Wheelchairs - Types and Parts

Types and Parts of Wheelchair (compiled by Dr. Sanjib Kumar Das)

1. WHEELCHAIRS
Dr.SanjibKumar Das,FellowDoctoral
MPT (Musculoskeletal Disorders)
PhD (Ergonomics & Human Factors), NITIE

2. Introduction
•Awheelchairisnotjusta‘chairwithwheels’.Itisasecond“home”tothe
patient,sincehespendssomuchtimeinit.
•Thepatient’swheelchairshouldbedesignedforcomfortandeaseof
manipulation.Wheelchairsdifferindesignandconstructionbasedonthe
needsofindividualsandtheirdisabilities.
•Wheelchairscomeinthreesizes:adult,childandtinytot.
•Sincemanyofthedisabledindividualsliveoutofwheelchairsitis
importanttoprescribethemostcomfortableoneforapatientinthegiven
circumstances.

14. BASICCONCEPTS

15. PARTSOFAWHEELCHAIR
•Frames
Wheelchairframesareeitherrigidorfolding.Thetypeofframe
affectsthemaneuverabilityofthechair.Arigidframeinonesolid
pieceislighterandusedmoreforsportsandotherrugged
activities.Afoldingframeisheavierandrequiresmoreeffortto
maneuverbutismoreconvenientforstorageinthehomeandfor
placingintothecarwhiletravellingsinceitoccupiesmuchless
space.
Figure:The wheelchair and its parts: (1) Handgrip (2) Backrest (3) Armrest
(4)Clothes guard(5) Seat (6) Footrest (7) Casters (8) Heel-loop (9) Brake
(10)Axle/anti-tip bar (11)Handrim(12) Wheel andtyre

16. •Tyres
Theselectionoftyresdependsontheuseofthechair.Tyresmadewith
solid,hardpolyurethaneandhavingasmoothtreadaredesignedfor
indooruse,allowingforeasymaneuverabilityonsmoothsurfaces.If
usedoutdoorsthesetyresoffernoshockabsorption.
Pneumatic(airfilled)tyresprovideforshockabsorptionandasmooth
ride,particularlyoutdoorsonunevenorroughterrain.Thesetyres
requiremoreefforttomaneuverandaddslightlytotheoverallwidthof
thechair.

17. •Wheels
Twotypesofwheelsareavailable:solidmagnesiumandwithspokes.
Solidmagnesiumwheelsneverlosetheirshapeorneedadjustments.
Spokedwheelsarelighterandthereforeeasiertomanoeuvre.
Thedisadvantageofspokedwheelsisthatthespokesareeasilybroken
andwillcausethewheeltoloseitsshape.Theymustthereforebe
tightenedfrequently.Wheelsizesmayvarydependingonthesizeand
weightoftheuser.Therearetwosizes-12''and18''diameter.Asmaller
wheelsizerequiresmorepushingstrokesthanalargerwheelsizeto
propelthechairoverthesamedistance.Asmallwheelreducesheightto
thewheelchairduringtransfers.

18. •Brakes
Thereisaseparatebrakeforeachwheelofthechair.Brakesmustbe
putonwhenstoppingthechair,wheneverthepersonisbeing
transferredinoroutofthechair,orwheneveraprocedurelikestanding
upinthewheelchair,oreatingfromatrayplacedonitiscontemplated.
•Casters
Thereare2castersinfrontofthewheels.Theyaredifferentfrom
wheelsinthattheycanrevolveinalldirections,andallowforbetter
frontendmaneuverabilityonsmoothsurfaces.
Castersarepneumatic,semipneumaticorsolid.Thesemipneumatic
typeisbetteronuneventerrain.Pneumaticcastersprovideforgreater
shockabsorption;however,thereisanincreaseddragduringpropulsion
ifnotfilledwithairproperly.Thisincreasestheexpenditureofenergy.
Solidcastersaregoodonsmoothterrain.Castersmayalsohavelocks.

19. •PushRims(HandRims)
Thetypeofpushrimdependsontheuser’sgrip.Therearebasicallythreetypes:
•Standardmetalrims,
•Frictionrims,and
•Rimswithprojections.
Standardmetalrimsareusedwhengripisnotaproblem.
Frictionrimsarestandardrimscoveredwithfrictiontapeorfoamtubingtoprovideadditionalgrip
ontherimsurface.
Projectionrimsareusedbypeoplewithlimitedreachandgrip.Theseareknobsareplacedat
intervalstogivetheuserbettergripandleverageforpropulsion.Thegreaterthenumberofknobs
thegreateristhefacilitationformovement.Projectionknobsmaybeeitheratanobliqueangleor
vertical.However,theymayhitagainstthesidesofthewallorfurnitureandaddtotheoverall
width.
Thechairusedbyahemiplegichastwohandrimsonthesame(unaffected)sideandtheuser
propelsitusingthesamehand.Tonegotiateturnsheuseseitheroneofthehandrims.

