Differences in gait between children with and without developmental coordination disorder

Quantification of early gait development: Expanding the application of Catwalk technology to an infant rhesus macaque model

BACKGROUND

Understanding gait development is essential for identifying motor impairments in neurodevelopmental disorders. Defining typical gait development in a rhesus macaque model is critical prior to characterizing abnormal gait. The goal of this study was to 1) explore the feasibility of using the Noldus Catwalk to assess gait in infant rhesus macaques and 2) provide preliminary normative data of gait development during the first month of life.

NEW METHOD

The Noldus Catwalk was used to assess gait speed, dynamic and static paw measurements, and interlimb coordination in twelve infant rhesus macaques at 14, 21, and 28 days of age. All macaque runs were labeled as a diagonal or non-diagonal walking pattern.

RESULTS

Infant rhesus macaques primarily used a diagonal (mature) walking pattern as early as 14 days of life. Ten infant rhesus macaques (83.3%) were able to successfully walk across the Noldus Catwalk at 28 days of life. Limited differences in gait parameters were observed between timepoints because of the variability within the group at 14, 21, and 28 days.

COMPARISON WITH EXISTING METHODS

No prior gait analysis system has been used to provide objective quantification of gait parameters for infant macaques.

CONCLUSIONS

The Catwalk system can be utilized to quantify gait in infant rhesus macaques less than 28 days old. Future applications to infant rhesus macaques could provide a better understanding of gait development and early differences within various neurodevelopmental disorders.

DEVELOPMENT OF COORDINATION ABILITIES IN 6-10 YEARS OLD BOYS WITH POSTURAL DISORDERS

OBJECTIVE

The aim: To develop, substantiate and experimentally test the methodology for the development of coordination abilities in 6-10 years old boys with postural disorders during their physical education training sessions.

PATIENTS AND METHODS

Materials and methods: The experimental (EG) and the control groups (CG) were formed to organize the pedagogical experiment. The EG included 17 boys and the CG consisted of 19 boys. The EG was engaged in sports activities according the developed methodology and the CG followed the current school curricula on physical education.

RESULTS

Results: The methodology for the development of coordination abilities in 6-10 years old boys with postural disorders in the process of their physical education has been developed. Its peculiarity lies in the accentuated influence on the vestibular, motor and visual analyzers with the help of a system of exercises aimed at controlling movements in space in static positions and during movement.

CONCLUSION

Conclusions: The obtained results testify to the effectiveness of the developed methodology. The EG boys had significantly higher indicators of static balance and coordination abilities at body position change, as well as general coordination of movements (p ≤ 0.05) at the end of the academic year than those of the CG. In addition, the number of 6-10 years old boys with various postural disorders decreased by 7.4 % (from 26.8 % to 19.4 %).

Atypical adaptive postural responses in children with developmental coordination disorder: Implications for rehabilitation

BACKGROUND

Adaptive postural control is an important yet underexamined area in children with developmental coordination disorder (DCD). This study compared adaptive postural responses between children with DCD and those with typical development.

METHODS

This was an exploratory cross-sectional study. Fifty-two children with DCD (aged 6-9 years) and 52 age- and sex-matched children with typical development participated in the study. Their adaptive postural (motor) responses were assessed using the Adaptation Test (ADT) on a computerized dynamic posturography machine. The sway energy score (SES) for each ADT trial and the average SES of five trials for both toes-up and toes-down platform inclination conditions were recorded.

RESULTS

The SESs were lower in the DCD group than in the control group in ADT toes-up trial 1 (p = 0.009) and on average (p = 0.044). In the control group, the SES decreased from trial 1 to trial 2 for both the ADT toes-up (p = 0.005) and toes-down conditions (p < 0.001).

SIGNIFICANCE

Adaptive postural responses were absent in children with DCD, and these children used less force (i.e., sway energy) to overcome postural instability. Therefore, both adaptive balance and neuromuscular training should be factored into rehabilitation programs for children with DCD.

Correction of Body Posture Disorders in Young Children of School Age in the Process of Physical Education Classes

Aim: To develop, substantiate and experimentally test the method of correction of body posture disorders in 6-10-years-old girls in the process of their coordination skills development. Materials and Methods: The research involved 138 girls including 40 girls who had various deviations in body posture development and 98 girls without body posture disorders. The experimental (EG) and the control group (CG) of 20 girls each were formed to organize the experiment. The EG was engaged according to the developed method of correction of body posture disorders, the CG – according to the current school curricula of physical education. Results: It was found that 29.0 % of primary high schoolers have various deviations in body posture development. Kyphotic body posture is observed in 80.6 % of cases and scoliotic body posture – in 19.4% of cases. The research determined the relationship between the level of coordination manifestation and the state of body posture in schoolers, in particular the presence of abnormalities in its development. The method of correction of body posture disorders in 6-10-years-old girls during physical education training sessions was developed. Conclusions: The obtained results indicate the effectiveness of the developed method. The EG girls revealed significantly better indicators of motion coordination and coordination skills when changing body position as well as static balance than the CG girls (p≤0.05). The number of girls with various deviations in body posture development decreased by 9.9%.

Physical Functions among Children before and during the COVID-19 Pandemic: A Prospective Longitudinal Observational Study (Stage 1)

One major impact of the COVID-19 pandemic on children's lifestyles is the lack of exercise owing to activity restrictions. However, information regarding the way in which physical functions among children decline under these circumstances remains scarce. In this study, we compared the physical functions and life habits among children before and during the COVID-19 pandemic in Japan. The participants involved 40 children aged between 9-15 years (23 girls and 17 boys) who were examined medically both before and during the pandemic. The compared variables included muscle strength, static and dynamic balance functions, gait speed, body fat percentage, screen and sleep times, quality of life, and physical activity time. During the pandemic, compared to before the pandemic, children had lower levels of dynamic balance functions (p = 0.039), increased body fat percentages (p < 0.0001), longer screen time per day (p = 0.002), and shorter sleep time per day (p < 0.0001). Between the two periods, there were no significant differences in muscle strength, static balance functions, gait speed, quality of life, and physical activity time. The activity restrictions imposed as a result of the COVID-19 pandemic negatively affect dynamic balance functions, body-fat levels, and life habits among children.

