The Treadle wheelchair is the next step in elderly mobility. It solves 3 major current design issues:
Capable of travelling over rough surfaces including grass and gravel, users can now go into parks, gardens etc;
The user can exercise to their desired level by pushing on the treadle mechanism;
Double handlebars allow an upright posture for carers of different heights.

(Display model shown. Please see following photo.)

Other solutions reached with this design:

Rear uniforks save weight;

Disc breaks reduce maintenance;

Grooved armrests stop tired arms falling off;

Handles encourage engagement by the user;

Changeable cushion allows personalisation- different colour options e.g. tartan;

Y-shaped frame/raising and lowering armrests allow safe access to the chair.

The brief was to engage young people in 3D play again. My solution was a 6" windup cheetah kit, that ran. Unfortunately I ran out of time (it was a 1 semeter project), but hope to complete it after university if there is a market for it.