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Abstracts* of Platform Presentations at the 2012 Combined Sections Meeting

doi: 10.1097/PEP.0b013e318241c9d9

*Abstract are presented in alphabetical order of the first author's last name

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A. Areval, T.H. Kolobe, S. Arnold, B. DeGrace, Department of Rehabilitation Science, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.

PURPOSE/HYPOTHESIS: This prospective longitudinal study examined whether parenting behaviors and childrearing practices in the first three years of life among Mexican-American (MA) families could predict children's academic performance at school age. The study also examined the contribution of the parents' level of education (LED), socioeconomic status (SES) and level of acculturation to academic performance.

NUMBER OF SUBJECTS: Thirty-six children from an original cohort of 52 parent-child dyads.

MATERIALS/METHODS: Parent behaviors, childrearing practices and the children's developmental status were assessed annually during the first three years of age using the Parent Behavior Checklist (PBC), Nursing Child Assessment Teaching Scale, Home Observation for Measurement of the Environment Inventory, and Bayley Scales of Infant Development II, respectively. No differences were found between the childrearing and developmental scores of the 36 participants and the 16 non-participant. The Illinois Standards Achievement Test (ISAT) was used to assess academic performance (math and reading) in 3rd grade. The Pearson product moment correlation coefficient, multiple regression analyses, and partial correlation were used to examine the relationship between the early parenting behaviors and childrearing practices, developmental status, demographic factors, and academic performance. One-way ANOVA and t-tests were used to determine if there were differences in mean ISAT national percentile rank based on SES, LED, and level of acculturation.

RESULTS: Only the correlation coefficients between parents' developmental expectations and nurturing behaviors (measured by the PBC) and academic performance were statistically significant (P = .03). Developmental expectations and discipline strategies predicted 30% of the variance in ISAT reading; and developmental expectations predicted 15% of the variance in ISAT math. The mean ISAT math national percentile rank of children with high maternal LED was higher than those with low LED (P = .03).

CONCLUSIONS: The results of this study suggest that early developmental expectations MA parents have on their children and the nurturing behaviors they engage in are related to how well the children perform on academic tests at school age. Unlike findings from studies of Caucasian children, the contribution of early quality and quantity of stimulation in the home, parent children interactions, and motor developmental status in this cohort was relatively small suggesting resilience. Although this is the first longitudinal study to examine performance at school age and childrearing practices, the small sample size is a limitation.

CLINICAL RELEVANCE: Mexican-Americans are the fastest growing minority group in the US and children from this population are disproportionally represented among those receiving Part C and B services. Because of the association between early intervention and later school performance, the findings from this study suggest that early child development providers working with MA families should pay more attention to early parenting behaviors.

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I. Arpan, S. Forbes, D. Lott, C. Senesac, S. de Vos, E. Senesac, W. Triplett; Physical Therapy, University of Florida, Gainesville, FL, USA; G.A. Walter, Physiology & Functional Genomics, University of Florida, Gainesville, FL, USA; K. Krista Vandenborne, Physical Therapy, University of Florida, Gainesville, FL, USA.

PURPOSE/HYPOTHESIS: Skeletal muscles of boys with Duchenne muscular dystrophy (DMD) have enhanced susceptibility to damage and progressive lipid infiltration, which contribute to an increase in magnetic resonance proton transverse relaxation time (T2). Examining various measures of T2 within muscles in DMD may provide a better understanding of the disease process in this population. Therefore, the aims of this study were: 1) to compare the mean T2 of the soleus (SOL) muscle in children with DMD to healthy controls, 2) to estimate the percentage (%) of muscle affected, and 3) to quantify heterogeneity by examining the distribution of T2 in dystrophic SOL muscles and compare it to healthy control muscles.

NUMBER OF SUBJECTS: 15 healthy controls (9.7±2.5 yrs) and 33 boys with DMD (9.0±2.4 yrs).

MATERIALS/METHODS: All the subjects underwent T2-weighted imaging (12–18 axial slices) of their lower leg in a 3T magnet using a SENSE knee volume coil. Pixel by pixel T2 maps were generated for the SOL by applying a mono exponential decay model to four echo times (TE: 40, 60, 80, and 100 ms) using a custom written program with IDL software. The SOL muscle was manually traced on the obtained maps. For each subject, T2 values of each pixel within the muscle were plotted as a histogram, and mean T2 values of the SOL were obtained. Also, a normalized histogram for the SOL muscle was obtained by summing all the control histograms and the 95th percentile of the normalized histogram was used as a threshold for healthy muscle. Pixels with an elevated T2 above the 95th percentile were considered involved and were expressed as% of affected muscle. The heterogeneity within muscle was determined by measuring the width {full width at half maximum (FWHM}) of the T2 histograms. Independent sample t-tests were done to make comparisons of age, mean T2,% of elevated pixels and FWHM across the two groups.

RESULTS: There was no significant difference between the ages in the two groups (p = 0.4). The mean T2 of the SOL muscle was elevated (p < 0.05) in DMD subjects (49.5±6.1ms) compared to controls (40.3±1.1ms). Also, the percentage of elevated pixels were greater (p < 0.05) in DMD subjects (41.6±27.8%) than controls ((5.4±2.6%). The SOL muscle was significantly more heterogeneous (p < 0.05) in DMD subjects (FWHM: 12.3±3.8ms) than healthy controls (9.7±1.6ms).

CONCLUSIONS: The higher mean T2 values, greater percentage of elevated pixels and greater heterogeneity in DMD compared to controls suggest that dystrophic muscles have increased regions of damage, edema, and fatty tissue infiltration. The methods employed in this study appear to offer a novel means to quantify these differences in muscle tissue.

CLINICAL RELEVANCE: T2 mapping may prove clinically useful in monitoring the subtle changes in muscles during the disease progression and therapy in DMD. Furthermore, using various T2 measures to monitor the percentage of affected region and heterogeneity of tissue may be useful for obtaining a global and more complete view of muscle involvement in muscular dystrophy.

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C.Y. Chen, S. Mrowzinski, J. Heathcock, Ohio State University, Columbus, OH, USA.

PURPOSE/HYPOTHESIS: The development of midline movements is an important developmental skill for infants. The ability to bring both arms to midline of the body allows for not only object manipulation, but refinements of fine and gross motor skills and the development of higher cognitive processes that accompany independent exploration. Midline behaviors are thought to be impaired in infants with neonatal stroke because of focal damage over one side of the brain which limits bilateral and midline movements of the arms. Therefore, the purpose of this project is to compare the difference in performance of midline movements in supine and sitting positions in infants with and without neonatal stroke.

NUMBER OF SUBJECTS: 37 subjects starting at 2 months of age have participated in this longitudinal project. Each infant was seen every other week for 10 visits for a total of 370 data collections. Results of the first 5 visits from 14 participants (8 infants with typical development; 6 infants with neonatal stroke) are presented here.

MATERIALS/METHODS: In Supine play, participants were undressed to a diaper or onsie and placed in supine. Three toys were passively put in each hand of 30 seconds while infant behaviors were recorded at 30 frames per second. The time that infants touched the toy with both hands simultaneously was calculated to represent infants' midline movement performance in supine.

In sitting play, a toy was showed in front of infants for three trials of 30 seconds. The average number of bilateral initiation during reaching was calculated to represent infants' midline movement performance in sitting.

RESULTS: In supine play, both infants with typical development and infants with neonatal stroke significantly increased the duration of midline behaviors over time (F = 14.292, p < 0.001; F = 4.317, p = 0.011, respectively). Infants with typical development outperformed infants with neonatal stroke at each time point. Specifically, infants with TD demonstrated an increased percentage of midline behaviors from 5.36±13.27% to 58.00±18.28% from visit 1 to visit 5 where as infants with NS increased percentage of midline behaviors from 0.74±1.09% to 34.89±21.46%.

In the sitting play, infants with TD significantly increased the number of bilateral initiations when reaching for a midline toy over time (F = 3.48, p = 0.045). The infants with NS did not show any changes.

CONCLUSIONS: The results suggest that infants with typical development demonstrated more consistency and a faster developmental trajectory of midline related movements in both supine and sitting positions than infants with neonatal stroke. In the absence of a diagnosis of neurological dysfunction, infants with neonatal stroke show delays in midline behaviors from their typically developing counterparts.

CLINICAL RELEVANCE: Midline behaviors in 2 body positions, sitting and supine may be used as assessment for the early detection of high-risk infants with future developmental delay. These results will also be meaningful in guiding the development of early treatment programs in neonatal stroke population.

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N. Darr, School of Physical Therapy, Belmont University, Nashville, TN, USA; M.R. Franjoine, B. Brenda Young, Physical Therapy, Daemen College, Amherst, NY, USA.

PURPOSE/HYPOTHESIS: Many static upright positions, including standing unsupported (SU), standing with eyes closed (SEC), standing with feet together (SFT), tandem standing (TS), and single limb standing (SLS) are routinely examined when evaluating balance and motor skills in children. Standardized developmental assessments such as the PDMS-2, BOT-2, and the MABC-2 contain many variations of these static standing items. Despite the frequent examination of these standing positions in children, a review of the literature revealed no recent timed reference values based on age. The purpose of this study was to examine the developmental profiles of 5 static standing positions (SU, SEC, SFT, TS, and SLS) in children developing typically, ages 2 to 13 years.

NUMBER OF SUBJECTS: Data were collected on 161 healthy children (81 girls, 80 boys) developing typically per parent report.

MATERIALS/METHODS: Data were collected as part of a larger study of the Pediatric Balance Scale. Each child performed three trials of each of the five static standing positions under investigation for a maximum of 2 minutes per trial. A practice trial was provided for each test position prior to recording times. Test position was standardized for each item using the protocol described within the Pediatric Balance Scale. Each child's best time of 3 trials in seconds (s) was used for data analysis.

Children were divided into 10 groups in one-year increments for data analysis. Children ages 11 to 13 years were collapsed into one group. Descriptive statistics were calculated for each age group by standing position, and one way ANOVAs with post-hoc analyses using Tukey's tests identified significant differences among age groups for log-transformed data.

RESULTS: For all 5 standing positions, performance times improved significantly between ages 2 and 13 years, although temporal patterns of change varied greatly between tasks. For example, SEC position times improved very rapidly between ages 2 (mean = 9.3 ± 6.6 s) and 6 years (mean = 98.8 ± 37.8 s). A much more gradual improvement continued in SEC up through 13 years (mean = 115.8 ± 11s). In contrast, SLS improved very gradually between ages 2 (mean = 3.5 ± 2.2 s) and 5 years (mean = 11.3 ± 9.5s) then increased much more rapidly up through 13 years of age (mean = 54.9 ± 42.9 s). By age 8 years, the majority of children could perform SU, SEC, and SFT for at or close to 2 minutes. However, even in the oldest age groups, SLS and TS continued to improve (means for children ages 10 to 13 years for SLS and TS = 66.9 ± 40.5 s and 54.9 ± 42.9 s respectively). Variability increased greatly with task difficulty across all ages, but was most pronounced in the oldest children.

