A Video-Based Classification System for Assessing Locomotor Skills in Children.

The Test of Gross Motor Development 2 (TGMD-2) is currently the standard approach for assessing fundamental movement skills (FMS), including locomotor and object control skills. However, its extensive application is restricted by its low efficiency and requirement of expert training for large-scale evaluations. This study evaluated the accuracy of a newly-developed video-based classification system (VCS) with a marker-less sensor to assess children's locomotor skills. A total of 203 typically-developing children aged three to eight years executed six locomotor skills, following the TGMD-2 guidelines. A Kinect v2 sensor was used to capture their activities, and videos were recorded for further evaluation by a trained rater. A series of computational-kinematic-based algorithms was developed for instant performance rating. The VCS exhibited moderate-to-very good levels of agreement with the rater, ranging from 66.1% to 87.5%, for each skill, and 72.4% for descriptive ratings. Paired t-test revealed that there were no significant differences, but significant positive correlation, between the standard scores determined by the two approaches. Tukey mean difference plot suggested there was no bias, with a mean difference (SD) of -0.16 (1.8) and respective 95% confidence interval of 3.5. The kappa agreement for the descriptive ratings between the two approaches was found to be moderate (k = 0.54, p < 0.01). Overall, the results suggest the VCS could potentially be an alternative to the conventional TGMD-2 assessment approach for assessing children's locomotor skills without the necessity of the presence of an experienced rater for the administration.

Cross-Cultural Validity: Canadian Norm Values of the Alberta Infant Motor Scale Evaluated for Dutch Infants.

PURPOSE: To examine whether the Canadian normative values of the Alberta Infant Motor Scale (AIMS) are appropriate for Dutch infants. METHOD: In a cross-sectional study, 499 infants developing typically (0.5-19 months) were assessed using the AIMS home video method. The scaling method was used for calculating item locations of the Dutch sample, and Welch test to compare Canadian and Dutch raw scores. RESULTS: THE: AIMS items (45 of 58) met the criterion for stable regression to calculate item locations of the Dutch data set and compare these with the Canadian data set. Dutch infants passed 42 of 45 items at an older age. Most monthly age groups of Dutch infants had lower mean AIMS scores. CONCLUSION: The Canadian norms are not appropriate for the Dutch study sample. Dutch infants appear to develop in a similar sequence but at a slower rate. This has implications regarding the clinical use of the AIMS in the Netherlands.

Predictors of childhood trajectories of overt and indirect aggression: An interdisciplinary approach.

The aim of this study was to advance our understanding of the development of aggression in boys and girls by testing a model combining insights from both evolutionary theory and developmental psychology. A sample of 744 children (348 girls) between six and 13 years old was recruited in schools with high deprivation indices. Half of the sample (N = 372; 40.1% girls) had received special educational services for behavioral and/or socio-emotional problems. Two trajectories for overt aggression and two trajectories for indirect aggression were identified and binomial logistic regressions were used to identify environmental predictors and sex-specific patterns of these trajectories. Results indicated that peer rejection predicted overt aggression and indirect aggression and that extraversion and male sex predicted overt aggression. The results also showed that interaction between parental practices and some child temperament traits predicted overt aggression (coercion and lack of supervision associated with extraversion or low effortful control) or indirect aggression (coercion and neglect associated with negative affect or low effortful control), and the absence of a father figure predicted high indirect aggression in girls.

The value of Gesell score in predicting the outcome of cochlear implantation in children.

