Wrist proprioceptive acuity is linked to fine motor function in children undergoing piano training.

Playing the piano involves rapid and precise upper limb movements, which require seamless integration of the proprioceptive and motor systems. In this study, we comprehensively assessed active and passive proprioception and different domains of motor function in young pianists, aiming to understand how their proprioceptive and motor functions are improved. Fifty-seven participants, including seventeen 11- to 12-yr-old (young) pianists, 20 children, and 20 adults, were included. The children in the pianist group had received piano training for 6 yr, whereas the children and adults in the control groups had no previous experience with instrumental training. All participants performed a psychophysical discrimination threshold hunting task and an ipsilateral joint position reproduction task, both of which measured the position sense acuity of the wrist. Their motor function was evaluated by the Movement Assessment Battery for Children, 2nd edition. The results revealed that the young pianists showed a significantly lower position sense discrimination threshold (31%) and fewer joint position reproduction errors (49%) than the nontrained children. Second, a higher level of manual dexterity, but not of ball skills or balance, was found in the young pianist group. Third, a higher proprioceptive acuity (i.e., decreased position sense discrimination threshold) significantly correlated with higher manual dexterity. This study documents that a high wrist position sense is a common characteristic among young pianists. The increased upper limb position sense acuity is correlated with better manual dexterity, suggesting that piano practice may benefit untrained fine motor skills in children.NEW & NOTEWORTHY We document that improved proprioceptive acuity is a common feature in young pianists. This proprioceptive improvement is associated with both proprioceptive processing and proprioceptive-motor integration. Higher wrist proprioceptive acuity in young pianists is linked to enhanced manual dexterity, which suggests that intensive piano training may improve untrained fine motor skills.

Differences in neurocognitive performance and metabolic and inflammatory indices in male adults with obesity as a function of regular exercise.

NEW FINDINGS: What is the central question of this study? Does regular exercise have benefits with regard to the neurocognitive problems related to obesity and are regular-exercise-induced neurocognitive changes associated with changes in the levels of metabolic/inflammatory biomarkers? What is the main finding and its importance? Although obese individuals with regular exercise showed higher C-reactive protein levels as compared to the healthy-weight individuals, only the obese individuals with a sedentary lifestyle showed deviant neurocognitive performance and higher metabolic and tumour necrosis factor-α levels. The P3 amplitude was correlated with the levels of leptin in the obese individuals with regular activity, implicating that the potential mechanism of neurocognitive facilitation as a result of regular exercise could be reduced serum leptin levels. ABSTRACT: Obesity has been shown to be highly associated with deterioration in executive functions, elevated energy metabolic indices and low-grade systemic inflammation. Exercise has the capacity to reduce these negative phenomena. This work examined the effect of regular exercise on neurocognitive deficits and metabolic/inflammatory markers in obesity. Fifty-four participants were divided into three groups: healthy-weight (HW), obesity with regular exercise (ORE) and obesity with sedentary lifestyle (OSL), according to their BMI and frequency of exercise. Dual-energy X-ray absorptiometry was applied to assess the whole-body composition of the participants. The assessment included neurocognitive measures during the Posner paradigm test and fasting blood measurements. Relative to the HW group, only the OSL group showed significantly longer reaction times and smaller P3 amplitudes, even when controlling for the cardiorespiratory fitness co-variable. Although the OSL group exhibited a greater N2 amplitude than the HW group, when controlling for cardiorespiratory fitness the difference between the two groups disappeared. The OSL group showed greater levels of metabolic indices (i.e. leptin, insulin and glucose) than the HW group. The three groups had comparable interleukin (IL)-1ß and IL-6 levels. However, the ORE and OSL groups showed higher levels of C-reactive protein than the HW group. The OSL group exhibited higher tumour necrosis factor-α levels than the HW and ORE groups. P3 amplitude was negatively correlated with the levels of leptin in the ORE group. Individuals with obesity can still obtain advantages with regard to neurocognitive and metabolic/inflammatory indices through engaging in regular exercise, possibly due to reduced serum leptin levels.

Effects of acute aerobic exercise on a task-switching protocol and brain-derived neurotrophic factor concentrations in young adults with different levels of cardiorespiratory fitness.

What is the central question of this study? Neurocognitive functions can be enhanced by acute aerobic exercise, which could be associated with changes in serum brain-derived neurotrophic factor (BDNF) concentrations. We aimed to explore acute exercise-induced changes in BDNF concentrations, neuropsychological and neurophysiological performances when individuals with different levels of cardiorespiratory fitness performed a cognitive task. What is the main finding and its importance? Only young adults with higher cardiorespiratory fitness could attain switching cost and neurophysiological benefits via acute aerobic exercise. The mechanisms might be fitness dependent. Although acute aerobic exercise could enhance serum BDNF concentrations, changes in peripheral BDNF concentrations could not be the potential factor involved in the beneficial effects on neurocognitive performance. This study investigated the effects of acute aerobic exercise on neuropsychological and neurophysiological performances in young adults with different cardiorespiratory fitness levels when performing a task-switching protocol and explored the potential associations between acute aerobic exercise-induced changes in serum brain-derived neurotrophic factor (BDNF) concentrations and various neurocognitive outcomes. Sixty young adults were categorized into one control group (i.e. non-exercise-intervention; n = 20) and two exercise-intervention (EI) groups [i.e. higher (EIH , n = 20) and lower (EIL , n = 20) cardiorespiratory fitness] according to their maximal oxygen consumption. At baseline and after either an acute bout of 30 min of moderate-intensity aerobic exercise or a control period, the neuropsychological and neurophysiological performances and serum BDNF concentrations were measured when the participants performed a task-switching protocol involving executive control and greater demands on working memory. The results revealed that although acute aerobic exercise decreased reaction times across three (i.e. pure, switching and non-switching) conditions in both EI groups, only the EIH group showed a smaller switching cost and larger P3 amplitudes after acute exercise, supporting the view that the mechanisms of neural functioning that underlie the effects of such exercise may be fitness dependent. In addition, serum BDNF concentrations were elevated after acute exercise for both EI groups, but there were no significant correlations between the changes in BDNF concentrations and changes in neuropsychological and neurophysiological performances for either group, suggesting that serum BDNF could not be the potential factor involved in the beneficial effects on neuropsychological and neurophysiological performances seen in young adults after acute aerobic exercise.

Coupling of postural activity with motion of a ship at sea.

On land, body sway during stance becomes coupled with imposed oscillations of the illuminated environment or of the support surface. This coupling appears to have the function of stabilizing the body relative to the illuminated or inertial environment. In previous research, the stimulus has been limited to motion in a single axis. Little is known about our ability to couple postural activity with complex, multi-axis oscillations. On a ship at sea, we evaluated postural activity using measures of body movement, as such, and we separately evaluated a direct measure of coupling between body movement and ship motion. Participants were tested while facing fore-aft and athwartship. We compared postural activity between participants who had been seasick at the beginning of the voyage and those who had not. Coupling of postural activity with ship motion differed between body axes as a function of body orientation relative to the ship. In addition, coupling differed between participants who had been seasick at the beginning of the voyage and those who had not. We discuss the results in terms of implications for general theories of postural control, and for prediction of susceptibility to seasickness in individuals.

Postural Control of Anteroposterior and Mediolateral Sway in Children With Probable Developmental Coordination Disorder.

PURPOSE: To examine postural control of anteroposterior (AP) and mediolateral sway of children with probable developmental coordination disorder (pDCD) and children with typical development (TD). METHODS: Forty-eight children (24 in each group) aged 11 to 12 years performed an aiming task, maintaining a laser beam within targets placed in 2 locations (front/side). Precision was compromised primarily by the control of mediolateral sway for the front target and by the control of AP sway for the side target. The task was performed with large and small targets. RESULTS: In the side target condition, only (1) the TD group showed reduced AP sway in response to reduced target size, whereas the pDCD group increased AP sway, and (2) aiming performance for reduced target sizes deteriorated to a greater degree in the pDCD group than in the TD group. CONCLUSION: These findings suggest children with pDCD have specific deficits in controlling AP sway.

The relationships between motor skills and executive functions in children with and without autism spectrum disorder.

To date, information on associations between motor skills and executive functions (EF) in autistic children is limited. The purpose of this study was to compare motor skills and EF performance between autistic children and typically developing (TD) children and to examine the relationships between motor skills and EF in these two groups. Forty-eight autistic children and 48 TD children aged 6 to 12 years were recruited for this study. Motor skills were measured with the Bruininks-Oseretsky Test of Motor Proficiency-2 (BOT-2). EF was assessed with the Stroop Color and Word Test, the Wisconsin Card Sorting Task (WCST), and the Test of Attentional Performance: Go/No-go test. Independent sample t-tests were used to compare the BOT-2 scores and EF measures between autistic children and TD children. Pearson product-moment correlation and regressions were conducted to assess the relationships between the BOT-2 scores and the EF measures for each group. Results showed that autistic children scored significantly lower than TD children on all four BOT-2 composite scores and a total motor composite. Autistic children also demonstrated significantly lower levels of performance on all EF measures than TD children. Further, autistic children showed more significant associations between motor skills and EF than TD children, particularly pronounced in the domains of fine manual control and manual coordination to cognitive flexibility, as well as manual coordination and inhibitory control. Continued development of motor skills and EF in autistic children is important. The relationships between motor skills and EF were significant among autistic children, suggesting future research on promoting EF through motor skill interventions in autistic children is required.

Console video games, postural activity, and motion sickness during passive restraint.

We examined the influence of passive restraint on postural activity and motion sickness in individuals who actively controlled a potentially nauseogenic visual motion stimulus (a driving video game). Twenty-four adults (20.09 ± 1.56 years; 167.80 ± 7.94 cm; 59.02 ± 9.18 kg) were recruited as participants. Using elastic bands, standing participants were passively restrained at the head, shoulders, hips, and knees. During restraint, participants played (i.e., controlled) a driving video game (a motorcycle race), for 50 min. During game play, we recorded the movement of the head and torso, using a magnetic tracking system. Following game play, participants answered a forced choice, yes/no question about whether they were motion sick, and were assigned to sick and well groups on this basis. In addition, before and after game play, participants completed the Simulator Sickness Questionnaire, which provided numerical ratings of the severity of individual symptoms. Five of 24 participants (20.83 %) reported motion sickness. Participants moved despite being passively restrained. Both the magnitude and the temporal dynamics of movement differed between the sick and well groups. The results show that passive restraint of the body can reduce motion sickness when the nauseogenic visual stimulus is under participants' active control and confirm that motion sickness is preceded by distinct patterns of postural activity even during passive restraint.

Effects of kinesio taping on static balance performance and muscle activity in children with developmental coordination disorder: a single-group pretest-posttest study.

OBJECTIVE: To compare the effects of various kinesio tape applications on static balance and muscle activity in children with developmental coordination disorder.  Methods: Four taping conditions were applied to 48 children with developmental coordination disorder: no taping, gastrocnemius taping, tibialis anterior taping; and peroneus longus taping. Postural sway and electromyographic data were assessed, with eyes closed (30 s), standing still in 2-leg stance, dominant-leg stance, and non-dominant-leg stance. RESULTS: Kinesio taping significantly reduced postural sway in both anteroposterior and mediolateral directions for dominant-leg stance and non-dominant-leg stance, but not 2-leg stance. During single-leg stances, anteroposterior sway was significantly lower for the gastrocnemius taping condition than for the no taping, tibialis anterior and peroneus longus taping conditions, and significantly lower in the tibialis anterior and peroneus longus taping conditions than in the no taping condition (gastrocnemius < tibialis anterior = peroneus longus < no taping). In addition, mediolateral sway was significantly lower in the tibialis anterior and peroneus longus taping conditions than in the no taping and gastrocnemius taping conditions, and significantly lower in the gastrocnemius taping condition than in the no taping condition (tibialis anterior = peroneus longus < gastrocnemius < no taping). Electromyographic data showed that muscle activity was significantly greater only for muscles where kinesio tape was applied. CONCLUSION: Various kinesio tape applications can differentially reduce postural sway and increase muscle activity during single-leg stances in children with developmental coordination disorder.

