Initial results from the PHEFREE longitudinal natural history study: Cross-sectional observations in a cohort of individuals with phenylalanine hydroxylase (PAH) deficiency.

Over fifty years have passed since the last large scale longitudinal study of individuals with PAH deficiency in the U.S. Since then, there have been significant changes in terms of treatment recommendations as well as treatment options. The Phenylalanine Families and Researchers Exploring Evidence (PHEFREE) Consortium was recently established to collect a more up-to-date and extensive longitudinal natural history in individuals with phenylketonuria across the lifespan. In the present paper, we describe the structure and methods of the PHEFREE longitudinal study protocol and report cross-sectional data from an initial sample of 73 individuals (5 months to 54 years of age) with PAH deficiency who have enrolled. Looking forward, the study holds the promise for advancing the field on several fronts including the validation of novel neurocognitive tools for assessment in individuals with PKU as well as evaluation of the long-term effects of changes in metabolic control (e.g., effects of Phe-lowering therapies) on outcome.

Chronic stroke survivors underestimate their upper limb motor ability in a simple 2D motor task.

BACKGROUND: Stroke survivors can exhibit a mismatch between the actual motor ability of their affected upper limb and how much they use it in daily life. The resulting non-use of the affected upper limb has a negative impact on participation in neurorehabilitation and functional independence. The factors leading to non-use of the affected upper limb are poorly understood. One possibility is that non-use comes about through inappropriately low confidence in their own upper limb motor abilities. OBJECTIVE: We asked whether chronic stroke survivors underestimate the motor ability of their affected upper limb. METHODS: 20 chronic stroke survivors (Mean FM: 28.2 ± 10.5) completed a 2D reaching task using an exoskeleton robot. Target sizes were individually altered to ensure success rates were similar for both upper limbs. Prior to each reaching movement, participants rated their confidence about successfully hitting the target (estimated upper limb motor ability). RESULTS: Confidence ratings were significantly lower for the affected upper limb (estimated ability), even though it was equally successful in the reaching task in comparison to the less affected upper limb (actual ability). Furthermore, confidence ratings did not correlate with level of impairment. CONCLUSIONS: Our results demonstrate that chronic stroke survivors can underestimate the actual motor abilities of their affected upper limb, independent of impairment level. Low confidence in affected upper limb motor abilities should be considered as a therapeutic target to increase the incorporation of the affected upper limb into activities of daily living.

Neuropsychological assessment of adults with phenylketonuria using the NIH toolbox.

Among researchers and clinicians, there is a call for the development and validation of new measures to better assess and characterize neurocognitive difficulties associated with early-treated phenylketonuria (ETPKU) and other metabolic disorders. The NIH Toolbox represents a relatively new computer-administered assessment tool and provides a sampling of performance across multiple cognitive domains, several of which (e.g., executive function, processing speed) are at risk for disruption in ETPKU. The goal of the present study was to provide an initial evaluation of the value and sensitivity of the NIH Toolbox for use with individuals with ETPKU. To this end, a sample of adults with ETPKU and a demographically-matched comparison group without PKU completed the cognitive and motor batteries of the Toolbox. Results indicate that overall performance (as reflected by the Fluid Cognition Composite) was sensitive to both group differences (ETPKU vs non-PKU) as well as blood Phe levels (a marker of metabolic control). The present findings offer preliminary support for the utility of the NIH Toolbox as a measure of neurocognitive functioning in individuals with ETPKU. Future research including a larger sample size and broader age range is needed to fully validate the Toolbox for clinical and research use with individuals with ETPKU.

Growth Velocities Across Distinct Early Life Windows and Child Cognition: Insights from a Contemporary US Cohort.