The purpose is to determine the value of preoperative evaluation on developmental levels using Gesell score in predicting the postoperative outcome in pediatric cochlear implantation (CI) recipients. 78 children who underwent CI were included in our study. Age at the time of CI ranged from 6 to 67 months. The Gesell score including adaptability, fine motor, gross motor, language, and social skill was used for evaluating the patients' developmental levels before the CI, and a developmental quotient (DQ) was calculated by the following formula: (developmental age/actual age) × 100. The auditory perception and speech production abilities were evaluated using the categories of auditory performance (CAP) and speech intelligibility rating (SIR) before CI and at 1 year after CI. The associations between the preoperative Gesell score/DQ and the improvement of postoperative CAP/SIR outcomes were analyzed. Preoperative developmental evaluation of CI candidates suggested that the developmental delay was common in children with profound hearing loss. The mean of language DQ (46.72 ± 17.59) was significantly decreased than the mean of others' ability DQ in the enrolled children. The older the pediatric CI candidates were, the lower the DQ were. Age/adaptability DQ and improvement of postoperative CAP/SIR 1 year after CI were related. Age was negative correlation with the CI outcome and adaptability DQ was positive correlation with the CI outcome. The mean of CAP 1 year after CI was 4.16, and the mean of SIR 1 year after CI was 2.03. The first logistics regression equation was Y1 = exp (-18.123 + 0.199 × adaptability DQ - 0.163 × age), and Y1 was the possibility which CAP was lower than 5 1 year after CI. The sensitivity of first regression equation was 84.2% and specificity was 70.8%. The second logistics regression equation was Y2 = exp (-23.347 + 0.268 × adaptability DQ - 0.164 × age), and Y2 was the possibility which SIR was lower than 3 1 year after CI. The sensitivity of second regression equation was 85.7% and specificity was 72.7%. Preoperative Gesell score may be value in predicting the postoperative outcome in pediatric CI recipients. The older children are more serious developmental delay occur, so the CI operation should be finished as early as possible. Adaptability DQ combined with age has predictive effect on the postoperative outcome of cochlear implantation in children.

Language profiles and literacy outcomes of children with resolving, emerging, or persisting language impairments.

BACKGROUND: Children with language impairment (LI) show heterogeneity in development. We tracked children from pre-school to middle childhood to characterize three developmental trajectories: resolving, persisting and emerging LI. METHODS: We analyzed data from children identified as having preschool LI, or being at family risk of dyslexia, together with typically developing controls at three time points: t1 (age 3;09), t3 (5;08) and t5 (8;01). Language measures are reported at t1, t3 and t5, and literacy abilities at t3 and t5. A research diagnosis of LI (irrespective of recruitment group) was validated at t1 by a composite language score derived from measures of receptive and expressive grammar and vocabulary; a score falling 1SD below the mean of the typical language group on comparable measures at t3 and t5 was used to determine whether a child had LI at later time points and then to classify LIs as resolving, persisting or emerging. RESULTS: Persisting preschool LIs were more severe and pervasive than resolving LIs. Language and literacy outcomes were relatively poor for those with persisting LI, and relatively good for those with resolving LI. A significant proportion of children with average language abilities in preschool had LIs that emerged in middle childhood - a high proportion of these children were at family risk of dyslexia. There were more boys in the persisting and resolving LI groups. Children with early LIs which resolved by the start of formal literacy instruction tended to have good literacy outcomes; children with late-emerging difficulties that persisted developed reading difficulties. CONCLUSIONS: Children with late-emerging LI are relatively common and are hard to detect in the preschool years. Our findings show that children whose LIs persist to the point of formal literacy instruction frequently experience reading difficulties.

Impact of torticollis associated with plagiocephaly on infants' motor development.

OBJECTIVE: This study investigated whether torticollis (congenital or acquired) in infants with plagiocephaly affects the achievement of specific gross motor milestones. METHODS: A total of 175 infants affected by plagiocephaly with or without torticollis were recruited and included in this prospective trial. Anthropometric and clinical variables were recorded at baseline. The infants were included in a physiotherapy treatment program, and they were monthly assessed until hospital discharge. RESULTS: Significant differences (P < 0.05) were observed in the achievement of rolling over, crawling, and standing skills depending on the specific profile (plagiocephaly and plagiocephaly with congenital or acquired torticollis). After adjusting for the severity of the plagiocephaly and the age at referral, the torticollis was significantly (P < 0.05) associated with crawling and standing skills. CONCLUSIONS: The findings suggest that the presence or absence of congenital or acquired torticollis is an important factor that affects gross motor development in infants with plagiocephaly.

The MAL-ED cohort study: methods and lessons learned when assessing early child development and caregiving mediators in infants and young children in 8 low- and middle-income countries.

More epidemiological data are needed on risk and protective factors for child development. In The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) cohort study, we assessed child development in a harmonious manner across 8 sites in Bangladesh, Brazil, India, Nepal, Pakistan, Peru, South Africa, and Tanzania. From birth to 24 months, development and language acquisition were assessed via the Bayley Scales of Infant and Toddler Development and a modified MacArthur Communicative Development Inventory. Other measures were infant temperament, the child's environment, maternal psychological adjustment, and maternal reasoning abilities. We developed standard operating procedures and used multiple techniques to ensure appropriate adaptation and quality assurance across the sites. Test adaptation required significant time and human resources but is essential for data quality; funders should support this step in future studies. At the end of this study, we will have a portfolio of culturally adapted instruments for child development studies with examination of psychometric properties of each tool used.

