Than Typically Developing Research Articles

Multilingualism impacts children's executive function and core autism symptoms.

Autism spectrum disorder (ASD) is associated with marked heterogeneity in executive function (EF) abilities. EF components including inhibition and shifting are related to ASD core symptoms such as perspective taking, social communication, and repetitive behavior. Recent research suggests that multilingualism may have a beneficial impact on EF abilities, especially in children with ASD. However, there remains a lack of comprehensive understanding regarding the relationships between multilingualism, EF, and core symptoms in children with ASD. Here, we examined these associations in 7-12-year-old children with and without ASD (N = 116; 53 ASD, Mean age = 9.94 years). Results suggest that multilingual children have stronger parent-reported inhibition, shifting, and perspective-taking skills than monolingual children. Furthermore, we found a significant interaction between diagnosis and multilingual status on inhibition, such that the effects of multilingualism were stronger for children with ASD than typically developing (TD) children. Finally, we found indirect effects of multilingualism on perspective taking, social communication, and repetitive behaviors mediated by EF skills. These results demonstrate the supportive influences multilingual experience might have on bolstering EF and reducing ASD-related symptoms.

Idiosyncratic pupil regulation in autistic children.

Recent neuroimaging and eye-tracking studies have suggested that children with autism exhibit more variable and idiosyncratic brain responses and eye movements than typically developing (TD) children. Here, we extended this research to pupillometry recordings. We successfully acquired pupillometry recordings from 111 children (74 with autism), 4.5-years-old on average, who viewed three 90 s movies, twice. We extracted their pupillary time-course for each movie, capturing their stimulus evoked pupillary responses. We then computed the correlation between the time-course of each child and those of all others in their group as well as between each autistic child and all children in the TD group. This yielded an average inter-subject correlation value per child, representing how similar their pupillary responses were to all others in their group or the comparison group. Children with autism exhibited significantly weaker inter-subject correlations than TD children in all comparisons. These differences were independent of previously reported differences in gaze inter-subject correlations and were largest in responses to a naturalistic movie containing footage of a social interaction between two TD children. The results demonstrate the utility of measuring the idiosyncrasy of pupil regulation, which can be performed with passive viewing of movies even by young children with co-occurring intellectual disability. These findings reveal that a considerable number of children with autism have significantly less stable, idiosyncratic pupil regulation than TD children, indicative of more variable, weakly regulated, underlying neural activity.

NAO robot promoting sensorimotor synchronization in high-functioning autism spectrum disorder children

Objectives Sensorimotor synchronization (SMS) refers to an individual’s motor rhythm is temporally coordinated with a predictable external rhythm. Autism spectrum disorder (ASD) children have weakened SMS performance than typically developing (TD) children, which may affect their relationship with peers and caregivers, and social cognition abilities. Synchronization referent (e.g. an adult or a non-social beat) and the length of inter-stimulus interval (ISI) would influence SMS performance. Methods In this study, we adapted a tapping task to investigate the SMS ability in twenty-one 5–8-year-old high-functioning ASD and twenty-one age-, gender- and IQ-matched TD children. Children were asked to tap on a computer keyboard with videos of a woman or a robot tapping with one finger. We compared the synchronization performance of the two groups when they synchronized with different partners (an adult or an NAO robot) and under different ISIs (800 ms or 1500 ms). The relationships with participants’ autistic traits (Social Responsiveness Scale (SRS-2) and Autism Spectrum Quotient), and cognitive ability (IQ) were also examined. Results We found that ASD children had an overall attenuated synchronizing accuracy and stability than TD children only when ISI was longer than one second. Both groups performed better when synchronized with the NAO robot than the adult partner. The synchronization performance was correlated with the cognitive ability of ASD children when ISI was 1500 ms. Conclusions Results show that tapping with the robot could improve the SMS performance of ASD children since it promoted a higher motivation level. ASD children have an attenuated SMS ability, which may be caused by abnormal temporal perceptions when ISI is longer than one second, while their SMS ability may be intact in sub-second ISIs.

