ISO 7176-26:2007

INTERNATIONAL ISO
STANDARD 7176-26
First edition
2007-04-15
Wheelchairs —
Part 26:
Vocabulary
Fauteuils roulants —
Partie 26: Vocabulaire
Reference number
©
ISO 2007
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©  ISO 2007
The reproduction of the terms and definitions contained in this International Standard is permitted in teaching manuals, instruction
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ii © ISO 2007 – All rights reserved

Contents Page
Foreword. iv
Introduction . vi
1 Scope . 1
2 Rules and elements used in vocabulary . 1
2.1 Rules used in vocabulary . 1
2.2 Organization of elements used in the vocabulary . 1
3 Abbreviated terms . 1
4 Terms and definitions . 2
4.1 Wheelchairs and related mobility devices. 2
4.2 Wheelchair operators. 3
4.3 Overall dimensions . 4
4.4 Drive systems . 5
4.5 Wheels . 8
4.6 Wheel features . 10
4.7 Postural supports. 14
4.8 Postural support characteristics . 23
4.9 Seating dimensions. 26
4.10 Testing equipment and configuration . 29
4.11 Transportation in a motor vehicle . 31
4.12 Product information . 34
Annex A (informative) Characterization of wheelchairs. 36
Bibliography . 38
Alphabetical index . 39

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 7176-26 was prepared by Technical Committee ISO/TC 173, Assistive products for persons with
disability, Subcommittee SC 1, Wheelchairs.
This first edition cancels and replaces the first edition (ISO 6440:1985), all clauses and annexes of which have
been technically revised.
ISO 7176 consists of the following parts, under the general title Wheelchairs:
⎯ Part 1: Determination of static stability
⎯ Part 2: Determination of dynamic stability of electric wheelchairs
⎯ Part 3: Determination of the effectiveness of brakes
⎯ Part 4: Energy consumption of electric wheelchairs and scooters for determination of theoretical distance
range
⎯ Part 5: Determination of overall dimensions, mass and turning space
⎯ Part 6: Determination of maximum speed, acceleration and deceleration of electric wheelchairs
⎯ Part 7: Measurement of seating and wheel dimensions
⎯ Part 8: Requirements and test methods for static, impact and fatigue strengths
⎯ Part 9: Climatic tests for electric wheelchairs
⎯ Part 10: Determination of obstacle-climbing ability of electric wheelchairs
⎯ Part 11: Test dummies
⎯ Part 13: Determination of coefficient of friction of test surfaces
⎯ Part 14: Power and control systems for electric wheelchairs — Requirements and test methods
⎯ Part 15: Requirements for information disclosure, documentation and labelling
⎯ Part 16: Resistance to ignition of upholstered parts — Requirements and test methods
iv © ISO 2007 – All rights reserved

⎯ Part 19: Wheeled mobility devices for use in motor vehicles
⎯ Part 21: Requirements and test methods for electromagnetic compatibility of electrically powered
wheelchairs and motorized scooters
⎯ Part 22: Set-up procedures
⎯ Part 23: Requirements and test methods for attendant-operated stair-climbing devices
⎯ Part 24: Requirements and test methods for user-operated stair-climbing devices
⎯ Part 25: Requirements and test methods for batteries and their chargers for electrically powered
wheelchairs and motorized scooters
⎯ Part 26: Vocabulary
Introduction
The provision and selection of wheelchairs and associated seating products relies on clear communication of
information relating to these devices. Over time, many terms and definitions have evolved. Unfortunately, this
process has resulted in a lack of clear meaning for some terms and duplication of other terms (sometimes with
conflicting messages).
For example, the terms tilt and recline are sometimes used interchangeably, but usually have quite distinct
meanings. If used inappropriately, an entirely inappropriate wheelchair may be specified or purchased.
The purpose of this part of ISO 7176 is to provide a collection of terms and their definitions to form the basis of
clear communication across the field of wheelchair and associated seating and to eliminate confusion from
duplication or inappropriate use of terms.
The vocabulary is drawn from surveys of the literature and language used by experts in this field. It excludes,
however, terms which are adequately defined in the everyday language of English, medicine and technology.
ISO 7176 recognises that there are a number of terms in use which, because of duplication or inadequacies of
meaning, should be replaced by terms from this vocabulary. To help people move towards a common
vocabulary, these deprecated terms are included along with a reference to the preferred term.
The development and application of wheelchair standards is particularly dependent upon clear and consistent
terms and definitions. Hence, a major proportion of this part of ISO 7176 includes terms and definitions used
in more than one of the ISO standards specifically related to ISO Wheelchair Standards. These include the
ISO 7176, ISO 10542, and ISO 16840 series, and ISO 7193. Future standards in these series will cite this
document for definition of terms wherever possible, thus facilitating the consistent use of a common
vocabulary.
This part of ISO 7176 is intended purely as a means of specifying terms and definitions. It does not attempt to
classify wheelchairs and associated seating into any classification of device groupings as this is the purpose
of ISO 9999. Annex A provides a standard set of descriptors for characterizing wheelchairs.