Early-life predictors of internalizing symptom trajectories in Canadian children.

BACKGROUND: Previous research examining the development of anxious and depressive symptoms (i.e., internalizing symptoms) from childhood to adolescence has often assumed that trajectories of these symptoms do not vary across individuals. The purpose of this study was to identify distinct trajectories of internalizing symptoms from childhood to adolescence, and to identify risk factors for membership in these trajectory groups. In particular, we sought to identify risk factors associated with early appearing (i.e., child onset) symptoms versus symptoms that increase in adolescence (i.e., adolescent onset). METHOD: Drawing on longitudinal data from the National Longitudinal Survey of Children and Youth, latent class growth modeling (LCGM) was used to identify distinct trajectories of internalizing symptoms for 6,337 individuals, from age 4-5 to 14-15. Multinomial regression was used to examine potential early-life risk factors for membership in a particular trajectory group. RESULTS: Five trajectories were identified as follows: "low stable" (68%; reference group), "adolescent onset" (10%), "moderate stable" (12%), "high childhood" (6%), and "high stable" (4%). Membership in the "adolescent onset" group was predicted by child gender (greater odds for girls), stressful life events, hostile parenting, aggression, and hyperactivity. Membership in the "high stable" and "high childhood" trajectory groups (i.e., child-onset) was additionally predicted by maternal depression, family dysfunction, and difficult temperament. Also, several significant gender interactions were observed. CONCLUSIONS: Causal mechanisms for child and adolescent depression and anxiety may differ according to time of onset, as well as child gender. Some early factors may put girls at greater risk for internalizing problems than boys.

Validating a developmental scale for young children using the Rasch model: applicability of the teaching strategies GOLD assessment system.

This article reports the results of an application of the Rasch rating scale model to the Teaching Strategies GOLD assessment system in a norm sample of children aged birth to 71 months. The analyses focused on the examination of dimensionality, rating scale effectiveness, the hierarchy of item difficulties, and the relationship of developmental scale scores to child age. Results show that each subscale satisfies the Rasch model for unidimensionality. Ratings were found to be less reliable at the lowest and highest ends of the scale and less distinct at 'In-between' levels. Items appear to form theoretically expected hierarchies, supporting evidence for construct validity for the measures. Moderately high correlations of developmental scale scores with child age suggest that teachers are able to make valid ratings of the developmental progress of children across the intended age range.

Latent class analysis reveals five homogeneous behavioural and developmental profiles in a large Dutch population sample of infants aged 14-15 months.

Precursors of child psychiatric disorders are often present in infancy, but little is known about the prevalence and course of general psychopathology in population-based samples of children 0-3 years. We examined whether homogeneous behavioural and developmental profiles could be identified in children aged 14-15 months (M = 14.84; SD = 2.19), and we explored whether or not these profiles corresponded with existing classifications of DSM-IV-TR, ICD-10, and DC 0-3R. Parents of 6,330 children answered 74 items about externalizing, internalizing, and social-communicative behaviour. Exploratory factor analysis revealed nine factors: deviant communication, negative emotionality, deviant reactive behaviour, deviant play behaviour, demanding behaviour, social anxiety/inhibition, advanced social interaction problems, basic social interaction problems, and sleep problems. Latent class analysis yielded five profiles, of which three were associated with increased behavioural and developmental problems. Some infants (5.7 %) had communication and social interaction problems corresponding to multisystem developmental disorders (DC 0-3R) and suggestive of anxiety, mood, or pervasive developmental disorders (DSM-IV-TR, ICD-10). Other infants (16.4 %) had communication problems, possibly precursors of communication, language, or speech disorders (DSM-IV-TR, ICD-10). Yet other infants (10.8 %) showed negative and demanding behaviour suggestive of regulation disorders (DC 0-3R), attention-deficit and disruptive behaviour disorders (DSM-IV-TR), or hyperkinetic and conduct disorders (ICD-10). Thus, even in infancy certain distinct behavioural and developmental profiles can be recognized. This combined approach will enable follow-up research into the stability of factors, classes, and profiles over time, and will facilitate early detection, diagnosis, and treatment of behavioural and developmental problems.

Childhood trajectories of anxiousness and disruptiveness explain the association between early-life adversity and attempted suicide.

