Power wheelchairs to enable community access

Enabling community access with a Power wheelchair may sound simple, but there are many factors which combine to determine whether it is ultimately successful or not. No one wants to prescribe – or fund – a product which doesn’t get used, so what influences this?

Before even exploring potential solutions, the nature of access needs to be determined: sealed or unsealed paths? What happens after rain? Are there unique terrain needs such as a distant paddock, steep incline, or kerbs which must be negotiated? What about the narrowest manoeuvring locations such as a shed, local pub or the home? These will assist in determining whether one item can meet their needs, or whether exploration of additional may be necessary. Ultimately, the clinician is working with the user and dealer to identify the solution which best facilitates their independence.

Beyond the chair itself, it is important to recognise the value of training and programming. Training was discussed in our March blog, and programming in May. If the user and their supports (when applicable) don’t know how or aren’t confident using the equipment, or it doesn’t respond how they require, it does increase the likelihood of it simply not being used.

When prescribing a PWC which enhances community access, there are three key components which will be discussed here. They are the base, inner workings, and seating. Each needs to be considered uniquely to the individual to determine what product would best meet their goals. Although these are discussed separately, the interface between the base and drive system is critical to the eventual performance and ability of the PWC.

Base

Specifically relating to the base, the drive wheel configuration, wheel location and to some extent, tyres, all impact the PWC’s ability to climb and manoeuvre. There should also be consideration of how the PWC will be transported: Are tie down points needed? Is a docking station more convenient, but not impact ground clearance needs? Is the base heavy and secure enough to be used on public transport? What is the weight limit for taxis, platform raisers and portable ramps?

When considering drive wheel configuration, front, mid and rear wheel drives all have unique strengths, and the environments of use and drivability should be a key factor.

Tips

• Outdoor-specific bases as well as scooters may not facilitate indoor use due to varying factors such as reduced manoeuvrability, larger base size, and increased torque wearing flooring.
• Larger front wheels will often assist when climbing obstacles, however there may be terrains it can be more challenging to get traction if there isn’t enough weight on them.
• Front-wheel drives can feel like a smoother ride due to the large front wheel and only two sets of wheels, however, can require some practice manoeuvring in tighter environments.
• Mid-wheel drives have three sets of wheels, so thresholds can be felt and impact position and comfort more than alternate options. They however can be most manoeuvrable in tighter spaces.
• Rear wheel drives can have great traction for outdoor terrains, however often have a large turning circle which can limit their indoor manoeuvrability. Some are realistically only able to be used outdoors.
• Pneumatic (air-filled) tyres are likely to have better climbing capacity and have a softer ride feel.
• The distance between all the wheels will also impact the vertical and horizontal centre of gravity.
  • Wider bases, or having larger distances between these wheels, typically provide greater stability. However, the interaction between the wheels, suspension, and the drive system play a critical role with how these ultimately perform.
  • Narrower bases are typically more manoeuvrable in an indoor environment.

Inner workings

Each chair is designed to perform in a particular way, with the components under the shroud significantly contributing to its durability and drive feel. Due to this, knowing the size of motors (watts), battery chemistry, size, as well as energy held (amp hour), torque and mechanisms for suspension will all impact the PWC’s ultimate performance. This can mean in some cases that a smaller base may outperform a larger base, depending on their respective set ups and components.

Questions to consider:

• Is a ‘run up’ needed to go over an obstacle? [Torque, motors, suspension, drive wheel configuration]
• Is the suspension adjustable to a user’s preference or weight? How does suspension perform when using power seat functions?
• Did a previous chair require more maintenance, such as replacing motors or tyres, more frequently than expected [Motor & battery size]
• Is a specific battery needed to maximise performance, or can any battery replacement be used when needed? [Batteries]

Seating and functionality

Seating cannot be a last-minute thought when considering community access, as power seat functions and seating systems are critical for improving access and outcomes. This requires knowing the client, their goals, and functional capacity, and how this relates to seating.

Questions to consider:

• Does the seating provide stability, or restrict movement for function?
• Does the seating system maximise features such as anti-shear?
• Where are the pivot points for the different power seat functions; does it negatively or positively affect the user’s positioning?
• What power seat functions are critical to maximise function in the community?
  • Tilt is often needed in the community for stability descending slopes and under low height clearances.
  • Recline may facilitate independence with self-catheterisation or other personal hygiene tasks.
  • Elevation improves vertical reach, but requires good reach and/ or trunk dexterity to twist.
  • Active reach improves horizontal reach, which can reduce the load and effort.
  • Could a combination of recline and elevating leg supports allow for a pseudo-change table when in the community? How flat can the model actually go, and is this functional? Is elevation also needed to improve the safe working height in this position?
  • Does standing allow participation or completion of tasks otherwise unable to be achieved?
• Can memory positions or profiles be utilised to set parameters around specific tasks or driving to increase function?
• Can power seat functions be retrofitted if needs change in the future?

The next time you are exploring the need for a PWC for a user, and they are needing it both in the home and community environment, I would encourage you to consider these three key areas.

PWCs have different capacities, however the better you know the user and their goals, the easier it can be to determine which device will best meet their needs.

Author

Roseanna Tegel BHthSc/MOT

Clinical Services Specialist