Risk factors in early life for developmental coordination disorder: a scoping review.

AIM: To perform a scoping literature review of associations between risk factors in early life and developmental coordination disorder (DCD). METHOD: PubMed, Embase, CINAHL, PsycINFO, and Web of Science (January 1994-March 2019) were searched to identify studies on early risk factors and motor impairment or DCD. The effect of single and multiple risk factors was assessed. Level of evidence was evaluated following the Centre for Evidence-Based Medicine guidelines. Meta-analysis on the effect of preterm birth was performed. RESULTS: Thirty-six studies fulfilled inclusion criteria; 35 had evidence level 3, one had level 4. Highest evidence was available that preterm birth and male sex in term-born children were associated with DCD. The odds ratio of preterm birth was 2.02 (95% confidence interval: 1.43-2.85). Low to moderate evidence was available that parental subfertility, maternal smoking during pregnancy, postnatal corticosteroid treatment in infants born preterm, extra corporeal membrane oxygenation, retinopathy of prematurity, abnormalities on magnetic resonance imaging scans at term age, and accumulating perinatal or neonatal risk factors were associated with motor impairment. INTERPRETATION: Limited information on early risk factors of DCD is available. Only preterm birth and male sex were consistently associated with an increased risk of DCD. WHAT THIS PAPER ADDS: Preterm birth is a risk factor for developmental coordination disorder (DCD). In term-born children, male sex was consistently associated with DCD. Risk factors for DCD are similar to risk factors for cerebral palsy.

Effects of forward tilted seating and foot-support on postural adjustments in children with spastic cerebral palsy: An EMG-study.

OBJECTIVE: To evaluate the effect of 15° forward (FW) seat inclination and foot-support in children with cerebral palsy (CP) on postural adjustments during reaching. DESIGN: Observational study repeated-measures design; step two of two-step-project. SETTING: Laboratory unit within University Hospital and two special education schools. PARTICIPANTS: 19 children (ten unilateral spastic CP (US-CP); nine bilateral spastic CP (BS-CP); Gross Motor Function Classification System levels I-III; 6-12 years old). Participants were able to take part for one one-hour session. INTERVENTION: Reaching while sitting in four seating conditions (FW or horizontal seat; with or without foot-support) applied in randomized order. OUTCOME MEASURES: Simultaneously, surface electromyography (EMG) of neck, trunk and arm muscles and kinematics of head and reaching arm (step one of two-step-project) were recorded. Primary outcome parameters were the ability to modulate EMG-amplitudes at baseline and during reaching (phasic muscle activity). Other EMG-parameters were direction-specificity (1st control level), and 2nd level of control parameters: recruitment order, and anticipatory postural activity. Motor behaviour measures: ability to modulate EMG-amplitudes to kinematic characteristics of reaching and head stability. RESULTS: Only foot-support was associated with increased tonic background EMG-amplitudes and decreased phasic EMG-amplitudes of the trunk extensors in children with US-CP and BS-CP (mixed-models analyses; p-values <0.01). The foot-support effect was also associated with better kinematics of reaching (Spearman's Rho; p-values <0.01). CONCLUSION: In terms of postural adjustments during forward reaching, foot-support enhanced the children's capacity to modulate trunk extensor activity, which was associated with improved reaching quality. FW-tilting did not affect postural muscle activity.

Variability in coordination patterns in children with developmental coordination disorder (DCD).

High motor variability is an often-found characteristic of Developmental Coordination Disorder (DCD). Still, the role of high motor variability in DCD needs further examination. This study focused on variability in coordination patterns, which is essential considering that DCD is a coordination disorder. We examined variability in coordination patterns of the arm over repetitions of trials in goal-directed reaching movements. This variability was partitioned into variability that does not affect the index fingertip position (Vucm) and variability that does affect the index fingertip position (Vort). This study aimed to increase the understanding of motor variability in DCD by comparing Vucm and Vort between children with DCD and typically developing (TD) children in a goal-directed reaching task. Twenty-two children (eleven with DCD) ages 6-11 performed 30 reaching movements. The Uncontrolled Manifold method was used to quantify Vucm and Vort. Results showed that children with DCD had more Vucm than TD children while Vort was similar between groups, showing that coordination patterns in children with DCD are more variable, but interestingly, this higher variability does not affect performance. This study indicates that high motor variability in DCD is not necessarily negative. Possible roles of motor variability in DCD are discussed.

Best seating condition in children with spastic cerebral palsy: One type does not fit all.

