flexion. If there is disease or damage to the spinal cord at L4-S2 or in the corticospinal tract the big toe dorsiflexes (curls back towards the top of the foot) and the other toes fan out. This is called Babinski's sign, and it also appears in normal healthy infants because their neurons are not fully developed.
As for a sign of motor, perhaps. However, I believe that (and more experienced folks correct me if I'm wrong) if you have someone who's totally unresponsive, it's not really necessary to check for motor and sensation since it's basically impossible.