Reference Values of Spatial and Temporal Gait Parameters in a Contemporary Sample of Spanish Preschool Children: A Cross-Sectional Study

The aim of this study was to analyze the influence of age and sex on kinematic gait parameters in preschool children, and derive reference values for this population. A total of 383 preschool children (age 3–5 years; 207 girls, 176 boys) participated in this study. We used the OptoGait system to assess the kinematics of gait at a comfortable and self-determined speed. No significant differences between the sexes were found for the main gait parameters. Among the participants, there was a significant increase in double support, reductions in absolute cadence and the coefficient of variation (CV) of cadence, an increase in absolute step length (SL), and an increase in the walk ratio (WR) from 3 to 5 years of age. However, the normalized SL and normalized WR displayed a significant reduction in both sexes. Partial correlation indicated a significant association of age with SL and normalized SL, and WR. Additionally, WR showed a significant correlation with the CV of cadence. To summarize, no relevant differences in gait performance were found according to sex; however, age was found to influence gait maturation. The normative values established for Spanish preschool children can be used to monitor healthy gait development.

Three-dimensional gait analysis of lower extremity gait parameters in Japanese children aged 6 to 12 years

We aimed to develop gait standards for gait parameters in school-aged Japanese children and assess age-related differences in gait patterns and parameters. Children aged 6–12 years (n = 424) were recruited from two elementary schools. An instrumented three-dimensional gait analysis system was used to record each child's gait kinematics, kinetics, and spatiotemporal parameters. Participants were subdivided into three age groups (Group A, 6–8 years; Group B, 9–10 years; and Group C, 11–12 years). LMS Chartmaker, version 2.54, was used to create a developmental chart for the gait pattern. The non-normalized step and stride lengths were significantly longer, and the cadence was lower in older children; however, the opposite outcome occurred when analyzing normalized data. Ankle moment differed significantly by age, and the maximum ankle moment was higher in older children than that in younger children. Furthermore, the hip and knee flexion angles during gait and the normalized spatiotemporal parameters of Japanese children aged 6–12 years differed by age and from those of children from other countries. The centile chart of the gait pattern is a useful tool for clinicians to assess developmental changes in the gait pattern and detect gait abnormalities in children.

Primitive Reflex Factors Influence Walking Gait in Young Children: An Observational Study

Background: Primitive reflexes (PRs) are observed as an automatic response to a specific stimulus. They are vivid from intrauterine life to 6 months postnatal. The reactions are inhibited with the growing maturation of the central nervous system (CNS). In some cases, when the natural process of development is incorrect, PRs manifest later. The analysis of differentiation in gait parameters in children with persistent PRs is important for better understanding their specific behaviour and movement. This study’s aim was to investigate the influence of active PRs on the gait parameters of preschool children. Methods: There were 50 children examined, 30 girls and 20 boys. They were 3.5−6 years old. The children had persistent PRs in the trace form. Each child was examined by S. Goddard’s Battery Test. The acquisition of the spatial-temporal gait parameters was performed using a BTS G-SENSOR measurement instrument. Participants walked barefoot, in the most natural way for them, at a self-selected speed on a 5 m walkway, then turned around and went back. They performed this twice. Results: The reflex activity influences gait cycle duration (p = 0.0099), the left step length (p = 0.0002), the left double support phase (p = 0.0024), the right double support phase (p = 0.0258) and the right single phase. Difficulties in recreating the crawling pattern and GRASP reflex influence gait cadence (p < 0.05). The left GRASP reflex corresponds to step length (p < 0.05). The activeness of the symmetrical tonic neck reflex correlates with the right single support (p < 0.05). Conclusion: The presence of PRs affect walking gait in preschool children.

Foot posture index and body composition measures in children with and without developmental coordination disorder

Background

Foot posture which forms the distal supporting structure influences on postural stability. Children with developmental coordination disorder (DCD) who are more likely to be overweight or obese may present with flat foot with symptoms that affect daily activities. The aim of this study was to compare the foot posture and body composition measures between children with and without DCD. In addition, this study aimed to investigate the relationship between foot posture and fat percentage.

Methods

Fifty-nine children with DCD (mean age = 8.07±1.10) and sixty-two typically developing children (mean age = 7.97±1.05) were recruited to the DCD and control group respectively. All children received a foot posture assessment and a whole-body dual-energy X-ray absorptiometry (DXA) scan. Foot Posture Index 6 (FPI-6) total scores, sub-scores and lower limb body composition measures including fat mass, lean mass, total mass, fat percentage and fat mass index were measured.

Results

Children with DCD revealed a significantly higher FPI-6 left (1.12; 95% CI: 0.172, 2.061) and right (1.15; 95% CI: 0.218, 2.079) total score. FPI-6 sub-scores (talar head palpation and abduction/adduction forefoot on rearfoot) illustrated significant differences between children with and without DCD. Children with DCD had a significantly higher total fat mass (1247.48g; 95% CI: 121.654, 2373.304), total fat percentage (1.82%; 95% CI: 0.115, 3.525) and fat mass index (0.56kg/m²; 95% CI: 0.036, 1.069). There was a significant relationship between FPI-6 right total score and total fat percentage.

Conclusion

The findings of this study showed that children with DCD exhibited significantly more pronated foot posture and higher body composition measures compared to typically developing children. Moreover, with FPI-6 right total score significantly related to the total fat percentage, it may require more than just detecting abnormal foot structures in children with DCD but also promoting a healthy lifestyle to prevent obesity.

Bilateral asymmetry in the gait deviation index in school-aged children with the trait of developmental coordination disorder

BACKGROUND

Although previous studies have identified asymmetry in gait parameters in children with developmental coordination disorder (DCD), they have not investigated whether these findings coexist with asymmetry in gait quality, as represented by the gait deviation index (GDI).

RESEARCH QUESTION

This study sought to measure gait symmetry in children with traits of DCD (DCD trait) to elucidate the characteristic gait pattern.

METHODS

This study included 172 (82 girls, 90 boys) participants with and without DCD trait (age: 6-12 years), as assessed using the Japanese version of the Developmental Coordination Disorder Questionnaire (DCDQ-J), which consists of three subscales. Three-dimensional gait analysis data were obtained during the gait trials. GDI, step length, and step time data were recorded for both the right and left legs, and symmetry ratios were calculated.

RESULTS

Participants in the DCD trait group (n = 30) had a significantly lower GDI score (p < 0.0001) and a higher GDI symmetry ratio (p = 0.004) than typically developing children. Furthermore, DCD trait was related to the GDI symmetry ratio (odds ratio, 1.2; p = 0.001; 95 % confidence interval, 1.062-1.289). The control during movement, which was a DCDQ-J subscale, was negatively correlated with the GDI symmetry ratio (r=-0.257, p<0.001).

SIGNIFICANCE

This study's results lend support to the hypothesis that an increase in the GDI symmetry ratio is associated with the DCD trait. A quantitative assessment of gait performance is important to help identify gait asymmetry, including gait quality, in children with a DCD trait. Children with a DCD trait have a poor ability to control the interaction of lower leg movements, which may cause bilateral asymmetry in gait quality.