OBJECTIVE: To evaluate the relative importance of overall and period-specific postnatal growth and their interaction with fetal growth on cognition in a generally well-nourished population. STUDY DESIGN: We included 1052 children from Project Viva, a prospective cohort in Boston, Massachusetts. Using linear spline mixed-effects models, we modeled length/height and body mass index (BMI) trajectories from birth to 7 years and estimated standardized overall (0-7 years) and period-specific growth velocities ie, early infancy (0-4 months), late infancy (4-15 months), toddlerhood (15-37 months), and early childhood (37-84 months). We investigated associations of growth velocities as well as their interactions with birthweight-for-gestational age on mid-childhood (mean age: 7.9 years) IQ, visual memory and learning, and visual motor ability. RESULTS: Greater overall height velocity was associated with modestly higher design memory score, (adjusted ß [95% CI] 0.19 [-0.01,0.38] P = .057])points per SD increase but lower verbal IQ (-0.88 [-1.76,0.00] P = .051). Greater early infancy height velocity was associated with higher visual motor score (1.92 [0.67,3.18]). Greater overall BMI velocity was associated with lower verbal IQ (-0.71 [-1.52,0.11] P = .090). Greater late infancy BMI velocity was associated with lower verbal IQ (-1.21 [-2.07,-0.34]), design memory score (-0.22 [-0.42,-0.03)], but higher picture memory score (0.22 [0.01,0.43]). Greater early infancy height velocity (-1.5 SD vs 1.5 SD) was associated with higher nonverbal IQ (margins [95% CI] 102.6 [98.9106.3] vs 108.2 [104.9111.6]) among small-for-gestational age infants (P-interaction = 0.04). CONCLUSIONS: Among generally well-nourished children, there might not be clear cognitive gains with faster linear growth except for those with lower birthweight-for-gestational age, revealing the potential importance of early infancy compensatory growth.

Effects of dual-task training on gait and motor ability in patients with Parkinson's disease: A systematic review and meta-analysis.

OBJECTIVE: Parkinson's disease is one of the most common neurodegenerative diseases in the world, which seriously damages motor and balance ability. Dual-task training is discussed as an appropriate intervention. The aim of this review was to synthesize the existing research findings on the efficacy of dual-task training for people with Parkinson's disease. DATA RESOURCES: A systematic search on PubMed, CENTRAL, Embase, Web of Science, and PEDro, randomized-controlled trials (RCTs) of dual-task training for individuals with Parkinson's disease. METHODS: Articles published until 1 November 2022 were included. Our search identified 7 RCTs with a total of 406 subjects. Review Manager 5.4 software was used for bias evaluation and to process the results of the outcome measures collected from the investigations. RESULTS: Dual-task training was associated with significant improvement in most motor and balance outcomes including gait velocity (standard mean difference (SMD) = 0.62; 95% CI, 0.37-0.87; I2 = 31%; P = 0.21), cadence (SMD = 0.29; 95% CI, 0.05-0.53; I2 = 0%; P = 0.71), timed-up-and-go test (mean difference (MD) = -2.38; 95% CI, -3.93 to -0.84; I2 = 32%; P = 0.22) and mini-balance evaluation systems test (MD = 2.04; 95% CI, 1.05-3.03; I2 = 0%; P = 0.92). CONCLUSION: Evidence from meta-analyses suggests that dual-task training may improve motor and balance abilities in Parkinson's disease patients. Future research should focus on finding the most appropriate dual-task treatment model for patients with different degrees, in order to further improve the rehabilitation treatment of Parkinson's disease.

Transcriptomics and Phenotypic Analysis of gpr56 Knockout in Zebrafish.

The adhesion G-protein-coupled receptor is a seven-transmembrane receptor protein with a complex structure. Impaired GPR56 has been found to cause developmental damage to the human brain, resulting in intellectual disability and motor dysfunction. To date, studies on gpr56 deficiency in zebrafish have been limited to the nervous system, and there have been no reports of its systemic effects on juvenile fish at developmental stages. In order to explore the function of gpr56 in zebrafish, the CRISPR/Cas9 gene-editing system was used to construct a gpr56-knockout zebrafish. Subsequently, the differentially expressed genes (DEGs) at the transcriptional level between the 3 days post fertilization (dpf) homozygotes of the gpr56 mutation and the wildtype zebrafish were analyzed via RNA-seq. The results of the clustering analysis, quantitative PCR (qPCR), and in situ hybridization demonstrated that the expression of innate immunity-related genes in the mutant was disordered, and multiple genes encoding digestive enzymes of the pancreatic exocrine glands were significantly downregulated in the mutant. Motor ability tests demonstrated that the gpr56-/- zebrafish were more active, and this change was more pronounced in the presence of cold and additional stimuli. In conclusion, our results revealed the effect of gpr56 deletion on the gene expression of juvenile zebrafish and found that the gpr56 mutant was extremely active, providing an important clue for studying the mechanism of gpr56 in the development of juvenile zebrafish.

