RESNA Position on the Application of Ultralight Manual Wheelchairs.

RESNA Position on the Application of Ultralight Manual Wheelchairs.
RESNA Position on the Application of
Ultralight Manual Wheelchairs
Rehabilitation Engineering & Assistive Technology
Society of North America
1700 N. Moore Street, Suite 1540
Arlington, VA 22209
Phone: 703-524-6686
Fax: 703-524-6630
Approved by RESNA Board of Directors March 27, 2012
RESNA Position on the Application of
Ultralight Manual Wheelchairs
Background
Since its beginning, the manual wheelchair industry has transitioned from wheeled
devices that required the individual to adapt to fit the device, to an era when the device is
designed to fit the individual and the individual’s lifestyle. The first manual wheelchairs
were essentially wooden chairs with wheels. In 1930s and 40s the X-frame folding
wheelchair was developed by Herbert A. Everest and Harry C. Jennings. A design
revolution occurred during the 1970s and 80s, which incorporated advances in wheelchair
design and fabrication including decreasing the weight of the wheelchair, increasing the
maneuverability and decreasing the wear and tear on individuals using the wheelchair.
The most recent advancements in the 1990s and 2000s are in the manufacturing sector,
which allows individuals who utilize a wheelchair, to obtain a wheelchair customized to
match her/his specific anatomical dimensions, provide mobility in her/his unique
environment, and to perform a wide range of activities.1-3
A range of manual wheelchairs is currently available with features that vary in frame
design and configuration, weight, durability, adjustability, customization, and
accessories. These features can be customized to meet the intended use of the wheelchair
and the expected lifespan of the wheelchair. The ideal manual wheelchair is as light as
possible, durable for long-term continuous use, and custom-configured to meet the
specific mobility and postural needs of the intended user.
It is RESNA’s position that fully customizable manual wheelchairs that are as light as
possible, durable for long-term continuous use, have customizable rear wheel and caster
wheel location and configuration, and customizable seating configuration are the only
acceptable option for individuals who rely on manual wheelchairs for independent
manual mobility. Currently, these wheelchairs are typically identified as ultralight
manual wheelchairs. The purpose of this document is to provide external evidence, as
part of the evidence-based practice, which include rehabilitation and engineering
principles to support the appropriate application of fully customizable manual
wheelchairs.
Whenever possible this paper uses terminology from the RESNA standard for
Wheelchairs – Volume 1: Requirements and Test Methods for Wheelchairs (including
Scooters) – Section 26: Vocabulary.4
The purpose of this document is to share typical clinical applications as well as provide
evidence from the literature supporting the application of this Assistive Technology
intervention, to assist practitioners in decision-making and justification. It is not intended
to replace clinical judgment related to specific client needs.
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Scope:
For the purposes of this document, an ultralight manual wheelchair (ULWC) is defined as
a fully customizable (adjustable and/or configurable) wheelchair that is as light as
possible, is designed as an individual’s primary mobility device and does not include
features such as tilt or recline. Depending on the source, an ultralight wheelchair has
been defined as less than 30 lbs.5, (13.61 kg).6 or less than 25 lbs. (11.34 kg).2 Given the
intent of this document as a guide for application as opposed to design, a specific product
weight cut-off will not be utilized to define the recommendations made in this position
paper. Currently, numerous wheelchairs weigh less than 20 lbs. ( 9.07 kg). Further
weight reduction is anticipated as technology continues to advance.
The weight of an ULWC depends on numerous features incorporated into the overall
design of the wheelchair, and includes seating as well as any other accessories added.
These additional features and accessories, often incorporated into the seating system (seat
cushion and back support), are necessary to meet the unique postural support
requirements of the individual with a disability. Consequently, the final overall weight of
the system (wheelchair, seat cushion, back support and postural supports) may vary.
Therefore, the focus of this document is on wheelchairs that are as light as possible.
Ergonomics
The most appropriate manual wheelchair for individuals with disabilities who will utilize
the wheelchair for an extended period is a properly configured, fully customizable
wheelchair of the lightest weight possible. Ergonomic principles require that the device
match the individual given a specific level of ability, environment and activity.
Therefore, the appropriate manual wheelchair must have characteristic features that can
be specified to match the anatomical dimensions of the individual as well as the
individual’s functional ability. That is, the person cannot conform to the wheelchair, but
the wheelchair must conform to the individual. The principles of user-centered design7
and universal design8 prescribe to this fact. To meet these principles, a manual
wheelchair must, at a minimum, have the following features set to specific measurements
and/or positions for each individual at the time of acquisition.