vi © ISO 2007 – All rights reserved

INTERNATIONAL STANDARD ISO 7176-26:2007(E)

Wheelchairs —
Part 26:
Vocabulary
1 Scope
This part of ISO 7176 specifies a vocabulary consisting of terms and definitions used in the field of manual
and electrically powered wheelchairs (including scooters) and associated seating systems. This part of
ISO 7176 includes, but is not limited to, the preferred terms used in two or more ISO standards of the
ISO 7176, ISO 10542, and ISO 16840 series, but does not include terms considered to be adequately defined
in everyday English.
NOTE 1 In addition to terms used in the three official ISO languages (English, French and Russian), this International
Standard gives the equivalent terms in United States English; these are published under the responsibility of the member
body/National Committee for the United States. However, only the terms and definitions given in the official languages can
be considered as ISO terms and definitions.
NOTE 2 Annex A provides a standard set of descriptors for characterizing wheelchairs.
2 Rules and elements used in vocabulary
2.1 Rules used in vocabulary
Most terms defined are used in more than one of the ISO standards relating specifically to wheelchairs and
seating supports. Terms used in only one of these standards, are defined in the terms and definitions clause
of that standard.
Within Clause 4, terms are organized by function. Terms (and the function) can be further specified by adding
an adjective as shown in 4.8.
2.2 Organization of elements used in the vocabulary
The structure used throughout the nomenclature is based upon ISO 10241.
3 Abbreviated terms
ATD anthropometric test device
PSD postural support device
RLG reference loader gauge
UDIG universal docking interface geometry
WTORS wheelchair-tiedown and occupant-restraint system
4 Terms and definitions
4.1 Wheelchairs and related mobility devices
4.1.1
wheelchair
device to provide wheeled mobility with a seating support system for a person with impaired mobility
NOTE A walking aid with wheels is not a wheelchair.
4.1.2
manual wheelchair
wheelchair (4.1.1) which relies on an occupant (4.2.2) or an assistant (4.2.3) to provide power for its operation
4.1.3
handrim-drive wheelchair
manual wheelchair (4.1.2) designed to be propelled and steered using handrims (4.5.11)
4.1.4
lever-drive wheelchair
manual wheelchair (4.1.2) intended to be propelled and steered by a lever or levers
4.1.5
foot-propelled wheelchair
manual wheelchair (4.1.2) designed to be propelled and steered by contact of the occupant’s (4.2.2) foot or
feet with the floor
4.1.6
push wheelchair
manual wheelchair (4.1.2) intended to be pushed by an assistant (4.2.3)
4.1.7
aisle wheelchair
push wheelchair (4.1.6) intended to be used in narrow aisles such as on aircraft
4.1.8
electrically powered wheelchair
e chair (deprecated)
electric wheelchair (deprecated)
powered chair (deprecated)
powered wheelchair (deprecated)
wheelchair (4.1.1) in which the motor power is derived from an integral source of electric power
NOTE A scooter (4.1.9) is an electrically powered wheelchair.
4.1.9
scooter
electrically powered wheelchair (4.1.8) with a tiller (4.4.7) to control direct steering (4.4.8)
4.1.10
electrically powered wheelchair with integral seat
electrically powered wheelchair (4.1.8) with a seating system (4.7.2) and drive system that cannot be
separated
4.1.11
powerbase wheelchair
electrically powered wheelchair (4.1.8) with a powerbase (4.4.3)
4.1.12
balancing wheelchair
electrically powered wheelchair (4.1.8) that electronically maintains the balance of the wheelchair
2 © ISO 2007 – All rights reserved

