Case Report
䢇
Use of Power Mobility for a Young
Child With Spinal Muscular Atrophy
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Background and Purpose. Young children with severe motor impairments, such as spinal muscular atrophy, are often unable to move
around their environment independently; therefore, they may be at
risk for delays in areas of development not directly related to their
motor limitations. Power mobility is an intervention that provides
young children a means of independent movement and enables them
to independently explore their environment. Case Description. The
participant was a 20-month-old girl with type II spinal muscular
atrophy. Intervention. The authors provided the child with a power
wheelchair and gave her mother and physical therapist general guidelines to encourage her use of the power wheelchair. Outcomes. Within
6 weeks after receiving the power wheelchair, the child operated the
wheelchair independently. She showed developmental gains in all
domains of the Battelle Developmental Inventory and the Pediatric
Evaluation of Disability Inventory over 6 months. The authors conducted an interview with the child’s mother before and after intervention. She reported that the child was more independent after receiving
the power wheelchair. Discussion. The power wheelchair may have
been associated with the changes in the child’s mobility and her
developmental changes over 6 months. [Jones MA, McEwen IR,
Hansen L. Use of power mobility for a young child with spinal
muscular atrophy. Phys Ther. 2003;83:253–262.]
Key Words: Developmental skills, Power mobility, Young children.
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Maria A Jones, Irene R McEwen, Laura Hansen
Physical Therapy . Volume 83 . Number 3 . March 2003
253
Early power mobility may enhance the
M
otor skills develop rapidly during the first
3 years of a child’s life1 and provide a
means for exploration of the environment
and socialization with others. For children
with severe neuromuscular or musculoskeletal impairments, exploration and socialization often are limited
because of the difficulty these children have moving on
their own.2,3 Power mobility devices allow children with
severe physical disabilities to move independently within
their environment and to compensate for mobility limitations. Hays4 identified 4 categories of children who are
thought to benefit from power mobility, including children who: (1) will never walk, (2) cannot efficiently
move in a walker or manual wheelchair, (3) lose their
ability to move as the result of a traumatic injury or
progressive neuromuscular disorder, and (4) require
temporary assistance for mobility, most commonly due
to surgical intervention. For children in each of these
categories, power mobility is believed to promote independence and prevent functional limitations and disabilities that the children otherwise might encounter.4,5
Even though children with disabilities under the age of
3 years experience functional limitations and disabilities
similar to those of older children and adults, physical
therapists often do not consider power mobility as an
option to assist young children.2 Advocates for power
mobility consider it an essential component of a child’s
early intervention program2,6,7 and have demonstrated
that young children are capable of successfully using
power mobility.8 –12 Only one child less than 2 years of
age has been shown to use power mobility,12 and our
case report provides further support.
Not only are young children capable of using power
mobility, but independent mobility may promote development in other areas. Independent mobility is believed
to be essential for perceptual-motor and social skill
development.8,13 Self-produced locomotion also is
believed to have an impact on cognition, communica-
development of children who have
severe mobility limitations.
tion, and psychosocial development.14,15 Campos and
Bertenthal16 contended that self-produced locomotion
is an organizer of psychological changes in typically
developing infants, especially developmental changes in
social understanding, spatial cognition, and emotions.
Locomotion influences the development of infants’ fear
of heights,17 successful retrieval of hidden toys,14,18 –20
performance on Piagetian search tasks,14,15 and the
development of social behaviors and physical play.21,22
Although a growing body of literature suggests that early
power mobility could enhance the development of children who have severe mobility limitations,7,10,14 –16 little
research has addressed the developmental effects of
power mobility on children of any age. McEwen,7 Butler,10 and Kangas23 have suggested that service providers
should consider providing children with severe motor
impairments a means of independent mobility at an
early age, when other children are crawling and walking
to explore their environments. In our view, service
providers, including physical therapists, also should be
prepared to teach young children how to use power
wheelchairs so they can achieve independent mobility in
a variety of settings.24 –26
In our opinion, applying motor learning principles may
assist physical therapists in teaching young children to
use power mobility. Motor learning has been defined as
processes that lead to relatively permanent changes in a
person’s ability to produce a skilled action due to
practice or experience.27 Application of the concepts of
transfer of behavior or generalization, practice, and
feedback may be important when training a child to use
power mobility.
