Because the internal construction and drive mechanisms on earlier model powered wheelchairs and rehab wheelchairs are virtually the same, they share identical manuevering characteristics:

Earlier Power/Rehab Wheelchair Turning Radius

When one of these earlier model powered or rehab wheelchairs is being moved forward or backward while making a gradual turn, the rear drive wheel on the innermost side of the turn rotates slightly slower than the wheel on the outermost side of the turn and thus the wheelchair travels in an arc.

When a very tight turn must be performed, however, the rear drive wheel on the inner side of the turn becomes stationary during the turn while the rear drive wheel on the outer side of the turn continues to rotate. Thus, the vertical center of the momentarily stationary inner rear wheel becomes the center point of the earlier-model powered or rehab wheelchair's turning radius. The outer edge of the turning radius is defined by the forwardmost extension of the user's foot or in some cases the forwardmost extension of the pedal on the side of the wheelchair outside the turn. In the case of a counterclockwise or left turn -- as shown in the drawing above, the forwardmost extension of the user's right foot or the wheelchair's right pedal defines the outer edge of the turning radius.

It can thus be seen that the tightest possible turning radius for an earlier-model powered or rehab chair is larger than the turning radius of the manual wheelchair considered previously.

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