The evidence ratio is based on the analysis of the following four studies.
In a RCT study by Sit et al. «Sit CH, Yu JJ, Wong SH, ym. A school-based physica...»1 participants were 127 children (DCD N = 69; typically developing, TD N = 62) from Hong Kong with normal or appropriately corrected visual acuity and no neurological or intellectual impairments or medical conditions that limited participation. The sample size achieved 90% power with p level of .05 and with an effect size of 0.40. Children were 6–10 years old. DCD was identified by using MABC-2 (cut off: 5%) and verified by teachers' (MABC-2 Checklist) and / or parents' (Caregiver Assessment of Movement Participation). Participants were randomly allocated to experimental (multi-skills fundamental motor skill training, FMS) and age matched control groups (conventional physical education lessons, C). The final grouping consisted of four groups: DCD-FMS (N = 35: boys = 25), TD-FMS (N = 29: boys = 17), DCD-C (N = 34: boys = 22), and TD-C (N = 33: boys = 18).
The intervention period was 8 weeks, 40 minutes per week during physical education (PE) classes in schools. FMS training focused on practice of running, jumping, catching, kicking, and throwing. The aim of the motor learning was to reduce the occurrence of errors during practice by progressively increasing the difficulty either increasing the distance (jumping, catching, kicking and, throwing) or adjusting the size and weight of objects (jumping, catching, kicking, and throwing). The control group had conventional PE lessons.
Outcome measures were gross motor skills (locomotor: running & jumping; object control: catching, kicking & throwing, Test of Gross Motor Development-2), physical activity (PA; three levels: sedentary, light PA and moderate-to-vigorous PA; ActiGraph accelerometer), perceived competence in PA (Physical Self-Descriptive Questionnaire), and enjoyment and participation during leisure time (recreational, physical, social, skill-based, and self-improvement activities, (Children's Assessment of Participation and Enjoyment). Age, sex, and BMI was used as confounders.
The general linear mixed method analysis revealed that both FMS-intervention and conventional PE improved motor skills and PA among children with TD and DCD. However, among children with DCD the FMS intervention impacted for greater enjoyment of physical leisure time immediately (mean coefficient, B = 0.514, p < .05), 3 months (B = 0.583, p < .05), and 12 months (B = 0.837, p < .01) after intervention compared to baseline. B-value indicates how big the difference is in units between the baseline and comparison time point. Further, among children with DCD the conventional PE lessons impacted for greater improvement in jumping (B = 0.890, p < .05) and throwing (B = 1.280, p < .05). Also amount of moderate to vigorous physical activity was greater during weekdays (B = 1.213, p < .05) in post assessment compared to baseline. No significant effects were found on self-perceived competence.
In a RCT study conducted in Australia by Ward et al. «Ward EJ, Hillier S, Raynor A, ym. A Range of Servi...»3 the aim was to investigate whether the environment and personnel providing intervention to children with developmental coordination disorder make a difference in motor outcomes and perceived competency. Participants were 93 children (66 male) aged 5 to 9 years of age (mean age 6 y 5 mo; SD 12 mo), meeting the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Revised (DSM-IV-TR) criteria of DCD. Participants with DCD were randomized to receive a 13-week group-based task-oriented intervention.
The 3 modes of delivery in this stratified cluster randomized trial were: 1) in school (participant's own school) with a school assistant (SA) (N=37), 2) in school (participant's own school) with a physical therapist (N=30), or 3) in a clinic with a physical therapist (N=26). Sample size calculations determined 26 children in each mode of delivery were required for 80% power, with an α level of 0.05 based on a 6.5-point change in MABC score.
Intervention was delivered in groups of 4 to 6 children, with a ratio of 1 staff to 3 children. The sessions lasted 60 minutes and occurred once a week. An example of an intervention session plan included a fine motor warm-up (e.g., play-dough activity), fine motor activity (e.g., an animal collage, including cutting, pasting, and scrunching paper), body awareness activity (e.g., animal walks), a gross motor warm-up (e.g., pulling along while prone on scooter board), and a gross motor circuit or skills practice (e.g., task-specific training of fundamental motor skills).