BACKGROUND: Suicidal behavior is frequently associated with a history of childhood abuse yet it remains unclear precisely how early life adversity may increase suicide risk later in life. As such, our aim was to examine whether lifetime trajectories of disruptiveness and anxiousness trait dysregulation explain the association between childhood adversity and suicidal behavior; and moreover, to test the potential modifying effects of mental disorders on these associations. METHOD: A sample of 1776 individuals from a prospective school-based cohort followed longitudinally for over 22 years was investigated. We tested the influence of disruptiveness and anxiousness trajectories from age 6 to 12 years on the association between childhood adversity (i.e. sexual and physical abuse) and history of suicide attempts (SA) using logistic regression models. Both adolescent externalizing and internalizing Axis I disorders and gender were tested as potential modifiers of these associations. RESULTS: Four distinct longitudinal trajectories were identified for both disruptiveness and anxiousness. The high disruptiveness trajectory accounted for the association between childhood adversity and SA, but only for females. The high anxiousness trajectory also explained the association between adversity and SA; however, in this case it was not sex but mental disorders that influenced the potency of the mediating effect. More specifically, anxiousness fully explained the effect of adversity on SA in the presence of externalizing disorders, whereas in the absence of these disorders, this effect was significantly attenuated. CONCLUSIONS: This study provides evidence that both disruptiveness and anxiousness play an important role in explaining the relationship between childhood adversity and SA.

CUE: the continuous unified electronic diary method.

In the present article, we introduce the continuous unified electronic (CUE) diary method, a longitudinal, event-based, electronic parent report method that allows real-time recording of infant and child behavior in natural contexts. Thirty-nine expectant mothers were trained to identify and record target behaviors into programmed handheld computers. From birth to 18 months, maternal reporters recorded the initial, second, and third occurrences of seven target motor behaviors: palmar grasp, rolls from side to back, reaching when sitting, pincer grip, crawling, walking, and climbing stairs. Compliance was assessed as two valid entries per behavior: 97 % of maternal reporters met compliance criteria. Reliability was assessed by comparing diary entries with researcher assessments for three of the motor behaviors: palmar grasp, pincer grip and walking. A total of 81 % of maternal reporters met reliability criteria. For those three target behaviors, age of emergence was compared across data from the CUE diary method and researcher assessments. The CUE diary method was found to detect behaviors earlier and with greater sensitivity to individual differences. The CUE diary method is shown to be a reliable methodological tool for studying processes of change in human development.

Review Article: Mapping of children's health and development data on population level using the classification system ICF-CY.

AIM: The aim of this study was to investigate if essential health and development data of all children in Sweden in the Child Health Service (CHS) and School Health Service (SHS) can be linked to the classification system International Classification of Functioning, Disability and Health--Children and Youth (ICF-CY). METHOD: Lists of essential health terms, compiled by professionals from CHS and SHS, expected to be used in the national standardised records form the basis for the analysis in this study. The essential health terms have been linked to the codes of ICF-CY by using linking rules and a verification procedure. RESULTS: After exclusion of terms not directly describing children's health, a majority of the health terms could be linked into the ICF-CY with a high proportion of terms in body functions and a lower proportion in activity/participation and environment respectively. Some health terms had broad description and were linked to several ICF-CY codes. The precision of the health terms was at a medium level of detail. CONCLUSION: ICF-CY can be useful as a tool for documenting child health. It provides not only a code useful for statistical purposes but also a language useful for the CHS and SHS in their work on individual as well as population levels. It was noted that the health terms used by services mainly focused on health related to body function. This indicates that more focus is needed on health data related to child's functioning in everyday life situations.

A description of adaptive and maladaptive behaviour in children and adolescents with Cri-du-chat syndrome.

BACKGROUND: Psychological tests can be useful to record adaptive and maladaptive behaviours of children with intellectual disability. The objective of this study was to describe the adaptive and maladaptive behaviour of children and adolescents with Cri-du-chat syndrome. METHODS: The sample consisted of 10 children and adolescents with Cri-du-chat syndrome (mean chronological age=11.3 years, mean mental age=18 months). The developmental quotient was calculated through the Psychoeducational Profile - Revised. An observational protocol was used to record adaptive and maladaptive behaviours. RESULTS: The number of maladaptive behaviours observed was different among participants. However, all of them had high rates of adaptive behaviours, such as rule-following. CONCLUSIONS: These results, though preliminary, justify that we continue to think about the need for psychoeducational interventions aimed at stimulating the repertoire of adaptive behaviours, in people with Cri-du-chat syndrome.

