Whether the dimensions of the main parts of the wheelchair are appropriate or not is directly related to the sitting posture and stability of the passengers, local skin pressure and the safety of transfer. A proper wheelchair can not only save energy for passengers in use, but also effectively prevent other adverse events.
The main parameters for wheelchair selection are as follows:
1. Seat width
It refers to the distance between the side plates of the armrests on both sides of the wheelchair.
Measurement method: When the tested person is sitting in a wheelchair, the distance between the wider hips on both sides plus 5cm, that is, there is a 2.5cm gap between the two sides of the hips and the side plate. The width of the wheelchair is generally 40-46cm.
If the seat is too wide, it is not only difficult for passengers to maintain body balance, but also inconvenient to drive the handwheel, which will increase the physical consumption of passengers during the use of wheelchair.
If the seat is too narrow, it may make it inconvenient for passengers to get on and off the wheelchair, and easily scratch the skin. In serious cases, it may even increase the risk of pressure ulcers.
2. Seat length
Also called seat depth, it refers to the distance between the backrest and the front edge of the seat.
Measurement method: The subject sits in a wheelchair, with the knee flexion 90 °, and the horizontal distance between the prominent part behind the hip and the calf gastrocnemius muscle is reduced by 5cm, generally 41-43cm.
If the seat is too long, the front edge of the seat will compress the popliteal fossa and affect the blood circulation.
Too short seat will make the load bearing of ischial tubercle too large, increasing the risk of pressure ulcers.
3. Seat height
Measurement method: The subject sits in a wheelchair, with the knee flexion of 90 ° and the foot touching the ground, and measures the height from the popliteal fossa to the ground.
The height of the seat is too high, which will cause inconvenience to the use of the wheelchair. For example, the wheelchair cannot enter under the table when eating.
Low seating will increase hip pressure.
4. Handrail height
Measurement method: The passenger sits in the wheelchair, with his upper arm naturally sagging and his elbow bent 90 °. The distance from the lower edge of the elbow to the seat surface is measured plus 2.5 cm. When using the cushion, the height of the cushion should also be added.
The appropriate handrails can comfortably support the limbs and help the passengers to maintain good posture.
If the armrest is too high, the upper arm will be lifted; If the handrails are too low, the torso needs to lean forward, thus affecting the sitting posture.
5. Height of backrest
The height of the backrest depends on the function of the torso. The lower the backrest, the greater the range of motion of the trunk and upper limbs, and the higher the requirements for trunk control.
The height of the low backrest is the actual distance from the wheelchair surface to the armpit minus 10 cm, that is, the height of the upper edge of the backrest should be about 10 cm below the armpit of the passenger.
The height of the high backrest is the actual height measured from the seat surface to the shoulder or rear headrest.
6. Foot rest height
It is related to the seat height.
The appropriate height is 90 ° flexion of the passenger's knee joint. Place both feet on the foot pedal. There is about 4 cm space between the front end of the thigh at the popliteal fossa and the seat cushion.
If the distance between the seat cushion and the pedal is too large, the feet can not be placed on the pedal, thus losing stability.
If the distance between the seat cushion and the pedal is too small, it will increase the hip weight bearing.
In addition, the foot pedal should be about 5cm high from the ground to cross some small obstacles