The relationship between metabolic control and basal ganglia morphometry and function in individuals with early-treated phenylketonuria.

Abnormalities of the cortical white matter are the most prominent and widely-reported neurological findings in individuals with early-treated phenylketonuria (ETPKU). Much less is known regarding the effects of ETPKU on gray matter structures in the brain such as the basal ganglia. Previous findings on basal ganglia in ETPKU have been mixed. The current study was designed to further elucidate the effects of ETPKU and elevated phe levels on the morphometry of basal ganglia structures (i.e., putamen, caudate nucleus, nucleus accumbens, and globus pallidus). High resolution magnetic resonance imaging (MRI) data was collected from a sample of 37 adults with ETPKU and a demographically-matched comparison group of 33 individuals without PKU. No overall group differences (ETPKU vs. non-PKU) in basal ganglia volumes were observed. However, within the ETPKU group, poorer metabolic control (as reflected by higher blood phenylalanine levels) was associated with larger putamen volume. Vertex-wise shape analysis revealed that the volume increase was accompanied by shape changes in the middle left putamen. Consistent with this area's role in motor control, a significant correlation between left putamen volume and motor performance was also observed. Additional research is needed to fully understand the cellular level processes underlying this effect as well as to better understand the clinical impact of these morphometric changes and their potential relation to treatment response.

Sevoflurane impairs m6A-mediated mRNA translation and leads to fine motor and cognitive deficits.

Clinical surgical practices have found that children who undergo multiple anesthesia may have an increased risk of deficiencies in cognition and fine motor control. Here, we report that YT521-B homology domain family 1 (YTHDF1), a critical reader protein for N6-methyladenosine-modified mRNA, was significantly downregulated in the prefrontal cortex of young mice after multiple sevoflurane anesthesia exposures. Importantly, sevoflurane led to a decrease in protein synthesis in mouse cortical neurons that was fully rescued by YTHDF1, suggesting that anesthesia may affect early brain development by affecting m6A-dependent mRNA translation. Transcriptome-wide experiments showed that numerous mRNA targets related to synaptic functions in the prefrontal mouse cortex were associated with m6A methylation and YTHDF1. In particular, we found that synaptophysin, a critical presynaptic protein, was specifically modified by m6A methylation and associated with YTHDF1, and m6A methylation of synaptophysin decreased with multiple sevoflurane exposures. Importantly, we showed that fine motor control skills and cognitive functions were impaired in mice with multiple anesthesia exposures, and these effects were fully reversed by reintroducing YTHDF1 through a blood-brain barrier (BBB)-crossing viral delivery system. Finally, we found that the fine motor skills in children who underwent prolonged anesthesia were compromised 6 months after surgery. Our findings indicated that impairment in the translational regulation of mRNA via N6-methyladenosine methylation is a potential mechanism underlying the effects of anesthesia on neural development in the young brain. 1. N6-methyladenosine (m6A) modifications were involved in anesthesia-induced neurotoxicity. 2. Sevoflurane impairs m6A-mediated mRNA translation and leads to fine motor deficits in young mice. 3. YTHDF1, a m6A reader protein, rescued sevoflurane-induced protein synthesis inhibition and fine motor deficits in young mice.

Effects of unilateral dynamic handgrip on reaction time and error rate.

Quick and accurate reactions to environmental stimuli are often required. Researchers have investigated ways to improve these reactions, which are critical components of perceptual-motor abilities. To optimize individual performance, different techniques, such as embodied interventions and brain stimulation, have been examined. The evidence from EEG studies shows that upper limb muscle contractions lead to changes in brain oscillations associated with changes in mental states and behavioral outcomes. Much research has been conducted on whether muscle contractions of a particular hand have a greater effect on a perceptual-motor ability, as a trigger to facilitate cortical processes (a mediator) for skilled motor performance. While previous studies have shown that left- (vs. right-) hand contractions can lead to greater alpha activation, we hypothesized that left dynamic handgrips have different impacts on motor performance, reflected by simple RT (SRT) and choice RT (CRT). We recruited 64 right-handers, for a within/between-subjects experiment consisting of performance measurements in SRT and CRT tasks after the intervention (either right or left dynamic handgrip approximately twice a second for 30 s for each hand) or assignment to paired passive control groups. We did not find left-hand contractions improve response accuracy in neither SRT nor CRT tasks. Further, left-hand contractions did not affect RTs. The findings indicate that the effects of dynamic handgrips are smaller on behavioral outcomes such as RTs than what can be inferred from published studies. More research is needed to establish the effect of dynamic handgrips on optimizing performance.

