While additional cushions may provide a wheelchair occupant greater comfort, the cushion may not be compatible with a given wheelchair manufacturers make and model. This can compromise the occupant’s stability, and ultimately their overall safety, and should be removed prior to transport.
The back support of a wheelchair should ideally be set to the occupant’s shoulder height. The addition of a seat cushion onto a standard wheelchair seat will raise the occupants seating position in the wheelchair. Subsequently, this raises the occupants center of gravity, leading to compromised forwards, rearwards, and sideways stability. This effect on stability can be critical should an accident occur, especially for occupants with poor core strength. Additionally, by raising the occupants center of gravity, the angle of a slope or ramp that a wheelchair can remain stable on, is reduced. This increases the chances of the occupant tipping over more easily when met with even the slightest of angles.
Any impact can be considerable regardless of the rate of speed the vehicle is traveling. Permitting the use of additional cushioning for wheelchair passengers only increases the likelihood of a more severe injury if an impact were to occur. Additionally, by raising the center of gravity of the occupant, the probability of the occupant tipping over inside the vehicle during a cornering or breaking event is also increased.
It is perfectly acceptable that additional cushioning may be an integral component to a wheelchair user’s level of comfort. However, the cushion should be specifically designed by the manufacturer, and integrated into the original design of the wheelchair by that manufacturer. If it isn’t, then it should be removed from the wheelchair prior to transport in an effort to reduce the likelihood of severe injury if an accident were to occur.
While a passenger’s personal comfort is important; ultimately their safety, and the safety of those around them is more important.