Motion sense sensitivity of the ankle is abnormal and correlated with motor performance in children with and without a probable developmental coordination disorder.

This study systematically examined ankle motion sense sensitivity and its relation to motor functions in children with and without a probable developmental coordination disorder (pDCD). Seventy-two children aged 10-11 years were recruited, including thirty-six children with pDCD and 36 age- and sex-matched typically developing (TD) children. Children placed their dominant foot on a passive ankle motion apparatus that induced plantar flexion of the ankle under nine constant velocities ranging between 0.15 and 1.35°/s. The adjusted movement detection time (ADT) to passive ankle motion was obtained to measure ankle motion sense sensitivity. The results showed that, in comparison to that in the TD group, ankle ADT was significantly increased by 22-59% for the range of velocities in the pDCD group. A correlation analysis showed that mean ADTs were significantly correlated with the manual dexterity (r = -0.33, p = 0.005) and balance (r = -0.24, p = 0.046) scores on the Movement Assessment Battery for Children (MABC-2) in the combined group. Similar correlations were found between the ADTs and the manual dexterity (r = -0.37, p = 0.028) and total motor (r = -0.34, p = 0.047) scores in the TD group. This study documents that ankle motion sense sensitivity to passive foot motion is reduced and is likely to contribute to poor motor performance in children with and without pDCD.

Nitric oxide-mediated the therapeutic properties of induced pluripotent stem cell for paraquat-induced acute lung injury.

The mortality rate associated with acute lung injury (ALI) and its severe form, acute respiratory distress syndrome, is high. Induced pluripotent stem cell (iPSC) therapy is a potential treatment method for ALI, but its therapeutic efficacy is limited in injured lungs. Nitric oxide (NO) has various physiological actions. The current study investigated the effect of iPSCs pretreated with NO donors in paraquat (PQ)-induced ALI mouse model. Male C57BL/6 mice were intraperitoneally injected with PQ, followed by infusion of phosphate-buffered saline, iPSCs, L-arginine pretreated iPSCs, or Nitro-L-arginine methylester (L-NAME) pretreated iPSCs through the tail veins. Histopathological changes, pulmonary microvascular permeability, and inflammatory cytokine levels were analyzed after 3 or 28 d. The effects on iPSC proliferation, migration, and adhesion were evaluated in vitro. More L-arginine-pretreated iPSCs were selectively trafficked into the injured pulmonary tissue of mice with LPS-induced ALI, drastically diminishing the histopathologic changes and inflammatory cytokine levels (IL-1ß and IL-6). There was also markedly improved pulmonary microvascular permeability and pulmonary function. The NO inhibitor abolished the protective effects of iPSCs. In addition, the ability of L-arginine to promote the proliferation and migration of iPSCs was decreased by L-NAME pretreatment, suggesting that NO might mediate the therapeutic benefits of iPSC. The improvement of the iPSC physiological changes by the endogenous gaseous molecule NO reduces lung injury severity. L-Arginine represents a pharmacologically important strategy for enhancing the therapeutic potential of iPSCs.

Postural adaptations to a suprapostural memory task among children with and without developmental coordination disorder.