Effect of frailty on kinematic characteristics of walking in community-dwelling elders.

OBJECTIVE: Frailty has a high prevalence in elders and impairs motor ability. This study aimed to investigate the influence caused by frailty in kinematic characteristics of walking and walking strategy adjustment from static standing to stable walking. METHODS: In this study, 80 community-dwelling elders performed tests. The Kihon checklist (KCL) was used to assess frailty. The timed up and go test (TUGT) and the 30-s chair stand test (30-s CST) were used to assess balance and muscle strength. The Xsens MVN BIOMECH Awinda was used to collect walking kinematic data. RESULTS: This study included 25 robust, 30 prefrail, and 25 frail elders. The TUGT completed time (P < 0.001) and the 30-s CST completed number (P = 0.002) had statistical differences among groups. The maximum peak of knee internal rotation showed an interaction between the frailty and the walking phase (P = 0.015). The peak angle of hip adduction, hip and knee flexion, and knee and ankle internal rotation were significantly lower in frail elders than others (P < 0.05). CONCLUSION: Frailty affects the kinematic characteristics of walking, resulting in the hip, knee, and ankle flexion, hip adduction, knee and ankle internal rotation reduced. Besides, frailty has a specific negative effect on the walking strategy adjustment from static standing to stable walking.

Association of physical fitness and motor ability at young age with locomotive syndrome risk in middle-aged and older men: J-Fit+ Study.

BACKGROUND: Physical fitness and motor ability are associated with the incidence of locomotive syndrome (LS) in older adults. The relationships between physical fitness and motor ability at a young age to LS risk in later life remain unclear. This study examined the association between physical fitness and motor ability among university students and their risk of LS in middle and old age. METHODS: The participants were 231 male alumni aged 48-65 years from the Department of Physical Education of a university in Japan. Physical fitness and motor ability test results during their fourth year at the university were used. Physical fitness tests included the side-step test, vertical jump test, back muscle, grip strength, trunk lift, standing trunk flexion, and step-test. Motor ability was tested using the 50-m and 1500-m run, running long jump, hand-ball throw, and pull-up test. LS risk was assessed using a seven-question standardized self-administered Loco-check questionnaire. Participants were divided into three groups (low, medium, and high) based on physical fitness and motor ability test results at young age, and LS risk was assessed at an older age across the three groups using Cox proportional hazards models. RESULTS: From the 2017 follow-up survey, the median follow-up period was 37 years (interquartile range, 33-41), and LS risk was suspected for 31 (13.4%) participants. Better performance on the side-step test was associated with the reduced risk of LS (hazard ratio 0.32; 95% confidence interval, 0.101-0.983, P = 0.047). CONCLUSIONS: Good agility (side-step test) at a young age may reduce the future risk of LS among middle-aged and older men.

Physical fitness components in relation to attention capacity in Latin American youth with overweight and obesity.

The aim of the study was twofold: (a) to examine the association between health-related physical fitness and attention capacity in Latin American children and adolescents with overweight and obesity and (b) to test whether body composition outcomes are moderators of this association. A cross-sectional design was used to study 201 overweight/obese participants (12.1 ± 2.1 years of age; 34.3% girls) from Chile (Active-Start study) and Colombia (HEPAFIT study). Body composition, muscular fitness, speed-agility, and cardiorespiratory fitness were evaluated using two similar test batteries (ALPHA and FUPRECOL). Attention capacity was measured by the d2 Test. Linear regression and moderation analyses were conducted. Linear regression analysis revealed an association between muscular fitness (ß = 0.245, P = .015), speed-agility (ß = -0.16, P = .027), cardiorespiratory fitness (ß = 0.331, P < .001) and overall fitness score (ß = 0.210; P = .004) and attention capacity (all analyses were controlled for age, sex, peak height velocity, maternal education, and study setting). Moderation analysis using the Johnson-Neyman technique revealed that the effect of the relationship between muscular fitness score and speed-agility and attention capacity was stronger as fat mass and fat mass index increased. In conclusion, physical fitness components are associated with higher attention capacity in youth with overweight/obesity, but body composition seems to moderate these relationships. Randomized controlled trials in this population would help to better understand whether improvements in different components of physical fitness lead to better attention capacity, especially in youth with excess adiposity.