MA Jones, PT, MS, ATP, is a clinical physical therapist and doctoral student, College of Allied Health, Department of Rehabilitation Science,
University of Oklahoma Health Sciences Center, 1600 N Phillips, Oklahoma City, OK 73104 (USA) (maria-jones@ouhsc.edu). Address all
correspondence to Mrs Jones.
IR McEwen, PT, PhD, is Presbyterian Health Foundation Presidential Professor and Vice Chairman, Department of Rehabilitation Science,
University of Oklahoma Health Sciences Center.
L Hansen, PT, MS, is a clinical physical therapist and doctoral student, College of Allied Health, Department of Rehabilitation Science, University
of Oklahoma Health Sciences Center.
This work was supported by the Provost’s Research Fund, University of Oklahoma Health Sciences Center, and the Maternal and Child Health
Bureau (MCH), Health Resources and Services Administration, US Department of Health and Human Services (grant #6T18MC00008).
Mrs Jones and Dr McEwen provided idea/project design. All authors provided writing. Mrs Jones and Ms Hansen provided data collection, and
Mrs Jones provided data analysis. Dr McEwen provided fund procurement.
This article was submitted June 28, 2002, and was accepted October 28, 2002.
254 . Jones et al
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When training a child to use power mobility, we believe
physical therapists should design practice and provide
feedback to ensure the skills performed will transfer and
generalize across all environments in which the child will
use the device.28 –31 Practice opportunities, we contend,
should occur in familiar environments, such as the
backyard, on sidewalks going to and from the home, and
in the grocery store. Opportunities for practice should
not be limited to times when the physical therapist visits
the child one time per week for an hour (blocked
practice), but should be incorporated into daily activities
(random practice), such as going to and from the car,
transitioning between rooms, and playing on the playground. Research indicates that blocked practice may be
beneficial for initial skill acquisition, but random practice is necessary for learning, retention, and refinement
of a skill.27,31–33
Feedback is another important consideration. Research
suggests that although feedback is important and may be
provided continuously during initial acquisition of a
skill, the frequency and intensity of feedback should
decrease over time for actual learning and refinement of
a skill to occur. Fading feedback also ensures the child
does not become dependent on the feedback to perform
the skill.31,32
Tefft et al2 suggested that the use of power mobility for
young children is not widespread. There is little literature that describes intervention strategies used to promote independent mobility and documents the developmental changes that occur when young children receive
power mobility. The purpose of this case report is to
show that a child as young as 20 months of age can learn
to use a power wheelchair. We also describe the procedures used in training a young child to use a power
wheelchair and in evaluating the developmental changes
made after receiving the power wheelchair.
Case Description
Participant
This case involves a 20-month-old girl, Molly, with spinal
muscular atrophy. Molly was part of a larger study
conducted to determine whether the Battelle Developmental Inventory (BDI)34 and the Pediatric Evaluation
of Disability Inventory (PEDI)35 were responsive to
change in children 14 to 30 months of age with severe
physical disabilities and to pilot test procedures to be
used in research on power mobility. Molly was the first
child with whom we tested the procedures, and we
selected her for this case report because she was the
youngest child (17 months of age) referred for the study.
States. Molly was diagnosed with type II spinal muscular
atrophy when she was approximately 9 months of age.
Her mother described her as developing normally
through 6 months of age, when she was rolling over and
pushing up into a sitting position. By the time she was 7
months of age, she could not perform these activities.
Shortly after her diagnosis, physical therapy services
through an early intervention program began. A physical
therapist provided services every other week in the home
of her day care provider. The focus of intervention was
on attaining developmental milestones. Molly spent
approximately 9 hours a day in home day care with her
brother and occasionally with a grandchild of the day
care provider.
