Acute effects of suspension training and other perturbative sources on lower limb strength tasks

Actualment, els dispositius de suspensió són un dels materials més utilitzats per produir pertorbació i enfortir de forma global la majoria de grups musculars. Encara que, manquen evidències dels seus efectes sobre l’extremitat inferior. Així, l’objectiu principal d’aquesta tesi doctoral va ser quantificar la producció de força, l’activitat muscular i la magnitud de la pertorbació a l’esquat búlgar i altres exercicis de l’extremitat inferior en condicions d’inestabilitat. Es van analitzar 18 estudis per dur a terme una revisió sistemàtica (estudi 1) i 75 participants físicament actius van ser reclutats per realitzar els diferents estudis transversals sobre els efectes dels dispositius de suspensió, les superfícies inestables i les vibracions mecàniques (plataforma vibratòria i vibració superposada) en exercicis de l’extremitat inferior (estudis 2-6). Es va confirmar que l’activació a la part inferior del cos només va ser investigada en el concentrat d’isquiosurals en suspensió (estudi 1). La posició i el ritme d’execució (70 bpm) van ser determinants per la producció de força exercida sobre el tirant de suspensió a l’esquat búlgar (estudi 2). El dispositiu de suspensió a l’esquat búlgar va augmentar les forces verticals contra el terra (estudi 3). Sobre el dispositiu la producció de força va ser major quan el nivell d’inestabilitat era baix (estudi 3 i 4), però a nivell muscular el dispositiu va ser igual de demandant que l’exercici tradicional (estudi 3). Un augment de la pertorbació, va incrementar l’activació muscular (estudis 3, 4, 5) i la magnitud de la inestabilitat per l’esquat búlgar i el mig squat amb barra (estudis 4 i 5). Així, la vibració superposada en un dispositiu de suspensió esdevé un repte per incrementar el nivell de pertorbació i millorar la força, la resistència muscular i l’estabilització (estudi 6). A més, els sensors de força són una eina adequada i usable per valorar les forces exercides sobre els dispositius de suspensió, i l’ús de l’acceleròmetre permet determinar la magnitud de la pertorbació que ofereixen els diferents materials desestabilitzadors mesurant l’acceleració del centre de masses corporal.Actualmente, los dispositivos de suspensión son uno de los materiales más utilizados para producir perturbación y fortalecer globalmente la mayoría de los músculos. Aunque, faltan evidencias de sus efectos sobre la extremidad inferior. Así, el objetivo principal de esta tesis doctoral fue cuantificar la producción de fuerza, la actividad muscular y la magnitud de la perturbación en la sentadilla búlgara y otros ejercicios de la extremidad inferior en condiciones de inestabilidad. Se analizaron 18 estudios para llevar a cabo una revisión sistemática (estudio 1) y 75 participantes físicamente activos fueron reclutados para realizar los diferentes estudios transversales sobre los efectos de los dispositivos de suspensión, las superficies inestables y las vibraciones mecánicas (plataforma vibratoria y vibración superpuesta) en ejercicios de la extremidad inferior (estudios 2-6). Se confirmó que la activación en la parte inferior del cuerpo sólo fue investigada en el concentrado de isquiosurales en suspensión (estudio 1). La posición y el ritmo de ejecución (70 bpm) fueron determinantes para la producción de fuerza ejercida sobre el tirante de suspensión en la sentadilla búlgara (estudio 2). El dispositivo de suspensión en la sentadilla búlgara aumentó las fuerzas verticales contra el suelo (estudio 3). Sobre el dispositivo la producción de fuerza fue mayor cuando el nivel de inestabilidad era bajo (estudio 3 y 4), pero a nivel muscular el dispositivo fue igual de demandante que el ejercicio tradicional (estudio 3). Un aumento de la perturbación incrementó la activación muscular (estudios 3, 4, 5) y la magnitud de la inestabilidad en la sentadilla búlgara y la media sentadilla con barra (estudios 4 y 5). Así, la vibración superpuesta en un dispositivo de suspensión se convierte en un reto para incrementar el nivel de perturbación y mejorar la fuerza, la resistencia muscular y la estabilización (estudio 6). Además, los sensores de fuerza son una herramienta adecuada y usable para valorar las fuerzas ejercidas sobre los dispositivos de suspensión, y el uso del acelerómetro permite determinar la magnitud de la perturbación que ofrecen los diferentes materiales desestabilizadores midiendo la aceleración del centro de masas corporal.Nowadays, suspension devices are one of the most widely used pieces of equipment to produce perturbation and strengthen most muscle groups globally. However, there is a lack of evidence of their effects on the lower limb. Thus, the main objective of this doctoral thesis was to quantify force production, muscle activity and the magnitude of perturbation in the Bulgarian squat and other lower extremity exercises under unstable conditions. Eighteen studies were analysed for a systematic review (study 1) and 75 physically active participants were recruited to perform the different cross-sectional studies on the effects of suspension devices, unstable surfaces, and mechanical vibrations (vibration platform and superimposed vibration) on lower limb exercises (studies 2-6). It was confirmed that lower body activation had only been previously investigated in the suspended hamstring curl (study 1). Position and pace (70 bpm) were determinants for the force exerted on the suspension strap in the Bulgarian squat (study 2). The suspension device in the Bulgarian squat increased the vertical ground reaction forces (study 3). The force production was higher on the device when the level of instability was low (study 3 and 4), but for muscle activity the device was just as demanding as a traditional exercise (study 3). Increased perturbation enhanced muscle activation (studies 3, 4, 5) and the magnitude of instability in the Bulgarian squat and barbell half-squat (studies 4 and 5). Thus, superimposed vibration on a suspension device becomes a challenge to increase the level of perturbation and improve strength, muscular endurance, and stabilisation (study 6). In addition, load cells are a suitable and practical tool to assess the forces exerted on suspension devices, and the use of an accelerometer makes it possible to determine the magnitude of the perturbation offered by different equipment providing instability by measuring the acceleration of the body's centre of mass