Auditory rhythm facilitates perception and action in children at risk for developmental coordination disorder

Developmental Coordination Disorder (DCD) is a common neurodevelopmental disorder featuring deficits in motor coordination and motor timing among children. Deficits in rhythmic tracking, including perceptually tracking and synchronizing action with auditory rhythms, have been studied in a wide range of motor disorders, providing a foundation for developing rehabilitation programs incorporating auditory rhythms. We tested whether DCD also features these auditory-motor deficits among 7–10 year-old children. In a speech recognition task with no overt motor component, modulating the speech rhythm interfered more with the performance of children at risk for DCD than typically developing (TD) children. A set of auditory-motor tapping tasks further showed that, although children at risk for DCD performed worse than TD children in general, the presence of an auditory rhythmic cue (isochronous metronome or music) facilitated the temporal consistency of tapping. Finally, accuracy in the recognition of rhythmically modulated speech and tapping consistency correlated with performance on the standardized motor assessment. Together, the results show auditory rhythmic regularity benefits auditory perception and auditory-motor coordination in children at risk for DCD. This provides a foundation for future clinical studies to develop evidence-based interventions involving auditory-motor rhythmic coordination for children with DCD.

Neural responses to syllable-induced P1m and social impairment in children with autism spectrum disorder and typically developing Peers.

In previous magnetoencephalography (MEG) studies, children with autism spectrum disorder (ASD) have been shown to respond differently to speech stimuli than typically developing (TD) children. Quantitative evaluation of this difference in responsiveness may support early diagnosis and intervention for ASD. The objective of this research is to investigate the relationship between syllable-induced P1m and social impairment in children with ASD and TD children. We analyzed 49 children with ASD aged 40-92 months and age-matched 26 TD children. We evaluated their social impairment by means of the Social Responsiveness Scale (SRS) and their intelligence ability using the Kaufman Assessment Battery for Children (K-ABC). Multiple regression analysis with SRS score as the dependent variable and syllable-induced P1m latency or intensity and intelligence ability as explanatory variables revealed that SRS score was associated with syllable-induced P1m latency in the left hemisphere only in the TD group and not in the ASD group. A second finding was that increased leftward-lateralization of intensity was correlated with higher SRS scores only in the ASD group. These results provide valuable insights but also highlight the intricate nature of neural mechanisms and their relationship with autistic traits.

Assessment of oppositional defiant disorder and oppositional behavior in children and adolescents with Down syndrome.

Children and adolescents with intellectual disability (ID) exhibit higher rates of oppositional defiant disorder (ODD) than typically developing (TD) peers. However, studies focusing on the investigation of ODD prevalence in youth with Down syndrome (DS) are still limited. The current study aimed to investigate the prevalence of ODD clinical and subclinical symptoms in a group of 101 youth with DS (63 boys, 38 girls) ranging in age from 6 to 18 years. Moreover, the prevalence of ODD symptoms, as detected by means of three parent-report questionnaires, was compared with that detected by a semi-structured psychopathological interview, namely, the Schedule for Affective Disorders and Schizophrenia for School Aged Children Present and Lifetime (K-SADS) Version Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5). We found that 17% of participants met diagnostic criteria for ODD on the K-SADS, whereas 24% exhibited subclinical symptoms. Results also suggest good specificity of Swanson, Nolan, and Pelham-IV Rating Scale (SNAP-IV), Conners' Parent Rating Scales Long Version (CPRS) and Child Behavior Checklist (CBCL) in detecting ODD symptoms. The investigation of the agreement in the prevalence rates of clinical and subclinical symptoms of ODD between K-SADS and the parent-report questionnaires indicated CPRS as the parent-report questionnaire with the best agreement with K-SADS. This study provides support for the use of parent-report questionnaires to assess ODD symptoms in children and adolescents with DS by evaluating their levels of agreement with a semi-structured psychopathological interview. In particular, our results suggest that CPRS could be considered a suitable screening tool for ODD clinical and subclinical symptoms in youth with DS.

