Temporal pattern in the muscles of the upper limbs and the trunk in the archery

• Autor(a) principal: Machado, Nadjila Tejo
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: http://www.teses.usp.br/teses/disponiveis/100/100139/tde-14052018-110235/
• topic: Archery; Atividade muscular; Biomecânica; Biomechanics; Controle motor; Electromyography; Eletromiografia; Motor control; Muscle activity; Tiro com arco

Central nervous system stabilizes body in disturbance by means of anticipatory and compensatory postural adjustments to maintain stable position. Disturbance effects in joint are reduced by activation of agonist and antagonist forearm muscles, the muscles allow consistency by steady posture during shot. Studies showed the importance of posture in the shot, but without focus on the anticipatory and compensatory postural adjustments. The objective of this study was to analyze an electrical activity of archers during the shot an arrow with the bow. Participants consisted of 10 archers of the Brazilian National Team of archery. Electromyography captured electrical activity in 12 muscles. Accelerometer in handle indicated the beginning of the movement. Temporal pattern separated in 500 milliseconds pre and post clicker fall. Protocol started by Maximal Voluntary Isometric Contraction of 12 muscles. Archers release 3 blocks of 6-arrows in warm-up. Archers throw arrows for 12 blocks with 6-arrows with interval of 20 minutes after the block 6. One-way Analysis of Variance and Tukey Test compared temporal pattern. One-way Analysis of Variance with repeated measures compared temporal pattern and 6-arrows. Results showed that all muscles (except m. Lumbar Multifidus) increase in their demand with the proximity of the arrow release. The muscles decreased their activity due to reduced demand in compensatory and modulation phase. Comparison between 12 blocks of 6-arrows showed 3 ways of temporal pattern: 1) muscles affected by phases and muscles affected by all/any phases in the blocks of 6-arrows, 2) muscles affected by phases and muscles unaffected by all/any phases in the blocks of 6-arrows and 3) muscles unaffected by phases and muscles affected by all phases in the blocks of 6-arrows. Muscles were not affected by phases/blocks maintain muscle activity along intervals by similar muscular demand. Cross-correlation between motor muscles showed that forearm muscles obtained inverse relationship between them. Other motor muscles were strong correlation between them. Postural muscles m. Lumbar Multifidus, m. Latissimus Dorsi, m. Upper Trapezius were strong correlation with all postural muscles. Motor and postural muscles showed that m. Triceps Brachii, m. Pectoralis Major Clavicular Head and m. Posterior Deltoid showed strong correlation with all postural muscles. In conclusion, muscle activity increases in anticipatory phase and muscle activity decrease after clicker fall. There are 3 ways to compare phases and blocks: affected by phases and 1) muscles affected/2) muscles unaffected by all/any phases in the blocks of 6-arrows and 3) muscles unaffected by phases and affected by all phase in the blocks of 6-arrows. Correlation in motor muscles showed that forearm muscles obtained inverse relationship between them. Postural muscles m. Lumbar Multifidus, m. Latissimus Dorsi, m. Upper Trapezius were strong correlation with all postural muscles. Motor and postural muscles showed that m. Triceps Brachii, m. Pectoralis Major Clavicular Head and m. Posterior Deltoid showed strong correlation with all postural muscles