BACKGROUND: The effect of forward-tilting of the seat surface and foot-support in children with spastic cerebral palsy (CP) is debated. AIM: To assess the effect of forward-tilting of the seat surface and foot-support in children with CP on kinematic head stability and reaching. METHODS: Nineteen children functioning at Gross Motor Function Classification System levels I-III participated [range 6-12y; ten unilateral spastic CP (US-CP) and nine bilateral spastic CP (BS-CP)]. Kinematic data were recorded of head sway and reaching with the dominant arm in four sitting conditions: a horizontal and a 15° forward (FW) tilted seat surface, each with and without foot-support. RESULTS: Seating condition did not affect head stability during reaching, but did affect kinematic reaching quality. The major reaching parameters, i.e., the proportion of reaches with one movement unit (MU) and the size of the transport MU, were not affected by foot-support. Forward-tilting had a positive effect on these parameters in children with US-CP, whereas the horizontal condition had this effect in children with BS-CP. IMPLICATIONS: A 15° forward-tilted seating and foot-support do not affect head stability. Reaching in children with US-CP profits from forward-tilting; in children with BS-CP forward-tilting worsens reaching - effects that are independent of foot-support.

Neural correlates of paediatric dysgraphia.

Writing is an important skill that is related both to school performance and to psychosocial outcomes such as the child's self-esteem. Deficits in handwriting performance are frequently encountered in children with developmental coordination disorder. This review focuses on what is known about the neural correlates of atypical handwriting in children. Knowledge of the neural correlates is derived from studies using clinical case designs (e.g. lesion studies), studies using neuroimaging, and assessment of minor neurological dysfunction. The two functional imaging studies suggest a contribution of cortical areas and the cerebellum. The largest study indicated that cortical areas in all regions of the brain are involved (frontal, temporal, parietal, and occipital). The two lesion studies confirmed cerebellar involvement. The findings of the study on minor neurological dysfunction in children with writing problems correspond to the imaging results. The limited data on the neural substrate of paediatric dysgraphia suggest that at least a subset of the children with dysgraphia have dysfunctions in extensive supraspinal networks. In others, dysfunction may be restricted to either the cerebellum or specific cortical sites.

Handwriting, visuomotor integration, and neurological condition at school age.

AIM: the study investigated the relationships between handwriting, visuomotor integration, and neurological condition. We paid particular attention to the presence of minor neurological dysfunction (MND). METHOD: participants were 200 children (131 males, 69 females; age range 8-13y) of whom 118 received mainstream education (mean age 10y 5mo, SD 1y 4mo) and 82 special education (mean age 10y 8mo, SD 1y 2mo). Each child had four assessments: a neurological examination, which paid attention to the type and severity of MND, a test to measure motor performance, a handwriting test, and the Developmental Test of Visual Motor Integration. RESULTS: dysgraphic handwriting and slow writing speed were closely related to the severity of neurological dysfunction (both p<0.001); impaired visuomotor integration was related to the presence of MND (p<0.001) but somewhat less to its severity. Impaired handwriting and visuomotor integration were strongly related to two specific dysfunctions: fine manipulative disability and coordination problems (both p<0.001). Impaired visuomotor integration was weakly related to dysfunctional muscle tone regulation (p=0.009) and sensory dysfunction (p=0.042). INTERPRETATION: poor handwriting and impaired visuomotor integration are related to MND, but in a differential way. Poor handwriting is related to the severity of neurological dysfunction and to dysfunctions of complex supraspinal circuitries. Impaired visuomotor integration is associated with the presence of any of the most common types of MND.

Test-retest and inter- and intrareliability of the quality of the upper-extremity skills test in preschool-age children with cerebral palsy.

OBJECTIVE: To investigate the test-retest, inter-, and intraobserver reliability of the Quality of Upper Extremity Skills Test (QUEST) in young children with cerebral palsy (CP). DESIGN: For test-retest reliability, a test-retest design was used; for the intra- and interobserver reliability, the videotaped test was scored on 2 occasions by 1 observer and by various observers. SETTING: Groups of preschool-age children in 2 general rehabilitation centers. PARTICIPANTS: Twenty-one children with CP (12 boys, 9 girls) aged 2 to 4.5 years (mean, 39 mo). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Spearman correlation coefficient. RESULTS: The data indicated that test-retest reliability was strong (rho range, .85-.94). Intraobserver agreement (rho range, .63-.95) and agreement between various observers (rho range, .72-.90) were moderate to strong. CONCLUSIONS: Test-retest and inter- and intraobserver reliability of the QUEST in preschool-age children with CP is good.