Altered Cytokine and BDNF Levels in Individuals with Autism Spectrum Disorders

Previous studies have shown that immunological factors are involved in the pathogenesis of autism spectrum disorders (ASDs). The present study examined whether immunological abnormalities are associated with cognitive and behavioral deficits in children with ASD and whether children with ASD show different immunological biomarkers and brain-derived neurotrophic factor BDNF levels than typically developing (TD) children. Sixteen children with TD and 18 children with ASD, aged 6–18 years, voluntarily participated in the study. Participants’ executive functions were measured using neuropsychological tests, and behavioral measures were measured using parent ratings. Immunological measures were assessed by measuring the participants’ blood serum levels of chemokine ligand 2 (CCL2) and chemokine ligand 5 (CCL5). Children with ASD showed greater deficits in cognitive functions as well as altered levels of immunological measures when compared to TD children, and their cognitive functions and behavioral deficits were significantly associated with increased CCL5 levels and decreased BDNF levels. These results provide evidence to support the notion that altered immune functions and neurotrophin deficiency are involved in the pathogenesis of ASD.

Adverse childhood experiences predict neurite density differences in young children with and without attention deficit hyperactivity disorder.

Adverse childhood experiences (ACEs) put millions of children at risk for later health problems. As childhood represents a critical developmental period, it is important to understand how ACEs impact brain development in young children. In addition, children with attention-deficit/hyperactivity disorder (ADHD) are more likely than typically developing (TD) peers to experience ACEs. Therefore, the current study examined the impact of ACEs on early brain development, using a cumulative risk approach, in a large sample of children with and without ADHD. We examined 198 young children (Mage =5.45, 82.3% Hispanic/Latino; 52.5% ADHD) across measures of brain volume, cortical thickness, neurite density index (NDI), and orientation dispersion index (ODI). For the NDI measure, there was a significant interaction between group and cumulative risk (ß=.18, p=.048), such that for children with ADHD, but not TD children, greater cumulate risk was associated with increased NDI in corpus callosum. No other interactions were detected. Additionally, when examining across groups, greater cumulative risk was associated with reduced ODI and volume in the cerebellum, although these findings did not survive a correction for multiple comparisons. Our results highlight the role early cumulative ACEs play in brain development across TD and children with ADHD.

Dietary Patterns and Weight Status in Italian Preschoolers with Autism Spectrum Disorder and Typically Developing Children.

Atypical eating habits are more common in children with autism spectrum disorders (ASD) than typically developing (TD) peers. Feeding problems may lead to the double burden of specific nutrient deficiencies and excessive weight gain, with a consequent increase in obesity prevalence. The dietary intake of Italian preschoolers with ASD compared to their TD peers and the impact of their dietary choices on their weight status and relationship to food selectivity (FS) were investigated. Dietary patterns and their associations with body mass index (BMI) were evaluated in 65 children with ASD and 82 peers with TD aged 1.3–6.4 years. Eating habits were assessed with a modified version of a parent-rated semi-quantitative Food Frequency Questionnaire. Moreover, the prevalence of FS and possible links with dietary patterns and BMI were investigated in the ASD group. Children with ASD consumed significantly higher amounts of simple sugars, processed and ultra-processed carbohydrates, both low- and high-fat animal proteins, and lower amounts of vegetables and fruits compared to peers with TD. The obesity rate was 1.5% in children with TD and more than fourfold (6.2%) in children with ASD, although the difference between groups was not statistically significant. FS was significantly more frequent in children with ASD than in peers with TD. Children with ASD and FS showed significantly lower annual intakes of vegetable proteins and fiber (considered essential nutrients for a healthy diet) than children with ASD without FS. Our results showed that children with ASD showed different dietary habits than those with TD, with the higher consumption of energy-dense foods and lower amounts of food-sourced fibers, which could place them at increased risk to develop overweight, obesity, and micronutrient deficiencies later in life.

