Differential effect of Taekwondo training on knee muscle strength and reactive and static balance control in children with developmental coordination disorder: A randomized controlled trial

This randomized controlled trial aimed to investigate the effect of short-term intensive TKD training on the isokinetic knee muscle strength and reactive and static balance control of children with developmental coordination disorder (DCD). Among the 44 children with DCD (mean age: 7.6 ± 1.3 years) recruited, 21 were randomly assigned to undergo daily TKD training for 1 h over three consecutive months, with the remaining 23 children being assigned to the DCD control group. Eighteen typically developing children (mean age: 7.2 ± 1.0 years) received no training as normal controls. Knee extensor and flexor muscle strength and reactive and static balance control were assessed using an isokinetic machine (with low, moderate and high movement velocities), a motor control test (MCT) and a unilateral stance test (UST), respectively. A repeated measures MANCOVA revealed a significant group through time interaction effect in isokinetic outcomes at 180°/s and in the UST outcome. Post hoc analysis demonstrated that DCD-TKD children's isokinetic knee muscle strength, specifically at 180°/s, was as high as that of the normal control children (p > 0.0083) after TKD training. Moreover, UST body sway velocity was slower in the DCD-TKD group than in the DCD control group (p < 0.001), and was comparable to that of the normal control group (p > 0.05) after TKD training. However, no such improvement in balance was observed in the MCT (p > 0.025). The results show that children with DCD who undergo a 3-month program of intensive TKD training experience improvements in isokinetic knee muscle strength at 180°/s and static single-leg standing balance control, but do not benefit from improved reactive balance control.     

Physical fitness in children with Developmental Coordination Disorder: Measurement matters

Children with Developmental Coordination Disorder (DCD) experience considerable difficulties coordinating and controlling their body movements during functional motor tasks. Thus, it is not surprising that children with DCD do not perform well on tests of physical fitness. The aim of this study was to determine whether deficits in motor coordination influence the ability of children with DCD to perform adequately on physical fitness tests. A case–control study design was used to compare the performance of children with DCD (n = 70, 36 boys, mean age = 8y 1mo) and Typically Developing (TD) children (n = 70, 35 boys, mean age = 7y 9mo) on measures of isometric strength (hand-held dynamometry), functional strength, i.e. explosive power and muscular endurance (Functional Strength Measurement), aerobic capacity (20 m Shuttle Run Test) and anaerobic muscle capacity, i.e. muscle power (Muscle Power Sprint Test). Results show that children with DCD were able to generate similar isometric forces compared to TD children in isometric break tests, but were significantly weaker in three-point grip strength. Performance on functional strength items requiring more isolated explosive movement of the upper extremities, showed no significant difference between groups while items requiring muscle endurance (repetitions in 30 s) and items requiring whole body explosive movement were all significantly different. Aerobic capacity was lower for children with DCD whereas anaerobic performance during the sprint test was not. Our findings suggest that poor physical fitness performance in children with DCD may be partly due to poor timing and coordination of repetitive movements.     

Taekwondo training improves sensory organization and balance control in children with developmental coordination disorder: a randomized controlled trial

Children with developmental coordination disorder (DCD) have poorer postural control and are more susceptible to falls and injuries than their healthy counterparts. Sports training may improve sensory organization and balance ability in this population. This study aimed to evaluate the effects of three months of Taekwondo (TKD) training on the sensory organization and standing balance of children with DCD. It is a randomized controlled trial. Forty-four children with DCD (mean age: 7.6 ± 1.3 years) and 18 typically developing children (mean age: 7.2 ± 1.0 years) participated in the study. Twenty-one children with DCD were randomly selected to undergo daily TKD training for three months (1 h per day). Twenty-three children with DCD and 18 typically developing children received no training as controls. Sensory organization and standing balance were evaluated using a sensory organization test (SOT) and unilateral stance test (UST), respectively. Repeated measures MANCOVA showed a significant group by time interaction effect. Post hoc analysis demonstrated that improvements in the vestibular ratio (p = 0.003) and UST sway velocity (p = 0.007) were significantly greater in the DCD-TKD group than in the DCD-control group. There was no significant difference in the average vestibular ratio or UST sway velocity between the DCD-TKD and normal-control group after three months of TKD training (p > 0.05). No change was found in the somatosensory ratio after TKD training (p > 0.05). Significant improvements in visual ratios, vestibular ratios, SOT composite scores and UST sway velocities were also observed in the DCD-TKD group after training (p ≤ 0.01). Three months of daily TKD training can improve sensory organization and standing balance for children with DCD. Clinicians can suggest TKD as a therapeutic leisure activity for this population.     

