Lightweight/Sports Chairs - The most popular type of wheelchair for everyday use for a person with good upper body mobility is the lightweight manual wheelchair. Lightweight chairs provide maximum independence of movement with a minimum of effort. Many active wheelchair users also prefer the sportier look of the lightweights compared with the more standard looking everyday chair. It should be noted, however, that heavy or obese persons may be unable to use these types of chairs because the lighter weight of the frame results in a reduced user capacity as compared to standard everyday chairs. Once used primarily by wheelchair athletes, the lightweight chair today is used by people in virtually all walks of life as a preferred mode of assisted mobility. Three-wheeled chairs, also developed for such sports as tennis and basketball, are also an everyday chair alternative.
Standard/Everyday Chairs - Some wheelchair users still prefer or require a standard wheelchair, which is characterized by a cross-brace frame, built-in or removable arm rests, swing-away footrests, a mid- to high-level back, and push handles to allow non-occupants to propel the chair.
Child/Junior Chairs - Children and young adults need chairs that can accommodate their changing needs as they grow. In addition, it is important that wheelchairs for children or teens be adaptable to classroom environments and be "friendly looking" to help the user fit more readily into social situations. Manufacturers today are becoming increasingly sensitive to these market demands and are attempting to address them with innovative chair designs and a variety of "kid-oriented" colors and styles.
Specialty Chairs - Because of the diverse needs of wheelchair users, wheelchairs have been designed to accommodate many lifestyles and user needs. Hemi chairs, which are lower to the floor than standard chairs, allow the user to propel the chair using leg strength. Chairs that can be propelled by one hand are available for people who have paralysis on one side. Oversized chairs and chairs designed to accommodate the weight of obese people are also offered. Rugged, specially equipped chairs are available for outdoor activities. Aerodynamic three-wheeled racing chairs are used in marathons and other racing events. Manual chairs that raise the user to a standing position are available for people who need to be able to stand at their jobs, or who want to stand as part of their physical conditioning routine. These and other specialized chair designs generally are manufactured by independent wheelchair manufacturers who are trying to meet the needs of specific target markets.
Institutional/Nursing Home/Depot Chair - The least expensive type of chair available, an institutional chair, is designed for institutional usage only, such as transporting patients in hospitals or nursing homes. It is not an appropriate alternative for anyone who requires independent movement, as the institutional chair is not fitted for a specific individual. These types of chairs are now also used as rental chairs and by commercial enterprises (such as grocery stores and airports) for temporary use.
Manual Wheelchair Components
Frame - The two most common types of frames currently available are rigid frame chairs (where the frame remains in one piece and the wheels are released for storage or travel), and the standard cross-brace frame (which enables the frame to fold for transport or storage).
Upholstery - must withstand daily use in all kinds of weather. Consequently, manufacturers provide a variety of options to users, ranging from cloth to new synthetic fabrics to leather. Many manufacturers also offer a selection of upholstery colors, ranging from black to neon, to allow for individual selection and differing tastes among consumers.
Seating System - are sold separately from the wheelchairs themselves, as seating must be chosen on an individual basis. It is important when selecting a wheelchair or a seating system to ensure that the two components are compatible.
Brakes - or wheel locks are available in several different designs, and can be mounted at various heights to maximize convenience to the user.
Wheels/Tire - Most wheelchairs use four wheels, with two large wheels at the back and two smaller ones (casters) at the front. The standard tire used for the rear wheels on most wheelchairs is a pneumatic tire, for which the standard size is 24 inches. Smaller and larger sizes, however, also are available. Many manufacturers now also offer other types of tires--such as solid tires, semi-pneumatic, or radial tires--at extra cost. Mag wheels and off road wheels also are options on some chairs. Casters, too, vary in size (ranging from six to eight inches in diameter) and composition (pneumatic, solid rubber, plastic, or a combination of these).
Footrests - usually are incorporated into the frame of the chair as part of the design. Cross-brace folding chairs often have footrests which swivel, flip up, and/or can be removed.
Armrests - Many lightweight manual chairs are designed to be used without armrests. The absence of armrests makes it easier for the user to roll up to a desk or table, and many active wheelchair users prefer the streamlined look of a chair with no armrests. However, armrests are helpful if the user has difficulty with upper body balance while seated. Armrests come in a variety of styles including desk length (to allow the user closer access to desks and tables) or full length and both types may be flip-up, fixed, or detachable.
A powered wheelchair must be selected carefully in order to ensure it not only meets the needs of the individual who will use it but also represents good value for the money being invested in it. Physical considerations include posture, strength, sensation, visual acuity and perception, and the ability to learn how to use the wheelchair safely. A functional evaluation should include actual use of the wheelchair in everyday settings; an evaluation of the individual's ability to get in and out of the wheelchair; and the ability to perform needed activities from the wheelchair. Transportation to and from various settings also is an important consideration: Is a van available to transport the individual in the chair, or is it necessary for the chair to fold or disassemble in order to be carried in an automobile trunk?
