The Development of Bimanual Coordination Across Toddlerhood

Characterization of bilateral reaching development using augmented reality games

Bilateral coordination is commonly impaired in neurodevelopmental conditions including cerebral palsy, developmental coordination disorder, and autism spectrum disorder. However, we lack objective clinical assessments that can quantify bilateral coordination in a clinically feasible manner and determine age-based norms to identify impairments. The objective of this study was to use augmented reality and computer vision to characterize bilateral reaching abilities in typically developing children. Typically developing children (n = 133) ages 6-17 years completed symmetric and asymmetric bilateral reaching tasks in an augmented reality game environment. We analyzed the number of target pairs they could reach in 50 s as well as the time lag between their hands reaching the targets. We found that performance on both tasks developed in parallel, with development slowing but not plateauing after age 12. Children performed better on the symmetric task than asymmetric, both in targets reached and with shorter hand lags. Variability between children in hand lag decreased with age. We also found gender differences with females outperforming males, which were most pronounced in the 10-11 year olds. Overall, this study demonstrates parallel development through childhood and adolescence of symmetric and asymmetric reaching abilities. Furthermore, it demonstrates the ability to quantify bilateral coordination using computer vision and augmented reality, which can be applied to assess clinical populations.

Fast and Fun: A Pilot Feasibility Study Using Dual Joystick-Operated Ride-on Toys for Upper Extremity Rehabilitation in Children with Hemiplegia

AIM

Our study investigates the feasibility and utility of implementing a dual joystick-operated ride-on-toy navigation training (RNT) program within a 3-week intensive camp based on principles of modified constraint-induced movement therapy and bimanual training, to improve upper extremity (UE) function in children with unilateral cerebral palsy (UCP).

METHODS

We employed a single-group pretest posttest, mixed methods study design. Eleven 4-to-10-year-old children with UCP received RNT as part of camp activities. Sessions required children to use both arms together for navigation and completing gross and fine motor UE challenges. We collected exit questionnaires from children, caregivers, and clinicians to assess the feasibility, acceptance, enjoyment, and perceived efficacy of RNT. Videos of training sessions were coded using Datavyu behavioral coding software to assess children's facial expressions and affective states, indicative of their level of engagement during intervention sessions.

RESULTS

We found high levels of child engagement during RNT sessions based on video data and stakeholder feedback. The RNT program was smoothly integrated into the camp. Stakeholders acknowledged the highly motivating nature of RNT. When combined with other camp activities, the program led to stakeholder-reported improvements in bimanual skills and spontaneous daily use of the affected UE.

CONCLUSIONS

Our pilot study provides promising evidence for using joystick-operated ride-on toys as engaging therapy adjuncts. Our findings call for future studies to systematically assess the efficacy of these devices in improving UE function among children with UCP.

Simultaneous structures in sign languages: Acquisition and emergence

The visual-gestural modality affords its users simultaneous movement of several independent articulators and thus lends itself to simultaneous encoding of information. Much research has focused on the fact that sign languages coordinate two manual articulators in addition to a range of non-manual articulators to present different types of linguistic information simultaneously, from phonological contrasts to inflection, spatial relations, and information structure. Children and adults acquiring a signed language arguably thus need to comprehend and produce simultaneous structures to a greater extent than individuals acquiring a spoken language. In this paper, we discuss the simultaneous encoding that is found in emerging and established sign languages; we also discuss places where sign languages are unexpectedly sequential. We explore potential constraints on simultaneity in cognition and motor coordination that might impact the acquisition and use of simultaneous structures.

Transitional Movement Skill Dependence on Fundamental Movement Skills: Testing Seefeldt's Proficiency Barrier

Purpose: In 1979 Vern Seefeldt postulated that individuals that did not achieve a given level of proficiency in the fundamental movement skills (FMS) would be limited in performance on new and more complex skills during development. This hypothesis, the proficiency barrier, inspired research in motor development but, to the best of our knowledge, was never empirically tested. The present article tested three potential mathematical functions (linear, sigmoidal and piecewise) describing the proficiency barrier relating FMS with a transitional movement skill (TMS, a more complex movement skill). Methods: 87 children aged 7 to 10 years were tested on six skills of the TGMD-2 test battery (running, hopping, leaping, kicking, catching and stationary bouncing) and dribbling (a combination of running and stationary bouncing). Results: The results showed evidence for the proficiency barrier based on a specific sigmoidal relation. We also identified critical movement aspects from FMS that seem to induce this relation. Conclusion: There is some evidence supporting Seefeldt's Proficiency Barrier.