4.1.13
rigid wheelchair
wheelchair (4.1.1) with frame components under the seat that are fixed and non-foldable
4.1.14
folding wheelchair
wheelchair (4.1.1) with frame components under the seat which can be collapsed
4.1.15
shower wheelchair
wheelchair (4.1.1) intended to be used in the shower
4.1.16
toilet wheelchair
wheelchair (4.1.1) intended to be used over a toilet
4.1.17
stand-up wheelchair
wheelchair (4.1.1) capable of transporting an occupant (4.2.2) in a seated position and which also has the
capability to raise and maintain the occupant in a stand-up position
4.1.18
stair-climbing device
device intended to transport a person or an occupied wheelchair by climbing up or down stairs, but that is not
fixed to the stairs
4.1.19
stair-climbing chair
stair-climbing device (4.1.18) that includes a seat for the occupant (4.2.2)
4.1.20
stair-climbing wheelchair carrier
stair-climbing device (4.1.18) that carries an occupied wheelchair
4.2 Wheelchair operators
4.2.1
operator
person who operates the wheelchair
NOTE Can be either the occupant or the assistant.
4.2.2
occupant
user (deprecated)
person supported by the wheelchair seating system (4.7.2)
4.2.3
assistant
attendant (deprecated)
carer (deprecated)
person, other than the occupant (4.2.2), who manoeuvres the wheelchair
4.3 Overall dimensions
4.3.1
overall length
distance between the most forward and most rearward points of the wheelchair when it is ready for use,
measured in a direction parallel to the forward direction of movement
NOTE The measurement methods are specified in ISO 7176-5.
4.3.2
overall width
distance between the outermost side-to-side points of the wheelchair when fully opened and ready for use,
measured in a direction perpendicular to the forward direction of movement
NOTE The measurement method is specified in ISO 7176-5.
4.3.3
overall height
vertical distance from the ground to the uppermost point of the wheelchair when it is ready for use with the
back support (4.7.9) in the upright position
NOTE The measurement method is specified in ISO 7176-5.
4.3.4
stowage length
distance between the most forward and most rearward points of the wheelchair when folded and/or
dismantled for transport or stowing purposes
NOTE The measurement method is specified in ISO 7176-5.
4.3.5
stowage width
overall width folded (deprecated)
distance between the two outermost side-to-side points of the wheelchair when folded and/or dismantled for
transport or stowing purposes
NOTE The measurement method is specified in ISO 7176-5.
4.3.6
stowage height
overall height folded (deprecated)
vertical distance from the ground to the uppermost point of the wheelchair when folded and/or dismantled for
transport or stowing purposes
NOTE The measurement method is specified in ISO 7176-5.
4.3.7
wheelbase
distance between the ground contact points of the front and rear wheels of the wheelchair, measured in a
direction parallel to the forward direction of movement
NOTE The measurement method is specified in ISO 7176-5.
4.3.8
ground clearance
shortest distance between the ground and any part of the wheelchair that is not a wheel
NOTE The measurement method is specified in ISO 7176-5.
4 © ISO 2007 – All rights reserved

4.3.9
turning diameter
turning radius (deprecated)
turning circle (deprecated)
diameter of the smallest cylindrical envelope in which the occupied wheelchair can be driven in a circle
through 360°
NOTE The measurement method is specified in ISO 7176-5.
4.3.10
reversing width
minimum corridor width required for the occupied wheelchair to turn through 180° where forward and
backward movements of the wheelchair may be used
NOTE The measurement method is specified in ISO 7176-5.
4.3.11
turning width
minimum corridor width required for the occupied wheelchair to turn through 180° where backward
movements of the wheelchair may not be used
NOTE The measurement method is specified in ISO 7176-5.
4.3.12
total mass
mass of the wheelchair when ready for use, but unoccupied
NOTE The measurement method is specified in ISO 7176-5.
4.4 Drive systems
4.4.1
control device
access method (deprecated)
control input device (deprecated)
input control device (deprecated)
input device (deprecated)
means by which the occupant (4.2.2) directs an electrically powered wheelchair (4.1.8) to move at the desired
speed and/or in the desired direction of travel
EXAMPLE joystick
4.4.2
controller
device that converts input signals from the occupant (4.2.2) into output signals that activate powered
components of the wheelchair
4.4.3
powerbase
component of an electrically powered wheelchair (4.1.8) which contains the drive system, batteries and
wheels, and can be separated from the seating system (4.7.2)
4.4.4
propulsion system
combination of parts needed to propel the wheelchair
4.4.5
handrim-activated power-assisted
operated with a combination of human power and electrical power, where the activation of the electrical power
is through application of a torque, displacement or force to the handrim or handrims (4.5.11)
4.4.6
steering system
combination of parts, mechanical and/or electrical, that control the direction of travel of the wheelchair
4.4.7
tiller
bar fitted to a pivot wheel(s) (4.5.4), for turning the pivot wheel(s) in steering
4.4.8
direct steering
control of direction by changing the orientation of the pivot wheel(s) (4.5.4) or pivot drive wheel(s) (4.5.5)
4.4.9
manual direct steering
direct steering (4.4.8) without powered assistance
NOTE A three-wheeled scooter (4.1.9) with a tiller (4.4.7) uses manual direct steering.
4.4.10
powered direct steering
servo steering (deprecated)
direct steering (4.4.8) with powered assistance
NOTE Typically, a secondary motor is used to adjust the orientation of the pivot wheel (4.5.4) or wheels.
4.4.11
differential steering
indirect steering (deprecated)
control of direction by applying different speed and/or direction to the manoeuvring wheels (4.5.2)
4.4.12
full differential steering
differential steering (4.4.11) where it is possible that the midpoint of the turn coincides with the centre-point of
the wheelchair
NOTE The wheelchair can turn about its centre-point.
4.4.13
limited differential steering
differential steering (4.4.11) where it is not possible that the midpoint of the turn coincides with the centre-point
of the wheelchair
NOTE A wheelchair with limited differential steering cannot turn about its centre-point.
4.4.14
manual differential steering
manual indirect steering (deprecated)
differential steering (4.4.11) in which the differential force is produced by the occupant (4.2.2)
NOTE A manual wheelchair (4.1.2) with handrims (4.5.11) uses manual differential steering.
4.4.15
powered differential steering
powered indirect steering (deprecated)
differential steering (4.4.11) in which the different wheel speeds are produced by two separate motors
NOTE Many electrically powered wheelchairs (4.1.8) with two drive wheels (4.5.1) use this type of steering.
4.4.16
parking brake
wheel lock (deprecated)
means of keeping the wheelchair stationary that does not require continuous force from the operator and does
not require continuous power from the wheelchair
6 © ISO 2007 – All rights reserved

4.4.17
automatic brake
parking brake (4.4.16) that applies automatically after the wheelchair stops and/or when no power is supplied
by the wheelchair
4.4.18
running brake
dynamic brake (deprecated)
friction brake (deprecated)
regenerative brake (deprecated)
service brake (deprecated)
means of stopping or slowing the wheelchair
NOTE The running brake may include one or more of the following types of brake: dynamic brake, regenerative brake
and friction brake (either fail-safe or manually applied).
4.4.19
push handle
push cane (deprecated)
component designed to be grasped by the hand of an assistant (4.2.3) to propel or tip the wheelchair
4.4.20
handgrip
material covering on the push handle (4.4.19) where the hand grasps
NOTE The handgrip may be integrated with or separate from the push handle.
4.4.21
anti-tip device
anti-tipper (deprecated)
anti-tipping lever (deprecated)
device that limits the extent of tipping of a wheelchair and that may operate in forward, rearward or lateral
directions of instability
4.4.22
circuit protection device
protective device that causes a circuit to open when the current and/or temperature in the device exceeds a
predetermined value
EXAMPLE fuse, thermal circuit breaker
4.4.23
battery pack
removable battery compartment that contains one or more batteries
4.4.24
rated capacity
nominal capacity (deprecated)
capacity value of a battery determined under specified conditions and declared by the manufacturer
[IEC 60050-482, definition IEV 482-03-15]
4.4.25
nominal voltage
suitable approximate value of the voltage used to designate or identify a cell, a battery or an electrochemical
system
[IEC 60050-482, definition IEV 482-03-31]
4.4.26
on-board battery charger
battery charger that is built into a wheelchair and cannot be removed without the use of tools
4.4.27
off-board battery charger
free-standing, self-contained battery charger separate from a wheelchair
4.4.28
carry-on battery charger
off-board battery charger (4.4.27) intended for transportation on a wheelchair
4.5 Wheels
4.5.1
drive wheel
wheel that transmits drive power, guides the wheelchair, but does not steer
EXAMPLE rear wheels of a rear-wheel drive scooter (4.1.9) with a pivot wheel (4.5.4) in front
4.5.2
manoeuvring wheel GB
maneuvering wheel US
one of a pair of wheels that are attached to the left and right side of the wheelchair, which transmits drive
power, guides the wheelchair, and steers the wheelchair by rotating with different speed and/or direction
EXAMPLE wheels with handrims (4.5.11) on a manual wheelchair (4.1.2) that also has castors (4.5.6)
4.5.3
guide wheel
wheel that guides the wheelchair but does not transmit drive power and does not steer
EXAMPLE rear wheels of a front-wheel drive scooter (4.1.9) with a pivot drive wheel (4.5.5) in front are guide wheels
4.5.4
pivot wheel
wheel that steers the wheelchair by changing its orientation to the wheelchair frame, but does not transmit
drive power
EXAMPLE wheel at the end of the tiller (4.4.7) of a three-wheeled scooter (4.1.9), which is driven by its two rear wheels
4.5.5
pivot drive wheel
wheel that transmits drive power and that steers the wheelchair by changing its angular orientation to the
wheelchair frame
4.5.6
castor wheel GB
caster wheel US
castor GB (deprecated)
caster US (deprecated)
wheel with a horizontal axle that can swivel freely about a vertical axis
See Figure 1.
4.5.7
castor assembly GB
caster assembly US
combination of the castor wheel (4.5.6), castor wheel axle, castor fork (4.5.8), castor stem (4.5.9), castor stem
housing (4.5.10), bearings and tyres
See Figure 1.
8 © ISO 2007 – All rights reserved