The temporal relation between regression and transition periods in early infancy.

According to the literature about developmental changes, periods of instability and disorganization in the social and emotional behavior in both human and non-human primate, infancy precedes major developmental achievements or transitions (Heimann, 2003; Sparrow & Brazelton, 2006). Developmental investigators have observed a more frequent and prolonged crying, clinging and bids for physical contact with mother during these periods of instability and disorganization. Some authors, according to Horwich (1974), called these periods regression periods. Rijt-Plooij and Plooij (1992) claimed that 10 regression periods could be identified during the first 20 months of human life. In an early study, Sadurní and Rostan (2002) confirmed the presence of 8 such regression periods during the first year of life of 18 Catalan babies. Their 8 regression periods were comparable to the first 8 of the 10 regression periods found by Van de Rijt Plooij and Plooij. The aim of the present study is to see whether the regression periods that we found are temporally related to some transition. We define a transition as the occurrence of a new developmental change in a child. In the present study we have used non-analyzed data from the same 18 Catalan babies (10 boys and 8 girls) as mentioned in our earlier published study on regression periods. The age of these babies was between 3 weeks and 14 months. Using a microgenetic methodology we have found 8 transitions periods in the first year of life. We have also observed a temporal relation between the regressions periods found earlier and the transition periods reported here.

Free-living Evaluation of Laboratory-based Activity Classifiers in Preschoolers.

Machine learning classification models for accelerometer data are potentially more accurate methods to measure physical activity in young children than traditional cut point methods. However, existing algorithms have been trained on laboratory-based activity trials, and their performance has not been investigated under free-living conditions. PURPOSE: This study aimed to evaluate the accuracy of laboratory-trained hip and wrist random forest and support vector machine classifiers for the automatic recognition of five activity classes: sedentary (SED), light-intensity activities and games (LIGHT_AG), walking (WALK), running (RUN), and moderate to vigorous activities and games (MV_AG) in preschool-age children under free-living conditions. METHODS: Thirty-one children (4.0 ± 0.9 yr) were video recorded during a 20-min free-living play session while wearing an ActiGraph GT3X+ on their right hip and nondominant wrist. Direct observation was used to continuously code ground truth activity class and specific activity types occurring within each class using a bespoke two-stage coding scheme. Performance was assessed by calculating overall classification accuracy and extended confusion matrices summarizing class-level accuracy and the frequency of specific activities observed within each class. RESULTS: Accuracy values for the hip and wrist random forest algorithms were 69.4% and 59.1%, respectively. Accuracy values for hip and wrist support vector machine algorithms were 66.4% and 59.3%, respectively. Compared with the laboratory cross validation, accuracy decreased by 11%-15% for the hip classifiers and 19%-21% for the wrist classifiers. Classification accuracy values were 72%-78% for SED, 58%-79% for LIGHT_AG, 71%-84% for MV_AG, 9%-15% for WALK, and 66%-75% for RUN. CONCLUSION: The accuracy of laboratory-based activity classifiers for preschool-age children was attenuated when tested on new data collected under free-living conditions. Future studies should train and test machine learning activity recognition algorithms using accelerometer data collected under free-living conditions.

Identifying latent subgroups of children with developmental delay using Bayesian sequential updating and Dirichlet process mixture modelling.

Identifying children who are at-risk for developmental delay, so that these children can have access to interventions as early as possible, is an important and challenging problem in developmental research. This research aimed to identify latent subgroups of children with developmental delay, by modelling and clustering developmental milestones. The main objectives were to (a) create a developmental profile for each child by modelling milestone achievements, from birth to three years of age, across multiple domains of development, and (b) cluster the profiles to identify groups of children who show similar deviations from typical development. The ensemble methodology used in this research consisted of three components: (1) Bayesian sequential updating was used to model the achievement of milestones, which allows for updated predictions of development to be made in real time; (2) a measure was created that indicated how far away each child deviated from typical development for each functional domain, by calculating the area between each child's obtained sequence of posterior means and a sequence of posterior means representing typical development; and (3) Dirichlet process mixture modelling was used to cluster the obtained areas. The data used were 348 binary developmental milestone measurements, collected from birth to three years of age, from a small community sample of young children (N = 79). The model identified nine latent groups of children with similar features, ranging from no delays in all functional domains, to large delays in all domains. The performance of the Dirichlet process mixture model was validated with two simulation studies.

Effects of fully-established Sure Start Local Programmes on 3-year-old children and their families living in England: a quasi-experimental observational study.