Wheelchair Features 9, 10, 11, 12, 13
• Seat surface height at front edge
• Seat surface height at rear edge
• Seat plane angle
• Seat width
• Seat depth
• Back support height
• Seat to back support angle
• Foot support to seat length
• Leg to seat surface angle
• Horizontal and vertical position of rear wheel axle
• Rear wheel camber
• Wheel type and size
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Caster type and size
The features of a manual wheelchair will significantly affect the performance of the
wheelchair in terms of postural support, wheelchair stability, wheelchair maneuverability,
and ease of propulsion. Numerous authors have addressed the affect of these features on
the wheelchair’s functional characteristics.14-18 A guide to the measurement of wheelchair
dimensions can be found in Chapter 2 of “Wheelchair Selection and Configuration”13,
online at the Greater Metropolitan Clinical Taskforce (GMCT) NSW State Spinal Cord
Injury Service (SSCIS) education website for seating and wheeled mobility19, or via the
RESNA Standards20.
Functional Characteristics 9, 10, 11, 12, 13
• Rolling Resistances
• Downhill Turning Tendency
• Yaw Axis Control (i.e. ease of turning, maneuverability)
• Pitch Axis Control (i.e. traversing obstacles)
• Propulsion Efficiency
• Static Stability
• Transportability
• Footprint
Effect of a Highly Customizable Wheelchair on Functional Characteristics
SEAT TO FLOOR HEIGHT
The seat surface height at front edge is necessary to match the anatomical dimensions of
the lower leg in conjunction with the foot support length as well as assure accessibility.
An appropriate height will also accommodate the wheelchair cushion required by the
individual. An appropriate seat surface height at the front edge provides proper support of
both the lower leg and the thighs within the seating system. The seat surface height at
rear edge is necessary for appropriate access to the handrim and postural support of the
thighs relative to the seat surface height at front edge. Many individuals with impaired
trunk control benefit from having the front seat height higher than the rear to provide
increased support for stability... The seat surface height for both the front and rear are
important for clearance under tables, footplate clearance over thresholds and facilitating
transfers.
SEAT PLANE ANGLE
The seat plane angle (aka seat slope) is important in properly supporting the thighs, and
minimizing the seat surface friction necessary to maintain an individual’s position within
the frame. Increased seat plane angle can reduce the individual’s tendency to slide out of
the wheelchair as long as the individual has sufficient range of motion at the hips and
knees. Conversely, increasing the seat plane angle can make transfers more difficult.
SEAT WIDTH
Achieving seat width is critical in postural support and propulsion efficiency. In terms of
postural support, if the seat width is too narrow it causes tissue compression by the
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clothing guards or armrests, which may cause a pressure ulcer to develop. If clothing
guards or armrests are not present, then the individual’s tissue can interfere with the
wheels, causing scrapes and other shear related injuries. If the seat width is larger than
necessary, the handrims will be difficult to access10, placing the upper extremities in
potentially injurious positions. Specifically, increased wrist flexion and shoulder
abduction can lead to long term secondary injuries at the joints.21 In addition, it may
limit the individual’s access to the environment by being too wide to maneuver through
some doorways as well as decreasing overall ease of maneuverability and propulsion.
SEAT DEPTH
Proper seat depth is critical to providing appropriate postural support and proper weight
distribution over the base. The seat depth not only affects the length of the support
surface, but also the overall length of the wheelchair frame. A seat depth that is too short
does not provide adequate surface for pressure redistribution nor appropriate postural
support of the thighs and buttocks. An inadequate surface for pressure redistribution will
lead to pain and discomfort. A short seat depth increases the load that must be supported
by the buttocks, thereby increasing the risk for developing pressure ulcers under the
sacrum and/or ischial tuberosities. A short seat depth also shortens the frame length,
which increases the percentage of weight carried by the casters. The goal is to maximize
the weight on the rear wheels to increase propulsion efficiency and maneuverability (ease
of turning and ease of getting over obstacles such as door thresholds).
