The vibration device 24, wherein a change in the direction of the combined vibration force corresponds to {TAIL ~ a change} in the direction of {HEAD ~ a simulated motion} in the computer simulation 
The vibration device 24 , wherein a change in the direction of the combined vibration force corresponds to { TAIL ~ a change } in the direction of { HEAD ~ a simulated motion } in the computer simulation
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH