Motor skill acquisition in children with poor motor coordination

Physical Activity is essential for growth, development and wellbeing. Children with poor motor coordination are known to have lower levels of participation in physical activity and exercise in comparison to their typically developing peers, at least partly due to the difficulty in acquiring the motor skills they need for participation. Reduced participation in physical activity in childhood increases the risk of developing obesity, cardiovascular disease and psychosocial problems which persist throughout adolescence and adulthood. Poor motor coordination in these children has been largely attributed to their difficulty in acquiring and performing motor skills. However, motor skill acquisition is not yet well understood in this group, in particular whether these children are able to improve the quality of their movement and the pattern of motor skill acquisition. The following thesis aims to investigate the motor skill acquisition in a group of children with motor coordination difficulties and is comprised of two main studies. The first one aims at creating a simple and easy tool for screening coordination in large cohorts of children in mainstream schools in order to identify children with poor motor coordination. The second study is a pilot/feasibility study aimed at informing the implementation of a fully powered follow-up motor learning intervention trial. It involved detection of a sample of children with poor motor coordination using the designed screening tool in 3 mainstream schools and recruiting them into a physical training intervention with an embedded practice of a novel rhythmic stepping task. The characteristics of their performance throughout the training program were investigated by instrumenting the stepping ask and comparing the performance with a group of children with normal motor coordination. Applying a reduction analysis on a large set of motor screening data (which included test items from The Bruininks-Oseretsky Test of Motor Proficiency-Short Form (BOT-SF) as well as Fundamental Movement Skill), we successfully designed a test which has face validity for detection of children with poor coordination. Using this test, we screened a total of 571 students (273 females and 298 males) from 3 main stream schools in Oxfordshire and invited students who scored below the 25th percentile on our screening test (117; 53 girls and 64 boys) to an 11 week training intervention. Thirty-three students attended the intervention (21 girls and 12 boys) with a great difference in recruitment and retention rates between the schools. The learning of the novel motor skill was measured by analysis of the participants’ performance on a novel stepping task, in which they stepped rhythmically in accordance to a sequence of visual stimuli presented on a computer screen. The performance (movement time), measured using accelerometry, was significantly worse in children with coordination problems (p<.001) mean±SD= 1.193±.036. Importantly, children with poor motor coordination were able to improve their performance on the task with no significant differences between the groups. However, we observed a tendency for difference in the pattern of improvement over time (p=.06). Given the nature of the conducted studies, i.e. as feasibility studies, our findings don’t allow of a straightforward generalisation. Still, they entail important implications in clinical and school-based training interventions, directed towards children with poor motor coordination, and it is recommended that a follow-up trial take place which takes into account the suggestions mentioned in this thesis with regards to the involvement of schools, importance of applying successful recruitment strategy and the requirements of successful intervention

School-based screening tool for adolescents with low motor coordination abilities

This study sought to select the most relevant test items from the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition (BOTMP-2) and from a selection of health-related fitness tests for identifying school teenagers with poor motor coordination. The 241 participants in this study (144 boys, 97 girls aged 13–14 years old) were tested on the short form of the BOTMP-2 and on the following additional fitness tests: (a) seated medicine ball test, (b) broad jump, (c) handgrip strength, (d) alternate hand ball wall toss, (e) 10 × 5-meter agility shuttle run, and (f) Chester step test. We performed a factor analysis of participant scores on these various tasks and BOTMP-2 test items to reduce them to the least number of meaningful and useful items. Four factors explained 45% of the data variance: gross motor skills and power (including broad jump, hand ball toss, shuttle run, and sit-ups tests); fine motor skills (including copying star, following the maze and paper folding); core strength and balance (including push-ups, hopping, and balance beam); and general body strength (including medicine ball throw and handgrip). We conclude that an efficient school-based battery of test items to screen 13-14 year old adolescents for fitness and coordination should assess these four factors and might especially rely upon the broad jump, copying a star shape, hopping handgrip strength, aerobic fitness, and wall ball toss

Neural Substrates of Cognitive Motor Interference During Walking; Peripheral and Central Mechanisms