A seat depth that is too long will interfere with the proper support of the lower
extremities. One potential consequence is that the individual could develop pressure sores
at the popliteal fossa. A more harmful potential consequence is that the individual will
slide forward to clear the front edge of the seat. This causes multiple problems. It may
cause the individual to slide forward in the seat, increasing the posterior pelvic tilt and
placing undue loading on the sacrum potentially producing a pressure sore. Prolonged
sitting in this position can lead to muscle tightness and postural asymmetries, such as
kyphosis, forward head, and rounded shoulders. Inducing a posterior pelvic tilt will also
place the individual in a mechanically disadvantaged position for propulsion, making
access to the handrims more difficult. Finally, there is also the possibility that the
individual could slide out the front of the wheelchair.
BACK SUPPORT HEIGHT
Proper back support height is important for providing appropriate postural support of the
posterior pelvis and the trunk for stability, as well as facilitating upper extremity
function. If the back support height is too high it could limit scapular excursion and
gleno-humeral range during upper extremity movement, thereby impairing upper
extremity range of motion required for efficient propulsion. This leads to decreased
maneuverability and pitch access control. If the back support height is too low, there is
not adequate back support, resulting in trunk instability. This could make it very difficult
for the individual to use their upper extremities to propel the wheelchair. Instead, the
individual will use his/her upper extremities to maintain their balance. Some individuals
with too low of a back support may slide forward in their seat to gain stability, resulting
in the short seat depth concerns previously noted. Too low of back support can also
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result in the development or worsening of postural deformities due to inadequate trunk
support.
SEAT TO BACK SUPPORT ANGLE
The seat to back support angle is important to assure proper positioning in the wheelchair
for propulsion. A seat to back support angle of less than 90 degrees will “lock” the pelvis
into a neutral or anterior pelvic tilt , creating a stable postural base. However, if the seat
to back support angle is too small for an individual given their hip flexion range of
motion they may not fit into the seating system. This will cause them to slide forward in
the system to take pressure off of the hip and/or back. A seat to back support angle
greater than 90 degrees can improve sitting balance for some individuals with decreased
trunk control. Individuals with postural asymmetries such as a posteriorly tilted pelvis or
kyphosis will often require a seat to back angle greater than 90 degrees to accommodate
their posture. A seat to back support angle that is too large may promote a posterior
pelvic tilt and kyphotic trunk posture and will change the line of sight upward.
FOOT SUPPORT TO SEAT LENGTH
The foot support to seat length (aka legrest length) is important for providing appropriate
postural support to the lower extremities. If the length is too short, it can raise the knees
and cause potential interference issues with objects (e.g. tables) in the environment. This
will also inhibit proper pressure re-distribution, concentrating pressure at the ischial
tuberosities and sacrum, leading to the possible development of pressure wounds.
Furthermore, raised knees will reduce the effectiveness of the seating system since the
thighs will not be properly supported by the front half of the seat cushion. Depending on
the individual’s hip flexion range-of-motion, raising the knees may cause a posterior
pelvic tilt, which has significant implications in the potential development of pressure
ulcers at, the ischial tuberosities, and the sacrum. Alternatively, if the foot support to seat
length is too long the feet will not be properly supported, which may decrease sitting
balance. A person may slide forward in the seating system – leading to lack of adequate
postural support for mobility and function. The feet may also have a tendency to fall off
of the footplates putting them at risk for dragging on the floor or interfering with the
casters. Furthermore, if the length is too long, then the footplates may interfere with
ground clearance, floor making it impossible to traverse thresholds, ramps, curbs and
other uneven surfaces.
LEG TO SEAT SURFACE ANGLE
The leg to seat surface angle is important for providing appropriate postural support to
the lower extremities. If the angle does not match the available passive range of motion
of the knee for the individual, it has the potential to cause the person to slide out of the
wheelchair or cause pressure ulcers on the posterior aspect of the calves. Furthermore,
the leg to seat surface angle has a significant effect on the overall height and depth of the
legrest as part of the overall wheelchair footprint.
POSITION OF THE REAR WHEEL AXLE
The horizontal and vertical position of the rear wheel axle has a significant impact on all
of the functional characteristics of the wheelchair including stability, weight distribution,
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and turning radius, as well as the individual’s propulsion style, propulsion efficiency, and
access to the environment. Due to the impact on an individual’s ability to gain access to
her/his environment and potential physical harm from improper placement, all manual
wheelchairs designed for long-term usage, must have the option to specifically prescribe
the placement of the rear wheel axle, either at the time that the wheelchair is ordered
from the manufacturer, or during the implementation process.
With regard to the horizontal position of the rear wheel axle, if it is too far rearward the
chair will be more stable, but an individual will have to place his/her upper extremities in
a less efficient and potentially injurious position22 23 to access the handrim during
propulsion. Moving the axle rearward increases the rolling resistance, making the chair
harder to propel, by placing a larger percentage of the weight on the casters, requiring the
user to work harder to propel the chair. Moving the axle rearward also increases the
forces necessary to turn the wheelchair, and the effort required to maintain a straight line
of travel when on a side slope. Moving the axle too far rearward makes it more difficult
to de-weight the casters to perform a transitory wheelie, which is necessary to traverse
obstacles. Finally, moving the axle too far rearward increases the turning radius and
length of the wheelchair footprint, making it difficult to maneuver in tight spaces.
If the axle is too far forward then the rearward stability of the wheelchair may be
compromised. This can increase the risk of the chair tipping over backward causing
injury or harm to the user. Best practice is to position the axle as far forward as possible
without compromising rearward stability or interfering with the casters.
When considering the vertical position of the rear wheel axle, if it is too high or too low
then the individual will have a difficult time accessing the handrim for effective /
efficient propulsion and this may place the upper extremities in a potentially injurious
position. Furthermore, if the vertical position is not set appropriately for individuals who
propel the wheelchair with their lower extremities, they will not be able to propel the
wheelchair. Finally, the vertical position affects the rear seat to floor height and the seat
angle, which have been discussed previously.
REAR WHEEL CAMBER
Choosing the correct camber angle for the rear wheels, can be critical to providing
appropriate lateral stability and promoting responsiveness with efficient propulsion.
Adding camber will widen the base of the chair for increased lateral stability, as well as
bring the top of wheels closer to the user for an efficient push. For some users, when
there is no camber (0 degrees) or minimal camber (1-2 degrees), lateral wheelchair
stability is affected and they may have difficulty maintaining an upright position, when
performing tasks that require leaning outside the footprint of the wheelchair. If the
degree of camber is too large, then the individual may have difficulty maneuvering
through doors, as this will increase the width of the wheelchair.
WHEEL TYPE AND SIZE
In terms of wheel type and size, the wheels are important to minimize the rolling
resistance, decrease the weight and increase the reliability of the system. A larger
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diameter wheel has a lower rolling resistance, however if the wheel is too large then the
seat-to-floor height may be compromised and access to the handrims may be
compromised. Furthermore, the larger diameter tire may interfere with the caster, and
will increase the length of the wheelchair footprint. A pneumatic tire should be
considered as, when properly inflated, they typically have a significantly lower rolling
resistance than solid tires or pneumatic tires with flat-free inserts. Non-pneumatic tires
should be considered when the environment dictates that a flat-tire is a safety issue.
CASTER TYPE AND SIZE
In terms of the caster type and size, including the caster trail, the casters are important for
stability, rolling resistance, and maneuverability. If the casters are too large, then they
may interfere with the footrests and the rear wheels, and will affect the seat-to-floor
height and seat angle. If they are too small and an individual is unable to perform a
partial or full wheelie24, then the person may not be able to traverse obstacles or rough
terrain. Large caster forks create a larger caster trail than smaller forks. If the caster trail
is too long then the caster wheel may interfere with the footplate and/or the rear wheel. A
short caster trail will increase maneuverability but potentially compromise forward static
stability when the casters are in a leading orientation.
Propulsion Biomechanics and Wheelchair Skills Acquisition:
The customizable features of ULWCs allow a practitioner to optimally match the
wheelchair geometry to the end user’s current and future needs. By selecting and
correctly configuring a ULWC, the end user is able to propel more effectively. For
example, the ability to select an appropriate seat height and wheelchair geometry
contributes to seated stability, postural support, and the ability to transfer independently
to surfaces such as a bed, car, and bathroom equipment.
ULWCs specifically address upper extremity pain and injury based on the following
evidence:
• A more forward axle position decreases rolling resistance and therefore increases
propulsion efficiency.16
• A forward placement of the rear axle decreases turning radius, downhill turning
tendency and caster flutter.25
• A more forward axle position has been found to increase the hand contact angle or
amount of the pushrim used by the individual.26 It is also associated with less
muscle effort, smoother joint excursions and lower stroke frequencies.16
• A lower seat position or a higher rear axle improves push biomechanics. A lower
seat position has been associated with greater upper limb motions, greater hand
contact angles, lower frequency and higher mechanical efficiency.25-27
• Customized wheelchair configuration that allows the wheelchair to act as an
orthotic device provides necessary postural support that is critical for optimal
function.28 The adjustable and/or selectable features inherent to the ultra
lightweight wheelchairs are required to provide individualized postural support.
• A forward placement of the rear axle shifts the wheelchair user’s center of gravity
closer to the center of rear wheel rotation, which increases the user’s ability to
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perform the wheelie skill.29 Wheelies can be used to prevent or reduce
impairments, and are the foundation of many other key skills. By simply tilting
backwards, sitting pressures can be reduced, overhead objects can be viewed
without extending the neck, and the incidence of injury can be reduced. The most
valuable application of this skill involves navigating rough ground, curbs, and
other obstacles as well as increasing user participation.30
Pediatric wheelchair users can propel longer distances independently when using
ULWCs as compared to lightweight wheelchairs. Their parents are also more
satisfied when using ULWCs when compared to lightweight wheelchairs.31
Upper Extremity Pain and Injury
Manual wheelchair users experience a high incidence of upper extremity pain and
dysfunction. The incidence of carpal tunnel syndrome (CTS) in manual wheelchair users
is between 49-73%32-35 while pain has been reported in up to 59% of individuals with
spinal cord injury (SCI) and becomes more prevalent as the number of years using
manual mobility increases.36, 37 These orthopedic upper extremity injuries, including CTS
and rotator cuff problems result in the need for costly medical interventions, loss of
function and diminished ability to independently perform activities of daily living
(ADL).38 Pain has been correlated with lower quality of life scores. It has been
identified as a major reason for decline of function in individuals with SCI who require
more assistance since initial injury, resulting in increased dependence on personal care
assistants and limitations to independence.39-42 Upper limb pain and injury also causes
disruptions in work, educational and social activities, which further contributes to
impaired quality of life. Chronic upper extremity pain may ultimately direct a transition
to a more costly powered wheelchair.
Due to the high incidence of upper limb pain and injury in individuals with spinal cord
injuries, numerous researchers have investigated these issues. Two documents that
summarize the information in this area and provide clinical recommendations are
“Preservation of Upper Limb Function Following Spinal Cord Injury: A Clinical
Practice Guideline for Healthcare Professionals.”43 and “Pushrim biomechanics and
injury prevention in spinal cord injury: Recommendations based on CULP-SCI
investigations”44. The clinical practice guideline (CPG) document was formulated by 10
expert panel members and was reviewed by 38 additional experts. Several of the
recommendations put forth in these clinical guidelines can be specifically applied to
wheelchair provision with respect to prevention of upper limb pain and injury. Following
the publication of this guideline, which references articles prior to 2004, Boninger,
Koontz, et al. (2005) 44 published their recommendations that reinforce the clinical
practice guideline. Although both documents are written for the population of
individuals with spinal cord injury, the information has universal application to anyone
who utilizes a manual wheelchair for her/his primary mode of mobility. Finally, Berner,
DiGiovine and Roesler provided an update on the evidence from when the CPG was
published in 2003, generating a review of the wheelchair literature based on the
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recommendations listed in the CPG. The update focused on the categories of ergonomics,
equipment selection, training and environmental adaptations.45
With respect to a highly adjustable and configurable wheelchair that is lightweight the
summary of recommendations within these two documents focus on three areas:
Ergonomics, Equipment Selection, and Training.
The ergonomic recommendations include minimizing the stroke frequency, minimizing
the forces generated during propulsion and minimizing extreme or potentially injurious
positions. The appropriate set-up and configuration of an ultralight wheelchair directly
addresses these three recommendations. The recommendations have been supported in
the literature by numerous researchers.38, 46-56
The equipment selection recommendations include “providing a high-strength, fully
customizable manual wheelchair made of the lightest possible material”, “adjusting the
rear axle as far forward as possible without compromising stability”, and “placing the
rear axle so that when the hand is placed at the top dead-center position on the pushrim,
the angle between the upper arm and forearm is between 100 and 120 degrees”. The
recommendations have been supported in the literature by numerous researchers.31, 57-70
Finally, the training recommendations include using long, smooth strokes in a semicircular pattern, and promoting appropriate seated posture and stabilization. Once again
the appropriate set-up and configuration of an ultralight wheelchair, specifically the
vertical and horizontal placement of the rear wheel, directly addresses an individual’s
ability to use long smooth semi-circular strokes. The set-up of the wheelchair, as this is
the foundation of the seating system, regardless of the seat cushion and back support, is
critical to promoting an appropriate seated posture and stabilization. These
recommendations have been supported in the literature by numerous researchers.71-73
Other types of wheelchairs cannot safely and effectively address the recommendations
for ergonomics, equipment selection and training because they are not adjustable to meet
the unique anthropometric dimensions, postural requirements, and functional abilities of
the individual. The significantly lower weight of ULWC’s (some weigh less than 15
pounds) and the selectable components and configurations, can decrease the risk of
repetitive strain injuries by limiting forces at the wrist and shoulder during wheelchair
propulsion.15, 16, 36 The risk of upper limb injury is also minimized when the individual is
managing the wheelchair, as in the case of stowing the wheelchair in a vehicle.
ULWC’s specifically address upper extremity pain and injury as supported by the
following research evidence:
• ULWC’s have reduced rolling resistance due to decreased weight, higher quality
components (e.g. tires, wheels, bearings) and proper set-up of the wheelchair,
which correlates to less force needed at the wrist to initiate and continue
propulsion.36 15, 16
• Individuals using lighter wheelchairs push faster, travel further and use less
energy, which means less fatigue during the day and over time. In older adults
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•
•
using wheelchairs who do not have spinal cord injuries, the decreased weight also
results in improved velocity, increased stroke length and decreased resultant and
tangential force.74, 75 Decreased wheelchair weight also results in a decrease in
push frequency.25, 76
An adjustable axle position is critical to ensure proper position of the wheels for
maximum propulsion efficiency.29 In tetraplegics, the further forward and higher
up the axle is placed results in improved ability begin propelling their chairs. 77
A lower seat position gives better access to the wheels. It correlates with better
upper extremity motion and lower push frequency. However, this position can be
too low as the ideal angle is between 100 and 120 degrees of elbow flexion when
the hand is placed on the pushrim.25, 27
An ULWC requires less upper extremity force to independently load in and out of
a vehicle.
Durability and Cost Effectiveness:
Stakeholders are constantly demanding that equipment last longer and provide functional
benefits in a variety of settings. The materials used to fabricate ULWC’s have high
strength to weight ratios. Examples include aerospace grade aluminum, chromoly steel
and titanium. They are therefore more durable, last longer, and resistant to fatigue and
corrosion. Increased durability helps to ensure that the end user will get longer use from
the ULWC with less need for costly repairs or replacements.
ULWC’s have been proven to be the most durable and cost effective manual wheelchair
option according to the following evidence:
• ULWC’s have been shown to last 13.2 times longer than standard manual
wheelchairs and to cost about 3.5 times less to operate.78
• In comparison to lightweight wheelchairs, which weigh 34-36 pounds as defined
by Medicare, the ULWC’s lasted 4.8 times longer and were 2.3 times less
expensive to operate.79, 80 When tested to failure, ULWC’s had the longest
survival rate and fewer catastrophic failures than both standard and lightweight
wheelchairs.81
Summary:
•
•
An ULWC is a highly adjustable and configurable wheelchair that is as light as
possible to meet the unique requirements of the individual today and in the future
Safe and functional manual wheelchair propulsion requires properly configured
equipment. All stakeholders must consider the characteristics of the human, the
activity, the assistive technology and the context (HAAT model).82 The Clinical
Practice Guidelines, in conjunction with the current peer-reviewed articles,
recommend a fully customizable wheelchair made of the lightest high-strength
materials. The evidence concerning upper extremity pain and injury in the
population of manual wheelchair users suggests that the proper selection and
configuration of ULWC’s can significantly reduce the secondary complications
associated with overuse syndromes. These include, but are not limited to, pain in
the upper extremity, loss of independent function, the costs associated with loss of
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work, social isolation and depression, the need to transition to more expensive
power mobility, and costly surgical interventions.
The evidence available regarding ultra-light manual wheelchairs suggests that a
properly configured ULWC will contribute to long-term functional success,
decreased incidence of secondary complications, and will cost less to maintain
over time. An ULWC should be considered for all individuals who are manually
propelling a wheelchair to ensure maximum function and safety.
In consideration of an individual’s anatomic and postural requirements, her/his
activities, and the context for utilization, we recommend an ultralight manual
wheelchair for individuals who utilize a wheelchair as her/his primary mode of
mobility.