The novel pesticide flupyradifurone (Sivanto) affects honeybee motor abilities.

Honeybees and other pollinators are threatened by changing landscapes and pesticides resulting from intensified agriculture. In 2018 the European Union prohibited the outdoor use of three neonicotinoid insecticides due to concerns about pollinators. A new pesticide by the name of "Sivanto" was recently released by Bayer AG. Its active ingredient flupyradifurone binds to the nicotinic acetylcholine receptor (AchR) in the honeybee brain, similar to neonicotinoids. Nevertheless, flupyradifurone is assumed to be harmless for honeybees and can even be applied on flowering crops. So far, only little has been known about sublethal effects of flupyradifurone on honeybees. Intact motor functions are decisive for numerous behaviors including foraging and dancing. We therefore selected a motor assay to investigate in how far sublethal doses of this pesticide affect behavior in young summer and long-lived winter honeybees. Our results demonstrate that flupyradifurone (830 µmol/l) can evoke motor disabilities and disturb normal motor behavior after a single oral administration (1.2 µg/bee). These effects are stronger in long-lived winter bees than in young summer bees. After offering an equal amount of pesticide (1.0-1.75 µg) continuously over 24 h with food the observed effects are slighter. For comparisons we repeated our experiments with the neonicotinoid imidacloprid. Intriguingly, the alterations in behavior induced by this pesticide (4 ng/bee) were different and longer-lasting compared to flupyradifurone, even though both substances bind to nicotinic acetylcholine receptors.

Distribution and motor ability of children with cerebral palsy in Scotland: a registry analysis.

BACKGROUND AND AIMS: Cerebral palsy is the commonest long-term physical disability in children with a prevalence of between 1.77 and 2.11/1000 live births. In 2013, the Cerebral Palsy Integrated Pathway Scotland (CPIPS) surveillance programme was introduced in all 14 Health Boards in Scotland and provides a standardised musculoskeletal examination of the spine and lower limbs. The purpose of this study was to report the prevalence, subtypes, motor classification and motor ability of children with cerebral palsy in Scotland. METHODS AND RESULTS: The family/carer's postal address, the child's neurological classification, motor subtypes, Gross Motor Functional Classification (GMFCS) Level and Functional Mobility Scale of 1972 children at first registration in CPIPS 2013-2018 were analysed. Their mean age at first assessment was 7.6 years. There was an overall prevalence of cerebral palsy in Scotland of 2.02/1000. GMFCS levels and Functional Mobility Scale data and prevalence were reported by Health Board and were comparable to that reported elsewhere. CONCLUSION: For the first time, data are available on the motor abilities of the total population of children with cerebral palsy in Scotland. This information will be highly relevant to resource management of current and future motor needs of these children.

[Substantiation of a procedure for correction of the properties of human motor abilities via biofeedback for support reaction]. / Obosnovanie metodiki korrektsii svoistv dvigatel'nykh sposobnostei cheloveka s ispol'zovaniem biologicheskoi obratnoi sviazi po opornoi reaktsii.

BACKGROUND: Stability training, including rehabilitation, using the principle of biofeedback for support reaction on the stabilometric platform, is used to restore the functions of maintaining balance in medicine and to increase vertical stability in athletes, etc. in sports. AIM: To substantiate a procedure to correct the properties of human motor abilities during stability training, which are based on the consideration of the consistently involved levels of the nervous system in the construction of movements during games using biofeedback for support reaction. MATERIAL AND METHODS: The multilevel motion construction concept proposed by N.A. Bernstein (1947) was analyzed. Computer-assisted stabilometry, including Romberg's test with the eyes open and closed in the European standing (for 51 sec), was used for objective instrumental assessment of postural function. The study included 7 university students who belonged to a special medical group for their health status. The training was stopped when the student felt worse, tired, and unwilling to continue the game. The training duration was 12 to 22 minutes. To obtain reliable results, all stabilometric examinations were made from 8 to 9 o'clock in the morning. The study results were statistically analyzed using the goodness-of-fit test: Z-test (equality of the observed frequencies of two events), Wilcoxon signed rank test (when comparing dependent samples). RESULTS: The paper describes a relationship between the provisions of the multilevel motion construction concept proposed by N.A. Bernstein and the information about the levelled organization of movements during games via biofeedback for support reaction; guidelines for their use and experimental confirmation for the higher function of motor abilities: muscle synergy and kinesthetic sensitivity. CONCLUSION: There is evidence for the positive training effect on the function of motor ability properties of the pallidothalamic level of the nervous system during games via biological feedback for support reaction, their informative value compared with other stabilometric indicators.

