Get the numbers right for the greatest comfort, efficiency, and durability in your new wheels.
When you order your wheelchair, you’ll be asked to provide a variety of measurements and specifications. These measurements will help the manufacturer determine the right frame dimensions, and they will automatically take into account choices you will make for wheel sizes and caster types.
The measurements are, of course, based on the size of the person who will use the chair. Some dimensions – such as seat width – are very precise, while others – such as seat height – are more flexible. These are the most critical dimensions of the wheelchair, and we will review them in detail in a moment.
If you already are using a chair, you have some idea of what measurements are right for you. They might even be exactly the same as your existing wheelchair, but this is also an opportunity for you to make refinements. Perhaps you want to sit a bit higher or lower, perhaps there is pressure against your hips and your seat should be another inch wider. These are some of the issues you’ll take into account as you determine the final specifications of your new wheelchair.
The model of wheelchair you choose might allow some adjustability once you receive it. Many ultralightweight wheelchairs, for instance, allow changes in the height of the main wheel and caster axles. Many models have a separate adjustment for the angle – or "dump"- of the seat. Wheelchair seats are not necessarily level. They typically slant towards the back – either a little or maybe a lot – to provide greater stability. So you will be asked to determine two seat height numbers, one for the front and one for the rear. These are measured from the floor.
Begin with the front floor-to-seat height. Measure the length of your leg from the heel to the inside of the knee, and add two inches, or the desired clearance from the bottom of the footplate to the ground. Then subtract the thickness of your cushion (when you are sitting on it, compressing it). That will be your minimum front seat-to-floor height. You may want more ground clearance or need to sit higher up – the choice is yours – in which case you might add an inch or two.
The rear seat-to-floor dimension will be at least equal to – and usually less – than the front dimension. If you have limited upper body balance, you will want to use more seat dump. Keep in mind that a substantial angle will make it harder to transfer out of the chair. If the dump is extreme, it can also lead to curvature in your spine in the long run because your pelvis will rotates back severely. Use only as much as you need to be stable and safe.
The seat width is the dimension across your hips, plus space for clothing. Take into account the type of clothing you wear such as a sport coat and jacket if they are common to your wardrobe. If you use clothing guards, ensure that there will not be pressure against your hips, which could cause skin breakdown. Of course your goal is to keep the seat and total width of the wheelchair narrow for access reasons, but try not to end up squeezed into your chair. You need a little room to shift your weight, which is also important for preventing pressure sores.
Seat depth is a function of the length of your thighs and, well frankly, the size of your bottom! Measure from where your backside contacts the chair back to just behind your knee. Choose the deepest seat depth option that is at least one inch shorter than your measurement. Allow more space behind the knee if you need it to be able to lift your leg for making transfers, but in general try to keep as much contact with the seat along your upper thighs as possible. Using a seat depth that is too shallow robs you of stability, and increases the pressures on your ischial bones, another major pressure sore location.
Getting these four dimensions correct will lead to natural, effortless posture, and provide you with a solid foundation for an active, comfortable day of wheeling.
|Shop for a wheelchair|