Effects of wearing a customized bite-aligning mouthguard on powerful actions in highly trained swimmers

The study was supported and funded by the Faculty of Faculty of Psychology, Education Sciences and Sport Blanquerna, Ramon Llull University, Barcelona, Spain, grant number PIF1920-PSITICBackground/objectives: The potential advantages of wearing customized bite-aligning mouthguards on several performance parameters such as muscular strength, power and reaction time have been reported. Literature shows that the concurrent activation potentiation phenomenon, elicited by a powered and balanced jaw clenching, can provide athletes with several neuromuscular advantages. The aim of the present study was to investigate the acute effects of jaw clenching while wearing a customized bitealigning mouthguard on swimming start, countermovement jump and swim bench test, in contrast to two other conditions: non-jaw clenching and jaw clenching without mouthguard. Methods: A randomized, repeated measure within study designwas used to compare the condition effect on eight highly trained elite male and female swimmers. Results: Statistical analysis revealed a significant increase in the countermovement jump height (p ¼ 0.041) when comparing the use of mouthguards with the non-jaw condition. In the swim bench, a significant greater time to peak force (p ¼ 0.049) was found when comparing the use of mouthguards with the jaw condition. Although, non-significant effects, small differences were found in the start reaction time and 15-m freestyle swimming when comparing the use of mouthguards with the non-jaw condition. Conclusion: This study demonstrated that wearing customized, bite-aligning mouthguards had an ergogenic effect on specific measures of vertical jump and swim bench test, whereas non-meaningful but small differences were found in swimming start.Faculty of Faculty of Psychology, Education Sciences and Sport Blanquerna, Ramon Llull University, Barcelona, Spain PIF1920-PSITI

Muscle activity and forces in different suspension lunge exercises

Although there are some researches about lunge exercise and instability conditions (i.e., Bosu, fitball), few researches were found comparing different methods using a suspension device and its load quantification. The purpose of this study was to examine the effect of suspension training and instability surfaces on muscle activity and force production while performing different variations of the lunge exercise. A randomized within-subjects design was used to study the effects of five conditions (traditional, suspension, suspension-Bosu, suspension-Vibro30 or Vibro40) on five different muscles (rectus femoris, biceps femoris, vastus medialis, vastus lateralis and gluteus medius) in physically active male university students (n = 7; age = 25.71± .06 years old). During lunge performance, muscle activation was recorded using surface electromyography (sEMG). Force production was obtained using both Wii Balance Board and a S-Type load cell. Mean peak force and normalized sEMG values were compared across the 5 exercises. Results showed no significant differences in muscle activity between traditional and suspension lunge. However lunges performed with dual instability increased sEMG activity in the analysed muscles in comparison with single instability condition. Furthermore, force output on the strap decrease when instability increase and suspension lunge showed significant differences (p< .05) on forward leg exerted force in comparison with traditional lunge. In conclusion, the results obtained in the present study could be useful for select the optimal lunge progression and the load cell seems to be an adequate tool to quantify the load while performing a suspension exercise