Uncovering neurodevelopmental windows of susceptibility to manganese exposure using dentine microspatial analyses.

BACKGROUND: Associations between manganese (Mn) and neurodevelopment may depend on dose and exposure timing, but most studies cannot measure exposure variability over time well. OBJECTIVE: We apply temporally informative tooth-matrix biomarkers to uncover windows of susceptibility in early life when Mn is associated with visual motor ability in childhood. We also explore effect modification by lead (Pb) and child sex. METHODS: Participants were drawn from the ELEMENT (Early Life Exposures in MExico and NeuroToxicology) longitudinal birth cohort studies. We reconstructed dose and timing of prenatal and early postnatal Mn and Pb exposures for 138 children by analyzing deciduous teeth using laser ablation-inductively coupled plasma-mass spectrometry. Neurodevelopment was assessed between 6 and 16 years of age using the Wide Range Assessment of Visual Motor Abilities (WRAVMA). Mn associations with total WRAVMA scores and subscales were estimated with multivariable generalized additive mixed models. We examined Mn interactions with Pb and child sex in stratified models. RESULTS: Levels of dentine Mn were highest in the second trimester and declined steeply over the prenatal period, with a slower rate of decline after birth. Mn was positively associated with visual spatial and total WRAVMA scores in the second trimester, among children with lower (< median) tooth Pb levels: one standard deviation (SD) increase in ln-transformed dentine Mn at 150 days before birth was associated with a 0.15 [95% CI: 0.04, 0.26] SD increase in total score. This positive association was not observed at high Pb levels. In contrast to the prenatal period, significant negative associations were found in the postnatal period from ~ 6 to 12 months of age, among boys only: one SD increase in ln-transformed dentine Mn was associated with a 0.11 [95% CI: - 0.001, - 0.22] to 0.16 [95% CI: - 0.04, - 0.28] SD decrease in visual spatial score. CONCLUSIONS: Using tooth-matrix biomarkers with fine scale temporal profiles of exposure, we found discrete developmental windows in which Mn was associated with visual-spatial abilities. Our results suggest that Mn associations are driven in large part by exposure timing, with beneficial effects found for prenatal levels and toxic effects found for postnatal levels.

The development of the physical fitness construct across childhood.

The measurement of physical fitness (PF) is an important factor from many different perspectives. PF is a determinant of healthy child development as it is related to several health outcomes. However, existing taxonomies of the construct and frequently used fitness assessments vary concerning their theoretical assumptions and practical implications. From a theoretical perspective, the construct of physical fitness covers a variety of motor domains, such as cardiovascular endurance, strength, coordination, or flexibility (eg, Caspersen et al., 1985). However, most fitness assessments provide a single (composite) score including all items as test outcome. This implicitly relates to a one-dimensional structure of physical fitness, which has been shown for other motor performance assessments in early childhood (eg, Utesch et al., 2016). This study investigated this one-dimensional structure for 6- to 9-year-old children within the item response theory framework (Partial Credit Model). Seven fitness subtests covering a variety of motor dimensions (6-minute run, pushups, sit-ups, standing broad jump, 20 m sprint, jumping sideways, and balancing backwards) were conducted to a total of 790 six-year-olds, 1371 seven-year-olds, 1331 eight-year-olds, and 925 nine-year-olds (48.2% females). Each item was transformed into five performance categories controlling for sex and age. This study indicates that a one-dimensional testing of PF is feasible across middle childhood. Furthermore, for 6- and 7-year-olds, all seven items including balancing backwards can be accumulated to one factor. From the age of about 8 and 9 years balancing backwards seems to become too easy. Altogether, analyses show no diversification of PF across childhood.

