When comparing power wheelchairs, attention usually goes to speed, drive wheel position, seating and overall dimensions. Suspension is easy to overlook, partly because it does its work quietly and mostly out of sight.

Suspension influences how the power base responds to the surface underneath it, how reliably the drive wheels stay in contact with the ground, and how much shock and vibration reaches the seating system and the person sitting in it.

So how does it actually work, and why does it matter?

What Is Power Wheelchair Suspension?

Power wheelchair suspension is a system that allows the wheels to move in a controlled way relative to the power base as the chair travels over changing terrain.

That movement is not free. Springs, elastomers or dampers resist the wheel as it rises over an obstacle and control how it returns. This is the difference between suspension and a wheel that simply pivot.

Suspension serves two purposes:

• Maintaining ground contact. Keeping the drive wheels loaded and in contact with the surface supports traction and directional control.
• Attenuating shock and vibration. Absorbing energy in the power base means less of it is transmitted through the frame to the seating system and the user.

Suspension designs vary considerably. Some suspend the casters, some suspend the drive wheels, and some allow the base to articulate as a whole. Systems are also tuned to a load range, so occupant weight and seating configuration affect how a given suspension behaves.

Why Do Power Wheelchairs Need Suspension?

A power wheelchair may encounter many different surfaces throughout an average day.

These could include:

• Carpet
• Tiles
• Footpaths
• Thresholds
• Ramps
• Grass
• Uneven pathways
• Changes between indoor and outdoor surfaces

Each asks the power base to respond. Without suspension, a wheel meeting an obstacle transmits that energy almost directly into the frame, the seat and the person.

This matters clinically. Extended driving on rough surfaces exposes users to whole body vibration, which has been associated with low back, neck and buttock pain and increased muscle fatigue. For a user with pain, altered tone or fatigue, ride quality is not a comfort feature. It determines how long they can tolerate being out in the community

Does Suspension Help With Traction?

Traction depends on keeping the drive wheels loaded and in contact with the ground. Suspension contributes by allowing wheels to follow terrain rather than lifting the base as a rigid unit.

It is only one contributor, though. Tyre type and pressure, drive configuration, weight distribution, ground clearance and controller programming all influence how the chair behaves on a given surface.

Is Suspension Only Important Outdoors?

No.

Indoor environments contain surface changes too. Door thresholds, transitions between flooring types, small ramps and lift entries all require the power base to respond.

Kerb ramps and threshold transitions deserve particular attention. Surface transitions built with a threshold for water drainage can produce noticeable vibration, especially where accessibility guidelines have not been met. These are everyday obstacles, not occasional ones.

Does Drive Configuration Affect Suspension?

Drive configuration and suspension are distinct features that interact as part of one power base.

Where the drive wheels sit determines which wheel meets an obstacle first and how the base pitches as it climbs. The suspension determines how that contact is absorbed and controlled. A mid-wheel drive and a front-wheel drive chair can respond quite differently to the same threshold because of geometry, wheel size and suspension design together.

This is why performance cannot be predicted from drive wheel position alone.

What Should You Consider When Comparing Power Wheelchair Suspension?

Rather than looking for a single suspension specification, consider how the complete power base has been designed.

Shock and vibration reaching the user are shaped by the suspension system, the seat frame mounting hardware, the cushion, the back support, armrests, legrests and headrest, the size and properties of the drive wheels and casters, and the programming. Cushion selection matters here in both directions, since some cushions attenuate vibration and others may transmit or amplify it.

Questions to consider can include:

• What type of suspension does this power base use, and which wheels does it act on?
• Is it tuned for this user's weight and seating configuration?
• How does the chair behave crossing the thresholds this user meets daily?
• How does the suspension work with the drive wheel configuration?
• What is the cushion and seat mounting contributing?
• How does it feel when trialled on the surfaces this user actually travels?

A real-world trial can be particularly valuable when comparing different power wheelchair bases.

Quantum Power Wheelchair Suspension

Quantum Rehab incorporates suspension technology across its range of complex rehabilitation power wheelchairs.

Different Quantum power bases are designed for different environments and user requirements, from manoeuvrable everyday power wheelchairs such as the Quantum Edge® 4 through to power bases designed with more adventurous environments in mind, such as the Quantum Outback 4x4.

Rather than looking at suspension in isolation, the complete power wheelchair should be considered, including its drive configuration, seating, electronics, tyres and intended environment.

Choosing a Power Wheelchair for Your Environment

Power wheelchair suspension is one part of a much larger picture.

The right power wheelchair should be considered in relation to the user's environment, functional goals, seating and positioning needs and the surfaces they regularly encounter.

Working with a therapist and experienced mobility equipment provider allows different power wheelchair options to be assessed and trialled based on the individual user's requirements.

 

Frequently Asked Questions

What does suspension do on a power wheelchair?

Power wheelchair suspension allows parts of the power base to respond to changes in the surface underneath the chair. It can contribute to traction, stability and overall driving performance.

Is power wheelchair suspension important outdoors?

It can be particularly important when navigating changing outdoor surfaces, but suspension also plays a role when travelling across thresholds, ramps and different surfaces indoors.

Does suspension improve power wheelchair traction?

Suspension can help the wheels maintain appropriate contact with changing terrain. However, traction is also influenced by tyres, drive configuration, weight distribution and the overall design of the power base.

Do all power wheelchairs have the same suspension?

No. Suspension design varies between power wheelchair models and manufacturers. The complete power base should be considered when comparing different options.

Should I trial a power wheelchair before choosing one?

Where possible, trialling a power wheelchair across environments and surfaces relevant to the user can provide useful information about its driving characteristics and overall suitability.