Key
1 bearing
2 castor stem housing
3 castor stem
4 castor fork
5 castor wheel axle
6 castor wheel
Figure 1 — Castor assembly
4.5.8
castor fork GB
caster fork US
castor support GB (deprecated)
caster support US (deprecated)
component of the castor assembly (4.5.7) to which the castor wheel (4.5.6) is connected
See Figure 1.
NOTE A castor fork does not necessarily have a fork design.
4.5.9
castor stem GB
caster stem US
shaft that the castor fork (4.5.8) is attached to which fits into the castor stem housing (4.5.10) and allows the
castor fork (4.5.8), castor wheel (4.5.6), and castor wheel axle to rotate about a vertical axis
See Figure 1.
4.5.10
castor stem housing GB
caster stem housing US
component of the castor assembly (4.5.7) which is connected to the wheelchair frame and contains the
bearings in which the castor stem (4.5.9) rotates
See Figure 1.
4.5.11
handrim
pushrim (deprecated)
outer, circular component of the manoeuvring wheel (4.5.2) intended for propelling a manual wheelchair
(4.1.2) with an upper limb
4.6 Wheel features
4.6.1
wheel diameter
propelling wheel diameter (deprecated)
outer diameter of a wheel
NOTE The measurement method is specified in ISO 7176-7 (see propelling wheel diameter).
4.6.2
handrim diameter
outer diameter of the entire handrim (4.5.11)
NOTE 1 The measurement method is specified in ISO 7176-7.
NOTE 2 The handrim diameter is not the diameter of the tubing.
4.6.3
camber
alignment of a wheel, expressed as the angle between vertical and a plane normal to the axis of the wheel
See Figure 2.
NOTE 1 Camber is negative if the top of the wheel is angled inward (see Figure 2), zero if the wheel is vertical, and
positive if the top of the wheel is angled outward. Camber is usually expressed in degrees.
NOTE 2 The measurement method is specified in ISO 7176-5.

a
Vertical.
Figure 2 — Negative camber (exaggerated, rear view)
4.6.4
toe
toe-in (deprecated)
toe-out (deprecated)
alignment between a pair of wheels (on opposite sides of the wheelchair), expressed as the angle in the
horizontal plane between planes normal to the axes of the wheels
NOTE 1 Toe is positive if the two wheels are closer at the front than at the rear (see Figure 3), zero if they are the same
distance apart at the front and at the rear, and negative if they are further apart at the front than at the rear. Toe is usually
expressed in degrees.
NOTE 2 The measurement method is specified in ISO 7176-5.
NOTE 3 A non-zero value of toe usually indicates a misalignment.
10 © ISO 2007 – All rights reserved

