51
CONVAID USER’S GUIDE
If the wheelchair is purchased without the optional lap belt or if the wheelchair
user elects not to use the belt, a vehicle-anchored lap and shoulder belt must be
used. As with the wheelchair-anchored lap belt, it is very important to position
the vehicle-anchored lap belt low over the pelvis so that the angle of the lap belt
is within the preferred zone of 45º to 75º to the horizontal or the optional zone of
30º to 45º to the horizontal, as shown in Fig.185.
Note:
Steeper side view pelvic-belt angles are especially important if the pelvic
belt is intended to be used for postural support in addition to occupant restraint
in a frontal crash. Steeper angles will reduce the tendency for a vertical gap to
develop between the user and the belt due to compliance of seat cushions and
belt movement, thereby reducing the tendency for the user to slip under the belt
for the belt to ride up on the soft abdomen during normal use.
Note:
Steeper belt angles also reduce the tendency for upper-torso belts to pull
the pelvic belt onto the abdomen during frontal impact loading.
Fig. 185