AIM: The present study investigated the effects of varying the cognitive demands of a memory task (a suprapostural task) while recording postural motion on two groups of children, one diagnosed with developmental coordination disorder (DCD) and an age-matched group of typically developing children. METHOD: Two groups, each comprising 38 child volunteers (21 males, 17 females) aged 9 to 10 years, participated in the study. Each child performed a digital memory task at two levels of difficulty, low and high. Positional variability (standard deviation of position) of the head and torso were recorded as the biomechanical responses to the variation in task difficulty. RESULTS: Both groups significantly reduced postural motion when engaged in the high-difficulty condition (p<0.05) compared with the low-difficulty condition. Children with DCD exhibited significantly higher levels of postural motion (p<0.05) than the typically developing children. The typically developing children significantly reduced their postural motion in the high-difficulty condition (p<0.05) compared with the low-difficulty condition, whereas children with DCD did not. INTERPRETATION: Our results suggest that the postural responses of children with DCD differ from those of typically developing children while engaging in a memory task with various levels of difficulty.

Dynamic changes of volatile and phenolic components during the whole manufacturing process of Wuyi Rock tea (Rougui).

Wuyi Rock tea (WRT), a top-ranking oolong tea, possesses characteristic woody, floral, nutty flavor. WRT flavor is mainly formed during the manufacturing process. However, details regarding its formation process are not fully understood yet. In this study, the dynamics of volatile and phenolic components over the whole manufacturing process of WRT were investigated. During withering, despite minor changes in volatile and phenolic components, the central vacuole shrunk remarkably, which reduced the cell mechanical performance and facilitated the subsequent enzymatic fermentation. During fermentation, approximately 78% of flavan-3-ols in fresh tea leaves were oxidized and converted to a diverse mixture of highly heterogeneous oxidation products, such as theaflavins, whereas flavonols, phenolic acids, and xanthine alkaloids remained stable throughout the manufacturing process. Aldehydes, ketones, and heterocyclic compounds, imparting woody, floral, and nutty scent, were mainly formed during the roasting steps. This detailed information can expand our understanding on the formation of WRT flavor.

Impaired wrist position sense is linked to motor abnormalities in young adults with a probable developmental coordination disorder.

Proprioceptive deficits have been found to underlie motor abnormalities in individuals with movement disorders. This study investigated wrist proprioceptive acuity in young adults with and without probable developmental coordination disorder (DCD) and examined how proprioceptive acuity is linked to different domains of motor function. Thirty participants were included in this study (age, 19-22 years), ten with probable DCD and 20 controls. Wrist proprioceptive acuity was assessed using a joint position sense paradigm under contralateral and ipsilateral conditions. The Bruininks - Oseretsky Test of Motor Proficiency 2nd Edition (BOT-2) was used to measure different domains of motor ability. Compared to the control group, young adults with probable DCD exhibited significantly increased proprioceptive error variability in contralateral (p < 0.0001) and ipsilateral conditions (p < 0.05). Furthermore, wrist proprioceptive error variability was significantly associated with the levels of body coordination measured by BOT-2 (r = - 0.55). This study verified impaired wrist proprioceptive function in young adults with probable DCD, which is likely to contribute to motor impairment in adults with DCD.

Levels and patterns of physical activity and sedentary behavior in adults with and without visual impairment.

BACKGROUND: Limited data are available on objectively measured physical activity (PA) and sedentary behavior (SB) among adults with and without visual impairment (VI). OBJECTIVE: To compare PA and SB levels and patterns in adults with and without VI and to examine how these differ based on sex and day of the week. METHODS: Thirty-two participants with VI and 32 participants without VI participated in this cross-sectional study. PA and SB were assessed using GT3X ActiGraph accelerometers during waking hours for 7 days, and variables were examined in terms of disability group, sex, and day of the week. Nonparametric Mann-Whitney U test and Wilcoxon signed-rank test were used, and significance was set at p < 0.05. RESULTS: PA did not differ in terms of sex or day of the week in participants with VI. The PA of participants without VI was significantly higher for men than it was for women and was significantly higher during weekdays than on weekend days. Total sedentary time and the duration of SB breaks were significantly longer for female participants with VI than for those without VI. The number of sedentary bouts lasting ≥10 min during weekend days was significantly higher for participants with VI than for those without VI. CONCLUSIONS: Most adults with and without VI did not meet the recommended levels of daily PA and spend a large portion of the day being sedentary. Interventions to enhance PA and reduce sedentary time in adults with and without VI are required.

