Door-sill height
The height of the door-sill affects the ease or difficulty in the phase of lifting ones legs in or out of the car. The higher the sill the more strain the subjects had to exert to lift their feet over the sill, and this was found also to affect the phase of moving their bodies in or out of the car. The subjects hardly noticed a sill of 45 mm above the floor, resulting in 350 mm above the ground. One of the ambulant disabled could not lift her feet over the sill of 135 mm by herself, but could just manage 90 mm. One wheelchair user found it difficult with the 90 mm sill. Three ambulant disabled and four wheelchair users found the 135 mm sill very difficult to cope with. A sloping side of 45” of the sill to the floor made it easier for the subjects to pull their feet out. The times when the subjects moved their bodies and feet in and out of the car were much increased by the high sill of 135 mm (Figure 7). The times were also increased by the 90 mm sill, but the low sill of 45 mm did not significantly affect the times.