20. •Footrests
Footrestsmaintainthefeetinneutralandpreventdeformitieslikeequinus.
Theyareeitherfixedormovable.Swingawayfootrestsaremoreconvenient
butincreasethelengthofthechair,whichaffectsturningandmaneuverability.
Theselacktoughnessandrequirefrequentrepair.Heelloopsorlegstrapscan
beaddedtothefootplate.Eitherorbothoftheseaccessoriesaddlengthtothe
wheelchair.
•TiltBars
Tiltbars,whichprojectfromthebackofframe,usually2to3inchesabovethe
floor,areusedbytheindividualwhoispushingthewheelchair.Byplacingthe
footonthetiltbarandpushingdownwiththefoot,thepersoncantiltthe
wheelchairback,allowingthecasterstoriseoffthesurface,thusenabling
themtoclearadoorsteporkerb.Thiscanalsobedonebydoingwhatiscalled
a‘wheelie’,whichisthesameactionasabove,donebythewheelchairuser
himself.

21. •Backrests
Highwheelchairbacksprovidetrunksupportandareidealfora
highlevelquadriplegicorachildwithcerebralpalsywithpoor
sittingbalance.Lowchairbacksprovideagreaterfreedomfor
movementandarepreferredbyindividualswithlowlevelspinal
cordlesionsandbythosewhoparticipateinsportingactivities.
Theangleofchairbackscanbechangedandmanywheelchairs
havetheirbackrestsdetachable,permittingabacktransfer.Chest
strapsareprovidedtothebackrestwhensittingbalanceispoor.
•Armrests
Removablearmrestsareconvenient,providesupport,andmake
transferringeasierwhendetached.Armrestscanalsobefixedor
adjustableinheightandmaybepartiallengthorfulllength.
However,theyrestrictmovementduringpropulsion.
Environmentcontrolunits,keyboards,booksortrayscanbe
placedonthesearmrests.

22. •Seats:
Patientscomeinallsizesanditmakessensetotakethe
measurementsfortheseat,sothatheismostcomfortable.The
dimensionstobetakenintoconsiderationaretheseatheight,
depthandwidth
Figure:Wheelchairmeasurement;Seatwidth:1inchwiderthanthewidthofthewidestpart
ofthebuttocks(A);Seatheight:2incheshigherthanthedistancefromthebottomoftheheel
tothepoplitealarea(B);Seatdepth:1to2incheslongerthanthedistancefromthepopliteal
areatothebackofthebuttocks(C);Backrestheight:2inchesless(mayvary)thanthe
distancefromtheinferiorangleofthescapulaetothesittingsurface(D);Armrestheight:
Distancefrombottomofbuttocks-to-elbow(E)

23. •Cushions
Cushionsareusedtoachievethemostcomfortableandsupportiveposition
possibleandsometimescanmakeallthedifferenceinthepreventionofa
secondarydisabilitylikepressuresore.Seatcushionsmaybeair-filled,gel-
insert/filled,contourfoam.Somehaveindividualinflatableaircells,whichare
availableinvaryingthicknessesandcanbecustomizedforposturecontroland
pressurerelief.
•Head-rest
Itisprescribedforthosewhohavenoheadcontrol,andhaveprimitiveneck
reflexes.Itisalsodetachable.
•ClothesGuard
Thispreventsloosefittingclothesfromgettingentangledinthewheels.
•Anti-tipBars
Anti-tipbarskeepthechairfromtippingtoofarbackward.Theyareused
primarilybynewusersandbythosewithahigh-levelspinalcordinjury.

24. TrainingtoUsetheWheelchair
•Thepatientistaughtbasicmovementswithinthewheelchair.
Helearnstousethebrakes,removeandreplacethearm,back
andfootrests.
•Inthemaneuveringofthewheelchair,hepracticestolifthis
buttocksinthechair,performawheelie,topushonaflat
surfaceorslopeandtoturnit.
•Objectswhichhecanuseonthechairlikeatrayorcomputer
keyboardmayalsogiventohimduringthepracticesession.

25. ThankYou
Dr.SanjibKumar Das, Fellow Doctoral
MPT (Musculoskeletal Disorders)
PhD (Ergonomics & Human Factors)
Mail: [email protected]
Contact No: [phone]/ 8169951520 (India)