CONCLUSIONS: Performance times improved significantly between ages 2 and 13 years for all 5 positions. Most children can perform SU, SEC, SFT for close to 2 minutes by age 8. TS and SLS continue to improve through 13 years of age.

CLINICAL RELEVANCE: Performance times of 5 different static standing positions are provided in children, ages 2 to 13 years.

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S.S. Kantak, Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, IL, USA; H.T. Hui-Ting Goh, K.J. Sullivan, Division of Biokinesiology and Physical therapy, University of Southern California, Los Angeles, CA, USA; R. Leinwand, P. Burtner, Occupational Therapy Graduate program, Department of Pediatrics, University of New Mexico, Albuquerque, NM, USA.

PURPOSE/HYPOTHESIS: Previous studies have reported that reduced frequency of feedback during practice is beneficial to learning in adults compared to typically developing children, who benefitted from more frequent feedback. It is unclear how central nervous system differences in children with cerebral palsy affect their ability to acquire skills with practice under different feedback frequencies. The purpose of this study was to determine the effect of different relative frequencies of knowledge of results (KR) on skill acquisition in children with hemiplegic cerebral palsy (HCP) compared to typically developing children (TDC).

NUMBER OF SUBJECTS: 8–17 years old TDC (n = 20) and children with HCP (n = 16) participated. All were screened for visual perception and manual dexterity, and had academic performance within one grade level.

MATERIALS/METHODS: Participants practiced a discrete movement with specific spatiotemporal parameters using a light weight lever. Children with HCP used their less affected hand for the task. Participants from each group (HCP and TDC) were randomly assigned to either a 100% feedback group or 62% feedback group. The 100% KR group received feedback about their performance after every trial while in the 62% KR group, the frequency of KR presentation was faded over trials. The feedback was provided in the form of knowledge of results that included a root mean square error (RMSE) and the participants' performance waveform superimposed on the target waveform. All subjects practiced the task for 200 trials (four 50-trial blocks) on day 1 and returned next day for no-feedback retention and with-feedback reacquisition tests. Performance was measured as RMSE between the target and the subject's response.

RESULTS: All participants improved in accuracy across practice and retained a level of practice performance during retention. During the acquisition phase, 2×2×20 ANOVA demonstrated that TDC performed with significantly less error than children with HCP. Further, children who practiced the task with 62% feedback had a significantly higher error than those who practiced with 100% feedback during practice, retention (p = .032) and reacquisition (p < .001). Children with HCP performed with greater error than TDC during the no-feedback retention test (p = .016) and the reacquisition test (p < .001).

CONCLUSIONS: Typically developing children and children with hemiplegic cerebral palsy are able to use visual feedback to learn and improve motor performance during practice of an upper extremity motor skill. The results suggest that reduced frequency of feedback presentation has a deteriorating effect on the performance and learning in typically developing children and children with HCP.

CLINICAL RELEVANCE: During therapy, compared to typically developing children, prolonged practice with extended feedback may be more beneficial to promote motor learning in children with hemiplegic cerebral palsy.

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K.A. Kunder, Texas Scottish Rite Hospital for Children, Dallas, TX, USA; S.S. Wang, School of Physical Therapy, Texas Woman's University - Dallas, Dallas, TX, USA; D.J. Sucato, M. Dempsey-Robertson, Texas Scottish Rite Hospital for Children, Dallas, TX, USA.

PURPOSE/HYPOTHESIS: Skeletally immature adolescents at greatest risk of curve progression may develop changes in paraspinal musculature. Trunk muscle imbalance, specifically the multifidus, may be associated with adolescent idiopathic scoliosis (AIS). Rehabilitative ultrasound imaging (RUSI) has been shown to be a reliable and valid method of assessing the multifidus in adults without scoliosis, but its reliability has not been studied in adolescents with and without scoliosis. The purpose of this prospective study is to examine paraspinal muscle asymmetry in patients with AIS who have mild curves and compare them to patients without spinal deformities using RUSI, and to determine its reliability.

NUMBER OF SUBJECTS: Twenty 10–12 years old adolescents, 10 with AIS and 10 age-matched controls, completed the study. The participants with AIS had curves of 15–24° and Risser 0–1.

MATERIALS/METHODS: An ultrasound machine with a curved array transducer with a frequency range of 1 to 4 MHz was used to capture the image of the multifidus muscle. The para-sagittal method was used to determine muscle thickness of the multifidus at both sides of T8, L1, and L4 vertebral levels. The transducer was placed centrally and longitudinally over the spinous process and then moved laterally with a 30–45° angle toward the spinous processes to locate the zygapophyseal joints. Images were taken in the relaxed prone and standing positions for two sessions on the same day. Muscle thickness was measured from the zygapophyseal joints to the inner edge of the fascia between the multifidus and superficial muscles. A dependent t-test was used to compare differences between sides, and an independent t-test to compare differences between groups. Significance was set at P < 0.05. Intraclass Correlation Coefficients (ICC3,3) were used to calculate intrarater reliability.

RESULTS: Ultrasonographic measurements of multifidus thickness had good intrarater reliability (ICC = 0.88 − 0.99) at T8, L1, and L4 in the relaxed prone and standing positions for both groups. The AIS group had significantly greater multifidus thicknesses on the concave side of the curve at T8 and L1 (P < 0.05) compared to the convex side. There were no significant muscle asymmetries in the control group. When normalized to body-mass index, there were significantly greater multifidus thicknesses on the concave side at T8, L1 and L4 (P < 0.05) compared to controls.

CONCLUSIONS: Significant paraspinal muscle asymmetries were found in mild curves of adolescents at risk of curve progression. The results demonstrate that RUSI is reliable in measuring the thoracic and lumbar multifidus in adolescents with and without IS in the relaxed condition.