Anxiety, confidence and self-concept in adults with and without developmental coordination disorder

BackgroundPrevious research suggests that adults with Developmental Coordination Disorder (DCD) report lower general wellbeing and higher general anxiety levels than typically developing (TD) adults. AimsTo examine and explore relationships between anxiety and confidence (self-efficacy and resilience) generally and in a movement-specific context, along with self-concept among adults with DCD and TD adults. Methods74 adults with diagnosed DCD, 26 adults with suspected DCD and 79 TD adults (18−60 years) completed an online questionnaire composed of a mixture of existent psychometric measures and novel scales. ResultsGeneral and movement-specific anxiety, self-efficacy and general resilience were all poorer in adults with diagnosed and suspected DCD compared to TD adults. Higher resilience was related to higher self-efficacy and lower anxiety in adults with DCD. Individuals with suspected DCD for whom motor skills difficulties were an important aspect of their self-concept had lower movement-specific self-efficacy. ConclusionsInterventions to improve the psychosocial wellbeing of adults with DCD should include a focus on lowering anxiety and building self-efficacy and resilience, with particular attention to movement-related domains. ImplicationsThis would facilitate the effective development of strategies to manage motor skills difficulties and their impact on everyday life for adults with DCD.

Physical Activity Levels of Adolescents and Adults With Cerebral Palsy in Urban South Africa.

Background: Research in high income countries shows that people with cerebral palsy (CP) are less physically active than typically developing (TD) peers, but less is known regarding physical activity (PA) in those with CP in low-to-middle income countries. The aim of this study was to determine daily step count and levels of PA in adolescents and adults with CP living in urban South Africa, compared to TD peers, and to determine associations with sex, Gross Motor Function Classification System (GMFCS) level, body mass index and socio-economic status.Materials and Methods: This case–control study included 26 adolescents and 22 adults with CP (GMFCS Level I-V) and matched TD peers (25 and 30, respectively). Participants wore an ActiGraph GT3X for 7 consecutive days to determine step count and time (minutes per hour) spent in PA levels, including sedentary (SED), low physical activity (LPA) and moderate to vigorous physical activity (MVPA).Results: The daily step count and PA levels for ambulant adolescents with CP (GMFCS level I-III) were similar to TD peers, while this was less for adolescents classified in GMFCS level IV-V. Daily step count, SED and MVPA were similar for adults classified in GMFCS level I-II compared to TD adults, while all parameters were lower for adults using assistive devices (GMFCS level III) and non-ambulant adults (GMFCS level IV-V) compared to TD peers. Daily step count and PA levels were inversely associated with GMFCS, while no other associations were found.Conclusion: People with CP who were more mobile dependent (higher GMFCS level) were less active. However, adolescents and adults with CP classified as GMFCS levels I-II living in urban South Africa recorded similar step count and PA levels as their TD peers. This was also the case for adolescents using assistive devices, though not for those in the adult group (GMFCS level III). Furthermore, it was apparent that even the ambulant individuals with CP and TD cohorts were relatively inactive. Intervention programs for CP and TD adolescents should be aimed at finding strategies to keep adolescents physically active well into adulthood, in order to promote physical health, social and emotional well-being and independence.

Dietary Fat Effect on the Gut Microbiome, and Its Role in the Modulation of Gastrointestinal Disorders in Children with Autism Spectrum Disorder

Children with autism spectrum disorder (ASD) report a higher frequency and severity of gastrointestinal disorders (GID) than typically developing (TD) children. GID-associated discomfort increases feelings of anxiety and frustration, contributing to the severity of ASD. Emerging evidence supports the biological intersection of neurodevelopment and microbiome, indicating the integral contribution of GM in the development and function of the nervous system, and mental health, and disease balance. Dysbiotic GM could be a contributing factor in the pathogenesis of GID in children with ASD. High-fat diets may modulate GM through accelerated growth of bile-tolerant bacteria, altered bacterial ratios, and reduced bacterial diversity, which may increase the risk of GID. Notably, saturated fatty acids are considered to have a pronounced effect on the increase of bile-tolerant bacteria and reduction in microbial diversity. Additionally, omega-3 exerts a favorable impact on GM and gut health due to its anti-inflammatory properties. Despite inconsistencies in the data elaborated in the review, the dietary fat composition, as part of an overall dietary intervention, plays a role in modulating GID, specifically in ASD, due to the altered microbiome profile. This review emphasizes the need to conduct future experimental studies investigating the effect of diets with varying fatty acid compositions on GID-specific microbiome profiles in children with ASD.

