Movement Control Strategies in a Dynamic Balance Task in Children With and Without Developmental Coordination Disorder

Abstract

Our study aimed to analyze movement control strategies using predefined criteria for amplitude and differences in these strategies between children with and without DCD. Children with (n?=?28) and without DCD (n?=?15) were included. A video-observation-tool was used to score the moving body parts during a Wii Fit slalom task over multiple time points. Two-step cluster analysis was used to extract distinct movement strategies. Two different movement strategies were identified that were independently validated by a measure of task performance and a subjective mark of quality of the movement. Initial differences between groups and changes over time toward the more successful strategy were found in both groups, albeit in a different percentage. This study shows that the more efficient movement strategy is seen in the majority of the TD children and only in a small number of children with DCD, even after practice.     

Roles of Visual Information for Control of Reaching Movements in Children

Poststroke hemiparetic individuals (n = 9) and a control group (n = 9) completed a frequency-scaled circle-drawing task in unimanual and bimanual conditions. Measures of intralimb spatial and temporal task accuracy and interlimb coordination parameters were analyzed. Significant reductions in task performance were seen in both limbs of the patients and controls with the introduction of bimanual movement. Spatial performance parameters suggested that the 2 groups focused on different hands during bimanual conditions. In the controls, interlimb coordination variables indicated predictable hand dominance effects, whereas in the patient group, dominance was influenced by the side of impairment and prior handedness of the individual. Therefore, in this particular bimanual task, performance improvements in the hemiplegic side could not be elicited. Intrinsic coupling asymmetries between the hands can be altered by unilateral motor deficits.     

发展性协调障碍的神经机制

发展性协调障碍是一种特殊的发育障碍, 它的一个显著特征是动作协调困难, 这种障碍影响着5%~8%学龄儿童的学业成绩和日常生活。发展性协调障碍常常与其他类型的学习困难并存。发展性协调障碍的病因非常复杂, 这种障碍与一定程度的视觉空间认知能力受损有关, 早期精细运动技能发育与脑神经发育进程可能存在时间的重合。近年来, 研究者们试图探索影响发展性协调障碍的神经基础, 并先后提出不同的神经关联假说。这些理论假说主要涉及到小脑、顶叶、胼胝体、基底神经节和大脑白质等脑区。本文全面回顾了该领域研究的最新进展, 并提出未来研究应该关注的方向与问题。     

Poor Imitative Performance of Unlearned Gestures in Children with Probable Developmental Coordination Disorder

It has been hypothesized that deficits in imitation, linked to abnormal functioning of the mirror neuron system (MNS), may contribute to the motor impairments associated with developmental coordination disorder (DCD). The authors aimed to examine imitation of complex novel postures and sequences of gestures in children with and without probable DCD (pDCD), using the postural praxis and sequencing praxis subtests of the Sensory Integration and Praxis Tests (Ayres, 1989 Ayres, A. J. (1989). Sensory Integration and Praxis Tests: SIPT manual. Los Angeles, CA: Western Psychological Services. [Google Scholar]). Participants were 29 boys with pDCD between 6.08 and 13.33 years old, and 29 group age-matched typically developing boys between 6.08 and 13.83 years old. Responses of children with pDCD on both imitation tasks were less accurate than controls, with group differences more apparent with increasing task complexity. Furthermore, as a group, children with pDCD were slower and had a higher number of non–mirror-imitated responses. There was considerable variability within the pDCD group, with some children displaying imitation scores within the normative range. Given the importance of imitation and visual learning for motor development, the difficulties in imitation displayed by some children with pDCD have the potential to impact on movement acquisition. Interventions to target imitation may be beneficial for these children. The results show that children with pDCD had difficulty imitating complex novel postures, children with pDCD had difficulty imitating gesture sequences, children with pDCD had slower responses than controls, group differences in imitation performance increased with task complexity, and not all children with pDCD displayed imitation deficits.     

