Maternal consumption of alcohol during pregnancy can induce a range of behavioral and cognitive deficits in offspring, which are collectively termed Fetal Alcohol Spectrum Disorders (FASD). There are significant delays in motor development and sensory-motor skills in children with FASD, but the underlying neurobiological mechanisms of these deficits are poorly understood. The goal of this research project is to test the hypothesis that the Kinesiological Instrument for Normal and Altered Reaching Movements (KINARM) will serve as an effective tool for identifying and measuring specific, neurologically-based motor deficits in children with FASD. These deficits were revealed through investigation of multi-joint upper limb movements during the performance of sensory-motor tasks. Children (31 FASD; 83 controls, aged 5 to 18 years, male and female) performed: (1) a visually-guided reaching task with fingertip feedback only; and children (31 FASD; 49 controls, aged 5 to 18 years, male and female) performed: (2) an arm position-matching task in the absence of visual feedback. Children with FASD differed significantly from controls in many reaching task outcome measures, specifically those related to the initial motor response and corrective responses. In particular, large effect sizes were observed for outcome measures related to the first (initial) movement (corresponding to feedforward control; e.g., direction error; distance error), as well as for those measures related to corrective responses (corresponding to feedback control; e.g., difference between minimum and maximum hand speeds; number of speed peaks during movement). In the position-matching task, children with FASD constricted the spatial workspace of the subject-controlled arm relative to the robot-controlled arm, in the horizontal axis. There was also observed a systematic shift between the subject- and robot-controlled arms in the XY end position, resulting in significant error. Additionally, children with FASD exhibited significantly increased trial-to-trial variability for final hand position of the subject-controlled arm, over all targets, and for which large effect sizes were observed. The results suggest that children with FASD have difficulty integrating sensory information into planned motor movements. The KINARM is a promising research tool that may be used to assess motor control deficits in children affected by prenatal exposure to alcohol. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2010-09-02 15:10:25.653

The contribution of deficits in limb position sense to the motor impairments of children with cerebral palsy, as well as other neurodevelopmental disorders, is increasingly being recognized. A more complete understanding of the development of multi-joint upper limb position sense is needed and has been limited, to date, by the absence of a reliable measurement technique to produce clinically meaningful information. The KINARM Exoskeleton’s bilateral position matching task, which involves passive movement of one of the subject’s arms to one of eight positions requiring different combinations of elbow and shoulder positions and active matching by the participant’s other arm, was evaluated for interrater and retest reliability. Intraclass correlation coefficients, absolute difference, minimum detectable difference that would be considered a significant change in performance, standard error of the measure, coefficient of variation, index of reliability, limit of agreement and confidence intervals were used to determine reliability on three measures of multi-joint position sense: (1) inter-trial variability in end-point position, (2) the ratio between actual and matched position, or spatial contraction/expansion, which provides a measure of the absolute accuracy of position matching, and (3) systematic errors in matching. Interrater index of reliability was very good to excellent with values of 72% for systematic errors in matching to 93% for contraction/expansion. Interrater intraclass correlation values were fair to excellent at 0.46 for systematic errors in matching to 0.81 for contraction/expansion. Standard errors in measurement were low and ranged from 0.002 to 0.06, for inter-trial variability and contraction/expansion respectively. Similarly, minimal detectable difference values for retest reliability ranged from 0.005 for inter-trial variability to 0.161 for contraction/expansion. Retest intraclass correlation values were fair to excellent at 0.38 for systematic errors in matching to 0.82 for contraction/expansion. Moderate to strong interrater and retest reliability and high measurement precision support the use of robot-based assessment of multi-joint position sense for developmental studies and promises to be a reliable clinical and research tool in the advancement of knowledge on sensory-motor coordination difficulties in children with neurodevelopmental disorders. / Thesis (Master, Rehabilitation Science) -- Queen's University, 2011-09-29 05:43:47.255