Assessment of physical fitness and exercise tolerance in children with developmental coordination disorder

Children with developmental coordination disorder (DCD) have been shown to be less physically fit when compared to their typically developing peers. The purpose of the present study was to examine the relationships among body composition, physical fitness and exercise tolerance in children with and without DCD. Thirty-seven children between the ages of 7 and 9 years participated in this study. Participants were classified according to results obtained on the Movement Assessment Battery for Children (MABC) and were divided in 2 groups: 19 children with DCD and 18 children without DCD. All children performed the following physical fitness tests: The five-jump test (5JT), the triple-hop distance (THD) and the modified agility test (MAT). Walking distance was assessed using the 6-min walking test (6MWT). Children with DCD showed higher scores than children without DCD in all MABC subscale scores, as well as in the total score (p < 0.001). Participants with DCD were found to perform significantly worse on the MAT (p < 0.001), the THD (p < 0.001) and 5JT (p < 0.05). Moreover, children with DCD had poorer performance on the 6MWT than children without DCD (p < 0.01). Our results found significant correlations among body mass index (BMI), THD (r = 0.553, p < 0.05), 5JT (r = 0.480, p < 0.05) and 6MWT (r = 0.544, p < 0.05) only in DCD group. A significant correlation between MAT and 5JT (r = −0.493, p < 0.05) was found. Similarly, THD and 5JT (r = 0.611, p < 0.01) was found to be correlated in children with DCD. We also found relationships among 6MWT and MAT (r = −0.522, p < 0.05) and the 6MWT and 5JT (r = 0.472, p < 0.05) in DCD group. In addition, we found gender specific patterns in the relationship between exercise tolerance, explosive strength, power, DCD, and BMI. In conclusion, the present study revealed that BMI was indicative of poorer explosive strength, power and exercise tolerance in children with DCD compared to children without DCD probably due to a limited coordination on motor control.     

Aggressive interactions during free-play at preschool of children with and without developmental coordination disorder

This aim of this study was to investigate an unexpected finding from a larger study examining the play of preschool children with and without developmental coordination disorder (DCD). We found that children with DCD were more frequently involved in aggressive incidents during free-play than their peers. Children with (n = 32) and without DCD (n = 31) were videotaped during free-play at preschool and their play was assessed using the Play Observation Scale. A post hoc analysis was conducted using a specifically developed rating instrument to examine the aggressive incidents captured on video. Videos from 18 children with DCD and 8 typically developing children without DCD were found to contain aggressive incidents. Children with DCD were significantly more often involved as both aggressor (p = .016) and victim (p = .008) than children without DCD (p = .031). This is the first study to identify victimization and aggression as being problematic for children with DCD as young as 4 years of age and needs replication. Given the negative consequences of involvement in aggression and victimization, play-based early intervention focusing on prevention needs to be developed and implemented.     

Understanding physical activity and motivations for children with Developmental Coordination Disorder: An investigation using the Theory of Planned Behavior