Upper limb proprioception and fine motor function in young pianists.

BACKGROUND: This study investigated if intensive piano training may be associated with improved motor and somatosensory function. We systematically examined upper limb proprioception, which is known to play an essential role in skill movements, and motor function in young pianists. METHOD: Forty-four typically developing children who either regularly played piano for more than six years (N = 16) or had no experience playing musical instruments (N = 28) participated. Elbow and wrist joint proprioceptive acuity was assessed using a manipulandum. The wrist/elbow was passively flexed to a target with participants actively trying to match the just experienced target position. Motor function was assessed using the Movement Assessment Battery for Children (MABC-2). RESULTS: First, children in the pianist group exhibited significantly lower position sense bias (systematic error) at both the elbow and wrist when compared to controls. Position sense precision (random error) was not different between groups. Second, the piano group exhibited enhanced fine motor function as shown by higher manual dexterity MABC-2 scores. Performance in other motor domains (aiming and catching or balance) was not improved in young pianists. Third, a lower position sense bias was correlated with a higher level of manual dexterity. CONCLUSION: This study documents that children who regularly play the piano have superior upper limb position sense acuity. Specifically, smaller position sense bias, i.e., less systematic error. Superior upper position sense acuity in young pianists is associated with higher fine motor functions.

Effects of a Floor Hockey Intervention on Motor Proficiency, Physical Fitness, and Adaptive Development in Youths with Mild Intellectual Disabilities.

This study examined the effects of a 12-week floor hockey training program on the motor proficiency, physical fitness, and adaptive development of youths with mild intellectual disabilities (IDs). A total of 54 youths with IDs were divided into two groups: a floor hockey exercise group (EG; n = 27; age, 16.59 ± 0.56 years) and a control group (CG; n = 27; age, 16.65 ± 0.63 years). The participants in the EG attended sessions of a floor hockey training program 3 times per week over a 12-week period. The CG group maintained their standard activities of daily living. The participants' scores on the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition, Brockport Physical Fitness Test, and traditional Chinese version of the teacher form of the Adaptive Behavior Assessment System, Second Edition, were obtained before and after the intervention. The results of the study indicate that the 12-week floor hockey training program significantly increased the participants' scores for most indicators of motor proficiency (p < 0.01), physical fitness (p < 0.01), and adaptive development (p < 0.01). The findings provide evidence that physical activity interventions focusing on floor hockey training are a viable therapeutic option for treating youths with IDs.

Acute effects of high-intensity interval training and moderate-intensity continuous exercise on BDNF and irisin levels and neurocognitive performance in late middle-aged and older adults.

The purposes of the present study were (1) to explore and compare the acute effects of high-intensity interval training (HIIT) and moderate-intensity continuous exercise (MICE) on neurocognitive performance and molecular biomarkers in late middle-aged and older adults, and (2) to examine the relationships of HIIT/MICE exercise-induced neurocognitive changes with changes in circulating irisin and BDNF levels elicited by different acute exercise modes. Using a within-subject design, twenty-one participants completed an acute bout of 30 min of HIIT, MICE, or a non-exercise-intervention (REST) session in a counterbalanced order. The neuropsychological [i.e., accuracy rate (AR) and reaction time (RT)] and neurophysiological [i.e., event-related potential (ERP) P3 latency and amplitude] indices were simultaneously measured when the participants performed a working memory task at baseline and after an intervention mode. Blood samples were also taken before and after the intervention mode. The results showed that, although ARs were significantly increased only via the MICE intervention mode, the acute HIIT and MICE interventions improved RT performance and increased ERP P3 amplitudes in the late middle-aged and older adults under consideration. Serum BDNF levels were significantly increased with the acute HIIT and MICE interventions, and significant irisin level increases were only observed following the HIIT intervention. However, changes in the levels of Irisin and BDNF pre- and post-intervention were not correlated with changes in neurocognitive performance, with the exception of the correlation between the changes in irisin levels and RTs with acute exercise in the MICE intervention mode. The present findings suggested similar beneficial effects on neurocognitive performance (i.e., RTs and ERP P3 amplitudes) and peripheral BDNF levels following MICE and HIIT interventions in the middle-aged and older adults. In terms of ARs and irisin, the two acute exercise modes appear to induce divergent effects. Irisin may play a potential facilitating role in the neuropsychological (e.g., RT) performance of working memory in such a group. However, the mechanisms remain to be determined.