Dissecting online control in Developmental Coordination Disorder: a kinematic analysis of double-step reaching

In a recent study, children with movement clumsiness (or Developmental Coordination Disorder-DCD) were shown to have difficulties making rapid online corrections when reaching, demonstrated by slower and less accurate movements to double-step targets (Hyde & Wilson, 2011). These results suggest that children with DCD have difficulty using predictive estimates of limb position when making rapid adjustments to movement, in-flight. However, chronometric data alone does not provide strong evidence for this hypothesis: it remains unclear whether early (and rapid) control parameters or post-correction stages of the movement trajectory are affected. Thus, the overarching aim of this study was to conduct a kinematic analysis of double-step reaching in order to isolate the different control parameters that might explain the slower and less accurate double-step reaching performance of children with DCD. Participants were a new sample of 13 children with DCD aged between 8-12 years and 13 age-matched controls. Children were required to reach and touch one of three possible targets presented at the coordinates -20°, 0° and 20° on a 17 in. LCD touch-screen. For most trials (80%) the target remained stationary for the duration of movement (non-jump trials), while for the remainder (20%), the target jumped randomly to one of two peripheral locations at movement onset (jump trials). Consistent with earlier work, children with DCD were slower to initiate reaching compared to controls and showed longer MT and more errors on jump trials. Kinematic data showed that while the two groups did not differ on time to peak velocity or acceleration, children with DCD were slower to correct reach trajectory on jump trials. No group differences were observed on late kinematic markers, e.g., post-correction time. The pattern of results support and extend earlier work showing deficits in ROC in DCD. From a computational perspective, delayed corrections to the reach trajectory suggests some difficulty integrating information about the target perturbation with a predictive (or forward) estimate of limb position relative to the initial target. These conclusions are discussed, along with directions for future research.     

Neuroimaging and Occupational Therapy: Bridging the Gap to Advance Rehabilitation in Developmental Coordination Disorder

Developmental coordination disorder (DCD) is a neurodevelopmental disorder characterized by poor motor skills that interfere with a child's ability to perform everyday activities. Little is known about the neural mechanisms that implicate DCD, making it difficult to understand why children with DCD struggle to learn motor skills and selecting the best intervention to optimize function. Neuroimaging studies that utilize magnetic resonance imaging techniques have the capacity to play a critical role in helping to guide clinicians to optimize functional outcomes of children with DCD using evidence-based rehabilitation interventions. The authors' goal is to describe how neuroimaging research can be applied to occupational therapy and rehabilitation sciences by highlighting projects that are at the forefront of the field and elucidate future directions.     

Selective Mutism in Children: Comparison to Youths With and Without Anxiety Disorders

Fifteen children with selective mutism (SM), 15 children with anxiety disorders (AD) without selective mutism, and 15 children without anxiety disorders or selective mutism (CN) were compared to examine the relationship between selective mutism and anxiety. Data were collected from children (age 4–10 years), parents, teachers, and clinicians. Results indicated that children with SM closely resemble children with AD. All children with SM received a diagnosis of social anxiety disorder and 53% received a diagnosis for an additional anxiety disorder. In addition, the SM and AD groups differed substantially from controls with respect to parent- and teacher-rated internalizing behavior problems. No differences among the groups were found with respect to parent-and teacher-reported externalizing behavior problems. The results are consistent with prior research emphasizing the association between selective mutism and anxiety disorders, and suggest that selective mutism may be conceptualized, assessed, and treated as an anxiety-related problem.     

汉语发展性阅读障碍儿童的视觉大细胞-背侧通路功能

发展性阅读障碍是一种在获得阅读技能方面的特殊困难,其致病原因一直是该领域的核心问题。越来越多的研究表明视觉大细胞-背侧通路功能与阅读技能之间存在紧密联系。视觉大细胞-背侧通路缺陷可能是导致阅读障碍的主要原因之一。一些研究发现汉语阅读障碍儿童同样存在视觉大细胞-背侧通路缺陷。本文将回顾近些年汉语发展性阅读障碍儿童视觉大细胞-背侧通路功能的相关研究成果,并对该领域未来的发展方向做出展望。     

Determinants of Offline Processing of Visual Information for the Control of Reaching Movements

The authors investigated the use of visual feedback as a form of knowledge of results (KR) for the control of rapid (200-250 ms) reaching movements in 40 participants. They compared endpoint accuracy and intraindividual variability of a full-vision group (FV) with those of no-vision groups provided with KR regarding (a) the endpoint in numerical form, (b) the endpoint in visual form, or (c) the endpoint and the trajectory in visual form (DEL). The FV group was more accurate and less variable than were the no-vision groups, and the analysis of limb trajectory variability indicated that their superior performance resulted primarily from better movement planning rather than from online visual processes. The FV group outperformed the DEL group even though both groups were obtaining the same amount of spatial visual information from every movement. That finding suggests that the effectiveness with which visual feedback is processed offline is not a simple function of the amount of visual information available, but depends on how that information is presented.     