A influência de marcar primeiro no hóquei em patins

El principal objetivo de este trabajo fue estudiar la ventaja de marcar el primer gol del partido en hockey sobre patines y conocer su incidencia en el resultado final. Un objetivo secundario fue determinar si existen diferencias significativas en función de si el equipo que marca primero es el local o el visitante. Para ello se analizaron 240 partidos de la Ok Liga (la máxima categoría deportiva española) y 182 de la Primera División Nacional (segunda categoría más alta) de la temporada 2016-2017, valorando el resultado final de los equipos cuando se adelantaban en el marcador. Los resultados muestran que existe la ventaja de marcar primero tanto en la Ok Liga cómo en la Primera División Nacional con un efecto del 64.14% y 62.91% respectivamente. Asimismo, se obtiene una ventaja de marcar el primer gol significativamente mayor cuando los equipos juegan como locales en la Primera División Nacional y una alta correlación entre el rendimiento final de los equipos (puntos obtenidos en la clasificación) y la ventaja de marcar el primer gol. En consecuencia, se demuestra la importancia que tiene para un equipo dominar dicho aspecto y se sugiere que estos datos pueden ayudar a los equipos técnicos a decidir la estrategia deportiva en cada momento del juego según el resultado del marcador.Abstract: The main purpose of this study was to analyze the effect of the first goal in roller hockey and to know its impact on the final result. A secondary objective was to assess if there were significant differences when the team that scores first was the local or the visitor. For this purpose, 240 matches of Ok Liga (the highest Spanish division) and 182 of First National Division (the second highest division) were analyzed during the season 2016-2017, assessing the final result of the teams when they scored first. Results showed that the advantage of scoring first exists both in the Ok Liga and in the First National Division with 64.14% and 62.91% respectively. Likewise, the advantage of scoring the first goal when teams play at home is significantly greater for the First National Division teams than Ok Liga teams. In addition, it was obtained a high correlation between the final performance of the teams (points obtained in the classification) and the effect of scoring first. Therefore, it is demonstrated the importance for a team to dominate this aspect and it is suggested that this data can help the coach and staff to decide which strategy to use at each moment of the game according to the result.Resumo: O objetivo principal deste trabalho foi analisar a vantagem de marcar o primeiro gol do jogo em hóquei em patins e conhecer o seu impacto no resultado final. Um objetivo secundário foi avaliar se existem diferenças significativas dependendo se a equipa que pontua primeiro é a local ou a visitante. Para este fim, foram analisados 240 jogos da Ok Liga (a mais alta categoria desportiva espanhola) e 182 da Primeira Divisão Nacional (segunda maior categoria) da temporada 2016-2017, avaliando o resultado final das equipas quando estavam à frente no placar. Os resultados mostram que há a vantagem de marcar primeiro tanto na Ok Liga quanto na Primeira Divisão Nacional, com um efeito de 64.14% e 62.91%, respetivamente. Da mesma forma, obtém-se uma vantagem de marcar o primeiro gol significativamente maior quando as equipas jogam em casa na Primeira Divisão Nacional e uma alta correlação entre o desempenho final das equipas (pontos obtidos na classificação) e a vantagem de marcar o primeiro gol. Consequentemente, demonstra-se a importância que tem para uma equipa a dominar esse aspecto e sugere-se que esses dados possam ajudar às equipas técnicas a decidirem a estratégia tática a ser utilizada em cada momento do jogo de acordo com o resultado do placar