The impact of early auditory experience for the acquisition of morphosyntactic abilities and working memory

Difficulty in acquiring object clitics (OCs), and the omission of OCs more specifically, is used as a marker of developmental language disorder (DLD) in children learning French. Research also suggests that OCs are a complex morphosyntactic property of French and, as such, they could be particularly taxing for working memory (WM) resources. In light of previous research, it seems more likely that difficulties with OCs could be a marker for atypical early language acquisition. Children receiving a cochlear implant (CI) represent a case of delayed language exposure linked to a lack of early auditory exposure. Few studies have investigated the production of clitics in children with CIs. Studies suggest that children with CIs make significantly more clitic omissions on tasks of clitic production than typically-developing (TD) children. To our knowledge, no study has looked at clitic comprehension in children with CIs learning French or at the relationship between WM and performance on tasks of OCs in this population. The present study aimed at examining the production and comprehension of OCs, as well as the relationship between clitic omission and WM, in both typically-developing monolinguals children and CI recipients learning French. Children with CIs performed significantly lower than the control group on both comprehension and production tasks. Clitic omission was significantly related to WM, but only in the CI group suggesting a differential relationship between early auditory experience, WM, and language acquisition.

Children's Behavior and Maternal Parenting Stress in Young Children With Sex Chromosome Trisomies.

Children and adolescents with sex chromosome trisomies (SCTs) usually show a higher frequency of behavioral problems than typically developing (TD) children. However, little is known about the presence of behavioral issues in toddlers with SCT. This study aimed at investigating their behavioral profile in the second year of life and its impact on maternal stress. Participants were 87 children ranging in age from 18 to 26 months: 63 children with SCTs (all diagnosed prenatally) and 24 TD children. Their psychomotor and language development and their behavioral profile were assessed. In addition, the level of maternal parenting stress was evaluated. Both psychomotor and language development were significantly lower in children with SCTs than in TD children. Conversely, no significantly greater behavioral problems emerged in children with SCTs. However, a significantly higher level of parenting stress related to a dysfunctional interaction with the child emerged in the mothers of children with SCTs. In this population, maternal stress seemed positively related to their children's emotional problems and pervasive disorders and negatively related to their children's psychomotor and linguistic competence. Although no significant behavioral issues emerged in the second year of life, the relationships found between children's behavioral profiles and maternal parenting stress highlight the importance of prenatal counseling and support groups for parents of children with SCTs. This might help them recognize the first signs of behavioral problems and become aware of their influence on parenting stress.

Children with Poor Motor Skills Have Lower Health-Related Fitness Compared to Typically Developing Children.

Most of the current empirical evidence regarding the relationship between health-related fitness and level of motor performance is based on children from high-income countries. Yet, children from low-resource areas may have fewer opportunities to develop their fitness skills. The aim of the study was to determine if South African children from both low- and middle-income areas scoring below the 16th percentile on the Movement Assessment Battery for Children-2 (probable-Developmental Coordination Disorder (p-DCD)) have lower health-related fitness levels than typically developing (TD) children. We hypothesized that children with p-DCD would have lower overall health-related fitness than TD children. A sample of 146 participants aged 10 to 11 (10.05 years (SD = 0.41)) was collected from schools in the North West Province of South Africa, on the basis of their poverty classification. Children were tested for anaerobic capacity and strength using the Bruininks–Oseretsky test of motor proficiency second edition (BOT-2) and aerobic capacity using the Progressive Aerobic Cardiovascular Endurance Run (PACER). Body composition was evaluated using body mass index corrected for age and sex (BMI-z), body fat (BF), and waist circumference. The data was analyzed using Spearman correlations and chi-squared tests. Statistically significant differences (p < 0.05) were found between groups for running and agility, strength, and aerobic capacity. No significant differences were found between p-DCD and TD groups in terms of body mass (36.1 kg vs. 33.3 kg), waist circumference (62.2 cm vs. 59.8 cm), BMI-z (19.7 vs. 17.6), and fat percentage (20.2 vs. 18.1%). Overweight and obesity prevalence was 15% in those with low socio-economic status (SES) and 27% in high SES. In conclusion, children with p-DCD had lower muscular strength, aerobic capacity, and endurance than TD children. Although it has been reported that children with p-DCD have a higher risk for overweight/obesity than TD children, this is not (yet) the case in 10–11-year-old children living in rural areas in South Africa (North West Province).