Powered Wheelchair Components
Frames - Many traditional-style models utilize the traditional cross-brace frame which allows the chair to be folded or collapsed for storage and transport once the batteries have been removed. Other traditional models and some power base chairs disassemble for transport. A number of chairs, however, are designed to be transported while carrying the user; consequently, they do not fold or disassemble.
Upholstery - for wheelchairs must withstand daily use in all kinds of weather. Consequently, manufacturers provide a variety of options to users, ranging from cloth to new synthetic fabrics to leather. Many manufacturers also offer a selection of upholstery colors, ranging from black to neon, to allow for individual selection and differing tastes among consumers.
Seating System - are sold separately from the wheelchairs themselves, as seating must be chosen on an individual basis. It is important when selecting a wheelchair or a seating system to ensure that the two components are compatible. Power base chairs, because of their more modular construction, frequently feature customized chair-style seating systems.
Brakes - Most powered chairs utilize a dynamic braking system in which the motor and brakes work together to slow and stop the chair when the joystick or other controller is released, and which automatically engages the brakes when the power is off or when the chair is not being powered in a forward or reverse motion with the controller.
Wheels/Tires - Power base chairs typically use four wheels of the same size, usually 8 to 10 inches in diameter. These chairs may have pneumatic, semi-pneumatic, or solid tires.
Footrests - A variety of footrest assemblies are available on both types of wheelchairs. They may be a rigid single unit, 90 degree-90 degree platforms, folding, flip-up, detachable, adjustable length, hemi- height, or have a combination of features.
Armrests - Armrests also come in several styles or with a combination of features. They may be full- or desk-length, or wraparound, and they may be fixed, removable, pivoting, and/or adjustable height.
Controls - Powered chairs generally include as a standard feature a manually controlled joystick to regulate the chair's speed and direction. However, most manufacturers offer customized control options to accommodate the varied abilities of the user, including sip-n-puff systems, head and chin switches, push-button controls, trackballs, and tillers. Many chairs also have programmable control features which allow the user or a dealer to adjust or set the chair's speed and control limits as the user's abilities change.
Drive System - the means by which power is delivered to the chair's wheels. Standard drive systems include gear drive, direct drive, and belt drive. The type of drive system affects the power available to propel the chair and the amount and type of maintenance the chair requires.
Batteries - are a determining factor in the range and power of a powered chair. Generally, the larger the chair's batteries, the greater the power and the longer the chair's range between charges. Many chairs require two rechargeable 12-volt batteries. Most wheelchairs utilize U1, group 22 or 24 batteries, although other batteries are also used. More manufacturers are designing chairs around the group 24 battery because it affords a longer range. The type of battery required is also an important consideration in terms of safety, maintenance, and transport. Powered chairs may utilize lead acid, gel cell, or sealed wet batteries. Gel cell batteries require the least maintenance and have less danger of leaking than do the other battery types. Gel cell batteries are also required by a number of airlines when transporting powered wheelchairs.
Special Powered Features - Powered chairs may offer specialized powered features to meet the user's needs, either as customization or options on a standard chair or as a chair designed specifically for a particular purpose. Among the available features are elevating and lowering seats, and reclining and/or tilt-in-space seats. Specialized chairs have the capacity to raise the user to a standing position, to negotiate stairs, or to be used as a lift or in transferring.
Typically, scooter users have some ability to walk, but are limited in distance or stamina--people with milder forms of cerebral palsy, multiple sclerosis, post-polio syndrome, stroke survivors, arthritis, and cardiac conditions, among others. Scooters are used to increase and extend the range of personal mobility and help conserve energy. Scooter users often have difficulty propelling manual wheelchairs, but do not require the sophisticated electronic controls and seating systems common in powered wheelchairs.
A number of other physical factors must also be evaluated when determining whether a scooter is an appropriate mobility aid. A scooter user generally must be able to sit upright for extended periods and have sufficient seated balance to maintain an erect posture. Further, sufficient upper body and arm strength to master the controls and steer and maneuver the unit is required. In addition, uncorrected vision disabilities, or conditions which may cause confusion or memory loss or which inhibit proper safety awareness may render a scooter an unsatisfactory mobility aid.
Scooter Configurations and Components
Base Unit - is basically the body of the scooter. Generally it consists of a steel, aluminum, or composite frame with a fiberglass or composite floor to support the feet and batteries. Some scooter bases also include a shroud over the front wheel and drive head, creating a dashboard for the unit. The base also includes the wheels and the drive train. In some scooters, the seat post is also part of the base. The base unit is the primary determinant of whether the scooter is designed for indoor or outdoor use, the vehicle's maneuverability, the size of its wheelbase, its ground clearance, its turning radius, and its overall dimensions.