Molly’s intervention team, which consisted of a physical
therapist, a resource coordinator, and her mother,
determined that her primary limitation was her motor
development. Molly’s mother and the physical therapist
said they thought that she was “bright,” but they were
concerned that she was becoming frustrated because she
could not move to explore and play. Her mother
expressed interest in finding a way that Molly could
move on her own. The only specialized equipment that
Molly used prior to recruitment for the study was a
Tumble Forms TriStander.*
Examination
Examination of Molly included obtaining a brief history
from her mother and the physical therapist, observing
Molly in her daily environments, and administering tests
to obtain data for later comparison of developmental
and functional skills. During our observations, Molly was
attentive to people, objects, and activities in her environment. She consistently made choices by either saying or
shaking her head for “yes” and “no” and by pointing or
reaching for or verbally naming the desired object or
person. Some of Molly’s favorite activities appeared to be
playing “dress up,” taking care of her baby dolls, and
watching cartoons. She could play with toys that were
within her reach. Molly was unable to roll, crawl, and
walk. She could sit independently on the floor when
placed there, but she could not shift her weight in any
direction without losing her balance and falling over.
Molly’s attentiveness to and interaction with people,
objects, and activities in her environment, as well as her
desire to be engaged in activities, led us to believe that a
power wheelchair would allow her to interact independently in her environment and would have a positive
impact on other aspects of her development.
Although the administration of standardized tests is not
typically done to determine a child’s need for power
mobility, we administered tests to track Molly’s develop-
Molly lives with her mother and her typically developing
twin brother in a rural town in the south-central United
* Sammons Preston, PO Box 5071, Bolingbrook, IL 60440-5071.
Physical Therapy . Volume 83 . Number 3 . March 2003
Jones et al . 255
ment over a 6-month period. The tests administered
included a standardized developmental evaluation (ie, the
BDI)34 and a functional evaluation (ie, the PEDI35). The
BDI is a norm-referenced tool that is commonly used to
measure a child’s development in 5 domains: personalsocial, adaptive, motor, communication, and cognition.
The BDI test manual reports intraclass correlation coefficients (ICC) ranging between .90 and .99 for test-retest
reliability and interrater reliability of the BDI total scores
in a combined normative and clinical sample of 183
children. Using the Cohen Kappa, we calculated the
interrater reliability of the BDI total scores as part of the
larger study, and coefficients ranged between .92 and
.98. Several researchers34,36 –38 have examined and generally support the content, construct, concurrent, and
predictive validity of the BDI.
The PEDI measures a child’s ability to perform basic
skills, but also includes items related to the amount of
assistance or adaptation a child requires.35 The PEDI
manual reports good internal consistency, with coefficients ranging between .95 and .99 for all 6 scales using
Cronbach coefficient alpha. The test developers used
the ICC to calculate inter-interviewer reliability, and
coefficients ranged from .96 to .99 on all scales in a
normative sample of 30 children and from .84 to 1.00 in
a clinical sample of 12 children. Using the Cohen Kappa,
we calculated the inter-interviewer reliability of the PEDI
total scores on the functional skills and caregiver assistance scales as part of the larger study and achieved
coefficients between .92 and 1.00. Other researchers35,39,40 have examined and provide support for the
content, construct, concurrent, discriminative, and evaluative validity of the PEDI.
Intervention
The interventions that we provided to Molly included
providing a wheelchair that would meet her needs,
fitting and adjusting the seating system, and then training her to use the wheelchair. To decide on the features
of a wheelchair to meet Molly’s needs, a team that
included a durable medical equipment supplier, a physical therapist with assistive technology experience, Molly’s early intervention physical therapist, and her mother
discussed wheelchair options. We took physical measurements of Molly, including her thigh length, hip width,
lower leg length, chest width, shoulder width, and shoulder height. Because Molly required support to sit without leaning to the side, we ordered the chair with an
Invacare UltiMate seat cushion† and UltiMate curved
back cushion.† The seating system included a back
support that extended to the top of Molly’s shoulders;
swing-away, curved lateral trunk supports; a generically
(not custom-made) contoured seat cushion to keep her
†
hips centered in the chair and to position her knees in
line with her hips; and a pelvic belt. Joystick placement
was an important consideration because of Molly’s limited arm movement and muscle force. During our
observations, we noticed that she had difficulty manipulating toys or other objects that were positioned to the
right and left sides of her body. When items were
positioned in midline or slightly to either side of midline, Molly could use both hands to pick up the items
and pull them toward her. A standard joystick on a
wheelchair would be mounted to the side of the chair
and would require her to push the joystick to move it
forward. Because of Molly’s limitations, she needed a
midline joystick that would allow us to “reconfigure” the
joystick, so that pulling the joystick caused the chair to
move forward. The chair ordered for her, an Invacare
Action Power Tiger,† provided this option.