Case One:
Mr. Simmons is a 45-year-old father of two young children. He sustained a complete T8
spinal cord injury (SCI) ASIA A as a result of a motor vehicle accident. Prior to his
injury he had no medical issues and was very active and healthy. He returned home from
his inpatient rehabilitation and was able to resume his active lifestyle. He uses a manual
wheelchair as his only means of mobility. Mr. Simmons works full-time outside of the
home and is the primary caregiver for his two children. He drives a car and is required to
complete several transfers in and out of his car daily. His current equipment includes a
standard wheelchair with sling upholstery and appropriate seating.
In the past two years, Mr. Simmons has experienced increase pain in his right shoulder
and bilateral wrists that limit his ability to perform tasks such as transfers and reaching
overhead. He has found that by the end of the day he has difficulty completing is home
management and childcare needs as his arms are sore and he has difficulty propelling. He
currently skips activities he would participate in because of the discomfort in his
shoulders. These limitations impact his ability to complete instrumental activities of daily
living (IADL’s) including cooking, shopping, and other tasks related to care of his
children. Mr. Simmons reports that he fatigues easily throughout the day and needs to
transfer out of his chair for extended “rest periods”.
Mr. Simmons’ wheelchair needed repeated repairs so it was suggested that he pursue a
new frame. He went to the local seating clinic to get an evaluation where he was shown
many styles of frames available. He participated in musculoskeletal exams to identify the
cause of his pain and it was determined that the set up of his chair and the propulsion
method he used were inadequate. He evaluated equipment and completed a propulsion
analysis and several wheelchair skills tests.
After trial with an ultralight wheelchair with rear wheel axle adjusted
appropriately for efficient propulsion, Mr. Simmons reported a decrease in upper
extremity pain and fatigue. The custom fit of the new frame allows for improved seated
stability and postural control during completion of his daily ADL’s. As he experienced,
these results were not achievable with a standard wheelchair. The use of an ultra
lightweight manual wheelchair has had a significant impact on Mr. Simmons’ ability to
function independently and maintain a high quality of life.
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After he received his chair and participated in adjustments with the seating clinic team he
began applying the principles he learned along with the set up of his new frame. The data
gathered from his follow up outcomes assessment indicated that his pain in his shoulders
was significantly reduced and that he no longer had any disruption in accessing his
environment to carry out the activities he needed and wanted to do.
Case Two:
Joshua is a 5-year-old who is a functional C6 quadriplegic due to Transverse Myelitis at
two years of age. He is very motivated to be independent, play sports, and do all
activities of a child his age.
Joshua’s current wheelchair is a lightweight wheelchair with a significant amount
of postural support devices (e.g. lateral trunk supports, lateral upper leg support and
medial upper leg support) and a poorly adjusted center of gravity. The weight of the
postural support devices and lightweight wheelchair weigh as much as Joshua.
Previously, he had an ultralight wheelchair and had only gotten a new one due to his
growth. Since receiving this wheelchair, he and his parents report that he cannot propel
independently throughout the day due to fatigue.
After a trial of a properly adjusted ultralight wheelchair with lighter weight
postural support devices that together were over ten pounds lighter than his current
wheelchair set-up, it was determined that Joshua could be more independent and
functional with this type of equipment. Consequently, he was provided with an ultralight
wheelchair with appropriate positioning equipment. At delivery, the wheelchair was
adjusted properly to him to maximize his propulsion ability.
Since the new wheelchair was provided to him, his mother reports that he is
independent throughout the day and that he is now participating in wheelchair sports. He
and his mother report that his quality of life has improved significantly as a result of the
new properly configured ultralight wheelchair.
Authors:
Carmen DiGiovine, PhD, RET, ATP, Lauren Rosen, PT, MPT, MSMS, ATP/SMS,
Theresa Berner, OTR/L, ATP, Kendra Betz, MPT, ATP, Tina Roesler, PT, MS, ABDA,
and Mark Schmeler, PhD, OTR/L, ATP
RESNA, the Rehabilitation Engineering and Assistive Technology Society of North
America, is the premier professional organization dedicated to promoting the health and
well-being of people with disabilities through increasing access to technology solutions.
RESNA advances the field by offering certification, continuing education, and
professional development; developing assistive technology standards; promoting research
and public policy; and sponsoring forums for the exchange of information and ideas to
meet the needs of our multidisciplinary constituency.
Developed through RESNA’s Special Interest Group in Seating and Wheeled Mobility
12
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