An Innovative Motorized Wheelchair for Young Disabled Children
KENNETH M. JAFFE, MD*, CHARLENE BUTLER, EDD**ROSS M. HAYS, MD*, AND DANIEL H. S. EVERARD***Seattle, Washington
Powered mobility for young disabled children is gaining increased acceptance1,4.
Children as young as 11 months have demonstrated that within short
periods of time they are able to learn to drive skillfully with parental
supervision3,8. Researchers have reported more normal
socioemotional and learning behavior of children who acquire independent
mobility using powered wheelchairs and caster carts2,6.
Overall development from earliest childhood is largely dependent on the
ability to move freely. Until recently, powered mobility devices for the
very young have been available only through the efforts of university
design teams8 and creative parents. Commercial products
designed principally for an older population require extensive
modification for small children.
An innovative motorized wheelchair, the Turbo(r), (Fig. 1
) was created by a British electronics design engineer, Daniel H. S.
Everard, for his 18-month-old daughter who has spinal muscular atrophy.
From Everard's understanding of children's mobility needs from infancy
to preadolescence, a highly functional motorized wheelchair is now
commercially available. Between August 1984 and January 1986, 90
Turbos(r) have been prescribed in the United Kingdom. Tables 1
show the diagnostic categories and age distribution of the recipients.
Three children who have motorized wheelchairs used a Turbo(r) for an
extended trial period at their elementary school. Immediate important
changes in behavior were observed as a result of the additional freedom
allowed by the vertical movement and the arrangement of the associated
standing frame on the Turbo(r), as well as the ability to move in the
The Turbo(r) resembles a miniature fork lift with 41 cm (16 in) diameter
front pneumatic tires for good traction and 13 cm (5 in) diameter solid
rear wheels. A built-in jack aids removal of the front tires for
replacement with clean tires for indoor use. The rear tires, mounted on a
centrally pivoting axle, enable the Turbo(r) to climb and descend curbs
up to 10 cm (4 in) and to negotiate uneven terrain. The chassis (Fig. 2
), 60 cm wide by 80 cm long (23 x 31'/2 in), is made of durable
fiberglass in bright primary colors. The Turbo(r) weighs 86.4 kg (190
Two drive motors in the vehicle can propel children safely up a 1-in-4
occupant may be as heavy as 50 kg (110 lb), representing the 50th
percentile for children approximately 14 years of ages. Top speed is 6.4
kilometers per hour (4 mph); acceleration and maximum speed can be
controlled by inserting different electronic programs. Two 12-volt
rechargeable gel-cell batteries, fully charged, run for 8 to 12 hours.
The easily removable plastic seat shell (Fig. 3
) is available in widths of 25, 27.5, 30, and 32.5 cm (10, 11, 12, and
13 in), and is attached to a metal frame and mounted on a removable
motorized lift (Fig. 4
). When the seat is removed, an adjustable standing frame mounts on the
lift shaft. The lift allows the driver to raise and lower the seat or
standing frame independently between the ground and a maximum height of
65 cm (25 1/2 in). As the seat frame's hinged foot rest (Fig. 4
) meets the ground, it is passively rolled forward.
The driver's control panel contains a proportional joy stick, a battery
charge indicator light, horn, and up and down buttons. A parent control
panel with a button to turn the drive motors off for 20 seconds is
mounted on the chassis, facing rearward. An optional built-in microphone
which reacts to the sound of whistle also stops the Turbo(r) for 20
seconds, allowing adults to intervene in case of emergency. A braking
system which remains engaged unless the vehicle is being driven prevents
free-wheeling when the Turbo(r) is stopped on an incline.
Two children with cerebral palsy, aged 6 months and 10 years, used the
Turbo(r) for one week in their classrooms in lieu of their regular
motorized wheelchairs. Another 11-year-old boy with cerebral palsy had a
shorter trial period. In their regular wheelchairs, the children could
move independently throughout the building, but outdoors were restricted
to level, hard surfaces. Sidewalk access was limited to infrequently
placed curb cuts. In the classroom, the fixed height of the traditional
wheelchair rendered the users dependent on adults to move the control
boxes so that the children could maneuver close to desks and tables.
