Choosing the Drive Wheel Configuration in a Power Wheelchair

Power Wheelchair is an important aid for people with limited mobility. It has larger wheels (called drive wheels) and 2-4 casters that help with stability. Depending on your needs, there are several options to consider.

Tilt-in-space functionality allows the seat, backrest and legrest to recline simultaneously. This helps with pressure relief and posture support.

Choosing the drive wheel configuration in a power wheelchair can have a significant impact on how the chair drives and maneuvers in different environments. There are three main types of drive wheel configurations: front, mid and rear. The position of the drive wheel determines how well the wheelchair can overcome obstacles and traverse surfaces, how much stability it has, and its ability to move on varying terrains.

Rear-wheel drive chairs tend to have the largest footprint of any of the three types and may feel more stable on a variety of terrains, especially when travelling at high speeds. They can also have problems with steep inclines and hills because the drive wheels may lift off the surface, causing loss of traction. This problem can be addressed with the use of suspension.

Mid-wheel drive power chairs have two casters in the front and one in the back, so the client sits primarily over their rear set of wheels. This type of chair is typically easier to drive because it allows the user to turn on a dime, and it can be driven on uneven or side-sloping surfaces. It can be more challenging to navigate tight spaces because the footrests are angled forward at between 80 and 60 degrees to clear the larger front casters.

Front-wheel drive chairs are ideal for navigating curbs and other obstacles because the 14-inch drive wheels are the first ones to encounter an obstacle. This means that they pull the rest of the wheelchair over it, rather than pushing the front casters over it, which is harder and less efficient. The front casters can also take on more of the weight of the chair, so they might need more suspension than mid-wheel or rear-wheel drive models.

Mid-wheel drive

If you’re looking for a more intuitive driving experience, you may want to consider choosing a power wheelchair with a mid-wheel drive. This configuration features a central pair of drive wheels and two front and rear caster wheels, which provides excellent stability. It also allows users to recline their seats without changing their posture or losing support. Some seating systems even include programmable elevating leg rest functionality. These are useful for accessing cupboards and achieving comfortable, effective pressure relief.

A mid-wheel drive power chair is also known for its tight turning radius. The fact that the drive wheels are directly under the user’s center of gravity means the chair can make sharp turns more easily than RWD or FWD chairs. It’s also great for navigating narrow spaces, as the front and back caster wheels help it maintain a stable base.

However, it’s important to remember that mid-wheel drive chairs require more precision and higher upper body strength than RWD or FWD power wheelchairs. This is because they require the user to make precise driving inputs in order to maneuver in tight spaces. This is especially true when traveling straight at higher speeds.

Another downside of a mid-wheel drive power chair is that it can have a bumpy ride. Since the front and back caster wheels touch the ground first, they can transfer more energy to the user than the drive wheels. This can lead to discomfort and a lack of stability, but many manufacturers have developed suspension systems to mitigate this problem.

As suspension has improved over time, mid-wheel drive power wheelchairs have become more able to navigate outdoor terrain. They can do well on inclines and hills as long as the drive wheel remains loaded. If the wheel lifts off the surface, it can lose traction and become stuck.

Front-wheel drive

Front-wheel drive is one of the most popular power wheelchair configurations. It provides a balance between stability and manoeuvrability. Since the chair’s center of gravity is closer to the drive wheels, it has a small turning radius. In addition, its front turning aspect is smaller than the mid-wheel or rear-wheel drive chairs, which makes it easier to maneuver in tight spaces and around obstacles.

This configuration also performs well indoors. Its large drive wheel is the first to overcome uneven surfaces, allowing the caster wheels to follow – a key factor in indoor navigation. Additionally, individuals who want to drive over rough terrain can benefit from the front-wheel drive’s increased traction, and it can be customized with a number of seating functions, including elevating options.

The front-wheel drive configuration also provides a more stable base, especially in the front of the wheelchair, which reduces the risk of tipping. It also has inherent directional stability, which means the chair naturally tracks straight without requiring constant adjustments. This type of power wheelchair is the most common in geriatric settings and for people who spend most of their time outdoors or on uneven surfaces.

Another key advantage of the front-wheel drive configuration is its ability to get closer to objects, such as bathroom sinks. This is because the chair’s drive wheel is in the front and the casters are in the back. While mid-wheel drive wheelchairs are also able to reach these surfaces, the casters may interfere with knee flexion and make it difficult for the individual to position themselves close enough to access them. In addition, the mid-wheel drive configuration may not support all power seat functions, and it can be challenging to learn to operate a wheelchair with this configuration.

Free wheel mode

Power wheelchairs provide powered mobility assistance for people with medical conditions that make walking difficult. They are typically customized and prescribed by an occupational therapist. They are also available through the Assistive Device Program (ADP) for individuals who qualify. A power chair can be used to perform day-to-day tasks, travel from home to work or school, and to visit friends and family members. Some power chairs even offer a feature that allows the user to stand up and talk at eye level with others. This feature is called an elevating mechanism and is a popular option for many users.

A power wheelchair uses two motors to operate the drive wheels, similar to a car’s engine. The motors draw power from batteries to move the wheels. A power wheelchair can also be equipped with other systems, such as a tilt function.

There are three different types of power wheelchairs: front-wheel drive, mid-wheel drive, and rear-wheel drive. Each type serves a different purpose and requires unique skills to maneuver. Front-wheel drive power chairs are ideal for people who want to maneuver over small obstacles and have a respectable turning radius. However, they can fishtail when turned at high speeds.

Mid-wheel drive power wheelchairs have the tightest turning radius. They are best suited for indoor and outdoor use, but may not maneuver as well over steep or uneven surfaces.

A power wheelchair can also be equipped with a powered recline function, which allows the backrest to tilt in a range of positions. This can be useful for reducing swelling, improving circulation, preventing pressure sores, and sleeping comfortably. Some models of power wheelchair also come with a powered anti-sheer mechanism, which prevents shearing of the skin.

Elevating mechanisms

Elevating mechanisms in a power wheelchair raise the seat to allow a user to interact with their environment at standing height. They can communicate with others eye to eye and reach items they otherwise wouldn’t be able to, such as kitchen counters or shelves in a store. This helps to reduce stress on the upper body and improves their quality of life.

Some power wheelchairs include advanced steering systems that assist a user to maintain a straight course on cambered surfaces. This is particularly useful for users with impaired hand function or those using non-proportional control devices such as sip and puff or chin control. These systems can also help prevent the wheelchair from rolling when it is not being driven.

Another innovative feature of some power wheelchairs is a combination of the lift and tilt mechanism in a single unit. This is possible because a pair of linear actuators provide space into which the tilt mechanism nests when it is in its retracted position. The linear actuators perform both the functional movement of the lift mechanism and structurally support a portion of the tilt mechanism.

The unit comprises a pair of opposing scissor lift mechanisms, a pair of linear actuators, and a frame for supporting the seat base and the tilt mechanism. When supplied with electrical power, the actuators operate to turn screws 32a and 32b, which synchronize via a timing chain. When turned, the screws move first leg lower ends 58a and 58b either toward or away from second leg lower end 60a and 60b of each scissor lift mechanism. When the scissor lift mechanisms are retracted, the tilt mechanism nests in the space between them.