Current gait control models suggest that independent locomotion depends on central and peripheral mechanisms. However, less information is available on the integration of these mechanisms for adaptive walking. In this cross-sectional study, we investigated gait control mechanisms in people with Parkinson’s disease (PD) and healthy older (HO) adults: at self-selected walking speed (SSWS) and at fast walking speed (FWS). We measured effect of additional cognitive task (DT) and increased speed on prefrontal (PFC) and motor cortex (M1) activation, and Soleus H-reflex gain. Under DT-conditions we observed increased activation in PFC and M1. Whilst H-reflex gain decreased with additional cognitive load for both groups and speeds, H-reflex gain was lower in PD compared to HO while walking under ST condition at SSWS. Attentional load in PFC excites M1, which in turn increases inhibition on H-reflex activity during walking and reduces activity and sensitivity of peripheral reflex during the stance phase of gait. Importantly this effect on sensitivity was greater in HO. We have previously observed that the PFC copes with increased attentional load in young adults with no impact on peripheral reflexes and we suggest that gait instability in PD may in part be due to altered sensorimotor functioning reducing the sensitivity of peripheral reflexes

Neural substrates of cognitive motor interference during walking: Peripheral and central mechanisms

Current gait control models suggest that independent locomotion depends on central and peripheral mechanisms. However, less information is available on the integration of these mechanisms for adaptive walking. In this cross-sectional study, we investigated gait control mechanisms in people with Parkinson’s disease (PD) and healthy older (HO) adults: at self-selected walking speed (SSWS) and at fast walking speed (FWS). We measured effect of additional cognitive task (DT) and increased speed on prefrontal (PFC) and motor cortex (M1) activation, and Soleus H-reflex gain. Under DT-conditions we observed increased activation in PFC and M1. Whilst H-reflex gain decreased with additional cognitive load for both groups and speeds, H-reflex gain was lower in PD compared to HO while walking under ST condition at SSWS. Attentional load in PFC excites M1, which in turn increases inhibition on H-reflex activity during walking and reduces activity and sensitivity of peripheral reflex during the stance phase of gait. Importantly this effect on sensitivity was greater in HO. We have previously observed that the PFC copes with increased attentional load in young adults with no impact on peripheral reflexes and we suggest that gait instability in PD may in part be due to altered sensorimotor functioning reducing the sensitivity of peripheral reflexes

The relationship of gross upper and lower limb motor competence to measures of health and fitness in adolescents aged 13–14 years

Introduction: Motor competence (MC) is an important factor in the development of health and fitness in adolescence. Aims: This cross-sectional study aims to explore the distribution of MC across 13-14 year old school students and the extent of the relationship of MC to measures of health and fitness across genders. Methods: A total of 718 participants were tested from three different schools in the UK, 311 girls, and 407 boys (aged 13-14 years), pairwise deletion for correlation variables reduced this to 555 (245 girls, 310 boys). Assessments consisted of, body mass index, aerobic capacity, anaerobic power, upper limb and lower limb MC. The distribution of MC and the strength of the relationships between MC and health/fitness measures were explored. Results: Girls performed lower for MC and health/fitness measures compared to boys. Both measures of MC showed a normal distribution and a significant linear relationship of MC to all health and fitness measures for boys, girls, and combined genders. A stronger relationship was reported for upper limb MC and aerobic capacity when compared to lower limb MC and aerobic capacity in boys (t= -2.21, df= 307, p = 0.03, 95%CI -0.253 -0.011). Conclusion: Normally distributed measures of upper and lower limb MC are linearly related to health and fitness measures in adolescents in a UK sample. Trial Registration: NCT0251733

The relationship of gross upper and lower limb motor competence to measures of health and fitness in adolescents aged 13-14 years

Introduction: Motor competence (MC) is an important factor in the development of health and fitness in adolescence. Aims: This cross-sectional study aims to explore the distribution of MC across 13-14 year old school students and the extent of the relationship of MC to measures of health and fitness across genders. Methods: A total of 718 participants were tested from three different schools in the UK, 311 girls, and 407 boys (aged 13-14 years), pairwise deletion for correlation variables reduced this to 555 (245 girls, 310 boys). Assessments consisted of, body mass index, aerobic capacity, anaerobic power, upper limb and lower limb MC. The distribution of MC and the strength of the relationships between MC and health/fitness measures were explored. Results: Girls performed lower for MC and health/fitness measures compared to boys. Both measures of MC showed a normal distribution and a significant linear relationship of MC to all health and fitness measures for boys, girls, and combined genders. A stronger relationship was reported for upper limb MC and aerobic capacity when compared to lower limb MC and aerobic capacity in boys (t= -2.21, df= 307, p = 0.03, 95%CI -0.253 -0.011). Conclusion: Normally distributed measures of upper and lower limb MC are linearly related to health and fitness measures in adolescents in a UK sample. Trial Registration: NCT0251733