Behavior Problems in Toddlers With and Without Developmental Delays: Comparison of Treatment Outcomes

The purpose of this study is to examine the effectiveness of an in-home parent management program for toddlers with behavior problems and developmental delays by comparing outcomes for a group of toddlers with developmental delays (n = 27) and a group of toddlers without developmental delays (n = 27). The majority of children lived in single parent, low-income homes. Results suggest that the parent management program is equally effective for children with and without developmental delays. Parents from both groups reported clinically significant improvement in their children's behavior and parenting practices. Clinical implications regarding the importance of these findings for improving outcomes for toddlers with behavior problems and developmental delays living in poverty were discussed.     

Procedural learning,consolidation, and transfer of a new skill in Developmental Coordination Disorder

The aim of this study was to explore the differences in procedural learning abilities between children with DCD and typically developing children by investigating the steps that lead to skill automatization (i.e., the stages of fast learning, consolidation, and slow learning). Transfer of the skill to a new situation was also assessed. We tested 34 children aged 6–12 years with and without DCD on a perceptuomotor adaptation task, a form of procedural learning that is thought to involve the cerebellum and the basal ganglia (regions whose impairment has been associated with DCD) but also other brain areas including frontal regions. The results showed similar rates of learning, consolidation, and transfer in DCD and control children. However, the DCD children's performance remained slower than that of controls throughout the procedural task and they reached a lower asymptotic performance level; the difficulties observed at the outset did not diminish with practice.     

A Preliminary Investigation of Quality of Life Satisfaction Reports in Emerging Adults With and Without Developmental Coordination Disorder

Developmental coordination disorder (DCD) affects around 5% of the population and is diagnosed on the basis of poor motor coordination. Although we know rather little about the lifetime consequences of this disorder, it is clear that significant difficulties remain through adolescence and into adulthood for the majority. It is also clear that significant psychosocial consequences exist for many individuals with DCD. In the current study, quality of life satisfaction was investigated in a group of emerging adults with and without DCD using the Quality of Life Satisfaction Questionnaire (Endicott et al. Psychopharmacology Bulletin, 29, 321–326, 1993). Overall, the group of adults with DCD reported significantly lower levels of quality of life satisfaction across all domains on the scale. This finding has important implications for consideration of early and later intervention for these individuals, as well as for studies to consider the risk and protective factors at play in long-term outcome with respect to both the motor skills and psychosocial aspects of this disorder.     

Self-Sitting and Reaching in 5- to 8-Month-Old Infants: The Impact of Posture and Its Development on Early Eye-Hand Coordination

The relation between progress in the control of posture (i.e., the achievement of self-sitting posture) and the developmental transition from two-handed to one-handed engagement in infant reaching was investigated. Two groups of 5- to 8-month-old infants, who were either able or yet unable to sit on their own, were videotaped while they reached for objects in four different posture conditions that provided varying amounts of body support. Videotapes of infant reaches were microanalyzed to determine the relative engagement of both hands during reaches. Results demonstrate the interaction between postural development and the morphology of infant reaching. Nonsitting infants displayed symmetrical and synergistic engagement of both arms and hands while reaching in all but the seated posture condition. Sitting infants, by contrast, showed asymmetrical and lateralized (one-handed) reaches in all posture conditions. Results also show that, aside from posture, the perceived spatial arrangement of the object display is a determinant of infant reaching. Combined, these results are discussed as evidence for the interaction between postural and perceptual development in the control of early eye-hand coordination.     

Posttraumatic Stress Disorder in Children and Adolescents: A Review and Analysis

Only recently has the mental health community recognized the applicability of diagnostic criteria for posttraumatic stress disorder (PTSD) in children and adolescents, including a consideration of specific age-related features. This paper provides a current review of the literature on PTSD pertaining to children and adolescents. Following a discussion of issues on diagnostic criteria and assessment of this affective disorder in this population, there is an overview of the existing literature on prevalence, comorbidity, risk factors, parental and family factors, and issues of gender and age of onset. The remainder of the paper focuses on the range of traumatic stressors in children and adolescents that can result in PTSD, including natural or human disasters, war and violence, chronic or life-threatening medical conditions, community violence and the witnessing of traumatic events, and physical and/or sexual abuse and other forms of interpersonal violence. Throughout the paper, there is an emphasis on the importance of considering developmental factors. Finally, implications of the existing literature for future areas of research are addressed.     