CLINICAL RELEVANCE: RUSI imaging may provide a reliable and objective method for further understanding of the pathophysiology of AIS. Nonoperative treatments for scoliosis such as bracing and exercise may be improved with a clearer understanding of muscle mass and strength changes in scoliosis, especially in adolescents with a high likelihood of progression.

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M. Lillyblad, A. Copp, L. Scott, L. Timmerman, K.J. Krosschell, Department of Physical Therapy and Human Movement Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.

PURPOSE/HYPOTHESIS: Spinal Muscular Atrophy (SMA) is a neuromuscular disorder which leads to muscle weakness and impaired motor function. This can adversely affect a child's ability to participate in their environment. Therapists can potentially address factors that limit participation, and assist in creating additional opportunities. The purpose of this study was to determine how dimensions of participation (Diversity and Intensity) and various activity types (Recreational, Physical, Social, Skill-Based, Self-Improvement) vary across children by SMA type, age, gender, household, and community variables. It was hypothesized that participation patterns would be dependent on type, age, gender, household income, and community type and that there would be no correlation between activity involvement and activity preference in children with SMA.

NUMBER OF SUBJECTS: Fifty-six children (27 males, 29 females, mean age 9.1y, SD 1.9y, range 6–12.9y) with SMA and their primary caregivers participated; 21% had Type 1, 70% had Type 2, and 9% had Type 3.

MATERIALS/METHODS: Caregivers, as proxies for their child, completed a demographic questionnaire. Each child completed a standardized measure of participation (The Children's Assessment of Participation and Enjoyment) and preference (The Preferences for Activities of Children). One and Two-Way ANOVA and t-tests were used to determine effects of SMA type and demographic variables on participation (dimensions and types) using SPSS 19.0. Pearson's correlation was used to determine actual vs preferred participation.

RESULTS: Key findings (p ≤ .05): Social and overall diversity varied by type of SMA; children with Type 2 participated in a wider variety of these activities. Recreational diversity and intensity, and self-improvement diversity varied by age (<9, ≥9); children <9 participated in a wider variety of these activities, and participated in recreational activities more frequently. Children ≥9 participated in physical, recreation, and overall activities with a wider variety of people (with whom). Children <9 enjoyed formal, recreational, and self-improvement activities more than the children ≥9. Skill-based diversity varied by gender. Females did a wider variety of skill-based activities than males.

Community type and income were not significant. Participation in recreational activities correlated with children's preference for those activities (r = 0.36, p < 0.01). Children with SMA actually participated in the recreational activities that they preferred, but preferred more social and physical activities than they actually participated in.

CONCLUSIONS: Results suggest that participation patterns vary by age, SMA type and gender. The number of participants in this study was limited; therefore a larger study to confirm results is warranted.

CLINICAL RELEVANCE: This study enhances our understanding of participation patterns in children with SMA and has implications for services, interventions, and supports that optimize participation.

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K. Mattern-Baxter, Physical Therapy, University of the Pacific, Stockton, CA, USA; S. McNeil, Easter Seals, Sacramento, CA, USA; J.K. Mansoor, Physical Therapy, University of the Pacific, Stockton, CA, USA.

PURPOSE/HYPOTHESIS: Home-based treadmill training has been successfully used in children with neuromotor impairment in order to provide task-specific intervention in an effort to improve gross motor skills related to ambulation. This study examines if an intensive, home-based program of treadmill training helps pre-ambulatory children with cerebral palsy (CP) under 3 years of age improve walking skills, increase walking speed and decrease their reliance on outside support for walking.

NUMBER OF SUBJECTS: Six children ages 15 months to 31 months with CP with Gross Motor Function Classification System (GMFCS) levels I, II and III.

MATERIALS/METHODS: The children were tested pre-intervention, post-intervention, at a 1-month follow-up and at a 3 month-follow-up. Outcome measures included the Gross Motor Function Measure-66 (GMFM-66) Dimensions D and E, the Timed 10-meter Walk Test (10MWT), and the Functional Ambulation Categories (FAC). The children participated in intensive treadmill training using a small, portable treadmill in their homes 6 times/week, twice daily for 10–20 minute sessions, for 6 weeks. The intervention was carried out by the children's parents with weekly supervision by a physical therapist.

RESULTS: A repeated measures Friedman ANOVA with Dunn's multiple comparison test was performed. Significant differences were found in the GMFM-66 Dimensions D and E and in the 10MWT. Post hoc analysis for Dim D and the 10MWT revealed significance between pre-intervention and 1-month follow-up and between pre-intervention and 3-month follow-up. Post hoc analysis for Dim E revealed significance between pre-intervention and 3-month follow-up. All children improved their FAC levels, with all children learning to walk with a reverse walker by post-intervention, and with three children reaching independent ambulation by the 3-month follow-up.

CONCLUSIONS: The results of this study show preliminary evidence that intensive, home-based treadmill training can improve gross motor function related to standing and walking, increase walking speed, and decrease the amount of support used for walking.

CLINICAL RELEVANCE: Young children with CP reach their gross motor milestones at an increased rate compared to older children with CP. It is important to provide intensive physical therapy intervention for children with CP during the early years of childhood. Home-based treadmill training can provide high-intensity, task-specific training with multiple repetitions to provide optimal motor learning conditions for ambulation, when carried out by the parents with supervision of a physical therapist. The results of this study illustrate that a 6-week, intensive, home-based treadmill training protocol can improve gross motor milestones related to ambulation, walking speed and walking independence in children CP under 3 years of age. Future research should include randomized controlled designs in order to control for maturation.