Fine motor ability and psychiatric disorders in youth.

Impaired fine motor ability has been linked to several domains of psychopathology. However, studies validating the specificity of this association among several categorical psychiatric disorders are still needed. The aim of this study was to assess differences in fine motor ability performance among four non-overlapping groups of psychiatric disorders and a group of typical developing comparisons (TDC). Our sample consisted of 2035 subjects aged 6-14-year-old. Diagnoses of psychiatric disorders were performed with the Development and Well-Being Assessment (DAWBA). Five non-overlapping groups without comorbidity were formed: phobic disorders (n = 101), distress disorders (n = 82), attention deficit hyperactivity disorder (ADHD) (n = 133), oppositional defiant disorder/conduct disorder (ODD/CD) (n = 52) and one group of typical developing comparisons (TDC) (n = 1667). Fine motor ability was evaluated by three tasks: sequential finger-thumb opposition, Oseretsky, and pronation/supination tests. Each task was assessed by total time to perform the movement and levels of accuracy, fluency, symmetry, precision, and coordination. We found that, when compared to TDC, the ADHD group performed more poorly in total fine motor ability (mean difference = - 0.28; p = 0.014), time to complete the task (mean difference = 0.36; p < 0.001), accuracy (mean difference = - 0.30; p = 0.005), fluency (mean difference = - 0.26; p = 0.03), symmetry (mean difference - 0.25; p = 0.04), precision (mean difference = - 0.26; p = 0.026), and coordination (mean difference = - 0.25; p = 0.042). The ADHD group also took more time to complete the task than the ODD/CD group (mean difference = 0.45; p = 0.037). No other significant between-group differences were found. Additional analyses showed those differences were statistically significant for all ADHD dimensions. Our results suggest that children with ADHD present impairments in all aspects of fine motor abilities compared to TDC, a difference not found in other psychiatric disorders.

[Analysis of the relevance of age and toe out angle of normal adults' gait].

Due to the decline of motor ability and the impact of the diseases, abnormalities in gait is common in the elderly population, which will raise the risk of fall and cause serious injury. This study focuses on the analysis of the gait kinematics parameters of normal adults' gait, aiming to investigate the characteristics of gait parameters in different age groups and to explore the role of gait parameters in motor function assessment and clinical diagnosis. Based on the gait data gained by electronic walkway, the relationship among the toe out angles and their correlation with age and gender etc. were quantitatively analyzed. The results show that most normal subjects walk with positive toe out angles, and the angles increase with age. Such changes are slow in the young and middle age groups. However, the elevations of the left out toe angle and the angles between the feet are statistically significant after entering elder age ( >60 years). The results also suggest that the angle between the feet is a kind of practical gait parameter for varying applications. This study concludes that feet angle analysis is potential to provide a convenient and quantitative tool for the assessment of lower limb motor ability and the diagnosis of knee joint diseases.

Action ability modulates time-to-collision judgments.

Time-to-collision (TTC) underestimation has been interpreted as an adaptive response that allows observers to have more time to engage in a defensive behaviour. This bias seems, therefore, strongly linked to action preparation. There is evidence that the observer's physical fitness modulates the underestimation effect so that people who need more time to react (i.e. those with less physical fitness) show a stronger underestimation effect. Here we investigated whether this bias is influenced by the momentary action capability of the observers. In the first experiment, participants estimated the time-to-collision of threatening or non-threatening stimuli while being mildly immobilized (with a chin rest) or while standing freely. Having reduced the possibility of movement led participants to show more underestimation of the approaching stimuli. However, this effect was not stronger for threatening relative to non-threatening stimuli. The effect of the action capability found in the first experiment could be interpreted as an expansion of peripersonal space (PPS). In the second experiment, we thus investigated the generality of this effect using an established paradigm to measure the size of peripersonal space. Participants bisected lines from different distances while in the chin rest or standing freely. The results replicated the classic left-to-right gradient in lateral spatial attention with increasing viewing distance, but no effect of immobilization was found. The manipulation of the momentary action capability of the observers influenced the participants' performance in the TTC task but not in the line bisection task. These results are discussed in relation to the different functions of PPS.