Key
1 toe
Figure 3 — Positive toe (exaggerated, top view)
4.6.5
horizontal location of wheel axle
horizontal position of the manoeuvring wheel (4.5.2) or the drive wheel (4.5.1) relative to the seating system
(4.7.2)
NOTE The measurement method is specified in ISO 7176-7.
4.6.6
vertical location of wheel axle
vertical position of the manoeuvring wheel (4.5.2) or the drive wheel (4.5.1) relative to the seating system
(4.7.2)
NOTE The measurement method is specified in ISO 7176-7.
4.6.7
castor rake GB
caster rake US
castor stem angle GB (deprecated)
caster stem angle US (deprecated)
angle between the castor stem (4.5.9) and vertical, measured in the fore-aft direction
See Figure 4.
NOTE 1 Castor rake is positive if the top of the castor stem is in front of the bottom [see Figure 4 a)], zero if the castor
stem is vertical in the fore-aft direction [see Figuer 4 b)], and negative if the top of the castor stem is behind the bottom
[see Figure 4 c)]. Castor rake is usually expressed in degrees.
NOTE 2 A non-zero value of castor rake usually indicates a misalignment.
NOTE 3 The measurement method is specified in ISO 7176-5.
a)  Positive castor rake b)  No castor rake c)  Negative castor rake

Key
1 part of wheelchair frame
a
Direction of forward travel.
b
Castor rake.
c
Vertical.
d
Castor stem axis.
Figure 4 — Castor rake (exaggerated, side view)
4.6.8
castor cant GB
caster cant US
angle between the castor stem (4.5.9) and vertical, measured in the lateral direction
See Figure 5.
NOTE 1 Castor cant is negative if the top of the castor stem is angled inwards [see Figure 5a)], zero if the castor stem
is vertical in the lateral direction [see Figure 5 b)], and negative if the top of the castor stem is angled outwards
[see Figure 5 c)]. Castor cant is usually expressed in degrees.
NOTE 2 A non-zero value of castor cant usually indicates a misalignment.
NOTE 3 The measurement method is specified in ISO 7176-5.
12 © ISO 2007 – All rights reserved

a)  Negative castor cant b)  No castor cant c)  Positive castor cant
Key
1 part of wheelchair frame
a
Castor stem axis.
b
Vertical.
c
Castor cant.
Figure 5 — Castor cant (exaggerated, front view)
4.6.9
castor trail GB
caster trail US
trail effect (deprecated)
fore-aft distance between the ground contact point of a castor wheel (4.5.6) and that point where the castor
stem (4.5.9) axis intersects with the ground
See Figure 6.
NOTE 1 The measurement method is specified in ISO 7176-5.
NOTE 2 The castor trail is positive by definition in all cases.

a
Direction of forward travel.
b
Contact point of wheel with ground.
c
Intersection point of castor stem axis with ground.
d
Castor trail.
Figure 6 — Castor trail (side view)
4.6.10
trailing position
alignment of the castor wheel (4.5.6) relative to the wheelchair
4.6.11
forward trailing position
trailing position (4.6.10) when the wheelchair is driving straight ahead in the forward direction
See Figure 7.
Figure 7 — Forward trailing position
4.6.12
rearward trailing position
trailing position (4.6.10) when the wheelchair is driving straight backwards
See Figure 8.
Figure 8 — Rearward trailing position
4.7 Postural supports
4.7.1
body support system
those parts of the wheelchair which directly support or contain the body of the occupant (4.2.2) including the
seat (4.7.8), back support (4.7.9), arm support (4.7.13), and lower leg support assembly (4.7.12)
See Figure 9.
Key
1 back support
2 seat
3 arm support
4 lower leg support assembly
Figure 9 — Body support system
14 © ISO 2007 – All rights reserved