Developmental coordination disorder (DCD) is a neurodevelopmental condition, affecting approximately 5–6% of children. Previous research has consistently found children with DCD being less physically active compared to typically-developing (TD) children; however, the psychosocial factors associated with physical activity for children with DCD are poorly understood. The purpose of this study was to examine how theory-based physical activity cognitions impacts physical activity behaviors for children with and without DCD. Participants included a sample of boys (N = 61, M_age = 13.25 ± .46) with DCD (n = 19) and without DCD (n = 42), drawn from a larger prospective cohort study. A questionnaire with psychosocial measures was first administered, and accelerometers were used to assess their physical activity behavior over the subsequent week. Findings indicate that DCD was significantly associated with lower physical activity (F(1,58) = 6.51, p < .05), and poorer physical activity cognitions (F(4,56) Wilks Lambda = 2.78, p < .05). Meditational analyses found attitudes (B = .23, p < .05) and subjective norms (B = .31, p < .05) partially mediating the relationship between DCD and physical activity. Overall, this study further confirms that the activity deficit that exists among boys with DCD, and that the relationship is partially mediated through some physical activity cognitions. Interventions should target the perceived approval of influential people, and the personal evaluations of physical activity for boys with motoric difficulties. These findings further emphasizes the discrepancy in physical activity that exist between boys with DCD and TD boys, and highlight the need to better understand the psychological factors related to physical activity for children with DCD.     

Perceived athletic competence and physical activity in children with developmental coordination disorder who are clinically referred,and control children

The relationship between perceived athletic competence (PAC) and physical activity (PA) in children with developmental coordination disorder (DCD) is still unclear. This study investigated differences in PAC and PA between, and within, a group of children with DCD that were clinically referred (n = 31) and a group of control children (n = 38), aged 7–12 years. All children were categorized in four groups: (1) children with DCD/low PAC, (2) children with DCD/normal to high PAC, (3) control children/low PAC, and (4) control children/normal to high PAC. PAC was assessed with the Self-Perception Profile for Children, and PA was assessed with the Modifiable Activity Questionnaire. Children with DCD participated less in unorganized PA, but not in organized PA, compared with control children. Normal to high PAC was found in more than half of the children (64.5%) with DCD. Children with DCD/low PAC and children with DCD/normal to high PAC participated significantly less in unorganized physical activity compared with control children/normal to high PAC, but not compared with control children/low PAC. The results indicate that there are large individual differences in PAC in children with DCD.     

Physical fitness and overweight in Israeli children with and without developmental coordination disorder: Gender differences

Physical fitness and overweight among children has become paramount in the general population and more so in children with developmental coordination disorder (DCD). The purpose of the current study was to examine the association between physical fitness and overweight in a sample of Israeli children in comparison to typical children, and to examine gender differences. DCD was identified through total scores on the movement assessment battery for children 2 (MABC-2) equal to or less than the 16th percentile as well as parents’ report that the child's deficits in motor skills interfered with at least two daily life activities. The sample included a group of children with DCD (n = 22, M age = 8.70 [SD = 1.36], 16 boys [73%]) and a control group of typical children (n = 47, M age = 8.90 [SD = 1.52], 34 boys [72%]). Measures included the strength subtest of the Bruininks–Oseretsky test of motor proficiency (BOT-2), the six minutes’ walk test (6MWT) with heart rate measure, BMI and the percentage of body fat. Significant differences between DCD and typical children were found on all variables of physical fitness and weight. A two-way analysis of variance (ANOVA) analysis (group/gender) also revealed significant interactions for the percentage of body fat (F = 8.51, p < .005) and BMI (F = 4.50, p < .038) meaning that less fit children are more obese. The current study supports previous findings that children with DCD are less physically fit and more overweight compared to typically developing children. Moreover, in comparing between the genders, the girls in the study sample weighed more and had a significantly higher percentage of body fat than boys, it is essential to further our understanding of the relationships between obesity, physical fitness and gender among children with and without DCD.     

Sensory organization of balance control in children with developmental coordination disorder

This study aimed to (1) compare functional balance performance and sensory organization of postural control between children with and without developmental coordination disorder (DCD) and (2) determine the association between postural control and participation diversity among children with DCD. We recruited 81 children with DCD and 67 typically developing children. Balance was evaluated with the Sensory Organization Test (SOT) and the Movement Assessment Battery for Children-2 (Movement ABC-2). Participation patterns were evaluated using the Children Assessment of Participation and Enjoyment assessment. Analysis of variance was used to compare outcome variables between the two groups. A multiple regression analysis was performed to examine the relationship between participation diversity and balance performance in children with DCD. The DCD group had significantly lower Movement ABC-2 balance scores, SOT-derived equilibrium scores, and sensory ratios than the control group (p < 0.05). However, only the Movement ABC-2 balance score was significantly associated with participation diversity in children with DCD. After accounting for the effects of age and gender, Movement ABC-2 balance score remained significantly associated with participation diversity, explaining 10.9% of the variance (F_change1,77 = 9.494, p = 0.003). Children with DCD demonstrate deficits in sensory organization of balance control. This suboptimal balance ability contributes to limited participation in activities.     