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N.G. Moreau; Health Professions, Medical University of South Carolina, Charleston, SC, USA; N. Marlow, Health Sciences and Research, Medical University of South Carolina, Charleston, SC, USA; K. Holthaus, Health Professions, Medical University of South Carolina, Charleston, SC, USA.

PURPOSE/HYPOTHESIS: Everyday activities for a child with cerebral palsy (CP), such as walking, stair climbing, and sit to stand, require muscle power (product of force and velocity), but the velocity component of muscle contraction is neglected with traditional strength training (ST), performed at slow, controlled speeds. The purpose of this study was to determine whether velocity training (VT), which includes resistance training at increasingly higher velocities, would induce specific architectural and muscle performance adaptations not observed with ST, such as increases in fascicle length and muscle power.

NUMBER OF SUBJECTS: Sixteen ambulatory children with CP were randomized to either VT for speed and power (N = 9; Age: 14.3 ± 3.2 yrs) or traditional ST (N = 7; Age: 14.2 ± 4.3 yrs).

MATERIALS/METHODS: Participants trained the knee extensors 3 x week for 8 weeks on a Biodex dynamometer. At each session, 6 sets of 5 concentric repetitions were performed either at 30 deg/s (ST group) or progressively higher velocities from 30 to120 deg/s (VT group). Muscle thickness (MT) and fascicle length (FL) of the rectus femoris (RF) and vastus lateralis (VL) were examined by ultrasound imaging (GE Logiq i) in 2D B-Mode. Isokinetic strength was assessed at multiple speeds between 30 to 120 deg/s. Isotonic peak power and velocity were tested at 20% of isometric strength. Mixed models analyses were used to test for between and within group effects.

RESULTS: A statistically significant difference between interventions was observed with an increase in RF FL in the VT group and a decrease in the ST group (p = .02). However, MT increased after ST only (p = .01). Both groups showed significant increases in strength at all speeds (p < .05). However, peak velocity and peak power improved in the VT group only (p = .02 and .01).

CONCLUSIONS: Results suggest that muscle architecture in CP responds differentially to the type of training stimulus and is the first study to show increases in FL in response to an exercise intervention. FL is the primary determinant of muscle shortening velocity. As hypothesized, training at higher shortening velocities resulted in increases in RF FL whereas ST resulted in increases in MT only. Results also suggest that VT is equally effective as traditional ST in improving strength of the knee extensors but more effective in improving movement velocity and thus, muscle power.

CLINICAL RELEVANCE: Muscle power is an important component of muscle performance that is often neglected in rehabilitative interventions, despite the fact that children with CP have deficits in both strength and velocity of movement. These results suggest that strengthening interventions focused on improving velocity of movement, such as VT or power training, are more effective than traditional ST in improving muscle power and should be incorporated into everyday clinical practice. These differences may be partially attributed to specificity of training effects on muscle architecture, such as the increase in FL observed after VT.

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N.G. Moreau, Health Professions, Medical University of South Carolina, Charleston, SC, USA; N. Marlow, Health Sciences and Research, Medical University of South Carolina, Charleston, SC, USA; K. Holthaus, Health Professions, Medical University of South Carolina, Charleston, SC, USA.

PURPOSE/HYPOTHESIS: Although traditional strength training (ST) at slow, controlled speeds in children and adolescents with cerebral palsy (CP) has been shown to be modestly effective in increasing strength, positive carryover to functional walking performance, activity, and participation have been very limited. Muscle power as the product of strength and velocity is an important component of muscle performance that is often neglected in rehabilitative interventions, despite the fact that children with CP have difficulty with activities requiring faster movement times. The purpose of this study was to determine whether velocity training (VT), which includes resistance training at increasingly higher velocities, would result in increases in functional walking performance, activity, participation, and self-concept not observed with traditional ST.

NUMBER OF SUBJECTS: Sixteen ambulatory children (GMFCS levels I, II, and III) with CP were randomized to either VT for speed and power (N = 9; Age: 14.3 ± 3.2 yrs) or traditional ST (N = 7; Age: 14.2 ± 4.3 yrs).

MATERIALS/METHODS: Participants trained the knee extensors 3 times per week for 8 weeks on a Biodex dynamometer. At each session, 6 sets of 5 concentric repetitions were performed either at 30 deg/s (ST group) or progressively higher velocities from 30 to120 deg/s (VT group). Timed up-and-go (TUG), 10m walk test, 1-Min. Walk test (1MWT), Pediatric Outcomes Data Collection Instrument (PODCI), and Physical Self Description Questionnaire (PSDQ) were administered before and after the intervention. Mixed models analyses were used to test for differences.

RESULTS: Significant improvements in TUG (p = .04), 1MWT (p = .01), self-selected (p = .04), and fast walking speed (p = .03) were observed after VT only. PSDQ Strength and Appearance subscales improved in the ST group only (p = .03 and .01). The PODCI subscales for activity and participation did not improve for either group, although several approached significance.

CONCLUSIONS: VT resulted in significant improvements in all measures of functional walking performance, including walking speed. Furthermore, these improvements were not achieved with traditional ST, which is standard of practice. However, self-reported effects on strength and appearance were greater in those who underwent ST.

CLINICAL RELEVANCE: The results of this randomized clinical trial suggest that strengthening interventions focused on improving velocity of movement, known as VT or power training, of sufficient intensity and duration (3 times per week for 8 weeks) are more effective than traditional ST in improving functional walking performance and should be incorporated into everyday clinical practice. These results have significant implications for increasing movement velocity during strength training of all types (free weights, exercise machines, body weight, etc.) as well as in other types of lower extremity functional training activities for children and adolescents with CP and should be investigated further.

