Design Choices for Wheelchairs

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HealthWiki > Disabled Village Children > Chapter 64: Decisions About Special Seats and Wheelchairs > Design Choices for Wheelchairs

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In this chapter:

 

In this chapter:

WHEEL SIZE AND POSITION
2 BIG WHEELS with 1 or 2 small caster wheels	DESIGN DETAILS
INDOOR OUTDOOR one or 2 rear wheels Rear wheel set back to avoid tipping backward on slopes Child’s weight should be mostly over big wheels.	Large wheels let rider push herself. Small caster wheels allow easy turns (on cement, not sand). For leg amputees, rear wheels must be moved back to prevent tipping over backward.
ADVANTAGES	DISADVANTAGES
Child can move it herself if she has hand and arm control. Large wheels go over rough surfaces easier.	takes up more space harder to get in and out of from the side (because wheels need to be higher than seat so that rider can push herself)
4 SMALL WHEELS	DESIGN DETAILS
casters for easier turning	Very simple temporary chairs can be made by putting 4 wheels on an ordinary wood chair. chair leg pin rod wheels
ADVANTAGES	DISADVANTAGES
good only on smooth floors for a child who cannot push or help push his own chair cheaper takes up less space easier to move child in and out of.	not good on rough surfaces Child cannot move it herself. creates dependency
3 BIG WHEELS	DESIGN DETAILS
hand crank and steering	You can use 3 bicycle wheels. Some models have removable front wheels so that chair can be easily changed to have small front wheels for use inside the home.
ADVANTAGES	DISADVANTAGES
excellent for long distance and rough road travel can be used by a person with strength in one hand only	too big for use inside home more costly more difficult to make

BUILDING MATERIAL FOR FRAME
STEEL TUBE	DESIGN DETAILS
Whirlwind wheelchair	Thin-walled electrical conduit tubing can be used — ⅝ inch to 1 inch diameter. Healthlink Worldwide design
ADVANTAGES	DISADVANTAGES
A strong, long-lasting, fairly light chair can be made better and cheaper than most commercial chairs.	requires welding skills, some design ability, and a fair amount of equipment a good chair for a well-equipped rehabilitation center workshop to build, but not a family builders need to be trained
WOOD	DESIGN DETAILS
Healthlink Worldwide model	For wood design details, see "Health Link Wood Wheel Chair" and "Plywood Frame Wheel Chair" and references. wood chair model design
ADVANTAGES	DISADVANTAGES
relatively cheap and easy to make—mostly wood, few or no welds easy to adapt and to add supports or tray tables plywood model design	May not be as stable and long-lasting as other models. (For tighter joints and more adaptability, use nuts and bolts instead of nails.)
RE-BAR (metal reinforcing rod used to strengthen cement)	DESIGN DETAILS
woven plastic seat and back footrest slides in and out	Design can be the same as for metal tube chairs, but it is easier to adapt because the re-bar is easy to bend.
ADVANTAGES	DISADVANTAGES
relatively cheap easier to bend and weld than steel tubing can have plastic woven seat and back (easy to clean) especially good for small chairs	A heavy person or rough treatment may bend it out of shape. fairly heavy
PVC PIPE (plastic water pipe)	DESIGN DETAILS
	Use 15 mm PVC pipe. comes with joints so that it can be fitted together with a special glue For details see reference.
ADVANTAGES	DISADVANTAGES
lightweight can be built mostly by glueing pieces together	costly materials (around $100 US) Plastic tubing will in time sag or bend in the direction of stress. Therefore it may be necessary to fiberglass the frame— which adds to cost, work, and weight.

SEATS AND BACKS
SOFT CANVAS OR LEATHER STRETCHED BETWEEN SUPPORTS	DESIGN DETAILS
	For child who is likely to pee or shit in the chair, use a cloth that is easy to wash. Plastic-coated canvas makes cleaning easy but is hot and may irritate child’s bottom. Best to use an absorbent washable pad over it.
ADVANTAGES	DISADVANTAGES
easiest seating and back design for folding wheelchairs Adjustment to shape of butt gives comfort (but cushion is needed to protect against pressure sores). Curving back may help keep child from falling sideways.	Soft, curving back lets child bend in an unhealthy position. hard to attach positioning aids In children with spasticity or muscle imbalance, this may increase the risk of developing knock-knee contractures.
FIRM (BUT PADDED) BACK AND SEAT	DESIGN DETAILS
other possibilities for use under cushion metal slats wood slats	Use wood or thin plywood. Special designs allow a wood seat to swing up for folding.
ADVANTAGES	DISADVANTAGES
Wood seat and back allow easy addition of supports and adaptations. Firm wood back and seat help child sit with back straight and knees apart (especially important for children with spasticity).	may be less comfortable without cushion may cause pressure sores in child with no feeling in his butt heavier difficult or impossible to fold the chair
WOVEN SEAT AND BACK	DESIGN DETAILS
strips of old inner tube stretched tight	Use natural basket fibers, reeds, or rattan, or use plastic webbing, or use tightly stretched strips of car inner tube.
ADVANTAGES	DISADVANTAGES
An open weave is cooler in hot weather. Plastic or rubber woven seats can be easily washed. Can be used as a chair to bathe in.	must be kept stretched tight; not useful on folding chairs may not last long if material is not strong same sag problems as with canvas or leather