Psychometric properties of the DCD-Q-07 in children ages to 4–6

It is important to identify Developmental Coordination Disorder (DCD) early in a child's life to allow for proper and timely intervention and support, and to reduce the negative secondary consequences associated with this condition. In this study we assessed the psychometric properties (construct validity, concurrent validity, reliability and test accuracy) of the Developmental Coordination Disorder Questionnaire (DCD-Q-07) in preschool children. A community-based sample of children ages 4–6 (n = 181) were screened for motor difficulties using the Movement Assessment Battery for Children (M-ABC-2). Use of the M-ABC-2 resulted in the identification of 29 children below the 15th percentile, which we classified as probable DCD. Parents of these children concurrently completed the DCD-Q-07 to report their child's motor performance. The DCD-Q-07 demonstrated high internal consistency for both the full scale (alpha = 0.881) and each subscale: control during movement (alpha = 0.813), fine motor and handwriting (alpha = 0.869) and general coordination (alpha = 0.728). Moderate correlations (r = 0.47–0.63) were also seen between the subscales on the DCD-Q-07, the strongest correlation being between control during movement and general coordination (r = 0.63). Based on published age and sex cut points, the DCD-Q-07 showed poor sensitivity (20.7%) but high specificity (92.1%) against the M-ABC-2. Overall agreement with the M-ABC-2 was low using ROC analysis (area under the curve = 0.654). Although it is important to screen for DCD in young children, the DCD-Q-07 may not be the best choice as a screening tool for DCD in preschool children ages 4–6 due to its low test accuracy.     

Executive function and attention in young adults with and without Developmental Coordination Disorder – A comparative study

The current research aimed at examining the executive function (EF) of young adults with Developmental Coordination Disorder (DCD) in comparison to young adults without DCD. The study used a randomized cohort (N = 429) of young adults with DCD (n = 135), borderline DCD (n = 149) and control (n = 145), from a previous study. This initial cohort was asked to participate in the current study three to four years later. Twenty-five individuals with DCD (mean age = 24 years, 1 month [SD = 0.88]; 18 males), 30 with borderline DCD (mean age = 24 years, 2 month [SD = 0.98]; 18 males) and 41 without DCD (mean age = 25 years, 2 months [SD = 1.91]; 20 males) participated in this study. Participants completed the BRIEF-A questionnaire, assessing EF abilities and the WURS questionnaire, assessing attention abilities. The DCD and borderline DCD groups had significantly lower EF profiles in comparison with the control group but no significant differences were found between the DCD and borderline DCD groups. While a high percentage of attention problems were found in both DCD groups, the executive functioning profiles remained consistent even when using the attention component as a covariate. The study results suggest that young adults with DCD have EF problems which remain consistent with or without attention difficulties.     

Sit-to-stand movement in children with hemiplegic cerebral palsy: Relationship with knee extensor torque and social participation

This study aimed to investigate the relationship between sit-to-stand (STS) movement, knee extensor torque and social participation in children with cerebral palsy (CP). Seven spastic hemiplegic CP patients (8.0 ± 2.2 years), classified by the Gross Motor Function Classification System as I and II, and 18 typical children (8.4 ± 2.3 years) participated in this study. Trunk, hips, knees, and ankles angles and temporal variables of STS movement were obtained by means of kinematics evaluation. Isokinetic evaluation was performed at 60°/s in the concentric passive mode to measure knee extensors torque. Social participation was assessed by the Assessment of Life Habits for Children (LIFE-H) scale. Results showed that children with spastic hemiplegic CP have lower knee extensor torque in the affected limb and restriction in social participation in dimensions related with fine motor control and language skills when compared to their typical peers. Except for ankle excursion in frontal plane, and ankle excursion and range in transverse plane, patients were similar to typical children regarding the strategies adopted to perform the STS movement, as well as in the participation dimensions related with gross motor function. Moreover, we found a significant non-linear correlation between knee extensors torque and some lower limb and trunk angles for children with CP. Therefore, during evaluation and rehabilitation processes, impairments in body functions and structures should be related with how much they affect a child's ability to perform functional activities, so rehabilitation protocols could be focused on individual needs.     

