**4.8 Stability and suspension systems**

The stability of the wheelchair is established by the use of four wheels instead of three and the user is supported in such a way that their centre of mass is lowered. This is also ensured by the dimensions of the wheelchair base as well as the weight and stress distribution exerted on the wheelchair. The wheelchair seat is also equipped with seatbelts/straps that help restrain the user from falling over during driving of when standing up by supporting the upper body weight of the user. The

**Figure 12.** *Support mechanisms including seatbelt, arm rest and leg holding extension.*

#### *Development of an Intelligent Standing Wheelchair with Reclining Characteristics DOI: http://dx.doi.org/10.5772/intechopen.96110*

figure below shows the seatbelt slots on the wheelchair seat. A pair of leg holding extensions (shown in **Figure 12**) is mounted on the wheelchair in order to support the legs of the user hence aiding to the stability of the wheelchair.

The wheelchair hydraulic actuators absorb the vibrations during motion of the wheelchair along with the assistance of the wheels.
