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If you've ever shopped among scooters and power wheelchairs, you've likely noted some clear differences among them: Scooters steer with a tiller, whereas power wheelchairs steer with a joystick; scooters maneuver in a manner similar to an automobile, requiring more space to turn, whereas power wheelchairs rotate 360 degrees in tight spots; and, scooters feature basic seating, whereas power wheelchairs offer a vast array of seating and positioning. Nevertheless, if you're like some consumers, maybe you've still wondered about what technological differences among scooters and power wheelchairs reside beneath their shrouds, or why scooters are available at a fraction of the cost of a high-end power wheelchair - after all, they're both power mobility devices, right, so what's the big difference among technologies?

It's all in the Details
Interestingly, while scooters and power wheelchairs are obviously both power mobility devices, the way that they intrinsically function - as well as the technology that they use - is dramatically different, resulting in mobility platforms that have less in common than many realize, designed to meet specific needs.

From the start, the foremost factor that differentiate a scooter from a power wheelchair is also the most obvious - steering with a tiller versus a joystick - and dictates the complexity of their designs and components. Scooters steer via a mechanical front end, very much like a bicycle, motorcycle, or car. To steer a scooter, the user turns the tiller, which connects to the front wheel (or, wheels, if it's a 4-wheel scooter), and the scooter manually steers. To power the scooter, a single motor is used, typically driving the rear wheels via a transaxle (a combination of a "transmission" and "differential" of sorts that delivers power through gearing from the electric motor to the drive wheels). The electronic "controller module," then, regulates aspects like acceleration, speed, deceleration, and so on, as needed to power and operate the scooters.

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Power wheelchairs, however, have a far more complex steering and drive train mechanism, entirely interfaced through advanced electronics. Whereas a scooter features a tiller for manual steering, a power wheelchair uses an electronic joystick that relays directional input to a sophisticated controller module that then instructs the two motors - one powering each drive wheel - how to steer and power the wheelchair. Additionally, the controller module posesses far more parameters, having to control both motors, steering, and overall control all at once. Such electronic processing is very complex, requiring sophisticated components - all of which adds complexity, sophistication, and cost to a power wheelchair versus a scooter.

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Meanings Behind the Methods
Some may then wonder, if it takes so much more complexity and componentry to operate a power wheelchair versus a scooter, why not simply cross the two, where a power wheelchair steers mechanically like a scooter?

The answer is, maneuverability, accessibility, and feasibility - these are the reasons why power wheelchair technology requires distinction from that used on scooters. Firstly, power wheelchairs, as primarily full-time mobility devices, must maneuver in very confined spaces, able to turn 360 degrees with remarkable agility. This is only realistically accomplished by featuring free-pivoting casters, which move untethered in whatever direction needed (unlike a scooter, which has limited range on its mechanically-steered front wheel). In order to steer a "castered vehicle" like a power wheelchair, the drive wheels must be independently controlled, speeding up, slowing down, or reversing in relation to each other, as needed, all but intuitively. As a result of this exceptional requirement for utmost maneuverability - and the intrinsic complexity and components required to accomplish it - power wheelchairs must serve as castered vehicles with independently-controlled drive wheels, a contrast to scooter technology.

Secondly, power wheelchairs must operate via a joystick instead of a tiller due to needed accessibility by those with more involved disabilities. Scooter tillers require strength, coordination, balance, and posture by the user - capabilities that many with advanced disabilities simply don't have. However, a joystick is remarkably accommodating, allowing those with involved disabilities to operate the wheelchair despite limited physical abilities. What's more, the same advanced power wheelchair electronics that allow joystick control also allow "specialty control" devices, permitting one to operate a power wheelchair via one's chin, head, tongue, or even breath - amazingly liberating technologies. Therefore, it's vital that the advanced electronics of a power wheelchair not only allow one to simply steer a power wheelchair, but also allow those with even the most complex disabilities to access independent mobility.

Lastly, power wheelchairs, by nature of their "open base" design, allow vastly greater feasibility for mounting complex seating systems that are required for those with advanced positioning needs. While a basic "captain's" seat can be mounted on a scooter (and scooters are specifically designed for easy entry and exit for those who remain somewhat ambulatory), a scooter doesn't serve as a feasible platform for mounting rehab seating that requires complex positioning components or even legrests. For this reason, designs of power wheelchair bases are intentional toward allowing the mounting of seating that ranges all the way up to tilt, recline, and elevating legrests, technologies that are incompatible with scooters.

Surely, it's important to realize that there remarkable value to scooters and power wheelchairs alike. In fact, for those who have the capabilities, scooters are tools of tremendous liberation, just as with power wheelchairs for those with advanced needs. While the obvious natures of scooters and power wheelchairs distinguish them from each other, understanding the technology of each - why they're designed in their individual forms, with exclusive attributes - will assist you even more toward recognizing which mobility device may best meet your needs.  

Published 6/08, Copyright 2008, WheelchairJunkie.com