Relationship between the skeletal muscle mass index and physical activity of Japanese children: A cross-sectional, observational study

Regular physical activity is an important component of physical health of children and has been associated with increasing skeletal muscle mass and muscle strength. Children with low levels of physical activity may experience health problems, such as loss of muscle mass, later in life. Thus, it may be valuable to identify declining physical function in children who do not perform the recommended amount of physical activity. Therefore, we aimed to evaluate the relationship between the amount of physical activity performed for ≥60 min per day for ≥5 days per week and the skeletal muscle mass index and physical function in young children. In total, 340 typically developing children aged 6–12 years (175 girls; average age, 9.5±1.9 years) were included in this cross-sectional study. We evaluated the proportion of children performing the recommended minimum of 60 min of daily moderate-to-vigorous physical activity at least 5 days per week. The skeletal muscle mass and Gait Deviation Index scores, gait speed, grip strength, Five Times Sit-to-Stand test results, Timed Up-and-Go test results, one-leg standing time, and gait efficiency were evaluated. Multiple logistic regression analyses were performed to assess the association of moderate-to-vigorous physical activity with the skeletal muscle mass index, percent body fat, and physical function, after controlling for confounding factors (age and sex). A logistic regression analysis revealed that the skeletal muscle mass index was independently associated with moderate-to-vigorous physical activity (odds ratio, 2.34; 95% confidence interval, 1.17–4.71; P = 0.017). Performance of moderate-to-vigorous physical activity for ≥5 days per week for ≥60 min per day was associated with the skeletal muscle mass index score of Japanese children. Our findings highlighted the importance of performing moderate-to-vigorous physical activity for the development of skeletal muscle mass in children.

Balance control in individuals with developmental coordination disorder: A systematic review and meta-analysis

BACKGROUND

Although it is recognized that the majority of children with developmental coordination disorder (DCD) have balance deficits, comprehensive insights into which balance domains are affected, are still lacking in literature.

RESEARCH QUESTION

To what extent is balance control deficient in individuals with DCD compared to controls?

METHODS

Pubmed, Scopus and Web of Science were systematically searched. Risk of bias was assessed with the Scottish Intercollegiate Guidelines Network checklist for case-control studies. Mean and standard deviations characterizing balance control were extracted to calculate standardized mean differences (SMD) and pooled, if possible, using Review Manager.

RESULTS

The results of 31 studies (1152 individuals with DCD, 1103 typically developing (TD) peers, mean age 10.4 years old) were extracted of which 17 were used for meta-analysis. The mean SMD for the balance subscale of the Movement Assessment Battery for Children was 1.63 (pooled 95 %CI =[1.30;1.97]), indicating children with DCD to perform significantly poorer than their TD peers. Force plate studies also revealed that children with DCD present with a larger sway path during bipedal stance with eyes closed (pooled mean SMD = 0.55; 95 %CI=[0.32;0.78]). Children with DCD tend to have direction-specific limited stability limits and task-independent delayed onset of anticipatory postural adjustments.

INTERPRETATION

Children with DCD perform poorer on different domains of balance compared to TD peers. Future research should focus on comprehensive balance assessment in these children, preferably using a longitudinal design.

Differences in walking and running gait in children with and without developmental coordination disorder: A systematic review and meta-analysis

BACKGROUND

Developmental coordination disorder (DCD) is a common motor skills disorder in children. Although gait changes are often reported clinically, affecting children's participation in play and sport, there has been no synthesis of research evidence comparing gait of children with and without DCD. Thus, the aim of this research was to determine differences in gait between children with and without DCD METHODS: A search of electronic databases (AMED, CINAHL, Cochrane Library, Embase, Medline, SPORTDiscus, & Web of Science) was conducted from inception to August 2019 for studies comparing walking and/or running gait of children with and without DCD. The McMaster Critical Appraisal Form for Quantitative Studies was used to assess risk of bias amongst included studies. Meta-analysis was completed on measures with four or more homogenous outcomes.

RESULTS

20 studies fulfilled the inclusion criteria and were eligible for review - three of which were pre-post designs, and 17 were cross-sectional designs. Data was extracted in five domains: kinetics, kinematics, physical function, electromyography, and temporospatial parameters. Meta-analysis was performed on one outcome measure - the 6 min Walk Test (6MWT), finding that children with DCD walked significantly shorter distances, indicating reduced endurance in walking gait. Other statistically significant results all favoured typically developing children, however there is little consistency between studies.

CONCLUSION

Although a clear gait pattern for children with DCD is not evident, functional deficits appear to be present in endurance and cardiorespiratory fitness. The current evidence base for gait changes in DCD is currently low-level, and further high quality research is warranted.

PROSPERO REGISTRATION NUMBER

CRD42018106791.

Children With Developmental Coordination Disorder Show Altered Visuomotor Control During Stair Negotiation Associated With Heightened State Anxiety

Safe stair negotiation is an everyday task that children with developmental coordination disorder (DCD) are commonly thought to struggle with. Yet, there is currently a paucity of research supporting these claims. We investigated the visuomotor control strategies underpinning stair negotiation in children with (N = 18, age = 10.50 ± 2.04 years) and without (N = 16, age = 10.94 ± 2.08 years) DCD by measuring kinematics, gaze behavior and state anxiety as they ascended and descended a staircase. A questionnaire was administered to determine parents' confidence in their child's ability to safely navigate stairs and their child's fall history (within the last year). Kinematics were measured using three-dimensional motion capture (Vicon), whilst gaze was measured using mobile eye-tracking equipment (Pupil labs). The parents of DCD children reported significantly lower confidence in their child's ability to maintain balance on the stairs and significantly more stair-related falls in the previous year compared to the parents of typically developing (TD) children. During both stair ascent and stair descent, the children with DCD took longer to ascend/descend the staircase and displayed greater handrail use, reflecting a more cautious stair negotiation strategy. No differences were observed between groups in their margin of stability, but the DCD children exhibited significantly greater variability in their foot-clearances over the step edge, which may increase the risk of a fall. For stair descent only, the DCD children reported significantly higher levels of state anxiety than the TD children and looked significantly further along the staircase during the initial entry phase, suggesting an anxiety-related response that may bias gaze toward the planning of future stepping actions over the accurate execution of an ongoing step. Taken together, our findings provide the first quantifiable evidence that (a) safe stair negotiation is a significant challenge for children with DCD, and that (b) this challenge is reflected by marked differences in their visuomotor control strategies and state anxiety levels. Whilst it is currently unclear whether these differences are contributing to the frequency of stair-related falls in children with DCD, our findings pave the way for future research to answer these important questions.