Altered cortical activation associated with mirror overflow driven by non-dominant hand movement in attention-deficit/hyperactivity disorder

Mirror overflow is involuntary movement that accompanies unilateral voluntary movement on the opposite side of the body, and is commonly seen in Attention-Deficit/Hyperactivity Disorder (ADHD). Children with ADHD show asymmetry in mirror overflow between dominant and non-dominant hand, yet there are competing mechanistic accounts of why this occurs. Using EEG during a sequential, unimanual finger-tapping task, we found that children with ADHD exhibited significantly more mirror overflow than typically developing (TD) controls, especially during the tapping of the non-dominant hand. Furthermore, source-level EEG oscillation analysis revealed that children with ADHD showed decreased alpha (8–12 Hz) event-related desynchronization (ERD) compared with controls in both hemispheres, but only during tapping of the non-dominant hand. Moreover, only the ERD ipsilateral to the mirror overflow during non-dominant hand movement correlated with both magnitude of overflow movements and higher ADHD symptom severity (Conners ADHD Hyperactivity/Impulsiveness scale) in children with ADHD. TD controls did not show these relationships. Our findings suggest that EEG differences in finger-tapping in ADHD are related primarily to voluntary movement in the non-dominant hand. Our results are also consistent with the Ipsilateral Corticospinal Tract (CST) Hypothesis, which posits that the atypical persistence of mirror overflow in ADHD may originate in the sensorimotor areas ipsilateral to mirror overflow and be transmitted via non-decussating CST fibers.

Biomechanical analysis of gait patterns in children with intellectual disabilities

Children with intellectual disabilities (ID) typically master walking skills much later than typically developing (TD) children and have poor postural control ability. This study aimed to explore the gait ability and characteristics of children with ID and whether there is any difference in walking ability between them and TD children. In this study, integrating kinematic-biomechanic-dynamic measurement methods and corresponding analysis methods (video analysis, three-dimensional force analysis and electromyography test analysis) were used to characterise and compare the gait patterns between ID children and TD children. ID children's step length/leg length ratio was lower than TD children. The left-leg single-leg support time and step length of ID children were shorter than TD children. While walking, ID children touched the ground with the whole foot pad and could not powerfully thrust against the ground with their toes. Their left legs had obvious disadvantages compared with their right legs. ID children's lower limb muscle strength was lower than TD children, and their thigh muscles had an obvious compensation function. Correcting ID children's gait should be an important teaching goal for physical education institutors and teachers. Muscle-strength and flexibility training can help ID children reinforce core strength and better coordinate lower limbs.

In vivo operating lengths of the gastrocnemius muscle during gait in children who idiopathically toe-walk.