TIRES
PUMP-UP WITH AIR BALLOON TIRES	DESIGN DETAILS
	Bicycle tires and tubes work well for the large wheels—20 inch (51 cm), 24 inch (61 cm), or 26 inch (66 cm ), wide or narrow. Puncture-proof inner liners may be available.
ADVANTAGES	DISADVANTAGES
softer ride easy to replace wide tires good for sand and rough ground narrow tires better on smooth, paved roads	Puncture (hole in tire) may occur— especially on rough roads. more costly than some other tires wears out sooner than solid tires
SOLID TIRES (standard wheelchair wheels)	DESIGN DETAILS
	Buy from wheelchair supply center to fit diameter and width of rim.
ADVANTAGES	DISADVANTAGES
no flat tires good for speed on very smooth surfaces	costly hard to replace very hard, bumpy ride on rough surfaces very narrow—sinks into sand
RUBBER HOSE INSIDE BICYCLE TIRE	DESIGN DETAILS
	Overlap ends and cut at 45° angle Fit hose into tire.
ADVANTAGES	DISADVANTAGES
no flat tires softer ride than with solid tire cheap	Flattening of tire where it touches ground means it moves slower, and is harder to push.
THIN STRIP OF OLD CAR TIRE	DESIGN DETAILS
	Cut strip in wedge shape to fit rim. Wire ends together Wire ends together.
ADVANTAGES	DISADVANTAGES
no cost long-lasting Sink bolt head, and/or bolt the ends.	bumpy ride difficult to fit well on rim and to fasten ends firmly
LARGE MACHINERY FANBELT discarded	DESIGN DETAILS
	Use old power belts or fan belts from industrial machinery or tractors. Cut to fit and wire ends together.
ADVANTAGES	DISADVANTAGES
no cost long-lasting wedged to fit wedge rim	bumpy ride difficult to fit may be hard to find at the right width
PIECE OF OLD BICYCLE OR SCOOTER TIRE	DESIGN DETAILS
	used for middle-sized or small wood wheels Notch edges, glue, and nail to wheel.
ADVANTAGES	DISADVANTAGES
cheap If heavy tire is used it may last a long time. Protects edge of wood wheel	hard, bumpy ride (but softer than on wood wheel alone) may tear off

BIG WHEELS
STANDARD FACTORY-MADE WHEELCHAIR WHEELS	DESIGN DETAILS
	Buy to fit chair. available from wheelchair dealers 24 inch (61 cm) or 26 inch (66 cm) rims for adults 20 inch (51 cm) rims for small children (may be hard to find)
ADVANTAGES	DISADVANTAGES
little work needed (if they are bought to fit standard hubs) May come fitted with hand push rim.	costly may be hard to find wide-wheeled models often not available may not hold up on rough ground poor quality bearings
BICYCLE WHEELS (rims and spokes)	DESIGN DETAILS
	For children, standard thickness spokes may be enough. For large persons, heavy-duty spokes may be needed.
ADVANTAGES	DISADVANTAGES
less costly than standard wheelchair wheels available in different sizes and widths	Putting on and lining up spokes takes time and skill. axles weak (but stronger ones can be adapted)
BICYCLE RIMS WITH WOODEN SPOKES	DESIGN DETAILS
	notched wood crosspieces on a triangular wood base can be greased and used as the hub
ADVANTAGES	DISADVANTAGES
no need to know how to fit spokes works with wood hub	Rim may easily get bent—especially on rough roads. hard to line up evenly Hub wears out easily.
WOOD WHEELS — big or small	DESIGN DETAILS
	Use boards or plywood. To avoid splitting, screw and glue 2 layers together with grain running in opposite directions. Cut notch in rim to hold solid tire. tire edge of wheel
ADVANTAGES	DISADVANTAGES
relatively cheap little skill required— mostly carpentry works with wood axles heavy-duty bearing can be added	often heavy may not hold up long—especially in wet climate or mud (Keeping wood oil-soaked helps them last. Use old engine oil.)