Influencia de marcar primero en hockey sobre patines

El principal objetivo de este trabajo fue estudiar la ventaja de marcar el primer gol del partido en hockey sobre patines y conocer su incidencia en el resultado final. Un objetivo secundario fue determinar si existen diferencias significativas en funciónde si el equipo que marca primero es el local o el visitante. Para ello se analizaron 240 partidos de la Ok Liga (la máxima categoría deportiva española) y 182 de la Primera División Nacional (segunda categoría más alta) de la temporada 2016-2017, valorando el resultado final de los equipos cuando se adelantaban en el marcador.Los resultados muestran que existe la ventaja de marcar primero tanto en la Ok Ligacómo en la Primera División Nacional con un efecto del 64.14% y 62.91% respectivamente. Asimismo,se obtiene una ventaja de marcar el primer gol significativamente mayor cuando los equipos juegan como locales en la Primera División Nacional y una alta correlación entre el rendimiento final de los equipos (puntos obtenidos en la clasificación) y la ventaja de marcar el primer gol. En consecuencia, se demuestra la importancia que tiene para un equipo dominar dicho aspecto y se sugiere que estos datos pueden ayudar a los equipos técnicos a decidir la estrategia deportiva en cada momento del juego según elresultado del marcadorThe main purpose of this study was to analyze the effect of the first goal in roller hockey and to know its impact on the final result. A secondary objective was to assess if there were significant differences when the team that scores first was the local or the visitor. For this purpose, 240 matches of Ok Liga(the highest Spanish division) and 182 of First National Division (the second highest division) were analyzed during the season 2016-2017, assessing the final result of the teams when they scored first. Results showed that the advantage of scoring first exists both in the Ok Ligaand in the First National Division with 64.14% and 62.91% respectively. Likewise, the advantage of scoring the first goal when teams play at home is significantly greater for the First National Division teams than Ok Ligateams. In addition, it was obtained a high correlation between the final performance of the teams (points obtained in the classification) and the effect of scoring first. Therefore, it is demonstrated the importance for a team to dominate this aspect and it is suggested that this data can help the coach and staff to decide which strategy to use at each moment of the game according to the result.O objetivo principal deste trabalho foi analisar a vantagem de marcar o primeiro gol do jogo em hóquei em patins e conhecer o seu impacto no resultado final. Um objetivo secundário foi avaliar se existem diferenças significativas dependendo se a equipa quepontua primeiro é a local ou a visitante. Para este fim, foram analisados 240 jogos da Ok Liga (a mais alta categoria desportiva espanhola) e 182 da Primeira Divisão Nacional (segunda maior categoria) da temporada 2016-2017, avaliando o resultado final das equipas quando estavam à frente no placar. Os resultados mostram que há a vantagem de marcar primeiro tanto na Ok Liga quanto na Primeira Divisão Nacional, com um efeito de 64.14% e 62.91%, respetivamente. Da mesma forma, obtém-se uma vantagem de marcaro primeiro gol significativamente maior quando as equipas jogam em casa na Primeira Divisão Nacional e uma alta correlação entre o desempenho final das equipas (pontos obtidos na classificação) e a vantagem de marcar o primeiro gol. Consequentemente, demonstra-se a importância que tem para uma equipa a dominar esse aspecto e sugere-se que esses dados possam ajudar às equipas técnicas a decidirem a estratégia tática a ser utilizada em cada momento do jogo de acordo com o resultado do placar

Análisis de la influencia de jugar como local en hockey sobre patines

El propósito del estudio fue analizar la ventaja de jugar como local en la liga profesional masculina de hockey sobre patines (OkLiga). Para el estudio se analizaron los datos de las últimas 17 temporadas de la OkLiga (desde la 1999-2000 hasta la 2015-2016) y se analizaron 3964 partidos. Se analizaron también los goles marcados y recibidos cuando los equipos juegan como local. Además se ha analizado si el cambio en el reglamento del hockey sobre patines impuesto en 2009 ha repercutido sobre el home advantage y en los goles marcados por partido. Los resultados muestran que existe la ventaja de jugar en casa en la OkLiga con un valor del 59.8%. Asimismo, los resultados también indican que los equipos marcan un mayor número de goles cuando juegan como local. El cambio de reglamentación, revela que los equipos marcan una media de dos goles más por partido y también que la ventaja de jugar en casa ha disminuido dos puntos porcentuales.The aim of the current study was to analyze the home advantage effect in Spanish roller hockey male league (OkLiga). For this purpose, 3964 Spanish league roller hockey matches were analyzed from the 1999-2000 season to 2015-2016 season. Goals scored and received were also analyzed when the teams play at home. In addition, it has been analyzed whether the change in the regulation of roller hockey imposed in 2009 has affected in the home advantage and in the goals scored for match. Results show that exist the home advantage in Spanish roller hockey men’s league (OkLiga) with a value of 59.8%. Moreover, the results indicate that teams score more goals when playing at home. The change of regulation show that the teams score an average of two more goals per game and also that home advantage has decreased by two percentage points

Competitive balance using Accumulated Points Difference method in male and female roller hockey leagues

The purpose of this study was to quantify the competitive balance in both men’s and women’s professional division roller hockey competitions (Spanish and Portugal leagues) comparing the results obtained according to the sex of participants. The sample was composed of 5,942 roller hockey games (2,044 in Spanish male league, 1,580 in Spanish female league, 1,814 in Portuguese male league and 504 in Portuguese female league) between the 2009-2010 and 2017-18 seasons. To calculate the competitive balance, it was used the Accumulated Points Difference index andthe one way ANOVA followed by Tukey Post Hoc multiple comparison test. The results showed that male leagues are more balanced than female (71.41±11.29 vs. 79.65±5.75 for Spanish leagues and 75.56±7.54 vs. 80.16±15.01 for Portuguese leagues). The results in relation to the sex of participants are consistent with previous studies in other sports like football. The analysis of the competitive balance could be useful for the governing body of Roller Hockey Federations to have quantitative data of the equality that exists in each league and to asses if it is necessary to introduce changes in the competition to make it more equalized in order to increase the audience