Developmental Coordination Disorder in children with specific language impairment: Co-morbidity and impact on quality of life

Co-morbidity of Developmental Coordination Disorder (DCD) in children with specific language impairment (SLI) and the impact of DCD on quality-of-life (QOL) was investigated in 65 5–8 year old children with SLI (43 boys, age 6.8 ± 0.8; 22 girls, age 6.6 ± 0.8). The prevalence of DCD was assessed using DSM-IV-TR criteria (American Psychiatric Association (APA), 2000) operationally defined in the clinical practice guideline (CPG): movement ABC scores below 15th percentile, scores on DCDQ and/or MOQ-T below 15th percentile, absence of medical condition according to paediatric-neurological exam. Quality of life (QOL) was measured with the TNO-AZL-Child-Quality-Of-Life (TACQOL) Questionnaire filled out by parents for the SLI group with and without DCD, and compared to a reference group (N = 572; age 6.9 ± 0.9). The TACQOL covers 7 QOL domains: physical, motor, cognitive and social functioning, autonomy, positive and negative moods. Prevalence of DCD in children with SLI was 32.3%. In children with SLI, mean QOL scores were significantly lower in the autonomy, cognitive, social and positive moods domains compared to the reference group. Children with SLI and DCD differed from children with SLI without DCD by significantly lower mean overall-, motor-, autonomy-, and cognitive domain-QOL scores. Clinicians should be aware that about one third of children with SLI can also be diagnosed with DCD. Assessment of QOL is warranted in order to assess which domains are affected in children with SLI with or without DCD.     

Psychological distress in children with developmental coordination disorder and attention-deficit hyperactivity disorder

This study explored whether or not a population-based sample of children with developmental coordination disorder (DCD), with and without comorbid attention deficit/hyperactivity disorder (ADHD), experienced higher levels of psychological distress than their peers. A two-stage procedure was used to identify 244 children: 68 with DCD only, 54 with ADHD only, 31 with comorbid DCD and ADHD, and 91 randomly selected typically developing (TD) children. Symptoms of depression and anxiety were measured by child and parent report. Child sex and caregiver ethnicity differed across groups, with a higher ratio of boys to girls in the ADHD only group and a slightly higher proportion of non-Caucasian caregivers in the TD group. After controlling for age, sex, and caregiver ethnicity, there was significant variation across groups in both anxiety (by parent report, F(3,235) = 8.9, p < 0.001; by child report, F(3,236) = 5.6, p = 0.001) and depression (parent report, F(3,236) = 23.7, p < 0.001; child report, F(3,238) = 9.9, p < 0.001). In general, children in all three disorder groups had significantly higher levels of symptoms than TD children, but most pairwise differences among those three groups were not significant. The one exception was the higher level of depressive symptoms noted by parent report in the ADHD/DCD group. In conclusion, children identified on the basis of motor coordination problems through a population-based screen showed significantly more symptoms of depression and anxiety than typically developing children. Children who have both DCD and ADHD are particularly at heightened risk of psychological distress.     

Postural sway patterns in children with autism spectrum disorder compared with typically developing children

Postural control is a fundamental building block of each child's daily activities. The aim of this study was to compare patterns of postural sway in children with autism spectrum disorder (ASD) with typically developing children (TD). We recruited 21 schoolchildren diagnosed with ASD aged 9–14 and 30 TD pupils aged 8–15. Postural sway parameters in composite, anteroposterior and mediolateral axis were reported. Furthermore we examined the impact of age and characteristics of autism on postural sway. Children with ASD exhibited higher amount of sway in anteroposterior range (p < 0.001), mediolateral range (p = 0.002), root mean square (p = 0.001), mean velocity (p = 0.03), and sway area (p = 0.007) compared with their TD peers. Children with ASD showed higher instability in mediolateral than anteroposterior axis though TD children demonstrated higher sway scores in anteroposterior than mediolateral direction. The rate of autism symptom severity significantly affected the postural sway in children with ASD (p < 0.05). In conclusion, patterns of postural control seem to be different in children with ASD compared with TD counterparts. This could be partially due to clinical features were underlying in ASD.     