Reliability and construct validity of the Walking Adaptability Ladder Test for Kids (WAL-K): a new clinical test for measuring walking adaptability in children

PURPOSE

Walking adaptability is essential for children to participate in daily life, but no objective measurement tools exist. We determined psychometric properties of the Walking Adaptability Ladder test for Kids (WAL-K) in 6-12 year old children.

MATERIALS AND METHODS

In total, 122 typically developing (TD) children and 26 children with Developmental Coordination Disorder (DCD) completed the single and double run conditions of the WAL-K. Intra-rater, inter-rater and test-retest reliability were determined by ICCs and Smallest Detectable Change (SDC) in 53 TD children. Construct validity was determined by comparing WAL-K scores between 69 TD and all DCD children and correlating these scores with age and MABC-2 scores.

RESULTS

ICCs for reliability varied between 0.76 and 0.99. Compared to the first test performance, WAL-K scores were lower (i.e., better) at retest. SDCs for test-retest reliability varied between 20.8 and 26.1% of the mean scores. WAL-K scores were significantly higher (i.e., worse) in DCD children compared to TD children (p < 0.001). Significant negative correlations were found with MABC-2 (-0.52 and -0.60) and age (-0.61 and -0.68).

CONCLUSIONS

The WAL-K shows to be a valid, reliable and easy-to-use tool for measuring walking adaptability in children. Adding an extra practice trial may reduce the observed learning effect.Implications for rehabilitationWalking adaptability is an essential skill for children to participate in daily life, but no objective measurement tools are available.The Walking Adaptability Ladder test for Kids (WAL-K) is a new measurement tool for evaluating walking adaptability in children.The WAL-K shows to be a reliable and valid measurement tool for evaluating walking adaptability in 6-12 year old children.

Children With Developmental Coordination Disorder Exhibit Greater Stepping Error Despite Similar Gaze Patterns and State Anxiety Levels to Their Typically Developing Peers

This study examined stepping accuracy, gaze behavior, and state-anxiety in children with (N = 21, age M = 10.81, SD = 1.89) and without (N = 18, age M = 11.39, SD = 2.06) developmental coordination disorder (DCD) during an adaptive locomotion task. Participants walked at a self-selected pace along a pathway, placing their foot into a raised rectangular floor-based target box followed by either no obstacles, one obstacle, or two obstacles. Stepping kinematics and accuracy were determined using three-dimensional motion capture, whilst gaze was determined using mobile eye-tracking equipment. The children with DCD displayed greater foot placement error and variability when placing their foot within the target box and were more likely to make contact with its edges than their typically developing (TD) peers. The DCD group also displayed greater variability in the length and width of their steps in the approach to the target box. No differences were observed between groups in any of the gaze variables measured, in mediolateral velocity of the center of mass during the swing phase into the target box, or in the levels of self-reported state-anxiety experienced prior to facing each task. We therefore provide the first quantifiable evidence that deficits to foot placement accuracy and precision may be partially responsible for the increased incidence of trips and falls in DCD, and that these deficits are likely to occur independently from gaze behavior and state-anxiety.

Using a mouse model to gain insights into developmental coordination disorder

Motor impairments are a common feature of many neurodevelopmental disorders; in fact, over 50% of children with Attentional Deficit Hyperactivity Disorder or Autism Spectrum Disorder may have a co-occurring diagnosis of developmental coordination disorder (DCD). DCD is a neurodevelopmental disorder of unknown etiology that affects motor coordination and learning, significantly impacting a child's ability to carry out everyday activities. Animal models play an important role in scientific investigation of behaviour and the mechanisms and processes that are involved in control of motor actions. The purpose of this paper is to present an approach in the mouse directed to gain behavioral and genetic insights into DCD that is designed with high face validity, construct validity and predictive validity. Pre-clinical and clinical expertise is used to establish a set of scientific criteria that the model will meet in order to investigate the potential underlying causes of DCD.

Effect of Kinesio taping on electromyographic activity of leg muscles during gait in children with developmental coordination disorder: A randomized controlled trial

OBJECTIVE

This study aimed to evaluate the effectiveness of Kinesio tape (KT) on lower limb muscle activation pattern in children with developmental coordination disorder (DCD) during walking.

DESIGN

A parallel-group randomized controlled trial.

SETTING

University laboratory setting.

PARTICIPANTS

Twenty-five children with DCD were randomly allocated to the KT group (mean age = 7.97 years) and 24 to the control group (mean age = 8.04 years).

INTERVENTION

KT group received KT application to the quadriceps and gastrocnemius muscles whereas the control group received no intervention.

MEASUREMENTS

Peak muscle activation (in percentage of maximal voluntary isometric contraction [%MVIC]) in the lower limbs during gait was measured by means of surface electromyography, electrogoniometry, and foot contact switches.

RESULTS

Gastrocnemius medialis activation during mid stance (23.46%MVIC, 95% CI = -32.53, -14.39) and late stance phases (3.25%MVIC, 95% CI = -5.67, -0.81) of gait increased after the application of KT in the KT group compared to baseline values. The KT group demonstrated 26.87%MVIC (95% CI = 26.87, 7.11) higher gastrocnemius medialis muscle peak activation during mid stance phase at post-test when compared with the control group. Moreover, gastrocnemius medialis and biceps femoris muscle peak activation during loading response decreased by 8.36%MVIC (95% CI = 2.71, 14.02) and 3.54%MVIC (95% CI = 1.08, 6.01), respectively, in the control group overtime.

CONCLUSIONS

The application of KT on children with DCD had an increased gastrocnemius medialis muscle activation during stance phase. KT could be incorporated into gait re-education programmes to facilitate muscle contraction in these children.

Assessing the potential of the qualitative trajectory calculus to detect gait pathologies: a case study of children with developmental coordination disorder

The Qualitative Trajectory Calculus (QTC) is a qualitative spatio-temporal calculus for describing interactions between moving point objects. So far, it remained unclear whether QTC is useful for describing subtle differences, such as between the movements of different parts of a human body. We tested the applicability of QTC to detect differences in the gait patterns of children with or without Developmental Coordination Disorder (DCD). We found that using a combination of three markers (i.e. ankle, toe and trochanter), QTC can achieve a high classification accuracy (i.e. 83.3%) of classifying subjects correctly to either the DCD group or the control group.