What is the central question of this study? What are the in vivo operating lengths of the gastrocnemius muscle in children who idiopathically toe-walk? What is the main finding and its importance? Children who idiopathically toe-walk operate at more plantarflexed positions but at longer fascicle lengths than typically developing children during gait. However, these ranges utilised during gait correspond to where children who idiopathically toe-walk are optimally strong. This should be considered when prescribing clinical treatments to restore typical gait. Children who idiopathically toe-walk (ITW) habitually operate at greater plantarflexion angles than typically developing (TD) children, which might result in shorter, sub-optimal gastrocnemius fascicle lengths. However, currently no experimental evidence exists to substantiate this notion. Five children who ITW and 14 TD children completed a gait analysis, whilst gastrocnemius fascicle behaviour was simultaneously quantified using ultrasound. The moment-angle (hip, knee and ankle) and moment-length (gastrocnemius) relationships were determined from isometric maximum voluntary contractions (MVC) on an isokinetic dynamometer combined with ultrasound. During gait, children who ITW operated at more plantarflexed angles (Δ=20°; P=0.013) and longer muscle fascicle lengths (Δ=12mm; P=0.008) than TD children. During MVC, no differences in the peak moment of any joint were found. However, peak plantarflexor moment occurred at significantly more plantarflexed angles (-16 vs. 1°; P=0.010) and at longer muscle fascicle lengths (44 vs. 37mm; P=0.001) in children who ITW than TD children. Observed alterations in the moment-angle and moment-length relationships of children who ITW coincided with the ranges used during gait. Therefore, the gastrocnemius muscle in children who ITW operates close to the peak of the force-length relationship, similarly to TD children. Thus, this study indicates that idiopathic toe-walking is truly an ankle joint pathology, and children who ITW present with substantial alterations in the gastrocnemius muscle functional properties, which appear well adapted to the characteristic demands of equinus gait. These findings should be considered when prescribing clinical treatments to restore typical gait.

Muscle architecture and passive lengthening properties of the gastrocnemius medialis and Achilles tendon in children who idiopathically toe-walk.

Children who idiopathically toe‐walk (ITW) habitually operate at greater plantarflexion angles and thus, at shorter muscle‐tendon unit (MTU) lengths than typically developing (TD) children. Therefore, it is often assumed that habitual use of the gastrocnemius muscle in this way will cause remodelling of the muscle‐tendon architecture compared to TD children. However, the gastrocnemius muscle architecture of children who ITW has never been measured. It is essential that we gain a better understanding of these muscle‐tendon properties, to ensure that appropriate clinical interventions can be provided for these children. Five children who ITW (age 8 ± 2 years) and 14 TD children (age 10 ± 2 years) participated in this study. Ultrasound was combined with isokinetic dynamometry and surface electromyography, to measure muscle architecture at common positions and passive lengthening properties of the gastrocnemius muscle and tendon across full range of motion. Regardless of which common condition groups were compared under, both the absolute and normalised to MTU muscle belly and fascicle lengths were always longer, and the Achilles tendon length was always shorter in children who ITW than TD children (p < 0.05; large effect sizes). The passive lengthening properties of the muscle and tendon were not different between groups (p > 0.05); however, passive joint stiffness was greater in children who ITW at maximum dorsiflexion (p = 0.001) and at a joint moment common to all participants (p = 0.029). Consequently, the findings of this pilot study indicate a remodelling of the relative MTU that does not support the concept that children who ITW commonly experience muscle shortening. Therefore, greater consideration of the muscle and tendon properties are required when prescribing clinical interventions that aim to lengthen the MTU, and treatments may be better targeted at the Achilles tendon in children who ITW.

Dexterity of the Less Affected Hand in Children With Hemiplegic Cerebral Palsy.

To determine if the "unaffected" hand in children with hemiplegic cerebral palsy (CP) is truly unaffected. We performed a retrospective review of manual dexterity as measured by the Functional Dexterity Test (FDT) in 66 children (39 boys, 27 girls, mean age: 11 years 4 months) with hemiplegic CP. Data were stratified by Manual Ability Classification System (MACS) level, birth weight, and gestational age at birth, and compared with previously published normative values. The FDT speed of the less affected hand is significantly lower than typically developing (TD) children (P < .001). The development of dexterity is significantly lower than TD children (0.009 vs. 0.036 pegs/s/year, P < .001), with a deficit that increases with age. MACS score, birth weight, and age at gestation are not predictors of dexterity. The dexterity of the less affected hand is poorly correlated with that of the more affected hand. Both dexterity and rate of fine motor skill acquisition in the less affected hand of children with hemiplegic CP is significantly less than that of TD children. The less affected hand should be evaluated and included in comprehensive treatment plans for these children.