Simulating the Acquisition of Verb Inflection in Typically Developing Children and Children With Developmental Language Disorder in English and Spanish

Children with developmental language disorder (DLD) have significant deficits in language ability that cannot be attributed to neurological damage, hearing impairment, or intellectual disability. The symptoms displayed by children with DLD differ across languages. In English, DLD is often marked by severe difficulties acquiring verb inflection. Such difficulties are less apparent in languages with rich verb morphology like Spanish and Italian. Here we show how these differential profiles can be understood in terms of an interaction between properties of the input language, and the child's ability to learn predictive relations between linguistic elements that are separated within a sentence. We apply a simple associative learning model to sequential English and Spanish stimuli and show how the model's ability to associate cues occurring earlier in time with later outcomes affects the acquisition of verb inflection in English more than in Spanish. We relate this to the high frequency of the English bare form (which acts as a default) and the English process of question formation, which means that (unlike in Spanish) bare forms frequently occur in third-person singular contexts. Finally, we hypothesize that the pro-drop nature of Spanish makes it easier to associate person and number cues with the verb inflection than in English. Since the factors that conspire to make English verb inflection particularly challenging for learners with weak sequential learning abilities are much reduced or absent in Spanish, this provides an explanation for why learning Spanish verb inflection is relatively unaffected in children with DLD.     

Family Unification with Reactive Attachment Disorder Children: A Brief Treatment

This is a case study of a family with a child (age eight) with reactive attachment disorder and the subsequent individual and family therapy. Treatment of choice for the child was Eye Movement Desensitization and Reprocessing (EMDR) and supportive educational counseling for the parents and family. Qualitative evaluation of the process demonstrated that the parents observed an instant change in the child's attitude. The child reported that she felt better about family, school, and truthfulness, and stated about the therapy: It opened a window for me. A 12-month evaluation demonstrated continued positive effects.     

Visual Information and Object Size in the Control of Reaching

The role of vision in the control of reaching and grasping was investigated by varying the available visual information. Adults (N = 7) reached in conditions that had full visual information, visual information about the target object but not the hand or surrounding environment, and no visual information. Four different object diameters were used. The results indicated that as visual information and object size decreased, subjects used longer movement times, had slower speeds, and more asymmetrical hand-speed profiles. Subjects matched grasp aperture to object diameter, but overcompensated with larger grasp apertures when visual information was reduced. Subjects also qualitatively differed in reach kinematics when challenged with reduced visual information or smaller object size. These results emphasize the importance of vision of the target in reaching and show that subjects do not simply scale a command template with task difficulty.     

基于直线临摹的ADHD儿童眼手协调能力研究

ADHD儿童在精细动作方面通常伴随眼手协调运动障碍。以往采用的研究方法多为定性研究,且未在ADHD儿童的运动协调性与同龄正常儿童的差异上得出统一结论。本研究针对精细动作中眼手协调能力进行定量分析。实验要求被试在计算机触摸屏上分别临摹水平线、垂直线和斜线,通过记录临摹直线与呈现直线的偏差程度和拐点数,以分析ADHD儿童眼手协调能力与正常儿童之间的差异。结果表明,ADHD儿童在眼手协调和空间知觉能力上与正常儿童存在显著性差异。此外,本研究表明,改进的定量方法具有良好的可行性。     

ABA-Based Programs for Children Diagnosed With Autism Spectrum Disorder: Parental and Professional Experiences at School and at Home

Having a child diagnosed with Autism Spectrum Disorder (ASD) poses a range of challenges to families, many of which can be addressed through appropriate intervention. A study of parental (n = 95) and professional (n = 67) experiences was carried out in relation to two settings: (a) schools that provided intensive interventions based on the science of Applied Behavior Analysis (ABA), and (b) non-intensive ABA-based home programs. Results show that parents whose children attend ABA-based schools were generally more satisfied with their child's educational provision, monitoring procedures, and level of staff training, than parents who were not offered ABA-based education in schools.