4.7.2
seating system
seat (4.7.8) and back support (4.7.9) surfaces and their attachment hardware, plus those accessories deemed
necessary
4.7.3
postural support device
PSD
postural support (deprecated)
structure, attached to a wheelchair, which has a surface that contacts the occupant’s (4.2.2) body and is used
to either modify or accommodate the occupant’s sitting posture
EXAMPLE seat (4.7.8), back support (4.7.9), lateral support (4.7.26), head support (4.7.14)
4.7.4
integrated postural support device
integrated PSD
non-removable postural support device (4.7.3) built into the structure of the wheelchair
4.7.5
postural support device unit
PSD unit
PSD structure [seat (4.7.8) and back support (4.7.9)] joined together, not intended to be used as separate
components
4.7.6
postural support device component
PSD component
individual structure (piece) which may be added to the wheelchair or postural support device (4.7.3) to
increase the support being provided
4.7.7
support surface
part of the postural support device (4.7.3) that is intended to contact the wheelchair occupant (4.2.2)
4.7.8
seat
seat bottom (deprecated)
seat support (deprecated)
postural support device (4.7.3) intended to support the inferior surface of the buttocks and thighs
4.7.9
back support
back (deprecated)
backrest (deprecated)
seat back (deprecated)
postural support device (4.7.3) intended to support the posterior surface of the sacral, lumbar and/or thoracic
segments of the trunk
4.7.10
foot support
foot board (deprecated)
foot box (deprecated)
foot bucket (deprecated)
foot platform (deprecated)
footplate (deprecated)
footrest (deprecated)
postural support device (4.7.3) intended to support the foot
4.7.11
lower leg support
postural support device (4.7.3) intended to support the lower leg
4.7.12
lower leg support assembly
footrest assembly (deprecated)
front rigging (deprecated)
hanger (deprecated)
legrest (deprecated)
legrest assembly (deprecated)
combination of the lower leg support (4.7.11) and foot support (4.7.10) and their attachment hardware
4.7.13
arm support
arm trough (deprecated)
armrest (deprecated)
postural support device (4.7.3) intended to support the lower arm
4.7.14
head support
headrest (deprecated)
neck ring (deprecated)
occipital ring (deprecated)
postural support device (4.7.3) intended to support the head
4.7.15
seat cushion
pad (deprecated)
separate, removable postural support device (4.7.3) intended to support the inferior surface of the buttocks
and thighs
4.7.16
sling seat
seat (4.7.8) consisting of flexible material(s)
4.7.17
solid seat
seat (4.7.8) with a rigid surface that may or may not be covered by a cushioned material
4.7.18
inclined seat
seat dump (deprecated)
sloping seat (deprecated)
wedge seat (deprecated)
seat (4.7.8) that is angled in the fore-aft direction
NOTE Seat inclination is positive if the front of the seat surface is higher than the back of the seat surface, and negative
if the front of the seat surface is lower than the back of the seat surface.
4.7.19
anti-thrust seat
seat (4.7.8) intended to inhibit forward movement of the ischial tuberosities
4.7.20
solid seat insert
solid insert (deprecated)
rigid seat insert (deprecated)
rigidizer (deprecated)
sag compensator (deprecated)
additional, removable support structure inserted below the seat cushion (4.7.15) which is used without
removing the sling seat (4.7.16)
4.7.21
sling back
back support (4.7.9) consisting of flexible material(s)
16 © ISO 2007 – All rights reserved

4.7.22
solid back support
back support (4.7.9) with a rigid surface that may or may not be covered by a cushioned material
4.7.23
anterior support
postural support device (4.7.3) intended to contact the anterior surface of a body segment
See Figure 10 for examples 4, 5 and 6.
EXAMPLE 1 anterior head support
anterior head strap (deprecated)
forehead strap (deprecated)
forehead support (deprecated)
headband (deprecated)
EXAMPLE 2 anterior shoulder support
backpack straps (deprecated)
shoulder bar (deprecated)
shoulder hook (deprecated)
shoulder retractor (deprecated)
shoulder strap (deprecated)
EXAMPLE 3 anterior upper arm support
humeral strap (deprecated)
EXAMPLE 4 anterior trunk support
anterior thoracic support (deprecated)
butterfly strap (deprecated)
butterfly harness (deprecated)
chest harness (deprecated)
chest strap (deprecated)
H-strap (deprecated)
harness (deprecated)
spiderman strap (deprecated)
EXAMPLE 5 anterior pelvic support
lap belt (deprecated)
pelvic stabilizer (deprecated)
pelvic strap (deprecated)
seat belt (deprecated)
subasis bar (deprecated)
EXAMPLE 6 anterior lower leg support
knee block (deprecated)
knee strap (deprecated)
NOTE Anterior supports can be flexible or rigid.
Key
1 anterior trunk support
2 anterior pelvic support
3 anterior lower leg support
Figure 10 — Examples of anterior supports
4.7.24
posterior support
postural support device (4.7.3) intended to contact the posterior surface of a body segment
See Figure 11 for examples 3, 5 and 6.
EXAMPLE 1 posterior head support
EXAMPLE 2 posterior upper arm support
elbow block (deprecated)
humeral block (deprecated)
protractor (deprecated)
EXAMPLE 3 posterior lumbar support
lumbar pad (deprecated)
lumbar roll (deprecated)
EXAMPLE 4 posterior sacral support
posterior pelvic support (deprecated)
EXAMPLE 5 posterior lower leg support
calf pad (deprecated)
calf panel (deprecated)
calf strap (deprecated)
calf support (deprecated)
leg strap (deprecated)
leg support (deprecated)
legrest pad (deprecated)
lower leg support (deprecated)
posterior leg support (deprecated)
NOTE 1 In this case, the term “lower leg support” is deprecated as a synonym for “posterior lower leg support.”
EXAMPLE 6 posterior foot support
heel cup (deprecated)
heel loop (deprecated)
heel strap (deprecated)
NOTE 2 Posterior supports can be flexible or rigid.
18 © ISO 2007 – All rights reserved