After delivery of the wheelchair, when Molly was 20
months of age, the physical therapist with assistive technology experience adjusted the seating system to fit her.
Seating system adjustments included raising the footrests, positioning the lateral trunk supports, and adjusting the depth of the seat to leave approximately 2.5 cm
(1 in) between the bend of her knee and the edge of the
seat cushion. The durable medical equipment supplier
programmed the electronics on the wheelchair so that
pulling the joystick toward her caused the chair to go
forward and pushing the joystick away from her caused
the chair to move backward.
We applied motor learning principles when providing
practice opportunities for Molly in her power wheelchair. The principles included giving Molly daily opportunities to use the wheelchair in natural environments,
with adults providing verbal encouragement for her to
move in the chair but refraining from giving her directions of where and how to move. When we delivered and
adjusted the wheelchair, we showed her one time how
the joystick worked, moving it in each direction and
allowing Molly to experience the different movements.
Without providing any additional feedback, we allowed
Molly to “explore” on her own. She immediately placed
her hands on the joystick and pulled it toward her,
causing the wheelchair to move forward. We asked
Molly’s mother, who was sitting on the floor in front of
the fireplace, to provide her with encouragement to
move the power wheelchair by saying, “Come see
Mommy.” Following this verbal prompt, Molly moved
toward her mother. As she approached her mother and
was about to collide with her, Molly removed her hand
from the joystick to make it stop. Molly consistently
moved the chair forward for approximately 0.9 m (3 ft)
without stopping. She also was able to turn the wheelchair to the right, but she could not turn to the left or
move backward without physical assistance. Her inability
Invacare Corp, One Invacare Way, Elyria, OH 44036-4028.
256 . Jones et al
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Table 1.
Instructions for Training a Child to Use a Power Wheelchaira
Young children in power wheelchairs must be supervised at all times. Adults should be close by to monitor all activities and to ensure safety.
Do:
1. Encourage your child to explore the joystick first, then the
movement, then the environment. Let the child learn by doing,
giving the child time to learn and react.
Do Not:
1. Expect your child to learn how to functionally operate and
maneuver the device within a day or week. This is a gradual
learning experience. The goal is not to move accurately at first,
but rather to give your child a tool to begin moving, exploring,
discovering, and problem solving at his or her own speed. The
process should be enjoyable and rewarding.
2. Provide positive feedback (eg, “You found the ______ [object your 2. Say anything that sounds negative (eg, “You crashed into the wall
child ran into]” rather than “Oops, you crashed”).
again” or “You’re going the wrong way”).
3. Give your child time to figure out a situation before intervening.
If your child looks distressed, then intervene immediately.
3. Describe how to move by using directionality commands
(eg, “Turn this way,” “Come here,” “Press the colored button,”
“Turn right or left”). All of these directions sound like commands,
and many children will resist this type of interaction.
4. Help your child by using only words such as “come closer,”
“turn,” “go back,” “lift your hand off,” or “let’s go for a walk,”
rather than “push the joystick and come here” or “press the yellow
button and go forward, turn left, go in reverse, and stop.”
a
From Wright-Ott C. The transitional powered mobility aid: a new concept and tool for early mobility. In: Furumasu J, ed. Pediatric Powered Mobility: Developmental
Perspectives, Technical Issues, Clinical Approaches. Arlington, Va: Rehabilitation Engineering and Assistive Technology Society of North America; 1997:58 – 69.
to move the joystick to the left and backward was due, we
believe, to her lack of postural control, not her understanding of the operation of the wheelchair. When she
wanted to move backward, but could not generate the
muscle force necessary to push the joystick, she would
say “back,” indicating her desire to move backward.