Individual variability in the nonlinear development of the corpus callosum during infancy and toddlerhood: a longitudinal MRI analysis

The human brain spends several years bootstrapping itself through intrinsic and extrinsic modulation, thus gradually developing both spatial organization and functions. Based on previous studies on developmental patterns and inter-individual variability of the corpus callosum (CC), we hypothesized that inherent variations of CC shape among infants emerge, depending on the position within the CC, along the developmental timeline. Here we used longitudinal magnetic resonance imaging data from infancy to toddlerhood and investigated the area, thickness, and shape of the midsagittal plane of the CC by applying multilevel modeling. The shape characteristics were extracted using the Procrustes method. We found nonlinearity, region-dependency, and inter-individual variability, as well as intra-individual consistencies, in CC development. Overall, the growth rate is faster in the first year than in the second year, and the trajectory differs between infants; the direction of CC formation in individual infants was determined within six months and maintained to two years. The anterior and posterior subregions increase in area and thickness faster than other subregions. Moreover, we clarified that the growth rate of the middle part of the CC is faster in the second year than in the first year in some individuals. Since the division of regions exhibiting different tendencies coincides with previously reported divisions based on the diameter of axons that make up the region, our results suggest that subregion-dependent individual variability occurs due to the increase in the diameter of the axon caliber, myelination partly due to experience and axon elimination during the early developmental period.

Toddlers Using Tablets: They Engage, Play, and Learn

Although very young children have unprecedented access to touchscreen devices, there is limited research on how successfully they operate these devices for play and learning. For infants and toddlers, whose cognitive, fine motor, and executive functions are immature, several basic questions are significant: (1) Can they operate a tablet purposefully to achieve a goal? (2) Can they acquire operating skills and learn new information from commercially available apps? (3) Do individual differences in executive functioning predict success in using and learning from the apps? Accordingly, 31 2-year-olds (M = 30.82 month, SD = 2.70; 18 female) were compared with 29 3-year-olds (M = 40.92 month, SD = 4.82; 13 female) using two commercially available apps with different task and skill requirements: (1) a shape matching app performed across 3 days, and (2) a storybook app with performance compared to that on a matched paper storybook. Children also completed (3) the Minnesota Executive Functioning Scale. An adult provided minimal scaffolding throughout. The results showed: (1) toddlers could provide simple goal-directed touch gestures and the manual interactions needed to operate the tablet (2) after controlling for prior experience with shape matching, toddlers’ increased success and efficiency, made fewer errors, decreased completion times, and required less scaffolding across trials, (3) they recognized more story content from the e-book and were less distracted than from the paper book, (4) executive functioning contributed unique variance to the outcome measures on both apps, and (5) 3-year-olds outperformed 2-year-olds on all measures. The results are discussed in terms of the potential of interactive devices to support toddlers’ learning.

Promoting Participation in Physical Activity in Children and Adolescents With Down Syndrome

Children with Down syndrome (DS) often have lower physical activity (PA) levels compared with their peers with typical development, and face challenges to being physically active such as medical comorbidities, access issues, and societal stigma. Physical therapists are experts in exercise prescription and PA and are thus uniquely qualified to successfully promote participation in children with DS, in spite of inherent challenges. Our perspective is that a shift in physical therapy service delivery is needed. We suggest that physical therapists change the focus of their interventions for children with DS from underlying impairments such as low tone or joint laxity or from developing motor skills in isolation and "correct" movement patterns. Instead, physical therapists should allow the PA preferences and the environmental contexts of the children and adolescents they are working with to direct the treatment plan. In this way, physical therapist intervention becomes more child centered by concentrating on developing the specific skills and strategies required for success in the child's preferred PA. In this article, we consider the role of pediatric physical therapists in the United States, as well as in low- and middle-income countries, in promoting and monitoring PA in children with DS from infancy through adolescence. Examples of physical therapist interventions such as tummy time, movement exploration, treadmill training, bicycle riding, and strength training are discussed, across infancy, childhood, and adolescence, with a focus on how to successfully promote lifelong participation in PA.

LAY SUMMARY

Physical therapists are experts in exercise and physical activity and are thus uniquely qualified to promote participation in children with Down syndrome. Instead of focusing on impairments or "correct" movement patterns, physical therapists are encouraged to allow the child and the child's environment to direct the treatment plan.

Search Strategies in the Perceptual-Motor Workspace and the Acquisition of Coordination, Control, and Skill

In this paper we re-visit and elaborate-on the theoretical framework of learning as searching within the perceptual-motor workspace for a solution to the task. The central focus is the nature of search strategies to locate and create stable equilibrium regions in the perceptual-motor workspace and how these strategies relate to the emergent movement forms in the acquisition of coordination, control, and skill. In the ecological theory of perception and action, the enhanced stability of performance occurs through the attunement of the perceptual systems to the task dynamics together with modifications of action as task and intrinsic dynamics cooperate and/or compete. Thus, through practice in this search process, individuals adapt to the pick-up of task relevant perceptual variables and change their movement form according to the stability of the performed action and its outcome in relation to the task demands. Contemporary experimental findings have revealed features of the search process given the interaction of individual intrinsic dynamics in the context of task requirements and principles that drive the change – e.g., exploitation of more tolerant task-space solutions and emergence of compensatory mechanisms. Finally, we outline how the search strategy framework relates to traditional learning-related phenomena: including the dynamical pathways of learning, learning curves, factors of learning, individuality, motor development, and sport and rehabilitation interventions.