Key
1 posterior lumbar support
2 posterior lower leg support
3 posterior foot support
Figure 11 — Examples of posterior supports
4.7.25
medial support
postural support device (4.7.3) intended to contact the medial surface of a body segment
See Figure 12 for example 1.
EXAMPLE 1 medial upper leg support
adduction strap (deprecated)
adductor pad (deprecated)
adductor wedge (deprecated)
leg adductor support (deprecated)
leg dividing support (deprecated)
wedge (deprecated)
wedge pad (deprecated)
EXAMPLE 2 medial knee support
pommel (deprecated)
EXAMPLE 3 medial lower leg support
NOTE Medial supports can be flexible or rigid.

Key
1 medial upper leg support
Figure 12 — Example of a medial support
4.7.26
lateral support
postural support device (4.7.3) intended to contact the lateral surface of a body segment
See Figure 13 for examples 1, 3 and 5.
EXAMPLE 1 lateral head support
head side support (deprecated)
lateral headrest (deprecated)
EXAMPLE 2 lateral upper arm support
humeral block (deprecated)
protractor (deprecated)
EXAMPLE 3 lateral trunk support
body side support (deprecated)
lateral (deprecated)
lateral support (deprecated)
lateral pad (deprecated)
lateral thoracic pad (deprecated)
lateral thoracic support (deprecated)
scoliosis pad (deprecated)
side cushion (deprecated)
trunk pad (deprecated)
NOTE 1 In this case, the term “lateral support” is deprecated as a synomym for “lateral trunk support.”
EXAMPLE 4 lateral pelvic support
hip block (deprecated)
hip guide (deprecated)
hip pad (deprecated)
lateral hip support (deprecated)
EXAMPLE 5 lateral upper leg support
adductor pad (deprecated)
adductor wedge (deprecated)
lateral thigh support (deprecated)
leg block (deprecated)
leg pad (deprecated)
leg strap (deprecated)
thigh block (deprecated)
thigh strap (deprecated)
EXAMPLE 6 lateral knee support
adductor pad (deprecated)
adductor strap (deprecated)
EXAMPLE 7 lateral lower leg support
calf strap (deprecated)
calf support (deprecated)
leg block (deprecated)
leg guide (deprecated)
leg pad (deprecated)
leg strap (deprecated)
legrest pad (deprecated)
NOTE 2 Lateral supports can be flexible or rigid.
20 © ISO 2007 – All rights reserved

Key
1 lateral head support
2 lateral trunk support
3 lateral upper leg support
Figure 13 — Examples of lateral supports
4.7.27
superior support
postural support device (4.7.3) intended to contact the superior surface of a body segment
See Figure 14 for examples 1 and 3.
EXAMPLE 1 superior lower arm support
forearm hook (deprecated)
forearm strap (deprecated)
EXAMPLE 2 superior upper leg support
leg strap (deprecated)
thigh strap (deprecated)
EXAMPLE 3 superior foot support
toe cup (deprecated)
toe loop (deprecated)
NOTE Superior supports can be flexible or rigid.

Key
1 superior lower arm support
2 superior foot support
Figure 14 — Examples of superior supports
4.7.28
inferior support
postural support device (4.7.3) intended to contact the inferior surface of a body segment
NOTE 1 An inferior support usually applies to the buttocks and thighs, and is used with or as part of a seat cushion.
See Figure 15 for examples 1 and 2.
EXAMPLE 1 inferior pelvic support
obliquity pad (deprecated)
EXAMPLE 2 inferior upper leg support
thigh wedge (deprecated)
EXAMPLE 3 inferior lower leg support
stump support (deprecated)
NOTE 2 Inferior supports can be flexible or rigid.

Key
1 inferior pelvic support
2 inferior upper leg support
Figure 15 — Examples of inferior supports
4.7.29
circumferential support
postural support device (4.7.3) which supports a body segment on at least three sides from at least three
directions
See Figures 16 and 17 for examples.
EXAMPLE 1 circumferential neck support
cervical collar (deprecated)
circumferential cervical support (deprecated)
collar (deprecated)
...