Sensory and motor differences in Autism Spectrum Conditions and developmental coordination disorder in children: A cross-syndrome study

Recent research has shown that Developmental coordination disorder (DCD) can present with some similar symptomology as Autism Spectrum Conditions (ASC). This paper therefore explored the similarities and differences in coordination and sensory responsivity between DCD and ASC. 77 children took part: 42 (35 male, 7 female) with ASC (ages 7-21: mean age 12.23 years), 26 (19 male, 7 female) with DCD (ages 7-21; mean age 11.07 years) and 9 (2 male, 7 female) with ASC and DCD (ages 8-15; mean age 12.27). All groups completed a battery of validated parent report measures online that included motor coordination (DCDQ), sensory responsivity (SPC-R) and social communication measures (AQ). Results showed no significant differences in coordination, and some significant differences in sensory responsivity between ASC and DCD (increased visual and auditory responsivity and decreased proprioception). Exploratory analysis showed that these differences showed good validity in identifying the diagnosis of ASC and DCD. These results elucidate the underlying causes of motor coordination difficulties in both conditions. Specifically, ASC coordination difficulties appear linked to visual processing impairments, whilst DCD coordination difficulties appear to be linked to spatial processing. This may aid better diagnosis and intervention for these conditions.

Understanding the Functional Mobility of Adults with Developmental Coordination Disorder (DCD) Through the International Classification of Functioning (ICF)

PURPOSE OF REVIEW

This phenomenological study explored the lived experience of six adults with developmental coordination disorder (DCD) and its potential impact on functional mobility. Utilising the International Classification of Functioning (World Health Organisation, 2001), the data derived from interviews were analysed to consider how persistent motor impairments impact on activity engagement and participation.

RECENT FINDINGS

Much of the research evidence pertaining to DCD focuses on children. However, there is increasing acknowledgment that for some, the motor impairments synonymous with DCD continue into adulthood.

SUMMARY

The findings from this study suggest that for this group of participants, functional mobility can be compromised, restricting activity and participation. At a body structure/function level, participants identified additional impairments that moved beyond mobility, suggesting that the secondary consequences of fatigue and anxiety were disabling. However, personal factors were seen to mitigate some difficulties encountered to allow participants to remain actively engaged in a range of adult roles.

Leg muscle activation patterns during walking and leg lean mass are different in children with and without developmental coordination disorder

BACKGROUND

Previous studies have shown that children with developmental coordination disorder (DCD) have a higher body fat and greater gait variability. Little research has investigated the gait muscle activity and lean mass measures in children with DCD.

AIMS

To compare the leg muscle activation patterns of the gait cycle and leg lean mass between children with and without DCD.

METHODS

Fifty-one children were in the DCD group (38 males and 13 females; 7.95 ± 1.04 years) and fifty-two in the control group (34 males and 18 females; 8.02 ± 1.00 years). Peak muscle activation patterns of treadmill walking in the right leg for the eight-gait phases were measured by means of surface electromyography, an electrogoniometer, and foot contact switches. Leg lean mass measures were evaluated using a whole-body dual energy X-ray absorptiometry scan.

RESULTS

Children with DCD had a lower leg lean mass and appendicular lean mass index compared to the control group. Furthermore, they exhibited a less-pronounced peak muscle activation during the heel strike (gastrocnemius medialis), early swing (biceps femoris) and late swing phases (gastrocnemius medialis) of gait.

CONCLUSIONS AND IMPLICATIONS

Although lower limb total mass was similar between groups, the DCD group displayed lower lean mass measures than controls. Furthermore, children with DCD illustrated a lower leg peak muscle activation during the heel strike, early swing and late swing phases of gait when walking on a treadmill. Our results emphasize the need to incorporate lower limb phasic muscle strengthening components into gait rehabilitation programs for children with DCD.

Increased Anterior Pelvic Angle Characterizes the Gait of Children with Attention Deficit/Hyperactivity Disorder (ADHD)

Background

Children with attention deficit/hyperactivity disorder (ADHD) frequently have motor problems. Previous studies have reported that the characteristic gait in children with ADHD is immature and that subjects demonstrate higher levels of variability in gait characteristics for the lower extremities than healthy controls. However, little is known about body movement during gait in children with ADHD. The purpose of this study was to identify the characteristic body movements associated with ADHD symptoms in children with ADHD.

Methods

Using a three-dimensional motion analysis system, we compared gait variables in boys with ADHD (n = 19; mean age, 9.58 years) and boys with typical development (TD) (n = 21; mean age, 10.71 years) to determine the specific gait characteristics related to ADHD symptoms. We assessed spatiotemporal gait variables (i.e. speed, stride length, and cadence), and kinematic gait variables (i.e. angle of pelvis, hip, knee, and ankle) to measure body movement when walking at a self-selected pace.

Results

In comparison with the TD group, the ADHD group demonstrated significantly higher values in cadence (t = 3.33, p = 0.002) and anterior pelvic angle (t = 3.08, p = 0.004). In multiple regression analysis, anterior pelvic angle was associated with the ADHD rating scale hyperactive/impulsive scores (β = 0.62, t = 2.58, p = 0.025), but not other psychiatric symptoms in the ADHD group.

Conclusions

Our results suggest that anterior pelvic angle represents a specific gait variable related to ADHD symptoms. Our kinematic findings could have potential implications for evaluating the body movement in boys with ADHD.

Gait symmetry in individuals with and without Developmental Coordination Disorder

BACKGROUND

Symmetry between the left and right side of the body during locomotion is key in a coordinated gait cycle and is also thought to be important in terms of efficiency. Although previous studies have identified aspects of the gait cycle which are atypical in children and adults with Developmental Coordination Disorder (DCD), studies have not considered whether this could be explained by asymmetrical gait.

METHOD AND PROCEDURE

The current study included 62 participants with and 62 without DCD (aged 7-34 years). Participants were asked to walk continuously for 1min up and down a walkway while movement was captured using an optical tracking system. Measures of step length and step time were taken for both the right and the left leg and symmetry ratios were calculated.

RESULTS

The DCD group showed significantly higher symmetry ratios for both measures compared to the typically developing (TD) group, with approximately a third of DCD participants falling outside the normative range for symmetry. Furthermore, a relationship was found between movement variability and degree of asymmetry.

CONCLUSIONS

These findings demonstrate an asymmetry in the gait of individuals with DCD which, despite improving with age, does not reach the same level as that shown by TD individuals.

The three-dimensional kinematics and spatiotemporal parameters of gait in 6-10 year old typically developed children in the Cape Metropole of South Africa - a pilot study

Background

Functional gait is an integral part of life, allowing individuals to function within their environment and participate in activities of daily living. Gait assessment forms an essential part of a physical examination and can help screen for physical impairments. No three-dimensional (3D) gait analysis studies of children have been conducted in South Africa. South African gait analysis laboratory protocols and procedures may differ from laboratories in other countries, therefore a South African data base of normative values is required to make a valid assessment of South African children’s gait. The primary aim of this study is to describe joint kinematics and spatiotemporal parameters of gait in South African children to constitute a normative database and secondly to assess if there are age related differences in aforementioned gait parameters.

