Overall Length with Legrest

A power wheelchair with a long total length requires a large space for movement and turning. Transportation vehicles and elevators also need to have enough space to accommodate it. The key finding the correct overall length for you is in the type of chassis and available radius.

Overall Width

The general width of a front door is about 90 cm wide, and the bedroom or kitchen doors are about 80 cm wide. Usually the smallest door is the bathroom door, at only 70-75 cm wide. In order to avoid the problem of not being able to turn, pay attention to the wheelchair width when choosing a power wheelchair.

Overall Height

A power wheelchair that is too tall will limit the choice of transportation means. When necessary, changing the seat posture can be used to reduce the total height. The total height will influence the sitting height.

Folded Length

The longer the length of the folded wheelchair, the more storage space it takes up, which affects the convenience of transportation. The wheelchair’s foldable (or removable) components, such as footrests and anti-tipper, can affect the folded length.

Folded Width

The wider the width of the folded wheelchair, the more storage space it will take up, which will affect the convenience of handling. The wheelchair’s overall frame design will affect its folded width.

Folded Height

The higher the total height of the collapsed wheelchair, the higher the storage space is needed, which in turn affects the convenience of transportation. The wheelchair’s foldable (or removable) components, such as the headrest, foldable backrest, detachable armrests, can affect the folded height.

Total Mass

For lightweight power wheelchairs, it is the total weight for reference for human handling. For chassis-type power wheelchairs, it is the total weight for reference for transportation.

Total Mass (Without Battery)

This is the same as the Total Mass, but does not include the weight of the battery; disassembling the battery for transportation can reduce the burden. Sometimes the battery must be disassembled and separated during transportation.

Mass of the Heaviest Part

Dismantle all parts of the wheelchair by hand, regardless of the total volume or weight, so that every part of the power wheelchair can be transported and make it easier to go out; or reduce the total volume of the wheelchair for convenient storage.

Ground Clearance

Avoid obstacles higher than this range during wheelchair travel to avoid damage to the wheelchair body or accidents during driving.

Turning Radius 

Minimum Turning Radius, defines the smallest radius for a user to turn around on a wheelchair 360°. Before buying a wheelchair, it is important to check if the wheelchair can be navigated through all the confined places in one’s living environment, such as the elevator. The mid-wheel drive electric wheelchair offers the smallest turning radius, followed by the front-wheel drive and rear-wheel drive.

Reversing Width

Reversing a power wheelchair requires some practice. To accomodate small turning spaces or small walkways, a smaller reverse turning width is essential.

Wheelbase

The length of the wheelbase is related to the total length of the wheelchair. A shorter wheelbase wiill have a smaller minimum turning radius and good flexibility when turning, but the stability will be reduced.

Front, Middle, and Rear Wheel Track

The greater the distance, the higher the stability of driving, however the smaller the distance the better the flexibility of turning.

Seat Plane Angle

A positive seat plane angle means the front edge of the seat is higher than the rear, which stabilizes the pelvis and make it harder for the users hips to slide forward. A negative seat plane angle can help the user to stand up from the front of the wheelchair.

Tilt Angle

Sitting in a wheelchair for a long time will cause pressure to concentrate on the hips after a long time. When you ‘Tilt-in-Space’ over 30°, the pressure originally concentrated on the hips will be fully transferred to the back. By ‘Tilting-in-Space’ at a small angle, you can increase the stability of the users sitting position and avoid sliding.

Seat Depth

If the seat depth is shorter than user’s thigh length, the user is more likely to lean forward on the chair; if it is too deep, the legs will be blocked by the front edge of the seat, making it hard for the user to sit up straight, causing posterior pelvic tilt and other issues. Generally speaking, an appropriate wheelchair seat depth should be 2-3 cm shorter than the user’s thigh length.

Seat Width

Generally speaking, an appropriate wheelchair seat width should be 2-3 cm wider than the user’s hip width. A chair that is too narrow in width is not comfortable. A chair that is too wide in width might results in scoliosis because the user will have to lean to one side to remain in a stable sitting posture.

Seat Surface Height at Front Edge

When the seat height is too high, it is more difficult for the user to move to the wheelchair by themselves. If the seat height is low it is easier for the user to move but make sure that the distance between the seat surface and the footrests can still accomodate the calf length. The seat height also affects the accessibility of the environment, such as eating at a table and driving etc.

Seat to Back Angle

Function-wise, if the seat to back angle is less than 90°, the stability of the pelvis increases and the user has more control. When the angle is greater than 90°, the occupant can release any pressure on the hips and abdomen. Physically, the adjustment of the seat to back angle can be adapted to users with hip contractures or limited angles to stabilize their sitting posture.

Backrest Angle

The reference value is the same as the angle of the seat to back angle, but the measurement standard is different.

Backrest Height

If the height of the back is too high, the degree of support can be good, however the trunk is easily pushed forward and can cause instability. If the back is too low then it will lack trunk support and it will be easy for the body to slide forward and harder to maintain overall body stability.

Headrest Height Above Seat

If the height of the headrest is too high it can increase the risk of neck injury. If the headrest is too low, it will lack head support, and the head and neck will be prone to being excessively stretched.

Calf Length (Footrest to Seat Distance)

Everyone has different calf lengths. If the distance from the foot support to the seat is shorter than the user’s calf length, it will raise the user’s knees, increase the angle of the thighs, and therefore concentrate more pressure on the hip-bone area. If the distance from the foot support to seat is longer than the user’s needs, it will cause the user to slide forward and forece them to user their feet for support. This can increase the risk of posterior pelvic tilt or scoliosis in the long term.

Leg to Seat Surface Angle

This angle is related to the angle of the knee joint. For users with knee contracture, a smaller angle can increase the stability of the ride. A wheelchair with adjustable foot angles can provide knee joint mobility, and allow the user to comfortably stretch their lower limbs.

Armrest Height

When an occupant rides in a wheelchair, their hands naturally hang down, and the elbows are placed on the armrests. When the elbow is placed on the armrest and the user is in the “shrug” posture, it means that the height of the armrest is too high. If the elbows cannot fit on the armrest pads or they hang in the air, it means that the position of the armrests are too low, which will reduce the support of the shoulders and increase the risk of joint deterioration or dislocation of the user.

Front Location of Armrest Structure

The typical height of furniture table tops is usually 680mm. The height of the front end of the armrest will affect how close the wheelchair can be to the table. The closer the occupant’s body can be to the table, the easier it will be to carry out daily activities such as eating and writing.