Motor control of the lower extremity musculature in children with cerebral palsy

The aim of this investigation was to quantify the differences in torque steadiness and variability of the muscular control in children with cerebral palsy (CP) and typically developing (TD) children. Fifteen children with CP (age = 14.2 ± 0.7 years) that had a Gross Motor Function Classification System (GMFCS) score of I-III and 15 age and gender matched TD children (age = 14.1 ± 0.7 years) participated in this investigation. The participants performed submaximal steady-state isometric contractions with the ankle, knee, and hip while surface electromyography (sEMG) was recorded. An isokinetic dynamometer was used to measure the steady-state isometric torques while the participants matched a target torque of 20% of the subject's maximum voluntary torque value. The coefficient of variation was used to assess the amount of variability in the steady-state torque, while approximate entropy was used to assess the regularity of the steady-state torque over time. Lastly, the distribution of the power spectrum of the respective sEMG was evaluated. The results of this investigation were: 1) children with CP had a greater amount of variability in their torque steadiness at the ankle than TD children, 2) children with CP had a greater amount of variability at the ankle joint than at the knee and hip joint, 3) the children with CP had a more regular steady-state torque pattern than TD children for all the joints, 4) the ankle sEMG of children with CP was composed of higher harmonics than that of the TD children.     

Impact of tactile function on upper limb motor function in children with Developmental Coordination Disorder

This study investigated the presence of, and relationship between tactile dysfunction and upper limb motor function in children with Developmental Coordination Disorder (DCD) compared to typical developing (TD) children. Participants were 36 children aged 6–12 years. Presence of DCD (n = 20) or TD (n = 16) was confirmed using the Movement Assessment Battery for Children, second edition. All children participated in a comprehensive assessment of tactile registration (Semmes Weinstein Monofilaments); tactile spatial perception (Single Point Localisation (SPL) and two-point discrimination (2PD)); haptic perception (Stereognosis); speed of simple everyday manual tasks (Jebsen–Taylor Test of Hand Function (JTTHF)); and handwriting speed and accuracy (Evaluation Tool of Children's Handwriting (ETCH)). Compared to TD children, children with DCD demonstrated poorer localisation of touch in the non-dominant hand (p = 0.04), slower speed of alphabet writing (p < 0.05) and less legible handwriting (p < 0.01), but no difference in speed of simple everyday manual tasks (JTTHF: p > 0.05). Regression analysis showed that spatial tactile perception (SPL) predicted handwriting legibility (ETCH: r = 0.11) and speed of functional tasks (JTTHF: r = 0.33). These results suggest that tactile function, specifically single point localisation, should be a primary tactile assessment employed to determine reasons for upper limb motor difficulties experienced by children with DCD.     

Influence of effort intensity and gastrocnemius stretch on co-contraction and torque production in the healthy and paretic ankle

ObjectiveSpastic co-contraction is a misdirected supraspinal command in spastic paresis. We quantified the influence of effort and gastrocnemius stretch on plantar flexor co-contraction and torque during dorsiflexion efforts in hemiparetic and healthy subjects.MethodsEighteen healthy and 18 hemiparetic subjects produced “light”, “medium” and “maximal” isometric dorsi- and plantar flexion efforts in two gastrocnemius positions, stretched (knee extended) and slack (knee flexed), ankle at 90°. Measuring ankle torque and soleus and medial gastrocnemius surface EMG, we calculated the co-contraction index (CCI) as the ratio of the EMG root mean square (RMS) from the muscle acting as antagonist over its RMS when acting as agonist in a maximal effort, in each knee position.ResultsCo-contraction was abnormally high in hemiparetic subjects at all effort levels, e.g. for soleus in the knee extended position (CCI_SO 0.37 ± 0.08 in hemiparesis vs 0.18 ± 0.02 in healthy subjects, p < 0.05). In hemiparetic subjects knee extended, dorsiflexion torque, (i) was reversed or canceled in 26% trials; and (ii) correlated negatively with plantar flexor CCI.SignificanceMajor dynamometric impact of co-contraction with stretched position of the cocontracting muscle may justify muscle length modifications (e.g. through aggressive stretch programs) to improve function in spastic paresis.     