Methods

A descriptive study was conducted. Twenty-eight typically developing children were conveniently sampled from the Cape Metropole in the Western Cape, South Africa. The 3D lower limb kinematics and spatiotemporal parameters of gait were analyzed. The lower limb Plug-in-Gait (PIG) marker placement was used. Participants walked bare foot at self-selected speed. Means and standard deviations (SD) were calculated for all spatiotemporal and kinematic outcomes. Children were sub-divided into two groups (Group A: 6–8 years and Group B: 9–10 years) for comparison.

Results

A significant difference between the two sub-groups for the normalized mean hip rotation minimum values (p = 0.036) was found. There was no significant difference between the sub-groups for any other kinematic parameter or when comparing the normalized spatiotemporal parameters.

Conclusion

The study’s findings concluded that normalized spatiotemporal parameters are similar between the two age groups and are consistent with the values of children from other countries. The joint kinematic values showed significant differences for hip rotation, indicating that older children had more external rotation than younger children.

Adaptations to walking on an uneven terrain for individuals with and without Developmental Coordination Disorder

Given the importance of walking in everyday life, understanding why this is challenging for some populations is particularly important. Studies focusing on gait patterns of individuals with Developmental Coordination Disorder (DCD) have shown that whilst increased variability is characteristic of walking patterns for this group, differences in spatio-temporal gait variables seem only to arise when task demands increase. However, these differences occur under rather artificial conditions, for example using a treadmill. The aim of this study, therefore was to examine the step characteristics of individuals with and without DCD whilst walking along an irregular terrain. Thirty-five individuals with DCD aged 8-32years and 35 age and gender-matched controls participated in this study. Participants were divided into 3 age groups; 8-12years (n=12), 13-17years (n=12) and 18-32years (n=11). Participants walked up and down a 6m walkway for two minutes on two terrains: level and irregular. VICON 3D motion analysis was used to extract measures of foot placement, velocity and angle of the head and trunk. Results showed that both groups adapted their gait to negotiate the irregular terrain, but the DCD group was more affected than their TD peers; walking significantly slower with shorter, wider steps and inclining their head more towards the ground. This suggests an adaptive approach used by individuals with DCD to preserve stability and increase visual sampling whilst negotiating an irregular terrain.

Walking dynamics in preadolescents with and without Down syndrome

BACKGROUND

A force-driven harmonic oscillator (FDHO) model reveals the elastic property of general muscular activity during walking.

OBJECTIVE

This study aimed to investigate whether children with Down syndrome (DS) have a lower K/G ratio, a primary variable derived from the FDHO model, compared with children with typical development during overground and treadmill walking and whether children with DS can adapt the K/G ratio to walking speeds, external ankle load, and a treadmill setting.

DESIGN

A cross-sectional study design was used that included 26 children with and without DS, aged 7 to 10 years, for overground walking and 20 of them for treadmill walking in a laboratory setting.

METHODS

During overground walking, participants walked at 2 speeds: normal and fastest speed. During treadmill walking, participants walked at 75% and 100% of their preferred overground speed. Two load conditions were manipulated for both overground and treadmill walking: no load and an ankle load that was equal to 2% of body mass on each side.

RESULTS

Children with DS showed a K/G ratio similar to that of their healthy peers and increased this ratio with walking speed regardless of ankle load during overground walking. Children with DS produced a lower K/G ratio at the fast speed of treadmill walking without ankle load, but ankle load helped them produce a K/G ratio similar to that of their healthy peers.

LIMITATIONS

The FDHO model cannot specify what muscles are used or how muscles are coordinated for a given motor task.

CONCLUSIONS

Children with DS show elastic property of general muscular activity similar to their healthy peers during overground walking. External ankle load helps children with DS increase general muscular activity and match their healthy peers while walking fast on a treadmill.

How do i fit through that gap? Navigation through apertures in adults with and without developmental coordination disorder

During everyday life we move around busy environments and encounter a range of obstacles, such as a narrow aperture forcing us to rotate our shoulders in order to pass through. In typically developing individuals the decision to rotate the shoulders is body scaled and this movement adaptation is temporally and spatially tailored to the size of the aperture. This is done effortlessly although it actually involves many complex skills. For individuals with Developmental Coordination Disorder (DCD) moving in a busy environment and negotiating obstacles presents a real challenge which can negatively impact on safety and participation in motor activities in everyday life. However, we have a limited understanding of the nature of the difficulties encountered. Therefore, this current study considered how adults with DCD make action judgements and movement adaptations while navigating apertures. Fifteen adults with DCD and 15 typically developing (TD) controls passed through a series of aperture sizes which were scaled to body size (0.9-2.1 times shoulder width). Spatial and temporal characteristics of movement were collected over the approach phase and while crossing the aperture. The decision to rotate the shoulders was not scaled in the same way for the two groups, with the adults with DCD showing a greater propensity to turn for larger apertures compared to the TD adults when body size alone was accounted for. However, when accounting for degree of lateral trunk movement and variability on the approach, we no longer saw differences between the two groups. In terms of the movement adaptations, the adults with DCD approached an aperture differently when a shoulder rotation was required and then adapted their movement sooner compared to their typical peers. These results point towards an adaptive strategy in adults with DCD which allows them to account for their movement difficulties and avoid collision.

Short-term motor learning of dynamic balance control in children with probable Developmental Coordination Disorder

PURPOSE

To explore the differences in learning a dynamic balance task between children with and without probable Developmental Coordination Disorder (p-DCD) from different cultural backgrounds.

PARTICIPANTS

Twenty-eight Dutch children with DCD (p-DCD-NL), a similar group of 17 South African children (p-DCD-SA) and 21 Dutch typically developing children (TD-NL) participated in the study.

METHODS

All children performed the Wii Fit protocol. The slope of the learning curve was used to estimate motor learning for each group. The protocol was repeated after six weeks. Level of motor skill was assessed with the Movement ABC-2.

RESULTS

No significant difference in motor learning rate was found between p-DCD-NL and p-DCD-SA, but the learning rate of children with p-DCD was slower than the learning rate of TD children. Speed-accuracy trade off, as a way to improve performance by slowing down in the beginning was only seen in the TD children, indicating that TD children and p-DCD children used different strategies. Retention of the level of learned control of the game after six weeks was found in all three groups after six weeks. The learning slope was associated with the level of balance skill for all children. This study provides evidence that children with p-DCD have limitations in motor learning on a complex balance task. In addition, the data do not support the contention that learning in DCD differs depending on cultural background.