CASTERS AND WHEELS
STANDARD WHEELCHAIR CASTER WHEELS	DESIGN DETAILS
(“Caster” means that the wheel can swing in different directions for making turns.)	Casters come with hard or balloon tires in many sizes, weights, styles, and prices. If possible, get (or make) casters with ball bearings.
ADVANTAGES	DISADVANTAGES
little work to attach— especially if standard mount and bearings are used	usually very costly may not be locally available
CASTERS FROM OTHER (non-wheelchair) EQUIPMENT (used or new)	DESIGN DETAILS
for mounting on wood frame caster welded to metal plate for screwing to wood for mounting into metal tube frame	Use 3 inch to 6 inch wheels. larger, wider wheels for rough ground Be sure bearings are strong enough and in good condition. Drill holes in rubber wheels to make them weigh less.
ADVANTAGES	DISADVANTAGES
less costly (especially if not new) often full wheel and caster bearings come with them	Poor quality casters make wheelchair much harder and more awkward to use. Hard-rubber casters make a bumpy ride. Some used casters are too weak.
BENT AND WELDED STEEL CASTER FORKS	DESIGN DETAILS
30° angle bolt strong bronze weld bolt holes to make fork weigh less hole sized to fit axle	Choose bolt width to fit bearings. A bent steel tube can be used instead of a metal band.
ADVANTAGES	DISADVANTAGES
less costly than factory-made casters strong (if well made)	needs special equipment (bending jig) and welding skills

HUBS, BEARINGS, AND AXLES
STANDARD WHEELCHAIR BEARINGS	DESIGN DETAILS
ball bearings ball bearings at each end of hub axle hub	A standard wheelchair uses 12 bearings: 2 for each wheel axle and 2 for each upright caster bearing. How a ball bearing works: axle does not move turning wheel
ADVANTAGES	DISADVANTAGES
These bearings come as part of standard wheelchair hubs and wheels. Most factory-built wheelchairs have unusual sized axles and therefore must be fit with special wheelchair bearings.	Bearings on most factory-built chairs are costly, of poor quality, and wear out quickly. Unusual hub size makes it hard to replace commercial wheelchair bearings with other standard machine bearings.
BICYCLE BEARINGS AND AXLES	DESIGN DETAILS
front wheel axle hub axle	For mounting alternatives, see wheelchair designs "Design Choices for Wheelchairs" and "Health Link Wood Wheel Chair".
ADVANTAGES	DISADVANTAGES
cheap — especially if old bicycles are used easy to get can be used with complete bicycle wheels	Axle is too weak to be supported by one end only (except in a small child’s wheelchair).
REAR BICYCLE WHEEL AXLE AND BEARINGS	DESIGN DETAILS
hub metal plate wheelchair frame	First take free-wheel mechanism apart and remove ratchets. Then attach hub to a metal plate as shown and spot weld it.
ADVANTAGES	DISADVANTAGES
Allows axles to be attached by one end only.	Needs fairly skilled work and welding. heavy
USED MACHINERY BEARINGS	DESIGN DETAILS
thin metal pipe ⅝" bolt holes for spokes narrower tube to hold bearings apart bearing	Find used high-speed bearings of the size shown (or near the size). Volkswagen alternator bearings and certain power tool bearings work well. Use ⅝ inch steel bolts for axle. For details, see "How-to-Do-It Reference Materials for Wheelchairs, Wheelboards, and Other Seating", "Whirlwind and RoughRider Steel Tube Wheelchairs", and "Details of How to Make Wheelchair Parts".
ADVANTAGES	DISADVANTAGES
no need to adjust, grease, or clean usually free or very cheap In wheelchairs they will last a very long time. If done well, results are better than with commercial hubs and bearings.	very careful, exact work needed for good results
WOOD BEARING	DESIGN DETAILS
washer bolt (welded to fork) oil-soaked wood tube metal fork wood wheel (oil-soaked hole) bolt spot welded to fork	Use a hard wood that will not split. Soak wood in old motor oil.
ADVANTAGES	DISADVANTAGES
cheap and fairly easy to make	tends to wear out, wobble, or crack quickly unless very well made; not as smooth or easy to ride as with ball bearings

