Testing of the wheelchair tiedown devices involves a simulated ( impact sled) crash test using a surrogate (simulated standard) wheelchair with a mass of 185 lbs. In the suurogate wheelchair seat is placed an anthropometric test dummy ( ATD) with a mass distribution representing that of the average male, 75kg(168lbs). The secured wheelchair and restrained ATD is then subjected to a 20g, 48kph (30mph) simulated crash.