A scooter should not tip easily during sharp turns or on inclines such as curb cuts (if the scooter is designed for outdoor use). Anti-tip wheels should be included as part of the frame to help support and stabilize the scooter. On front-wheel drive units, anti- tips are often located laterally just behind the front wheel because they generally lack the power for steep inclines. Because most rear-wheel drive scooters are intended to negotiate more rugged terrain, they are usually equipped with rear anti-tips to support the scooter on hills. Side anti-tip wheels are sometimes offered as options. It should be noted that lateral anti-tippers may cause difficulties on curb cuts and ramps.
On some scooters, the base unit may be comprised of modular units or may otherwise be disassembled for transport and storage. These same features may also allow the scooter to be converted from three- to four-wheeled models and/or from indoor to outdoor use.
Drive Train, Brakes, and Power System - The drive train is an integral part of the base unit and provides either front- or rear- wheel drive for the scooter. Front-wheel drive is usually found on smaller scooters designed primarily to be used indoors or outdoors on flat, paved surfaces. The motor of the front-wheel drive scooter is located over the front wheel and drives only that wheel. Because of the motor and wheel configuration, front-wheel drive scooters are usually direct-drive units, eliminating chains and belts. However, this also means that the front wheel pulls the weight of the unit and the rider. Consequently, these types of scooters have a lesser capacity to move their load than do rear-wheel drive models, and are therefore less capable of handling hills, curb cuts, and other outdoor terrain. This is compounded by the fact that front-wheel drive models generally have smaller motors, causing them to have a shorter range, less speed and power, and a smaller rider weight capacity.
Rear-wheel drive scooters are powered by motors connected to the rear axle, either via a chain, a belt, a transaxle unit, or some combination. Because the scooter is driven by the rear wheels, they push the combined weight of the unit and the rider, rather than pull it. The combined weight of the rider, the motor, and the batteries over the rear wheels, generally create better traction than that usually provided by front-wheel drive models. The increased traction combined with the more powerful motors used on rear-wheel drive scooters results in better climbing ability. The units also have a greater maximum speed, a longer travelling range between battery charges, and a larger rider weight capacity. These scooters have a wider wheel base and a greater overall length, making them less maneuverable and rendering some models unsuitable for indoor use. They may also be too large for van or bus lifts.
Brakes - most rear-wheel drive scooters utilize an electronic or elctro-mechanical dynamic, regenerative braking system. This type of braking system works in tandem with the motor, first to slow and then stop the vehicle when the pressure is released on the thumb levers or the controls are otherwise disengaged. When the scooter is not being powered forward or in reverse, the brakes are engaged, thus preventing the scooter from moving. During the application of the brakes, excess power from the motor is channeled to the batteries, providing recharging. Because the brakes are engaged when the scooter is being actively powered, most scooters with this braking system are equipped with a clutch on the motor or another release lever to manually disengage the brakes to allow the scooter to be pushed in case of emergency.
Some scooters also use disc brakes or disc brakes in combination with the braking system discussed above. Some scooters--usually front-wheel drive models--are not equipped with electronic or electro-mechanical brakes. In the absence of a brake system, a manual parking brake applied by lever to a rear wheel is provided. Manual parking brakes may also be offered either as optional or standard features on other scooters to provide extra braking on hills and inclines.
Batteries - most scooters utilize 12- or 24-volt motors and electrical systems generally with one or two 12-volt batteries to power the drive train and controls. Twelve-volt systems are most frequently found on front-wheel drive scooters, and usually require one 12-volt battery, although two six-volt batteries are sometime used. Some manufacturers offer add-on units for 12-volt systems which allow them to utilize two batteries to extend the scooter's range between charges, although speed and power are not affected. Rear-wheel drive systems generally require two twelve-volt batteries to power 24-volt systems.
These batteries are "deep cycle" batteries intended for wheelchairs and scooters and generally last between 12 and 18 months, although with conservation and regular charging, longer life may be achieved. Deep cycle batteries are designed to provide a steady supply of power and be discharged and recharged on a regular basis. Automotive and marine batteries, on the other hand, are designed to be starter batteries, providing short bursts of power only. Consequently, marine and automotive batteries should never be substituted for deep cycle batteries.