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T.S. Moulton, R. Hawe, Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, IL, USA; D. Gaebler-Spira, Rehabilitation Institute of Chicago, Chicago, IL, USA; K.J. Krosschell, D. Hurley, J.P. Dewald, Biomedical Engineering, Northwestern University, Evanston, IL, USA.

PURPOSE/HYPOTHESIS: Neurological development is a dynamic process that involves both pruning and strengthening of neural pathways throughout early life. The timing of an injury that results in childhood hemiparesis (CH) is likely to change motor outcomes due to differences in neural resources available to reorganize. This study investigates isometric torque generating capabilities in the upper extremities (UE) in CH acquired pre-, peri-, or post-natally. Hypothesis: children with earlier injury will demonstrate greater residual strength compared to the postnatal injury group.

NUMBER OF SUBJECTS: A volunteer sample of 24 participants with CH (10 females, 14 males) and 8 typically developing controls participated. Individuals represented a range of functional mobility (GMFCS I-III), manual dexterity (MACS I-III), but were statistically similar in UE motor control as measured by the Fugl-Meyer assessment and QUEST dissociated movements and grasp sections.

MATERIALS/METHODS: Subjects were seated in a chair with straps to minimize trunk movement and secured to a 6-degree of freedom load cell and a custom wrist and finger force sensor using a lightweight fiberglass cast. In this isometric protocol the participant was asked to generate a maximum voluntary torque (MVT) in the primary direction specified and practiced briefly prior to the beginning of the trial. The participant received visual feedback to optimize performance. At least 3 MVTs were generated in each of 10 randomly ordered directions (shoulder flexion/extension – F/E, abduction/adduction, elbow F/E, wrist F/E, finger F/E). Adequate rest was provided between trials and extended upon subject request to reduce the effects of fatigue. Forces and moments were converted to torques at the shoulder, elbow, wrist and fingers based on a free body analysis of the upper limb. The maximum torque in each of the ten intended directions was identified after using a 250-ms moving average filter on each trial. A strength ratio was found by dividing the MVT on the paretic side by the MVT on the non-paretic side. A repeated measure mixed model ANOVA with factors of group (4 level) and direction (10 level) was used to determine statistical significance.

RESULTS: All CH participants demonstrated strength ratios of less than 1 between limbs. There was a significant effect of group (p < 0.001), direction (p < 0.001), and interaction between the two (p < 0.001). The postnatal group demonstrated less strength, and all groups were weaker distally.

CONCLUSIONS: Injury timing has a significant impact on the isometric strength ratio between paretic and non-paretic arms in CH. While all participants were weaker distally, the difference between the pre- and post-natal groups performance may be due to preserved corticospinal tract input to the paretic limb, typically withdrawn during development and not available to the postnatal injury group.

CLINICAL RELEVANCE: Interventions tailored with an understanding of injury timing are likely to have greater impact on improving outcomes by targeting the neural source of motor impairment.

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S. Mrowzinski, C.Y Chao-Ying Chen, J, Heathcock Ohio State University, Columbus, OH, USA.

PURPOSE/HYPOTHESIS: Infants who have experienced a stroke are more likely to have motor delays. Difficulty with distal control of the hand during reaching is a common deficit in children with a history of brain injury. It is unknown if infants with stroke demonstrate similar deficits or if they are identifiable in infancy. The purpose of this study was to compare hand position during the emergence of reaching in 2 groups of infants: 1) full-term and typically developing (FT) and 2) full-term with a history of neonatal stroke (NS).

NUMBER OF SUBJECTS: 29 infants participated in this longitudinal project. 12 infants, 7 infants in FT and 5 infants in NS have been analyzed to date.

MATERIALS/METHODS: Infants visited the testing laboratory every other week from 2–7 months of age for 10 visits. Infants were seated 30 degrees from vertical and presented with a midline toy at shoulder level for 3, 30-second trials. Total contacts, contacts with an open hand, and contacts on the ventral side of the hand were analyzed. Changes over time and between groups measured with a 2 (group) X 10 (visit) repeated measures ANOVA.

RESULTS: FT had a higher number of contacts than NS every visit. In addition, FT displayed a significant increase in the percentage of open-hand contacts over time, while the NS group did not. FT demonstrated 24% (±42%) open-hand contacts on visit 1, increasing to 96% (±6%) at visit 10 (p < .0001). Both groups showed an increase in ventral contacts over time. Ventral contacts for FT increased from 5% (±13%) at visit 1 to 82% (±7%) at visit 10 (p < .001). Ventral contacts for NS increased from 0% at visit 1 to 71% (±16%) at visit 10 (p < .05). Between group analysis revealed that there was a significant difference in hand-opening and ventral contacts starting at visit 5 (p = 0.012) and 4 (p = 0.038) respectively.

CONCLUSIONS: FT showed a main effect of time for both openhanded and ventral reaches, displaying a more functional pattern. NS showed a main effect for ventral reaches, but not openhanded reaches. The between group analysis indicates a separation in reaching skill level during visits 4 and 5, which corresponds to 3.5–4 months of age. These results suggest that hand position may be an early indicator of poor distal control during reaching and that these deficits are apparent at a very early age in infants with a history of stroke. The ability to open the hand during a reach may be more difficult for infants with stroke due to the integrity of the nervous system, spasticity, and voluntary control of the finger extensors.

CLINICAL RELEVANCE: Infants who have had a stroke demonstrate less mature reaching quality and quantity from their full-term counterparts from 2–7 months of age–before a diagnosis of developmental delay. Intervention could target these deficits by focusing on early reaching skills including hand opening and voluntary control. Lack of hand opening in particular, could be an early and discriminative sign of brain injury.