The primary outcome measure was motor skills assessed with the Movement Assessment Battery for Children (MABC) test, which has both the ability to identify motor difficulties and assess changes in motor abilities over time. The 15th percentile was chosen as a cut-off. Secondary outcome measures were The Test of Gross Motor Development, 2nd edition (TGMD-2), which was used to complement the results of the MABC, as it assesses the quality of gross motor movements (locomotor and object control skills) and The Pictorial Scale of Perceived Competence and Social Acceptance (PSPCSA) to gain information about the child's self-competence.
Motor skills were assessed 2 weeks before the intervention, immediately postintervention, and 6 months after the intervention. The motor outcomes and self-perception data were analyzed using a mixed model with time and group as fixed effects and participants as random effects. Effect size (Cohen's d) was calculated using the total raw scores, comparing preintervention and 6 months postintervention scores. Participants demonstrated a significant improvement in motor skills following intervention for all modes of delivery up to 6 months postintervention, MABC mean difference 7.20 (95% confidence interval, 5.89-8.81), effect size = 0.98; TGMD-2 effect size = 1.37. There was no-group effect (P = .09) between modes of intervention. Results also support a significant improvement (F2,173.18 = 2.72, P = .01) for perceived physical competence over time following intervention, effect size = 0.73, but no significant group effect (P = .62).
Group intervention programs for DCD can be run by a school assistant supported by a physical therapist and provide successful outcome.
The study by Yu et al. «Yu JJ, Burnett AF, Sit CH. Motor Skill Interventio...»4 aimed to determine the characteristics and effectiveness of motor skill interventions in children with developmental coordination disorder (DCD) and to identify potential moderators of training effects using meta-analysis.
CINAHL Plus, Cochrane Library, Embase, ERIC, PsycINFO, and PubMed databases were searched for articles published between 1995 and August 2017. Studies were included if they recruited children 3 to 17 years of age with DCD, reported performance of motor-related skills as outcomes, were published in peer-reviewed journals, and were written in English. DCD was defined either according to the criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition or as motor impairments evident using standardized motor tests with the 15th or lower percentile as a cutoff point. Quantitative synthesis was only conducted for studies using a (quasi) randomized controlled trial design.
Sixty-six studies met the inclusion criteria with 18 of the studies eligible for meta-analysis. Motor performance and cognitive, emotional, and other psychological factors were the most common outcomes. Other 3 outcome categories included perceptions and/or satisfaction regarding the children's improvement from significant others, physical fitness, and physical activity and participation. Of all studies 27 were implemented in a school setting and of which 11 studies were conducted a quantitative analysis. The included 11 studies were conducted in Australia, Canada, Hong Kong, Iran, South Africa, Sweden and Taiwan. The age range in the selected studies was 5-12 years. Moderator analyses for motor performance at posttest: school setting: g=0.82 (Hedges g value), 0.35 to 1.30 95% CI, p=.001, Q=3.48 (Q statistic value), p=.176.
Studies that were conducted in schools, used a combined process- and task-oriented approach, involved treatment lasting for at least 9 weeks, and had high methodologic quality yielding an effect size that was large and significantly different from zero. In addition, regardless of other intervention components (e.g., duration of each session, total number of sessions), training programs with more frequent practicing schedules (e.g., 4-5 times per week) significantly increased the training effects on motor performance.
Two reviewers independently assessed the risk of bias in studies included in the meta-analysis using a short scale of 6 criteria established by the Cochrane Collaboration. However, the pooled effect sizes were not weighted on the risk of the bias level of studies.
General comments: As these interventions were conducted in a natural school context, only single blinding was possible, which was not conducted in all studies either. Two other studies «Männistö, J-P., Cantell, M., Huovinen, T ym. A sch...»5, «Ericsson, I. Effects of increased physical activit...»6, conducted in Nordic countries (Finland and Sweden), were not included in this evidence summary, since they included children with not diagnosed DCD. Furthermore, the Finnish study by Männistö et al. «Yu JJ, Burnett AF, Sit CH. Motor Skill Interventio...»4, reported the results of per protocol analysis only.