BACKGROUND: Sure Start Local Programmes (SSLPs) are area-based interventions to improve services for young children and their families in deprived communities, promote health and development, and reduce inequalities. We therefore investigated whether SSLPs affect the wellbeing of 3-year-old children and their families. METHODS: In a quasi-experimental observational study, we compared 5883 3-year-old children and their families from 93 disadvantaged SSLP areas with 1879 3-year-old children and their families from 72 similarly deprived areas in England who took part in the Millennium Cohort Study. We studied 14 outcomes-children's immunisations, accidents, language development, positive and negative social behaviours, and independence; parenting risk; home-learning environment; father's involvement; maternal smoking, body-mass index, and life satisfaction; family's service use; and mother's rating of area. FINDINGS: After we controlled for background factors, we noted beneficial effects associated with the programmes for five of 14 outcomes. Children in the SSLP areas showed better social development than those in the non-SSLP areas, with more positive social behaviour (mean difference 0.45, 95% CI 0.09 to 0.80, p=0.01) and greater independence (0.32, 0.18 to 0.47, p<0.0001). Families in SSLP areas showed less negative parenting (-0.90, -1.11 to -0.69, p<0.0001) and provided a better home-learning environment (1.30, 0.75 to 1.86, p<0.0001). These families used more services for supporting child and family development than those not living in SSLP areas (0.98, 0.86 to 1.09, p<0.0001). Effects of SSLPs seemed to apply to all subpopulations and SSLP areas. INTERPRETATION: Children and their families benefited from living in SSLP areas. The contrast between these and previous findings on the effect of SSLPs might indicate increased exposure to programmes that have become more effective. Early interventions can improve the life chances of young children living in deprived areas.

From Kindergarten readiness to fourth-grade assessment: longitudinal analysis with linked population data.

Early child development (ECD)--the development of physical, social-emotional, and language-cognitive capacities in the early years--is a foundation of health, well-being, learning, and behaviour across the life course. Consequently, the capacity to monitor ECD is an important facet of a modern society. This capacity is achieved by having in place an ongoing flow of high-quality information on the state of early child development, its determinants, and long-term developmental outcomes. Accordingly, there remains a considerable need for research that merges community-centred, longitudinal, and linked-data approaches to monitoring child development. The current paper addresses this need by introducing one method of summarising and quantifying the developmental trajectories of British Columbian children at the neighbourhood- or district-level: computing the Community Index of Child Development (CICD) for each geographic area. A simple index that describes change in children's developmental trajectories at the aggregate level, the CICD is computable because of our capacity to conduct individual-level linkage of two population data sets: the Early Development Instrument (EDI), a holistic measure of children's readiness for school which is administered at Kindergarten, and the British Columbia Ministry of Education's Foundation Skills Assessment (FSA), a Grade 4 measure of academic skills. In this paper, we demonstrate: (a) wide variation in the CICDs according to the children's district of residence in Kindergarten; (b) an association of the CICDs with an indicator of the socioeconomic character of the neighbourhoods; and (c) contrasting patterns of neighbourhood convergence and divergence in two different school districts--such that, in some areas, children from high vulnerability neighbourhoods tend to catch up between Kindergarten and Grade 4 whereas, in other areas, they tend to fall further behind.

Motor function in 5-year-old children with cerebral palsy in the South Australian population.

The aim of this study was to describe the motor function of a population of children at age 5 years enrolled on the South Australian Cerebral Palsy Register. Among children born between 1993 and 1998, there were 333 with confirmed cerebral palsy (prevalence rate 2.2 per 1000 live births), in whom 247 assessments (56.7% males, 43.3% females) were completed. The distribution by Gross Motor Function Classification System (GMFCS) level was: level I, 50.6%; level II, 18.2%; level III, 9.3%; level IV, 9.7%; level V, 12.1%. The most common topographical classification was spastic diplegia (38.5%), followed by spastic hemiplegia (34.8%) and spastic quadriplegia (14.6%). Abnormal movements occurred at rest or with intention in 19.4% of children. A high proportion of the population with relatively mild gross motor impairments have difficulty with everyday bimanual tasks, reinforcing the need to assess upper limb function independently of gross motor function. The use of ankle-foot orthoses was common, particularly across GMFCS levels II to IV. Further refinement is indicated for this population's motor dataset, to include more recently described classification measures as well as future novel measures to better describe the presence of both spasticity and dystonia.