Following the initial training, which focused on Molly,
we shifted our training to Molly’s mother and the
physical therapist, who would be providing the practice
opportunities for Molly. We gave written guidelines to
Molly’s mother and the physical therapist, following
suggestions published by Wright-Ott41 for helping young
children learn to use power mobility (Tab. 1). Molly’s
mother and the physical therapist were primarily responsible for providing practice opportunities. We asked
Molly’s mother to provide her with daily opportunities to
sit in the device with the motor turned on during
supervised play in natural environments, such as her
home and yard, the day care provider’s home and yard,
the park, and the mall. We asked Molly’s physical
therapist to provide the same opportunities during her
typical therapy sessions. We initially asked them to
encourage Molly to experiment with movement in a
relatively large space under close supervision. We
advised Molly’s mother not be concerned if Molly spent
a period of time driving in circles, because we believed it
was important for Molly to experience the intrinsic
feedback (becoming dizzy) of going in circles. We
emphasized the importance of parental supervision, as
one would supervise any young child.42,43
To facilitate the use of her wheelchair and to ensure that
Molly’s mother and the physical therapist were comfortable with the use of the device, we made weekly telephone contacts with them until Molly could proficiently
Physical Therapy . Volume 83 . Number 3 . March 2003
Table 2.
Skills That Indicate a Child Has Become Proficient in Moving a Power
Wheelchaira
1. The child stops and starts the wheelchair upon command. Any
direction or distance is acceptable.
2. The child drives straight forward 3 m (10 ft) through wide
areas when the parent says, “Come to me.” The forward
movement does not have to be continuous for the 3 m.
3. The child upon command drives straight forward for 3 m
through narrow areas such as hallways and doorways without
colliding with either wall. Again, the forward movement does
not have to be continuous for the 3 m.
4. The child approaches furniture, stops near enough to touch it
without bumping it.
5. The child makes a 90-degree turn around a corner, even if the
movement is not continuous.
6. The child turns in a 360-degree circle. The movement does not
have to be continuous.
7. The child backs the wheelchair 0.3 m (1 ft) or more in an
approximate straight direction. The movement does not have to
be continuous.
a
From Butler C, Okamoto GA, McKay TM. Powered mobility for very young
disabled children. Dev Med Child Neurol. 1983;25:472– 474.
maneuver her power wheelchair according to the criteria of Butler et al11 (Tab. 2). We visited Molly to either
solve problems identified during the telephone contacts
or to observe Molly’s skills using the power wheelchair.
In the first 6 weeks, we visited Molly twice: once to adjust
the lateral trunk supports of her wheelchair and once to
observe Molly’s skills. To determine the frequency of
Molly’s practice opportunities with the power wheelchair, we asked her mother to complete a power mobility
record that tracked the amount of time and locations of
Molly’s practice opportunities. Molly sat in her wheelchair daily, and the duration of time varied from 15
Jones et al . 257
later. Molly received her power wheelchair between the 3- and 6-month
re-evaluations,
so
the
6-month
re-evaluation is described as postintervention. She received her power
wheelchair 10 days after the 3-month
evaluation and 2 months 27 days prior
to her 6-month evaluation. Figures 1
through 4 show the changes in her
scores on the BDI and the PEDI.
The BDI results indicate that Molly’s
development in all areas continued
after being provided a power wheelchair. With typically developing peers,
Figure 1.
Initial, 3-month, and 6-month Battelle Developmental Inventory age-equivalent scores for each we expect age-equivalent scores to
increase by 3 months over a 3-month
domain.
time period, but children with severe
motor impairments often do not demonstrate the same increases in ageequivalent scores over time. In Molly’s
case, however, her age-equivalent
scores increased by greater than 3
months in the following domains:
(1) communication, (2) personalsocial, and (3) cognition. Between the
second and third evaluations (3
months chronologically), Molly’s ageequivalent scores in communication
increased by 5 months, whereas the
scores increased by only 1 month
between her first and second evaluaFigure 2.
