Power Wheelchair Features and Components

Conventional Power Wheelchair Frames

The conventional power wheelchair frame is very similar to a manual wheelchair frame but has batteries, motors and electronics mounted on them. This class of power chair can be folding like the folding manual chairs or non-folding like the manual rigid chairs.

The obvious advantage of the folding power chair is it's transportability. Before you get too excited and decide this is the chair for you, there are a couple of things you need to know. The first is that disassembly, folding and loading the folding power chair into a vehicle is best done by a fairly strong, healthy young person. In order to fold the chair someone must disconnect and remove the batteries and the mounting hardware for the batteries. The batteries for this class of chair are usually U-1 sealed batteries which weigh about 25 pounds each, plus another 10 pounds approximately for battery boxes and hardware. Once the batteries are removed,  the chair will fold but there are still two motors and the electronics attached to the chair. The electronics can sometimes be removed to lighten the chair, but the motors can't and the weight of the chair stretches the definition of portable.

The non-folding power chair looks pretty much the same and you have the option of removing the batteries to make the chair lighter for lifting but you're still trying to lift about 100 pounds of chair. The one advantage of the non-folding version of the conventional power wheelchair is, the frame is stronger because there are fewer moving parts.

Both the folding and non-folding conventional power wheelchair have a couple of drawbacks which rule them out for many people. They never have electronics that can be upgraded, so if the user develops some added disability that prevents them from being able to operate the chair, a new chair must be purchased. If the user has a dramatic weight gain or loss, the frame can't be adjusted or re-sized to fit properly without incurring a fair amount of cost.

Power Wheelchair Bases

Power base wheelchair consist of two basic components, the base which includes the frame, wheels, batteries and electronics, and the chair which include an adjustable seat frame, arm, footrests, cushioning and drive control. Almost every power base has electronics which can be upgraded in the event of reduced abilities and the seat frames which can be adjusted for changes in size and seating options. This adaptability of power bases means the chair will not have to be replaced until it is actually worn out rather than when the user changes condition.

Power bases come in three wheel configurations, front wheel drive, mid wheel drive and rear wheel drive. The configuration the user chooses is dependent on the type of terrain the user will usually encounter and the features important to the user. Each type of wheel configuration has different driving characteristics and often a user who is replacing a previous power wheelchair will have a bit of difficulty getting used to a different configuration.

Front Wheel Drive Power Wheelchairs

The drive wheels of a front wheel drive power wheelchair are forward of where you sit making it a very stable configuration for uneven terrain. It has the best performance when trying to climb obstacles and travel through rough terrain. Where rear wheel drive power chairs and manual chairs swing at the front when turning the front wheel drive chair swings at the back. This characteristic is what can cause difficulty for a user who has had only experience with rear wheel chairs. Front wheel drive chairs tend to be slower than mid or rear wheel drive chairs because they tend to fishtail at speed. Front wheel drive configurations have swiveling casters at the back of the chair allowing for more footrest options than rear wheel drive.

Mid Wheel Drive Power Wheelchair

The mid wheel drive chair has the drive wheels positioned in the middle of the power base making it the best chair when it comes to maneuvering in small places. The early versions of the mid wheel drive chair had a tendency to tip forward when traveling down inclines which users found quite nerve racking but today's mid wheel drives have pretty much solved this problem. Because this configuration has all the weight balanced on the center wheels mid wheel drive chairs need front and rear anti-tippers. When traveling over rough terrain or trying to negotiate curbs the mid wheel drive chairs can get stuck if the anti-tippers prevent the drive wheels from maintaining traction on the ground. While more stable at speed than the front wheel drive the mid wheel drive chair is slower than the rear wheel drive configuration. As with front wheel drive chairs there are no swiveling casters to interfere with the footrests allowing for more footrest options.

Rear Wheel Drive Power Wheelchair

Rear wheel drive is the most conventional configuration and requires no learning by users who have experience with older models of chairs This chair is very stable at high speeds but has the largest turning radius making it a little challenging to use in small places.

Power Wheelchair Base Seat Frames

All power bases offer two basic choices in seat frames. One choice is sometimes known as a van style seat and consists of a padded seat and back support, a pair of flip back arms and sometimes a headrest. They can have a standard back height or tall back height and often feature the ability to fold down. There may be some adjustment in the van style seat arms in terms of height or seat width but there is no way to change the seat size in the event of a change in the user.  This seat is basically a comfort seat which was never designed for posture control or advanced seating products.

Rehab Seat Frames are the second type of seat frame available on power base wheelchairs. Rehab frames have huge variations in seat width, depth and back height which are usually adjustable after delivery for precise fit to the end user. They actually are just a frame that is designed for the installation of some type of seating system. Rehab seat frames have a solid plastic or steel seat pan which the user will need  to order a cushion for, separately. Some manufacturers supply back upholstery with their rehab seat frames, others simply supply two vertical back canes which the dealer must use to install a back support. In addition to being very adjustable in size these seat frames can be angled to provide a bit of fixed tilt if required for user function or stability.

When opting for a rehab style seat frame on a power wheelchair, decisions must be made as to the style of arms and footrests. The choices available for these options on a power wheelchair are virtually the same as for a manual wheelchair.

People who are able to shift their weight, control their posture, control their stability and are not likely to deteriorate in condition or abilities are candidates for the van style seat. People who cannot control their posture or stability, cannot shift their weight, may deteriorate in time or require either off the shelf or custom seating products, are the people who should be opting the rehab style seat frame.