Often they were restricted to designated work areas and special desks
which fit their particular wheelchair height. The children spent
approximately one hour during class time standing on prone boards to
prevent contractures. During this time, activities were severely
restricted because no self-initiated or controlled movement was
Teachers reported similar behaviors for all three children who used the
Turbo(r). Increased independence was immediately apparent. With variable
seat height, the children accommodated themselves to any desk or table
and could retrieve objects from the floor or from high shelves without
assistance. In order to see better in group instruction, they adjusted
their position by raising themselves slightly. During play, they lowered
themselves to the ground to be level with playmates and then raised
themselves and traveled to a new location for resumption of games.
Outside, they were able to keep up with peers regardless of how rugged
or soggy the terrain. Neighborhood travel became easy with the Turbo(r)
as the children could manage any curb. Although the trial candidates
were too physically disabled for independent transfer, other children
could enter the Turbo(r) themselves by lowering the seat to the floor.
The most surprising observations were made with upright locomotion.
Standing time tripled because now all activities, including independent
mobility, could be continued while standing. The learning program which
reduces the acceleration and speed was helpful to accustom the children
to moving while standing. A rear support offers little interference with
clothing, human interactions, or activities. Children explored the
fronts of their bodies and parts of their clothing not reachable when
sitting or on a prone board. They hugged and physically interacted with
peers and their teachers more intimately. They worked at the chalkboard
and other activity stations without having to lean forward out of the
conventional wheelchair. Boys used a urinal independently. Turbo(r)
users reached objects other children get to by climbing. They helped
peers in new ways, such as when one driver pushed a non-mobile friend in
her manual wheelchair.
The innovative design of the Turbo(r) meets many criteria for small powered mobility devices?7,8.
It is aesthetically pleasing, appearing more like a toy than a
traditional wheelchair, enhancing its acceptance by the child, family,
and community. The school staff, many of whom had never shown interest
in wheelchairs, requested a staff meeting to learn more and were very
The vehicle is hightly maneuverable indoors and outdoors. Being able to
go up and down curbs and over rugged terrain expands the child's
environmental accessibility and, therefore, participation in activities.
When the seat and lift assembly are removed (Fig. 2
), the chassis is extremely compact, facilitating its transport in
automobiles, in contrast to traditional powered wheelchairs which are
not easily transported without vans. New dimensions of mobility,
available because of adjustable seat and standing frame heights, expand
the child's reach, enabling users to obtain the physical and
psychological benefits deriving from upright mobility.
In the United Kingdom, the plastic seat is usually lined with sheepskin (Fig. 1
). The shell, however, easily accommodates custom positioning
requirements, such as a total contact system. Joy stick placement can
also be individualized. Growth is accommodated by replacing the plastic
seat shell with a larger one and adjusting the standing frame without
need to alter the chassis or lift assembly. Conceivably, one Turbo(r)
could serve a child from age one year until the individual attained a
weight of 50 kg (110 lb). The weight limit is determined, not by motor
power, but by the load that can be carried in the seat or standing frame
safely. Questions about long-term reliability, durability, and
maintenance remain to be answered. The drive and brake belts, drive
motors, and electronics appear to be well-protected from water and dirt
to which the chair is exposed during routine use.
Safety features include the mechanical braking system, engaged except
when the Turbo(r) is driven. This increases its suitability for hilly
environments. Even when moving at top speed, it will stop quickly when
the driver's hand leaves the joy stick. By switching programs for the
electronic control mechanism, the acceleration and speed can be tailored
to the skill, experience, and maturity of the driver. One program,
suitable for children with athetosis, dampens the effect of adventitious
joy stick movements. The chassis cover provides a suitable flat surface
to support an adult trying to instruct or supervise a juvenile
occupant, and can be used to carry additional equipment such as a
ventilator. The parent control panel and build-in microphone give a
watchful adult the ability to stop the vehicle by pushing a button or
blowing a whistle when a driver encounters danger.
Powered mobility is a developmentally appropriate intervention for many
young disabled children. The innovative aspects of the Turbo(r) offer
distinct advantages, making it an invaluable addition to the
armamentarium of adaptive equipment. Turbo(r) is now marketed in the
United States and Canada by Invacare Corporation, 899 Cleveland Street,
Elyria, OH 44036.
We acknowledge the assistance of Pat Schuppenhauer in preparing this manuscript
*Department of Rehabilitation Medicine, Children's Orthopedic Hospital
and Medical Center 4800 Sand Point Way NE, Box C5371, Seattle, WA 98105
**Seattle Public Schools, 2143 North Northlake Way, Seattle, WA 98103
***Everaids Ltd., 172 Cambridge Road, Great Shelford, Cambridge CB2 5JU, England
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