Standing scooter

Project  / Project number: A90/036  /  Status:

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The challenge

This project was a self-referral.  The client suffers from Ehlers Danlos syndrome, a connective tissue disorder, and as a result her joints easily dislocate.  She is unable to sit with her knees bent as the joints then dislocate.  Her initial approach had been to ask whether a Segway could be adapted to her needs for personal local mobility, but it was established that her upper body strength would be inadequate.  Her request then was for a ‘buggy’ which she could use in a standing position.  Standing on a scooter, with a consequently higher centre of gravity, introduces greater potential risks of tipping over when turning or on uneven ground.  The risks were assessed and it was decided that most could be mitigated in the design of the proposed pavement scooter.

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The solution

A second-hand Electric Mobility ‘Rascal’ pavement scooter was acquired.

The essential first step was to improve the lateral stability of the scooter as it has a narrow track.  Two folding ‘outriggers’ were fabricated and fitted to the scooter providing the necessary increase in stability.  The outriggers were fitted with small nylon wheels which were set about 40mm above ground level when the outriggers were deployed.  The wheels only contacted the ground if the scooter tipped to one side or other.  For transportation the outriggers could be readily folded up at the sides of the scooter and secured with drop-nose pins.  It was established that the client could carry out ths operation herself.

A normal seat was not appropriate as the client wanted to stand on the footplate of the scooter.  However a canvas se
at/backrest was made and mounted on a fabricated steel frame to provide support for her.  A pair of side restraint frames were made and fitted to the backrest to hold her upright in case the scooter should tip to the side.  The entire backrest assembly could be folded flat for transportation.  To accommodate the standing position the steering column was extended and the controls rewired, but the facility to fold the steering column flat for transport was retained.

Trials of the machine at different stages of completion were carried out with the client to ensure that her needs were met correctly and safety issues were mitigated or solved.

The benefit

The scooter was delivered to the client and she trialled it successfully for a few days.  On non-undulating surfaces she managed well and was extremely satisfied with the result, both on the flat and on mild inclines.

When travelling along a pavement, with drop kerbs for vehicle run-ins, the scooter tilts slightly sideways.  There is no risk of it overturning, and the stabilising outriggers work as expected.

Unfortunately, on one such occasion the client reacted reflexively and moved suddenly against the tilting direction and motion, and the sudden movement caused a tendon detachment in her ankle.  She says that this is not an unusual occurrence as sudden movements often cause similar events; an emergency stop in a car two weeks previously caused dislocation of her shoulder by the sudden pressure of the seatbelt.

However, it means that the current configuration of the modified pavement scooter is not suitable to the client’s needs and wellbeing.  We are now discussing with the client the possibility of further modifications to the scooter to increase the wheelbase, permitting her to sit with her legs straight (no bending of the knees).

This, together with a self-powered carrier to mount the scooter behind the client’s car, will be the basis of further referrals.

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