Declining fitness and physical education lessons in UK adolescents

Objectives. The objective was to determine recent cross-sectional trends in health-related fitness (HRF) in secondary school students by studying the 13–14 years old age group repeatedly over 6 years, considering parallel national trends in physical education (PE). Methods. Height, weight, broad jump, grip strength, 20 m shuttle run and throwing and catching skills were measured by the same research team using standardised techniques from 2014 to 2019. Trends in these HRF measures were assessed by linear regression, adjusting for school, sex and height. Interactions with fitness and body mass index (BMI) were tested. The number of PE lessons reported in the UK Annual School Workforce Census between 2010 and 2019 for all state-funded secondary schools was analysed. Results. Grip strength (B=−0.60, 95% CI −0.78 to –0.41), broad jump (B=−1.16, 95% CI −1.99 to –0.34), 20 m shuttle run (B=−1.85, 95% CI −2.58 to –1.12) and throwing and catching skills (B=−0.12, 95% CI −0.15 to –0.08) declined significantly over the study period. There was a greater reduction in broad jump and grip strength in adolescents with low fitness and a greater reduction in fitness and motor competence in adolescents with normal BMI. These declines coincided with a 16% reduction nationally in secondary school PE between 2010 (333 800 hours) and 2019 (280 725 hours). Conclusion. Adolescent HRF has declined in recent years, in parallel with PE lessons. Declines were observed across all young people and particularly those of low fitness and normal BMI. To reach the majority of young people, policy makers could increase PE in schools to increase activity and prevent worsening fitness and health in future generations

Challenges of neural interfaces for stroke motor rehabilitation

More than 85% of stroke survivors suffer from different degrees of disability for the rest of their lives. They will require support that can vary from occasional to full time assistance. These conditions are also associated to an enormous economic impact for their families and health care systems. Current rehabilitation treatments have limited efficacy and their long-term effect is controversial. Here we review different challenges related to the design and development of neural interfaces for rehabilitative purposes. We analyze current bibliographic evidence of the effect of neuro-feedback in functional motor rehabilitation of stroke patients. We highlight the potential of these systems to reconnect brain and muscles. We also describe all aspects that should be taken into account to restore motor control. Our aim with this work is to help researchers designing interfaces that demonstrate and validate neuromodulation strategies to enforce a contingent and functional neural linkage between the central and the peripheral nervous system. We thus give clues to design systems that can improve or/and re-activate neuroplastic mechanisms and open a new recovery window for stroke patients

A hybrid brain-muscle-machine interface for stroke rehabilitation: Usability and functionality validation in a 2-week intensive intervention

Introduction: The primary constraint of non-invasive brain-machine interfaces (BMIs) in stroke rehabilitation lies in the poor spatial resolution of motor intention related neural activity capture. To address this limitation, hybrid brain-muscle-machine interfaces (hBMIs) have been suggested as superior alternatives. These hybrid interfaces incorporate supplementary input data from muscle signals to enhance the accuracy, smoothness and dexterity of rehabilitation device control. Nevertheless, determining the distribution of control between the brain and muscles is a complex task, particularly when applied to exoskeletons with multiple degrees of freedom (DoFs). Here we present a feasibility, usability and functionality study of a bio-inspired hybrid brain-muscle machine interface to continuously control an upper limb exoskeleton with 7 DoFs.Methods: The system implements a hierarchical control strategy that follows the biologically natural motor command pathway from the brain to the muscles. Additionally, it employs an innovative mirror myoelectric decoder, offering patients a reference model to assist them in relearning healthy muscle activation patterns during training. Furthermore, the multi-DoF exoskeleton enables the practice of coordinated arm and hand movements, which may facilitate the early use of the affected arm in daily life activities. In this pilot trial six chronic and severely paralyzed patients controlled the multi-DoF exoskeleton using their brain and muscle activity. The intervention consisted of 2 weeks of hBMI training of functional tasks with the system followed by physiotherapy. Patients’ feedback was collected during and after the trial by means of several feedback questionnaires. Assessment sessions comprised clinical scales and neurophysiological measurements, conducted prior to, immediately following the intervention, and at a 2-week follow-up.Results: Patients’ feedback indicates a great adoption of the technology and their confidence in its rehabilitation potential. Half of the patients showed improvements in their arm function and 83% improved their hand function. Furthermore, we found improved patterns of muscle activation as well as increased motor evoked potentials after the intervention.Discussion: This underscores the significant potential of bio-inspired interfaces that engage the entire nervous system, spanning from the brain to the muscles, for the rehabilitation of stroke patients, even those who are severely paralyzed and in the chronic phase