Postural Control of Anteroposterior and Mediolateral Sway in Children With Probable Developmental Coordination Disorder

PURPOSE

To examine postural control of anteroposterior (AP) and mediolateral sway of children with probable developmental coordination disorder (pDCD) and children with typical development (TD).

METHODS

Forty-eight children (24 in each group) aged 11 to 12 years performed an aiming task, maintaining a laser beam within targets placed in 2 locations (front/side). Precision was compromised primarily by the control of mediolateral sway for the front target and by the control of AP sway for the side target. The task was performed with large and small targets.

RESULTS

In the side target condition, only (1) the TD group showed reduced AP sway in response to reduced target size, whereas the pDCD group increased AP sway, and (2) aiming performance for reduced target sizes deteriorated to a greater degree in the pDCD group than in the TD group.

CONCLUSION

These findings suggest children with pDCD have specific deficits in controlling AP sway.

The effectiveness of a fundamental motor skill intervention in pre-schoolers with motor problems depends on gender but not environmental context

This study evaluated the effect of a 10-week fundamental motor skill programme in pre-schoolers with motor problems. Alongside the general effect of the intervention, we also explored possible gender differences and the role of the environmental context (living community, socio-economic status, and recreational space inside/outside the house). The intervention group (n=47; 20 ♂ and 27 ♀) received twenty 60-min motor skill sessions (2 per week) in addition to the regular physical education curriculum for pre-schoolers; the control group (n=46; 21 ♂ and 25 ♀) did not receive additional practice. General motor competence, and locomotor and object control subscales, were assessed before and after the intervention using the Test of Gross Motor Development 2nd edition (TGMD-2). Data regarding environmental factors were gathered through a questionnaire. A Group×Gender×Time ANOVA revealed that the intervention group benefited significantly from the intervention and scored better than the control group at the post-test for general motor competence and both sub-categories (locomotor and object control skill). Moreover, the intervention programme was found to be effective in helping 49% of the intervention group to achieve an average motor skill level, according to the TGMD-2 norms, while a further decline in motor competence was observed in the control group. Interestingly, the effect appeared to be gender-specific, since object control skill improved only in girls of the intervention group. Considering the environmental context, none of the above-mentioned factors was found to have an influence on the effectiveness of the intervention. The present study highlights the need for an early motor skill programme with a gender-specific approach in order to help low skilled boys and girls master a diverse set of motor skills.

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.

"The problem with running"--comparing the propulsion strategy of children with developmental coordination disorder and typically developing children

Children with Developmental Coordination Disorder (DCD) often have difficulties running. This study compared strategies of propulsion and power generation at the ankle during late stance/early swing in both walking and running in children with and without DCD. Eleven children (six male) aged nine to 12 years with DCD were matched by sex and age with 11 typically developing (TD) children. Gait kinematics and kinetics were measured during 4 gait types; normal walking, fast walking, jogging and sprinting using three-dimensional motion analysis. Propulsion strategy during gait was calculated as ankle power divided by the sum of ankle and hip power (A2/A2+H3). The children with DCD ran slower than the TD children (mean difference [MD] when jogging 0.3m/s and sprinting 0.8m/s). Adjusting for speed, those with DCD had smaller propulsion strategy values during jogging (p=0.001) and sprinting (p=0.012), explained by reduced ankle power generation at push off (A2) (jogging, MD 2.5 W/kg, p<0.001) and greater hip flexor power generation at pull off (H3) (jogging, MD 0.75 W/kg, p=0.013). Similar findings were observed during sprinting. Children with DCD ran with a slow and less efficient running style compared with TD children. Physiotherapy targeting running-specific needs in relation to ankle muscle strength and coordination could enable more participation in running activities.

A comparison of running kinematics and kinetics in children with and without developmental coordination disorder

The aim of this study was to compare running gait in children with and without developmental coordination disorder (DCD). Fourteen boys with DCD (9.5 ± 1 yr) and 14 typically developing (TD) controls (9.6 ± 1 yr) ran at a velocity of 2.44 ± 0.25 m/s along a 15m track, with kinematic and kinetic data of the trunk and lower limb obtained for three cycles of each limb using a 12-camera Vicon MX system and AMTI force plate. Although features of the kinematic and kinetic trajectories were similar between groups, the DCD group displayed decreased peak knee extension compared with the TD group prior to initial foot contact (p = 0.016). Furthermore, the DCD group displayed increased variability in sagittal plane kinematics at the hip and ankle during toe off compared with the TD group. Kinetic analysis revealed that children with DCD displayed significantly reduced knee extensor moments during the stance phase of the running cycle (p = 0.033). Consequently, peak knee power absorption and ankle power generation was significantly lower in the DCD group (p = 0.041; p = 0.017). Furthermore, there was a trend for children with DCD to have shorter strides (p = 0.052, ES = 0.499) and a longer stance period than the TD controls (p=0.06, ES = 0.729). These differences may have implications for the economy of running and subsequently the planning of targeted intervention programs to improve running gait in children with DCD.

Sensory integration and activities of daily living in children with developmental coordination disorder

Objective

The aim of our study was to evaluate sensory integration and activities of daily living in children with developmental coordination disorder

Subjects and methods

37 cases with developmental coordination disorder and 35 healthy age-matched peers were included in this study. Ayres Southern California Sensory Integration Test was used for evaluating the sensory integration and Functional Independence Measure for Children (WeeFIM) was used for evaluating the activities of daily living.

Results

Significant differences were found in the visual shape perception, position in space, and design copying (p < 0.05). According to the results of somatosensory perception tests, significant differences were found in kinesthesia, manual form perception, finger identification, figure-ground perception, localization of tactile stimuli, double tactile stimuli perception (p < 0.05). Control group was better in motor planning (p < 0.05). Comprehension, expression, social communication, problem solving, and memory skills were significant in favor of the control group (p < 0.05). Graphestesia and self-care domain was found to be correlated (r = 0,491, p = 0.002) between the groups.

Discussion

Special education and rehabilitation programs including sensory integration therapy and motor performance will increase independence in the activities of daily living in children with developmental coordination disorder.

Are spatiotemporal gait characteristics reliable outcome measures in children with developmental coordination disorder?

PURPOSE

To evaluate the reliability of spatiotemporal gait parameters used in the clinical evaluation of children with developmental coordination disorder (DCD).

METHODS

Participants recruited were asked to ambulate across a 4.5-meter GAITRite walkway (CIR Systems, Inc, Havertown, Pennsylvania) at a self-selected walking speed. The spatiotemporal parameters recorded for both limbs were: velocity (cm/sec), stance phase duration (%), swing phase duration (%), stride length (cm), double support duration (%), and single support duration (%).