Made available in DSpace on 2016-06-02T20:19:14Z (GMT). No. of bitstreams: 1 3228.pdf: 1290499 bytes, checksum: b265c618eaa3f97d66f4b3ab4a0e214c (MD5) Previous issue date: 2010-08-19 / Universidade Federal de Minas Gerais / Repetitive throwing movement causes adaptations to athletes shoulders and predisposes them to the development of impingement symptoms. The objective of this study was to investigate if there are alterations in sensorimotor control and in the functional torque ratio of shoulder rotation in overhead athletes with impingement symptoms and to distinguish these from alterations due to sporting practice. To this end, three groups of subjects were evaluated: athletes with impingement symptoms, asymptomatic athletes and a control group of nonathletes. The participants were evaluated with a Biodex System 3 isokinetic dynamometer in a seated position with the shoulder at 90º of adduction and 90º of elbow flexion. Sensorimotor control was evaluated using an isometric torque steadiness evaluation. The isometric peak torque and submaximal torque steadiness at 35% peak torque were tested during medial rotation and lateral rotation of the shoulder. For each submaximal repetition, the standard deviation, coefficient of variation and time to stability were calculated. Only the standard deviation during medial rotation was greater in asymptomatic athletes than in control group. The isokinetic evaluation was carried out at the velocities 90°/s e 180°/s and 240°/ in concentric and eccentric modes. Peak torque-to-body weight and the functional torque ratios LREcc/MRCon and MREcc/LRCon were compared between groups. Asymptomatic athletes presented greater peak torque-to-body weight for concentric medial rotation at 180°/s and a lower LREcc/MRCon ratio at 90°/s and 180°/s than CG. The velocity 240°/s was excluded from the analyses because many participants were unable to reach the predetermined velocity in the eccentric tests, principally during lateral rotations. This difficulty was attributed to the low peak torque of lateral rotation that could be generated in this position. Overall, the results demonstrated that overhead sports training leads to adaptations in maximal torque and in the torque steadiness of medial rotation in healthy athletes, which may be related to throwing performance. Nevertheless, it is not possible to conclude that such alterations predispose these athletes to injury, since athletes with impingement symptoms group was not significantly different from the other groups in any of the evaluations. / O movimento repetitivo de arremesso gera adaptações no ombro de atletas, e os predispõe ao desenvolvimento de sintomas de impacto. O objetivo deste estudo foi investigar se há alterações no controle sensório-motor e na relação funcional de torque isocinético de rotação do ombro em atletas arremessadores com sintomas de impacto e diferenciar daquelas relacionadas a adaptações da prática esportiva. Sendo assim, foram avaliados três grupos de indivíduos: atletas com sintomas de impacto, atletas assintomáticos e um grupo controle de sujeitos não treinados. Os participantes foram avaliados no dinamômetro isocinético Biodex System 3, sentados, com o ombro posicionado a 90º de abdução e 90º de flexão do cotovelo. O controle sensório-motor foi avaliado por meio da flutuação do torque isométrico submáximo. O pico de torque isométrico e a flutuação do torque a 35% do pico de torque isométrico foram avaliados durante as rotações medial e lateral do ombro. Para cada repetição submáxima foram calculados o desvio-padrão, o coeficiente de variação e o tempo para atingir a estabilidade. Apenas o desvio-padrão de rotação medial foi maior no grupo de atletas assintomáticos comparado ao grupo controle. A avaliação isocinética foi realizada nas velocidades de 90°/s, 180°/s e 240°/s, nos modos concêntrico e excêntrico. O pico de torque/peso corporal e as relações funcionais de torque de rotação lateral excêntrico/rotação medial concêntrico (RLExc/RMCon) e rotação medial excêntrico/rotação lateral concêntrico (RMExc/RLCon) foram comparados entre os grupos. O grupo de atletas assintomáticos apresentou maior pico de torque/peso corporal de rotação medial concêntrica, a 180°/s, e menor relação RLExc/RMCon, a 90°/s e 180°/s, quando comparado ao controle. A velocidade de 240°/s foi excluída das análises, pois muitos participantes não conseguiram atingir a velocidade pré-determinada nos testes excêntricos, principalmente de rotação lateral. Essa dificuldade foi atribuída ao baixo pico de torque de rotação lateral capaz de ser gerado nessa posição. Em conjunto, os resultados demonstram que o treino de arremesso gera adaptações no torque máximo e na flutuação do torque submáximo de rotação medial em arremessadores saudáveis, possivelmente relacionados ao desempenho do arremesso. Entretanto, não é possível concluir se estas alterações predispõem esses atletas ao desenvolvimento de lesões, uma vez que o grupo de atletas com sintomas de impacto não se apresentou diferente dos outros grupos em nenhuma das situações avaliadas.