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K.N. Oriel, Physical Therapy, Lebanon Valley College, Annville, PA, USA; C.L. Geroge, Education, Lebanon Valley College, Annville, USA.

PURPOSE/HYPOTHESIS: Aerobic exercise prior to classroom tasks has been shown to improve correct responding and decrease stereotypic behaviors in preschool children with Autism Spectrum Disorder (ASD). The majority of studies identifying such an impact have been implemented by researchers within school settings. The purpose of this study was to determine the feasibility and impact of the integration of aerobic exercise into the school day for preschooler's with ASD by school personnel.

NUMBER OF SUBJECTS: The participants included 10 children between the ages of 3 and 5 years (mean age 4.4) with ASD. Participants were recruited from 3 Autism Support classrooms that have a total of 19 children enrolled.

MATERIALS/METHODS: This study employed a within subjects crossover design, using a treatment condition (aerobic exercise) and a control condition (no exercise), over a 6 week period. Participants were randomly assigned to a condition. The treatment condition included 15 minutes of running/jogging followed by a classroom task. The running/jogging was lead by a school-based physical therapist. The control condition included a classroom task not preceded by exercise. The number of stereotypic behaviors and correct responses were recorded by the participant's classroom teacher. Inter-rater reliability data was collected by the researchers, and analyzed using Intraclass Correlation Coefficents (ICC). The Wilcoxon Signed-Ranks Test was used to compare differences between conditions.

RESULTS: Inter-rater reliability data was collected on 25% of sessions. The ICC for stereotypic behavior data was 0.426, while the ICC for correct responding was 0.780. No statistically significant improvements were observed in stereotypic behaviors or correct responding. Visual analysis of the data revealed that in those participants that had observed stereotypic behaviors (7/10 participants), 4 demonstrated fewer stereotypic behaviors following exercise (57%). Three of the 10 participants demonstrated improved correct responding following exercise (30%). The school-based physical therapists were able to consistently implement the exercise in a group format with classroom aides assisting as needed.

CONCLUSIONS: The results of this study suggest that it is feasible for school-based physical therapists to integrate aerobic exercise into the school day for children with ASD. While statistical significance was not observed, data trends appear to indicate that aerobic exercise may assist in decreasing stereotypic behaviors and in improving correct responding. These results must be interpreted with caution given the poor reliability coefficient found for stereotypic behavior data. A third party observer may be necessary to observe participants after exercise in future studies.

CLINICAL RELEVANCE: Given the educational benefits of exercise that have been observed in preschooler's with ASD, it is important to determine if and how school personnel, including school-based physical therapists, can integrate such exercise effectively.

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M. Rivera, Gradute Program in Physical Therapy, University of California San Francisco/San Francisco State University, San Francisco, CA, USA; M. Minxuan He, P. Gutierrez, Institute of Human Development, University of California Berkeley, Berkeley, CA, USA.

PURPOSE/HYPOTHESIS: Early prone locomotion has been characterized as a systematic progression from belly crawling to quadrupedal creeping. However, only a handful of studies have attempted to describe the basic kinematic changes that occur as the infant becomes more skilled at mobility. The purpose of this pilot study is to provide a profile on the emergence and refinement of crawling as infants gain proficiency. A second aim is to relate changes in crawling skill to the infant's responsiveness to peripheral optic flow.

NUMBER OF SUBJECTS: 31 typical developing (TD) infants, ranging from 7.5 to 14 months.

MATERIALS/METHODS: Participants were recorded while crawling across an eight foot mat three times. Infants were coded on the following: velocity (feet/seconds), head posture, delay to initiate mobility, number of cycles (one limb movement constitutes one cycle), posture during mobility (quadruped, belly crawling) and limb coordination (reciprocal: two limbs in contact in a diagonal pattern, one limb at a time, belly crawler). Inter-rater reliabilities between two coders based on intraclass correlations ranged from .78 to .96, with limb coordination showing the greatest consistency between coders. Visual proprioception was measured by the cross correlation between the infant's postural sway and wall movement in response to motion of the side walls in a moving room.

RESULTS: The predominant coordination pattern was one limb at a time(51%), followed by reciprocal patterns (29%) and belly crawling (20%). Velocity ranged from 0.1 to 1.94 ft/sec, the delay in initiating mobility ranged from 0–62 seconds, and the number of cycles ranged from 5.6 to 15.5. Average velocity was 1.03 ft/sec for reciprocal crawlers, 0.98 ft/sec for one limb at a time, and 0.57 ft/sec for belly crawlers. Infants were divided into a young group (YG: 7.5–10 months) and an older group (OG: 10–14 months). Velocity ranged in the YG group from 0.1 to 1.06 ft/sec and in the OG group: 0.51 to 1.94 ft/sec. 90% in the YG group used one limb or a belly form of crawling while 62% used this form in the OG group. The correlation between velocity and responsiveness to peripheral optic flow in the moving room was 0.41.

CONCLUSIONS: A number of kinematic variables changed as infants became more proficient at prone locomotion. A moderate relation between locomotor skill (as measured by velocity) and visual proprioception was found.

CLINICAL RELEVANCE: Based upon this pilot data, TD infants demonstrate variable characteristics in crawling behavior. Clinicians should be aware of differences in characteristics when providing interventions.

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D. Roberts, Physical Therapy, Sprngfield College, Springfield, MA, USA; M. Gannotti, D.A. Veneri, R. Decker, University of Hartford, West Hartford, CT, USA.