RESULTS

Intraclass correlation coefficient values attained in this study ranged from 0.24 to 0.73, with good reliability achieved for one parameter (cadence = 0.73), and moderate reliability for step length (0.55-0.58), stride length (0.57-0.61), and double support duration (0.56-0.59).

CONCLUSION

The findings from this study indicate that the clinical evaluation of spatiotemporal gait parameters in children with DCD can yield reliable data for some parameters but further work on this is warranted.

Auditory and visual information do not affect self-paced bilateral finger tapping in children with DCD

Children with Developmental Coordination Disorder (DCD) are more variable in timing their fingers to an external cue. In this study, we investigated the intrinsic coordination properties of self-selected anti-phase finger tapping with and without vision and audition in children with and without DCD and compared their performance to that of adults. Ten children with DCD (Mean age=7.12±0.3 years), 10 age- and sex-matched typically developing (TD) children, and 10 adults participated in this study. Participants tapped their fingers in anti-phase at a self-selected speed under four different sensory conditions: (1) with vision and audition, (2) with vision but no audition, (3) with audition but no vision, and (4) without vision and audition. We assessed intertap interval (ITI), variability of ITI, mean relative phasing (RP) between the fingers and the variability in RP. Children with DCD adopted a similar mean frequency, but were less accurate and more variable than the other groups. The different sensory conditions did not affect performance in any of the groups. We conclude that visual and auditory feedback of tapping are not salient information sources for bilateral self-selected tapping and that children with DCD are intrinsically less accurate and more variable in their tapping frequency and coordination.

Variability in postural control during infancy: implications for development, assessment, and intervention

Variability is commonly considered a key to typical motor development. However, multiple definitions and quantification systems have limited the clinical interpretation of variability and the translation of developmental research to assessment and intervention. The purposes of this perspective article are to highlight the importance of statistical variability and complexity in postural control during development and to describe implications for assessment and intervention during infancy and early childhood. Five tenets are proposed describing the role of variability in postural control to support movement experiences, exploration, and global development. Evidence for assessment and intervention focused on variability in postural control are introduced.

Balance problems during obstacle crossing in children with Developmental Coordination Disorder

The present study investigated the visuomotor and balance limitations during obstacle crossing in typically developing (TD) children and those with Developmental Coordination Disorder (DCD) (7-9 years old; N=12 per group). Spatiotemporal gait parameters as well as range and velocity of the centre of mass (COM) were determined in three conditions: overground walking at a self-selected speed, crossing a low obstacle and crossing a high obstacle (5% or 30% of the leg length, respectively). Both groups walked more slowly during obstacle crossing than walking over level ground. In addition, both groups exhibited a significant decrease in the spatial variability of their foot placements as they approached the obstacle, which was then negotiated with a similar strategy. There were no differences in approach distance, length of lead and trail step, or lead and trail foot elevation. Compared to walking over level ground, obstacle crossing led to a longer swing phase of the lead and trail foot and increased maximal medio-lateral COM velocity. In children with DCD, however, medio-lateral COM velocity was higher and accompanied by significantly greater medio-lateral COM amplitude. In conclusion, the results indicate that while TD-children and those with DCD exhibit satisfactory anticipatory control and adequate visual guidance, the latter group have a reduced ability to control the momentum of the COM when crossing obstacles that impose increased balance demands.

A comparison of the oxygen cost of locomotion in children with and without developmental coordination disorder

AIM

The aim of this study was to compare the oxygen cost (V(O2)) of walking and running, as well as aerobic fitness, in children with and without developmental coordination disorder (DCD).

METHOD

Thirty-one males (17 with DCD and 14 in a comparison group; mean age 8 y 7 mo, SD 1 y 3 mo and 8 y 5 mo, SD 1 y 2 mo respectively) were tested on two separate occasions at least 1 week apart. On the first visit, motor proficiency was assessed by the McCarron Assessment of Neuromuscular Development instrument, which was followed by the determination of maximal aerobic capacity (V(O2max)). The second visit involved 4-minute bouts of treadmill walking (at 4.3 km/h and 5.8 km/h) and running (at 7.8 km/h and 8.4 km/h). Oxygen consumption, heart rate, respiratory exchange ratio, rating of perceived exertion (RPE), step rate, and qualitative assessment of locomotion were obtained for each speed.

RESULTS

Despite poorer locomotion proficiency, there was no significant difference in the oxygen cost of walking or running between males with and without DCD. However, the DCD group had significantly higher RPE while running at 7.8 km/h (p=0.011) and had greater difficulty achieving V(O2max), resulting in significantly lower scores for aerobic fitness.

INTERPRETATION

The differences in locomotion proficiency between children with and without DCD are not large enough to affect the oxygen cost of locomotion. However, children with DCD are more likely to withdraw from exercising at higher intensities before achieving peak performance.

Differences in gait complexity and variability between children with and without developmental coordination disorder

We used elliptical Fourier analysis (EFA) to examine potential differences in the complexity and variability of gait of children with (N=10) and without (N=10) Developmental Coordination Disorder (DCD). Children with DCD generated movement patters with larger variability and complexity than typically developing (TD) children. In addition, children with DCD exhibited greater asymmetry in their movement patterns compared to TD children. Our results suggest that children with DCD have significantly greater difficulty producing consistent movement patterns both across their left and right legs and over repeated strides. EFA techniques show promise for distinguishing between different groups of individuals.

Visual contribution to walking in children with Developmental Coordination Disorder

BACKGROUND

The motor co-ordination problems of children with Developmental Coordination Disorder (DCD) have been frequently associated with poor visuospatial processing. In order to extend these findings mainly based on fine motor experiments, the present study investigates the contribution of vision to the control of walking in children with DCD.

METHODS

Children with DCD (n = 12) walked at their preferred speed on a straight, firm and uncluttered walkway in a condition with normal lighting and in a dark condition. Spatiotemporal gait variables were assessed by means of a three-dimensional ProReflex camera system and compared with the gait pattern of matched, typically developing (TD) children (n = 12).

RESULTS

In normal lighting, the gait pattern of both groups was similar, with the exception of subtle differences in the temporal phasing, showing a slightly longer support phase in the children with DCD. In the dark, step frequency and step length were decreased in the children with DCD, resulting in a significantly slower walking velocity. In addition, the medio-lateral excursion of the centre of mass tended to increase in this group. In the TD children, adaptations to the spatiotemporal pattern remained absent.

CONCLUSIONS

These results suggest that children with DCD are more dependent on global visual flow information than TD children for the maintenance of balance and the control of velocity during walking. This increased dependency on visual control might be associated with a poorly developed internal sensorimotor model.