Initial, 3-month, and 6-month Battelle Developmental Inventory (BDI) age-equivalent scores for tions. These results indicate that prior
to the intervention, Molly’s communitotal scores.
cation skills were developing at a slower
rate than occurs in typically developing
minutes to 3 hours. The average amount of time Molly
peers, but that after the intervention, Molly’s communiused her wheelchair over the 6 weeks was 1.68 hours a
cation development exceeded that of typically developday. The duration gradually increased over time and as
ing peers.
she became proficient in using the wheelchair. The main
practice environments included her home, her grandMolly’s personal-social skills increased by 4 months
mother’s office, and the park. We provided a list of the
between evaluations, which is greater than we would
proficiency skills (Tab. 2) to Molly’s mother and asked
expect of typically developing peers. Her cognitive skills
her to call us immediately when Molly could perform all
increased by 7 months between the first and second
the skills listed. Molly’s mother called us 6 weeks after
evaluations and by 6 months between the second and
Molly received the power wheelchair. At that time, we
third evaluations. Based on typical development, we
visited Molly to verify that she could perform all the skills
expected Molly’s age-equivalent scores to increase by a
listed and to videotape her progress.
total of 6 months; however, she demonstrated a total
gain of 13 months, which is 7 months more than
Outcomes
expected. Molly’s adaptive and motor skills increased by
We measured Molly’s ability to maneuver the power
3 months between the first and second evaluations and
wheelchair using the skills listed in Table 2, her overall
by 1 month between the second and third evaluations.
development using the BDI, and her functional
These results indicate that Molly’s adaptive and motor
skills using the PEDI. We also interviewed Molly’s
development slowed in comparison with that of typically
mother. Administration of the BDI and PEDI occurred
developing peers. This finding is not surprising given
at the beginning of the study and 3 and 6 months
Molly’s diagnosis, which indicates she has pathology that
258 . Jones et al
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Figure 3.
Initial, 3-month, and 6-month Pediatric Evaluation of Disability Inventory functional skills scaled
scores for each domain.
leading to her house and making a
90-degree turn through the doorway
without hitting the door frame,
(2) moving from room to room in her
small house (approximately 92.9
square meters [1,000 square feet])
without hitting walls and door frames,
and (3) chasing her brother around
the yard while avoiding obstacles. Her
mother reported that she never had to
worry about Molly getting into trouble
or getting into dangerous situations
before receiving the power wheelchair;
however, after Molly received the
power
wheelchair,
her
mother
reported, “I’ve never had to deal with
stuff like this with her, but I’ve done it
with Chris (her twin brother), so I can
do it with her.” Just as parental supervision is necessary for any young child
to ensure safety, we observed that it
also is important to provide supervision
when a child receives a power
wheelchair.
During the initial interview, which
occurred prior to Molly receiving the
power wheelchair, we asked her
mother to describe Molly’s independence, and she replied,
Figure 4.
. . .[she’s] fairly independent, I
mean, as much as she can be. . .if
she was more mobile and things like
that, she would be very independent, but right now, she’s really
dependent on me for moving her from one place to
another.
Initial, 3-month, and 6-month Pediatric Evaluation of Disability Inventory caregiver assistance
scaled scores for each domain.
limits her ability to perform motor and self-care tasks
and results in the need for modifications to accommodate her functional limitations.
The PEDI results indicate a positive trend in all 3
domains (self-care, mobility, and social function).
Because the PEDI was designed for people with disabilities, it detected changes that the BDI did not. The
changes between her second and third evaluations indicated improvement in her functional mobility skills and
a decrease in the amount of assistance she required from
her caregivers for mobility, which we believe she would
not have achieved without the power wheelchair.
After 6 weeks of power mobility training, Molly became
skilled in moving her power wheelchair. She was 21
months of age. We believe she gained postural control
that allowed her to move the joystick in all directions.
Examples of skills Molly was able to accomplish in her
wheelchair included: (1) driving up and down the ramp
Physical Therapy . Volume 83 . Number 3 . March 2003
During the postintervention interview, Molly’s mother
described her independence as “something she is
learning to exert very well. . . .I think that’s a good
thing.” She also said,
. . .without the chair, she wouldn’t be able to get
around to see different things. Before, I was always
having to carry her and take her to the kitchen to
show her something or take her to the bedroom, and
now, she can. . .I put her in her chair and she can go
those places on her own. She can explore and get into
things. . .just like her brother.