Toward a motor signature in autism: Studies from human-machine interaction

BackgroundAutism spectrum disorder (ASD) is a heterogeneous group of neurodevelopmental disorders which core symptoms are impairments in socio-communication and repetitive symptoms and stereotypies. Although not cardinal symptoms per se, motor impairments are fundamental aspects of ASD. These impairments are associated with postural and motor control disabilities that we investigated using computational modeling and developmental robotics through human-machine interaction paradigms.MethodFirst, in a set of studies involving a human–robot posture imitation, we explored the impact of 3 different groups of partners (including a group of children with ASD) on robot learning by imitation. Second, using an ecological task, i.e. a real-time motor imitation with a tightrope walker (TW) avatar, we investigated interpersonal synchronization, motor coordination and motor control during the task in children with ASD (n = 29), TD children (n = 39) and children with developmental coordination disorder (n = 17, DCD).ResultsFrom the human–robot experiments, we evidenced that motor signature at both groups’ and individuals’ levels had a key influence on imitation learning, posture recognition and identity recognition. From the more dynamic motor imitation paradigm with a TW avatar, we found that interpersonal synchronization, motor coordination and motor control were more impaired in children with ASD compared to both TD children and children with DCD. Taken together these results confirm the motor peculiarities of children with ASD despite imitation tasks were adequately performed.DiscussionStudies from human-machine interaction support the idea of a behavioral signature in children with ASD. However, several issues need to be addressed. Is this behavioral signature motoric in essence? Is it possible to ascertain that these peculiarities occur during all motor tasks (e.g. posture, voluntary movement)? Could this motor signature be considered as specific to autism, notably in comparison to DCD that also display poor motor coordination skills? We suggest that more work comparing the two conditions should be implemented, including analysis of kinematics and movement smoothness with sufficient measurement quality to allow spectral analysis.     

Assessment of gait characteristics and orthotic management in children with Developmental Coordination Disorder: Preliminary findings to inform multidisciplinary care

Developmental Coordination Disorder (DCD) is a neurodevelopmental disorder characterised by impaired motor co-ordination and awkward gait. Despite self-reported findings of pes planus and joint hypermobility in children with DCD, there is little objective evidence regarding the clinical management of the foot in children with DCD. The aims of this research were to report clinical findings of foot posture and lower limb hypermobility in children with DCD and to evaluate the impact of foot orthoses on spatio-temporal gait parameters. Children with DCD were recruited into the study. Participants were randomly assigned to an intervention group who received foot orthoses at the start of their rehabilitation programme or to a second group who received foot orthoses at the end of their intervention programme. Foot posture was assessed with the Foot Posture Index and lower limb hypermobility assessed with the Lower Limb Assessment Score. The effect of foot orthoses was evaluated through assessment of spatio-temporal gait characteristics at baseline and post-rehabilitation programme. Fourteen children were recruited (mdn age 7.5 years) with nine children assigned to the group receiving orthoses early (mdn age 8 years) and five children assigned to the post-rehabilitation orthoses group (mdn age 6.5 years). A pes planus foot posture (FPI score = 8) and lower limb hypermobility (LLAS score = 11) were observed. Changes in spatio-temporal gait parameters failed to reach significance (p > .012) following orthotic invention but demonstrated a trend towards a decreased cadence and increased double support duration. Despite non-significant findings this work offers preliminary support for podiatric intervention in the rehabilitation of children with DCD. Further work is required to understand the biomechanics of gait in children with DCD and appreciate the role of podiatry as a component of multidisciplinary care.