SUPPORT OF AXLES
AXLE SUPPORTED ON ONE SIDE ONLY	DESIGN DETAILS
nut axle passes through metal tube welded to frame This is the standard mount for factory-built chairs.	Strong steel axles are needed for support at one side only. Axle should be at least ⅝ inch thick for a large person. For a very small child bicycle axles can be supported by one side only. One way is to weld bicycle axles to a thin metal pipe.
ADVANTAGES	DISADVANTAGES
Not as wide or heavy as the chair with 2-side support. easier for user to get a full-length push with hands and arms narrow size important for doorways and transporting Pass pipe through a wood frame, or weld to metal frame.	For adults and large children, standard bicycle axles are too weak for one-side support. Even for smaller children, bicycle axles are weak, and rough use can bend them. Put a sign on chair:
AXLE SUPPORTED ON BOTH SIDES	DESIGN DETAILS
This can be done in several ways: metal strips on wood frame metal tube on tube frame	Place outer bar of axle support so that it allows as much room for hand pushing by the rider as possible. single caster wood on wood frame
ADVANTAGES	DISADVANTAGES
2-sided support allows use of standard bicycle wheels and axles. easy to build and replace re-bar loop on re-bar frame	chair wider, more difficult to get through narrow doors and spaces; more difficult to transport Wheel supports get in the way of hands when user moves by pushing wheels. heavy

TO FOLD OR NOT TO FOLD
A TYPICAL FOLDING CHAIR	DESIGN DETAILS
	folding mechanism usually with 2 scissoring flexible cross pieces and cloth or leather seat See details of a make-it-yourself model.
ADVANTAGES	DISADVANTAGES
Folding: narrow when folded for easier transport or storage smoother ride due to flexibility Non-folding: cheaper and lighter easier to make more adaptable often stronger	Folding: heavier harder to make more costly less adaptable Non-folding: Transport in cars and buses more difficult. Consider how much this will affect the child’s ability to go where she wants. stiff ride

ARMRESTS
NO ARMRESTS	DESIGN DETAILS
	Note: Many chairs are built so that armrests are part of the main structure and strength of the chair. The armrests cannot be easily removed, even though this might benefit the child. Carefully consider the child’s need for armrests before buying or making a chair.
ADVANTAGES	DISADVANTAGES
Many children with strong arms and trunk control prefer a chair with no armrests and a very low back support. Moving by pushing the wheels is easier. less weight Getting off and on from the side is easier—especially important when legs are completely paralyzed and when arms are also weak.	Many small children need armrests for stability, for positioning, or for comfort.
FIXED ARMRESTS	DESIGN DETAILS
Fixed armrests	Armrest height and length should be determined for each child and her needs. For measurements, see "Fitting the Chair to the Child: Measurements". The so-called “desk arm” lets front of chair fit under a table—but is often too high or too short.
ADVANTAGES	DISADVANTAGES
especially helpful if child cannot use legs to get out of chair They can help child to sit in a better position and be more comfortable. They can sometimes be used for attaching a removable table.	They get in the way for pushing wheels and for getting off chair to the side. For many children, fixed armrests get in the way more than they help.
REMOVABLE ARMRESTS	DESIGN DETAILS
adjustable armrest Armrest fits into these tubes.	In folding chairs, armrest attachments must be placed so they do not get in the way of folding. child transferring from a chair on a board — one armrest removed
ADVANTAGES	DISADVANTAGES
Provides arm support when needed, yet can easily be removed for travel and transfer.	requires more work, materials, and exact fittings adds slightly to weight Separate armrests may get lost.