Physical and Sedentary Activity Patterns in Youths with Autism Spectrum Disorder.

Little is known about the patterns of sedentary behavior and physical activity (PA) within different school levels (i.e., primary school and secondary school) and on different day types (i.e., weekdays and weekend days) among youths with autism spectrum disorder (ASD). The sample was recruited from one city in Taiwan. A total of 68 male youths with ASD, aged 6-17 years, participated in the study. PA was assessed using an ActiGraph accelerometer, and sedentary behaviors (i.e., TV viewing, computer use, and reading time) were determined using a self-report log. The main findings were that (a) primary school youths with ASD were more active than secondary school youths with ASD on both weekdays and weekend days, but primary school youths with ASD also had more sedentary time than did secondary school youths with ASD on both weekdays and weekend days; (b) secondary school youths with ASD were more active but also more sedentary on weekdays compared with weekend days, but they had more screen use on weekend days compared with on weekdays. Future interventions are required to decrease sedentary behavior and increase PA to improve the health of these youths according to school level and day of the week.

Joint position sense of lower extremities is impaired and correlated with balance function in children with developmental coordination disorder.

OBJECTIVE: To determine the joint position sense of the lower extremities and its relationship with motor function in children with developmental coordination disorder (DCD) and typically developing (TD) children. METHODS: A total of 56 participants were recruited; 28 children with DCD (age 10.86±1.07 years; 13 females, 15 males) and 28 TD children (age 10.96±1.18 years; 12 females, 16 males). Knee and ankle joint position sense were assessed using a Biodex isokinetic dynamometer. Joint position acuity was measured by position error (PE) and position error variability (PEV). Motor function was examined using the 2nd edition of Movement Assessment Battery for children (MABC-2) and quantified via sub-scores from 3 MABC-2 domains. RESULTS: Both PE and PEV at knee and ankle joints were significantly greater in children with DCD compared with TD children. In addition, both PE and PEV were significantly greater at the ankle joints than the knee joints in children with DCD. For children with DCD only, joint position acuity in the lower extremities significantly and negatively correlated with MABC-2 balance sub-score. CONCLUSION: This study verifies that lower limb proprioception is impaired in children with DCD. Also, children with DCD displayed greater proprioceptive deficits at the ankle compared with the knee joint. Children with DCD who had poorer joint position acuity, i.e. greater PE and PEV, in the lower extremities tended to perform less well in balance function.

Motion Planning and Iterative Learning Control of a Modular Soft Robotic Snake.

Snake robotics is an important research topic with a wide range of applications, including inspection in confined spaces, search-and-rescue, and disaster response. Snake robots are well-suited to these applications because of their versatility and adaptability to unstructured and constrained environments. In this paper, we introduce a soft pneumatic robotic snake that can imitate the capabilities of biological snakes, its soft body can provide flexibility and adaptability to the environment. This paper combines soft mobile robot modeling, proprioceptive feedback control, and motion planning to pave the way for functional soft robotic snake autonomy. We propose a pressure-operated soft robotic snake with a high degree of modularity that makes use of customized embedded flexible curvature sensing. On this platform, we introduce the use of iterative learning control using feedback from the on-board curvature sensors to enable the snake to automatically correct its gait for superior locomotion. We also present a motion planning and trajectory tracking algorithm using an adaptive bounding box, which allows for efficient motion planning that still takes into account the kinematic state of the soft robotic snake. We test this algorithm experimentally, and demonstrate its performance in obstacle avoidance scenarios.