There are three basic types available for use with scooters: Lead acid (or wet cell) batteries, sealed lead-acid batteries, and gel cell batteries. Lead acid batteries are the least expensive of the three types, but they also require the most maintenance. In addition to regular charging, electrolyte and water levels must be checked regularly, with water added frequently to maintain appropriate levels. Because these batteries are not sealed, there is danger of acid spillage and explosion if the batteries are not handled properly. Despite these potential problems, lead-acid batteries provide the benefits of a two- to six-month longer battery life and up to a ten percent greater running time than other battery types. Sealed lead acid batteries are maintenance-free versions of these batteries. Because they are sealed in cases, it is unnecessary to add water and the danger of acid spillage is reduced or eliminated. The cases are vented to prevent gas build-up that can lead to an explosion. Finally, gel cell batteries are the most commonly used battery type on scooters. They are sealed in their cases and require no maintenance other than regular charging. Gel cells are the safest of the battery types, with no danger of spillage and limited risk of explosion. However, gel cells are more expensive, and may have a somewhat shorter life than other battery types.
Wheels and Tires - The size of the wheels and tires on a scooter have a direct affect on the scooter's ability to surmount obstacles and its stability. Scooters are generally equipped with six-, eight-, or ten-inch wheels, although other sizes may also be used. Some models use the same size wheels both front and rear, while others may have smaller wheels in front and larger rear wheels. Smaller wheels are generally found on front-wheel drive scooters intended for indoor use. As a rule, the intended use of the scooter should dictate the size of the wheels and tires. The larger the wheels, the more stable the unit. Similarly the larger and wider the tires, the greater the unit's traction and capacity to manage such obstacles as curb cuts and uneven outdoor terrain.
Several types of tires are available for scooters. Manufacturers generally offer a specific tire as standard equipment, with others available as extra-cost options. Pneumatic tires include air-filled tubes and are similar to those found on automobiles. Air pressure should be checked regularly to maintain proper levels, and tires may need to be replaced if punctured. The addition of an anti-flat compound before inflation reduces the risk of tires going flat. They provide good shock absorption when properly inflated. Foam filled tires are similar to pneumatic tires, but include foam inserts rather than air-filled tubes. These tires cannot be deflated and, therefore, require less maintenance. They may be more expensive than pneumatic tires and may not offer a consistently comfortable ride. The least expensive tire option is the solid rubber tire. These tires require the least maintenance, but provide minimal shock absorption and are intended primarily for indoor use.
Seating - The most common seat found on scooters is a chair-style seat similar to those found on boats. The basic seat is molded hard plastic or fiberglass, but most manufacturers offer a padded-seat option, usually with a choice of vinyl or fabric upholstery. Vinyl upholstery is frequently less expensive, but because it is a slipperier surface, it may not be the best choice for those whose disability makes it difficult to maintain position or balance.
Armrests - are another consideration in seating. Some scooters offer armrests only as an option; others offer fixed armrests as standard with flip-up armrests available.
Tiller - The control and steering mechanism for the scooter, usually containing the controls to drive the scooter forward or in reverse, as well as steering the front wheel or wheels. Most scooters offer one type of standard tiller with other controllers available as options. Possibilities include thumb levers, loop handles, joysticks, and others. Thumb levers are the most common controls, allowing the user to keep both hands on the handle bars while using the left thumb to power the scooter in reverse and the right to power the scooter forward. The amount of pressure applied to the lever will determine the speed of the vehicle (unless it is equipped with a proportional speed control). Consequently, a fair amount of hand control is necessary for safe operation. Finger control levers or a joystick may be alternatives. Some manufacturers may also be able to adapt controls to user requirements at extra cost.
The tiller itself is often an upright post attached to the front wheel. However, it is also becoming common to find flexible, accordion-style tillers which can be adjusted for height and/or position. This not only enables the user to place the tiller in the most comfortable position while driving, but also allows it to be moved up and out of the way during transfers. In the absence of a dashboard or shroud over the front wheel, a control box with the key lock, battery level indicator, speed controller, and other features may be affixed to the tiller handlebars.
Since a joystick controls both speed and direction, scooters equipped with them generally do not have the post-and-handlebar tiller; the joystick is usually attached to an armrest or to an armrest extension, with a choice of right or left mounting. While this frees the space in front of the user and may accommodate easier transitions for some, the lack of handlebars may make transfers more difficult for others.
Other Accessories - In addition to the standard features common to all scooters discussed above, manufacturers offer a variety of standard features and optional accessories. Most scooters are equipped with a key lock for turning the scooter on and off, thus conserving battery life and preventing unauthorized use; a battery-level indicator and a proportional speed controller to limit maximum speed.
A wide range of accessories also are offered on most scooters, such as crutch and cane holders, oxygen carriers, front and rear baskets, trailers, headlights, tail lights, horns, canopies, and others. Some manufacturers even offer sidecars to allow an additional passenger. As when purchasing a car, options and additional features increase the base cost of the unit, but accessories should be evaluated in light of their capacity to create a mobility aid which provides maximum user independence. At the same time, it should be kept in mind that some options may decrease battery life, maneuverability, and/or travel range.
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