FOOTRESTS
POSITIONS	DESIGN DETAILS
In adult chairs, footrests often angle legs forward to leave room for casters. For a small child, often footrests can position legs straight down. This is important in many cases. A larger child may need to sit on cushions so that his feet are above the casters.	Footrest should keep the knees and ankles at right angles and the legs slightly separated It should usually not twist them or force them together.
ADVANTAGES	DISADVANTAGES
Good positioning and support of the feet help the whole body to stay in a better position. A footrest like this, may help feet like these.	A footrest that keeps the leg at right angles may cause or increase knee contractures in some children. Children should not stay sitting too long and should do daily exercises to stretch their legs, feet, and hips. To prevent or correct contractures, one or both legs may need to be kept as straight as they will go.
FIXED POSITION FOOTRESTS	DESIGN DETAILS
The height of the rests should be carefully measured to fit the child who will use them. (For measurements, see "Fitting the Chair to the Child: Measurements".) REMEMBER: Cushions or seating adaptations will change the height needed for the footrests.	If the footrest is too low, blocks can be placed on it to make it higher They can be removed as the child grows. However, fixed footrests that are too high are more difficult to correct. So it is better if they are too low.
ADVANTAGES	DISADVANTAGES
easiest to build For a small child who can easily be lifted in and out of the chair, they are fine. If footrests are screwed or bolted onto a wooden wheelchair, their position can easily be changed as the child grows.	They often get in the way when the child gets in or out of the chair, or in the way of the person lifting a larger child. (See other methods below.)
REMOVABLE OR SWING-AWAY FOOTRESTS	DESIGN DETAILS
back-stop for feet wood chair swing-away footrest pin on which footrest swings stops	There are many designs. Here we show one for the wood chair shown above and one designed for a metal chair. Other designs for sliding or swing-away footrests are on pages "Re-bar and Woven Plastic Wheel Chairs", and "Whirlwind Steel Tube Wheel Chair". swing up metal chair footrest
ADVANTAGES	DISADVANTAGES
They make it easier to get in and out of chair. The best footrests are those the child can easily move out of the way herself.	Removable footrests may get lost. more work to make them Unless well-made, they may be less stable than fixed footrests.
ADJUSTABLE FOOTRESTS	DESIGN DETAILS
hand hole for pulling Footrest pulls out and slips back out of way. FRONT VIEW strips of wood to form slots adjustable height	There are many designs. Here is one of the simplest, for a plywood chair. For straight leg sitting, a longer board fits into high slots.
ADVANTAGES	DISADVANTAGES
very adaptable easy to make can support a casted leg leg board for both legs for one leg	A cushion or padding should be placed over the leg board (unless leg is casted). Side supports may be needed to keep leg from slipping off.
NO FOOTRESTS	DESIGN DETAILS
	Seat is mounted low so that feet rest flat on floor.
ADVANTAGES	DISADVANTAGES
useful for persons who can pull their chair along with their legs and feet— especially when one or both arms or hands are too weak to push the wheels	Feet may drag when someone else pushes the child in the chair. Swing-away footrests may be the best solution.

PARKING BRAKES
LEVER BRAKES	DESIGN DETAILS
Brake for wooden chair off on	There are many brake designs. This one is from Healthlink Worldwide. Two others are on "Details of How to Make Wheel Chair Parts". push handle out and up metal plate SIDE VIEW catch weld pivot split pin washer metal plate
ADVANTAGES	DISADVANTAGES
takes little space fairly easy to use if made right (which often they are not)	needs welding and skill to make Homemade brakes often give problems—yet it is important that chairs have them if possible.
PARKING BLOCK	DESIGN DETAILS
	Brakes on wheelchairs are for keeping the chair from rolling when getting in or out, or stopped on a hill. The simplest form of brake is a parking block that keeps the wheel from turning. To ‘brake’, roll wheel up ramp and into groove.
ADVANTAGES	DISADVANTAGES
easy to make, requires no welding, and is cheap If the child usually only gets in and out of the chair in one or two places in the home, blocks in these places may be all that is needed.	a heavy, awkward object to move from place to place not practical outside the house (or in it) have to tilt child to one side to “park” chair

HANDRIMS FOR PUSHING
HANDRIMS	DESIGN DETAILS
using thin metal tubing (cane or wood have also been used)	Designs taken from Healthlink Worldwide. jig for bending tube Cut down this line before removing from jig. Weld ends. Wrap tube around several times to make several rims at once.
ADVANTAGES	DISADVANTAGES
Handrims help keep hands clean. (Otherwise child has to push on tire.) especially important where there are very dirty paths and roads tire Attach rim with metal brackets like this. bracket rim	Added width makes it harder to get through narrow doorways. adds weight
HANDRIM GRIP IMPROVERS	DESIGN DETAILS
rim pegs wood or rubber tube rim Posts can be bolted or welded onto rim. nut bolt	Cut a piece of rubber hose lengthwise and tape it onto rim. cut rim hose metal post welded onto rim Posts can be bolted or welded onto rim.
ADVANTAGES	DISADVANTAGES
For child with weak or paralyzed hands, a smooth rim can be hard to grip—especially if it is chromed or galvanized. Putting rough cloth tape, a rubber hose, or many small handles on the rim will make pushing easier. Or you can wrap the rim with a long thin strip of car tire inner tube.	Pegs sticking out from rims increase width of chair. Pegs sometimes cause hand injuries— especially when going fast downhill. strip of inner tube rim wrap

This page was updated:04 Apr 2024