Discussion
This case report describes procedures we used in teaching a 20-month-old girl to move independently in a
power wheelchair. Although the research on power
Jones et al . 259
mobility suggests that young children can quickly learn
to use power mobility,11,12 only Zazula and Foulds12 have
described a child younger than 24 months of age using
such a wheelchair. Zazula and Foulds designed a powered cart for an 11-month-old with phocomelia and
reported that it took the child 10 months to gain
“complete control over all operations of the cart”12(p139)
We were surprised by how quickly Molly learned to
maneuver the wheelchair, even with limited practice
opportunities. While we expected that she would gain
basic maneuvering skills in the weeks following the
delivery of her wheelchair, we also were surprised by the
advanced skills (going up and down ramps, maneuvering in tight spaces) she mastered in such a short period
of time.
Although we demonstrated that a child as young as 20
months of age could learn to maneuver a power wheelchair, it would be inappropriate for us to conclude that
Molly’s developmental and functional gains were the
direct result of the power mobility intervention. In
addition to the power mobility intervention, Molly
received early intervention services that focused on the
acquisition of developmental skills. However, we believe
that the power mobility intervention provided her independence and allowed her to explore her environment
without the assistance of others. We contend it also
allowed her to experience a variety of situations that she
otherwise would not have encountered. These additional experiences may foster the acquisition of greater
developmental and functional skills. Although maturation also could have played a role in the developmental
and functional improvement Molly made, we would
expect her developmental and functional improvement
to be only the same as that of her typically developing
peers. Because Molly’s age-equivalent scores increased
more in communication, personal-social, and cognitive
skills than is typical for her peers, we believe that the
power mobility intervention, not just maturation, may
have been a contributing factor.
Our experiences with Molly are similar to those reported
by other authors12 who indicated that children younger
than 2 years of age can learn to competently maneuver a
power wheelchair. This case, however, indicates that a
child as young as 20 months of age can learn to
competently maneuver a power wheelchair. The case
also describes changes in age-equivalent scores on the
BDI and scaled scores on the PEDI that could be used to
track Molly’s progress over time.
In our opinion and the opinion of others,5,14,15 children
with limited mobility experiences often fall behind in
other areas of development because they cannot independently explore and act on their environment. Motor
skills develop rapidly during the first 3 years of life and
260 . Jones et al
become the bridge to more advanced learning, socialization, and psychological development.6,44 We believe
that physical therapists should consider power mobility
as an option to augment a young child’s mobility at a
time when their peers are mobile, which, in turn, may
prevent or minimize detrimental effects caused by
immobility. Based on the interviews with Molly’s mother
and the changes in Molly’s developmental and functional skills using the BDI and PEDI, we believe that
providing children with power mobility should be considered an intervention that may promote independence and positive trends in all areas of development.
In this case report, we described the procedures used to
teach a 20-month-old with spinal muscular atrophy to
use a power wheelchair, and the application of the
results to children with different diagnoses should be
done with caution. A study of children under 24 months
of age is needed to determine whether children with
spinal muscular atrophy and other types of disabilities
would acquire the skills necessary to successfully maneuver a power wheelchair at the same rate as Molly.
Research comparing the development of communication, personal-social, and cognitive skills of children who
receive power mobility with those who do not receive
power mobility is necessary to demonstrate that power
mobility leads to greater development in these areas.
Qualitative research evaluating parents’ perceptions of
the impact power mobility had on their children’s lives
and their perception of their children’s development
would provide physical therapists with information they
could use when discussing power mobility as a mobility
option for young children.
Summary
We described the intervention strategies used to support
a 20-month-old girl with spinal muscular atrophy in
learning to use a power wheelchair, and we tracked her
developmental changes over 6 months. The intervention
we used was based on principles of motor learning and
anecdotal experiences of teachers and therapists who
work with children with disabilities. Within 6 weeks,
Molly was independently mobile in her environment.
Molly also showed continued progression of communication, cognitive, and personal-social skills. We believe
that power mobility can be beneficial to young children
with severe motor impairments. For this reason, we
recommend considering power mobility as an intervention that may promote independence and continued
development for young children with severe motor
impairments.
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