Gross Motor Skills of Toddlers with Autism and PDD

1
Gross Motor Skills of Toddlers with Autism and
PDD Meghann Lloyd, MA, Susan Risi, PhD,
Catherine Lord, PhD University of Michigan
Autism and Communication Disorders
ClinicDivision of Kinesiology, University of
Michigan
Developmental Milestones Age of sitting,
co-varied for ratio-nviq, was not different in
the 36 month group only
the NS group was different from the Autism
(p.000), and PDD (p.006) groups. No
differences were found in age of walking,
co-varied for ratio-nviq, between the PDD and
Autism groups. Within the the children in the NS group walked significantly
later than the Autism (p.019), and PDD (p.016)
groups. The DS group also walked later than the
NS group (p.022). In the 36 month group NS
children walked later than Autism (p.000) and
PDD (.009) groups. Age of independent walking
and sitting were correlated (.675).
Abstract
Results
Using a composite Ratio-MotorIQ (Table 3), age
groups were compared. There is a definite trend
indicating the children with ASD become more
behind on their motor skills as they get older.
Even when co-varied with ratio-nviq, the
difference between the motor skills of children
36 months with Autism was
significant (p.001) the trend is also evident
for the children with PDD (p.055). The NS group
also fell significantly further behind (p.016).
Participants No differences were found for
gender. The sample was 70 Caucasian and 28.4
was African-American (table 1). In the Autism
group, each of the PDD (p.000), NS (p.000) and DS
(p.034) groups. No other differences were found.
In the 36 month group, ratio-viq was different
between the Autism and PDD (p.050) and NS groups
(p.016). Across age groups the ratio-viqs of
the Autism groups were different (p.001). The
ratio-viqs did not differ for the other
diagnostic groups over age.
Gross motor skills allow young children to
interact with peers and the environment,
including social settings such as playground
play. Gross motor skills of young children
(14-55 months) diagnosed with Autism, Pervasive
Developmental Disorder (PDD), Down Syndrome (DS)
or other non-spectrum (NS) developmental delay
were evaluated (n197). Results indicate that
children with autism and PDD achieve motor
milestones within normal ranges, however their
overall motor skills are behind and become
significantly more delayed over time. Motor
skills were significantly correlated with ratio
non-verbal IQ and fine-motor skills. The Mullen
and Vineland motor scales were highly correlated.
Table 3. Ratio Gross Motor Scores
Table 1. Demographic data
Introduction
Ratio Motor IQ Mullen gross motor age
equivalent/chronological age 100
Clumsiness has been described as a feature of
children with Autism Spectrum Disorder (ASD),
particularly in children with Asperger syndrome
(Ghaziuddin Butler, 1998). The research on the
motor skills of children with ASD has focused on
older children. Recently, the gross motor skills
of very young children with autism and PDD are
attracting more attention (Dawson, et al., 2000
Molloy, et al., 2003 Teitelbaum, et al., 1998).
Evidence indicates that children with ASD may
have atypical motor skills even early in life.
Early diagnosis studies should include
assessments of early motor functioning to better
understand how children with autism and PDD
interact with their peers, care-givers and the
environment. The purpose of this study was to
evaluate the gross motor skills of very children
who were part of two large early diagnosis
studies.
Table 2. Motor Age Equivalents
Discussion
Little is known about very young children with
ASD, including their motor skills. Delays in
motor skills have been shown in older children
with ASD (Morin Reid, 1985). The principle
finding of the current study is that very young
children with Autism and PDD, on average,
attained motor milestones within typical ranges.
However, their motor skills were behind even when
ratio non-verbal IQ was accounted for. As they
got older their motor skills fell further behind
age expectations. There are many implications of
poor motor skills in young children including
limiting opportunities to engage in social play
and learning activities on the playground. Much
of the learning that occurs in the early years of
life is facilitated through exploratory activity.
If motor skills are delayed or behind,
opportunities to learn will be limited. Evidence
also suggests that after bouts of exercise,
self-stimulatory behaviours often decrease in
children with ASD (Prupas Reid, 2001).
Therefore if motor abilities prohibit engagement
in such motor activities there are fewer
opportunities to realize the benefits of
exercise. A strength of the current findings is
that the Mullen and Vineland gross motor and fine
motor scales were highly correlated. This
finding increases the validity of the results.
More research is needed to follow the trajectory
of motor skill development in children with ASD.
Methodology
Participants Participants consisted of 98 young
children with Autism, 58 children with PDD, 35
children with developmental delays, and 6
children specifically with Down syndrome (Table
1). Diagnostic Measures Each child was assessed
using a toddler version of the Autism Diagnostic
Interview-Revised (ADI-R Lord, et al., 1994) and
the Pre-Linguistic Autism Observational Schedule
or Autism Observational Schedule (PL-ADOS
Divalore, et al, 1995 ADOS Lord, et al., 2001).
Most of the children in this study were followed
over an extended period of time, therefore the
most recent diagnosis was used. Cognitive and
Developmental Tests The Mullen Scales of Early
Learning was administered including the Gross
Motor subscale (Mullen, 1995). The Vineland
Adaptive Behavior Scale (Sparrow, et al., 1984)
was also administered.Age equivalent scores for
the Mullen and the Vineland Scales were
established for every child, age of sitting and
walking were determined from the ADI-R, ratio VIQ
and ratio NVIQ were taken from the Mullen as well
as a composite ratio MotorIQ.
Motor Skills Age equivalents on both the Mullen
Gross Motor Scale and Vineland Gross Motor Scale
reveal children with Autism and PDD are behind on
gross motor skills (Table 2). These two gross
motor scales are highly correlated (.753), as are
the two Fine Motor scales (.709). The
discrepancies in the gross motor skills of
children with ASD get worse as they get older
(Table 3). The fine motor skills of children
with Autism and PDD are also delayed (Table 2).
However, no differences were found in fine-motor
skills (Vineland scores) over age group when
co-varied with ratio-nviq for any group Autism
(p .699), PDD (p.764) and NS (p .649). Gross
motor and fine motor skills were highly
correlated using the Mullen (.756) and using the
Vineland (.703).
Selected References

• Ghaziuddin, M., Butler, E. (1998). Clumsiness
  in autism and Asperger syndrome a further
  report. Journal of Intellectual Disability
  Research,42(1). 43-48.
• Klin, A., et al. (2004). Autism in a 15-month
  old child. American Journal of Psychiatry,161(11),
  1981-1988.Morin, B., Reid, G. (1985). A
  quantitative and qualitative assessment of
  autistic individuals on selected motor skills.
  Adapted Physical Activity Quarterly,2, 43-55.
• Prupas, A. Reid, G. (2001). Effects of
  exercise frequency on stereotypic behviors of
  children with developmental disabilities.
  Education and Training in Mental Retardation and
  Developmental Disabilities,36, 196-206.
• Teitelbaum, P., et al. (1998). Movement analysis
  in infancy may be useful for early diagnosis of
  autism. Proc. Natl. Acad.Sci,95, 13982-13987.

?Special thanks to Shanping Qiu!