PURPOSE/HYPOTHESIS: Childhood obesity rates are increasing globally. Physical activity is one behavioral variable that influences weight status. Participation in physical activity requires basic gross motor proficiency in early childhood. The purpose of this study is to examine the relationship between gross motor skill level and weight status in a large national representative sample of kindergarten aged children. A better understanding of the relationship between gross motor skill level and weight status will provide important information for physical therapists on potential intervention strategies to reduce childhood obesity.

NUMBER OF SUBJECTS: 10,688 children from the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B).

MATERIALS/METHODS: Age, gender, height and weight were available from the ECLS-B database, and were used to calculate body mass index (BMI) and age adjusted body mass index percentile ranking (BMI-a). Children were classified into under, normal, at risk and overweight (OW) categories according to the Center for Disease Control recommended criteria. The Early Screening Inventory Revised was used to evaluate gross motor skill level. Skill items assessed included jumping, balancing and hopping on one foot, walking backwards, skipping, and catching a beanbag. Descriptive statistics, analysis of variance and odds ratios were used to identify differences among groups of children. The Bonferroni test was used for post hoc analysis with alpha level of .05. Data from boys and girls were analyzed separately, as gender is a covariate of gross motor skills.

RESULTS: 4629 children (2155 male), mean age 5.4 years met the inclusion criteria. The mean BMI-a ranking for the children was 65% (SD = 28). Both girls and boys in the normal weight and at-risk for overweight categories jumped further and hopped longer than children in the OW category (p < 0.05). OW boys and girls had lower overall gross motor composite cores compared to healthy weight and at risk for overweight children (p < 0.05). Odds ratios between normal weight and OW groups showed that OW boys were 1.6 times less likely (95% CI 1.3–2.0, p < 0.001) and OW girls were 2.2 times less likely (95% CI 1.8–2.8, p < 0.001) to pass left foot hopping test. Similar finding were seen on the right foot with OW boys 1.6 times (95% CI 1.3–2.1, p < 0.001) and girls 2.0 times less likely (95% CI 1.5–2.5, p < 0.001) to pass the hopping skill. Both OW boys and girls were less able to walk backwards with OW boys 1.3 (95% CI 1.1–1.6, p = 0.013) and OW girls 1.4 times as likely (95% CI 1.1–1.7, p = 0.003) 95% CI 1.1–1.6, p = 0.005) to not pass this gross motor test.

CONCLUSIONS: Weight status appears to impact gross motor skill level especially skills where movement or stabilization of mass is required.

CLINICAL RELEVANCE: Clinicians should consider weight status when interpreting gross motor skills in children. Future work should assess if early delays in children who are overweight impact future gross motor skill level or physical activity level. More specialized interventions may be required to prevent gross motor delays in these children.

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S.A. Ross, A. Pratt, K. Wiles, C. Freeman, K. Rupp, N. Hentis, Physical Therapy, MARYVILLE University, St. Louis, MO, USA; J. Leonard, J. Puglisi, Department of Neurosurgery, Washington University, St. Louis, MO, USA.

PURPOSE/HYPOTHESIS: The purposes of this study were to determine if muscle energy techniques (MET) are effective in reducing low back pain (LBP) potentially caused by sacroiliac joint dysfunction (SIJD) in adolescents and if this population responds similarly to a cluster of provocation tests used for diagnosing SIJD in adults.

NUMBER OF SUBJECTS: A neurosurgeon referred 45 participants aged 10–20 years (mean age 15.8±2.2) to a physical therapist (PT) if they had point tenderness over the SIJ, no pain below the knee, and MRI not suggestive of nerve impingement. Of the participants, 10.81% were previously treated by a chiropractor and 45.95% by a PT without resolution of symptoms. Two-phases of the study included thirty-two prospective participants and 13 in the retrospective phase so the number of participants in each analysis is included.

MATERIALS/METHODS: During the PT evaluation, participants rated their pain using a visual analog scale pre and immediately post-treatment. The PT then performed a passive straight leg raise (SLR) test for all participants to rule out a herniated nucleus pulposus. Twenty-five of the 32 prospective participants were assessed for SIJD using a cluster of provocation tests. The 5 tests included the thigh thrust, SIJ distraction, SIJ compression, sacral thrust and Gaenslen's. The cluster was positive when 2 or more of the tests reproduced the painful symptoms. Participants were treated during a single session with MET (resisted hip extension and/or hip flexion in supine). Follow-up phone surveys were conducted.

RESULTS: A significant difference was found between the pre/post-treatment pain scores (n = 32, t = 7.73, p < .001). After one session of treatment, 24% of participants reported decreased pain, and 56% of participants had complete resolution of their LBP. Participants who tested negative for the SLR had a significant decrease in pain (n = 29, t = 2.103, p = .045). No significant difference was found in the change in pain between those who tested positive on the cluster tests versus negative (n = 25, t = 27, p = .79). Of the 16 follow-up surveys; 10 reported being pain-free for time periods ranging from 2 weeks to 1 year, two reported improved pain and four reported continued pain without change.

CONCLUSIONS: Our results support MET targeting the SIJ as an appropriate treatment for relieving LBP in adolescents. Based on the number of participants who reported complete resolution of pain, it is possible that these participants avoided having costly spinal surgery and the potential of complications. Results suggest that the cluster of provocation tests does not follow a similar pattern as the adult population. Further research on provocation tests in the younger population needs to be conducted.

CLINICAL RELEVANCE: SIJD may be overlooked as a possible cause of LBP in adolescents. There does not appear to be an appropriate diagnostic tool to rule-in SIJD in this population. With a correct diagnosis, it appears that MET is an appropriate conservative treatment for LBP associated with SIJD.

© 2012 Lippincott Williams & Wilkins, Inc.