Cambios producidos en ciclistas amateurs sobre la percepción del esfuerzo, confort, cinemática angular y presiones en función del retroceso del sillín e intensidad del ejercicio.

El ciclismo es uno de los deportes más populares en todo el mundo y, uno de los más practicados en España. En este sentido, diferentes estudios han analizado el efecto de la altura del sillín sobre el rendimiento del ciclista, sin embargo, son escasos los estudios que analizan el efecto del retroceso del sillín. El presente trabajo de investigación pretende estudiar el efecto producido sobre el esfuerzo y confort percibido, las presiones en el sillín y en la cinemática angular de la extremidad inferior. Se llevó a cabo una prueba en cicloergómetro empleando 3 retrocesos del sillín (RS): libre, +10%, -10% y dos intensidades del ejercicio (baja y alta). La muestra estuvo compuesta por 34 ciclistas amateurs. El esfuerzo percibido solo fue significativamente mayor por el efecto de la intensidad durante la intensidad alta (p< 0.001, ES= 0.728) En cambio, el confort percibido y la cinemática mostraron diferencias significativas (p< 0.05) en función del retroceso del sillín, la intensidad y el sexo de los ciclistas. Además, también se encontraron diferencias significativas (p< 0.05) en función del retroceso y sexo en las presiones sobre el sillín. Una posición del sillín retrasada (+10%) produce una reducción de los niveles de confort, mayores niveles de extensión de cadera, rodilla y tobillo, así como una mayor presión máxima y media en la región del pubis. En cuanto a la intensidad de pedaleo, una intensidad alta aumenta la percepción del esfuerzo y disminuye los niveles de flexión en las extremidades inferiores

Effect of hamstring tightness and fatigue on dynamic stability and agility in physically active young men.

Hamstring extensibility has been defined as a factor to diminished dynamic stability and therefore increased risk of injury. The purpose of this study was to analyse the effects of hamstring tightness and fatigue on dynamic stability and agility. Nineteen participants were divided between the normal extensibility group (NEG) (n = 9, 82.2° ± 12.4°) and hamstrings tightness group (HTG) (n = 10, 64° ± 4.9°) using the passive straight leg raise test. To analyse dynamic stability and agility, they performed the modified Star Excursion Balance Test (mSEBT) and Dynamic Postural Stability Index (DPSI), and hexagon agility test, respectively, before and after a fatigue protocol. A two-way repeated measures ANOVA was used to determine differences among conditions: NEG vs. HTG, and rested vs. fatigued. HTG showed a significantly lower reach in the anterior direction in the mSEBT in pre- and post-fatigue than NEG. Participants in the NEG showed poor stability after landing in the mediolateral direction on DPSI post-fatigue. No significant changes were found in agility related with the group nor fatigue state. Participants with hamstring extensibility reduction has no differences in dynamic stability after landing nor agility after fatigue test, but significantly affects reaching distances during one-leg balance. As a conclusion, a reduction in range of motion in HTG was observed, but no other effects were observed on performance and dynamic stability after a local fatigue protocol depending on hamstring extensibility

Development of a cost-effective smart saddle mat for bike fitting purposes

Engineering of Sport 15 - Proceedings from the 15th International Conference on the Engineering of Sport (ISEA 2024) Commercially available pressure measuring mats (Novel, medilogic, GebioMized, SQlab, Tekscan) for assessment of pressure distribution on the saddle during bike fitting have a high sensor resolution, but are also relatively expensive. In addition to pressure distribution, the movement of the centre of pressure (COP) provides valuable information as its variability and entropy correlate with the level of discomfort while cycling. In general, greater pressure at the perineum represents a risk factor for pathologies of the urogenital system. According to Swart & Holliday (2019), “no studies have been conducted to assess how changes in the configuration of the bicycle affect the saddle pressure indexes, and there are no defined norms for these variables”. The aim of this study is to develop a cost-effective smart saddle mat and test its applicability for measuring performance parameters. </p

Effect of Hamstring Tightness and Fatigue on Dynamic Stability and Agility in Physically Active Young Men

Hamstring extensibility has been defined as a factor to diminished dynamic stability and therefore increased risk of injury. The purpose of this study was to analyse the effects of hamstring tightness and fatigue on dynamic stability and agility. Nineteen participants were divided between the normal extensibility group (NEG) (n = 9, 82.2&deg; &plusmn; 12.4&deg;) and hamstrings tightness group (HTG) (n = 10, 64&deg; &plusmn; 4.9&deg;) using the passive straight leg raise test. To analyse dynamic stability and agility, they performed the modified Star Excursion Balance Test (mSEBT) and Dynamic Postural Stability Index (DPSI), and hexagon agility test, respectively, before and after a fatigue protocol. A two-way repeated measures ANOVA was used to determine differences among conditions: NEG vs. HTG, and rested vs. fatigued. HTG showed a significantly lower reach in the anterior direction in the mSEBT in pre- and post-fatigue than NEG. Participants in the NEG showed poor stability after landing in the mediolateral direction on DPSI post-fatigue. No significant changes were found in agility related with the group nor fatigue state. Participants with hamstring extensibility reduction has no differences in dynamic stability after landing nor agility after fatigue test, but significantly affects reaching distances during one-leg balance. As a conclusion, a reduction in range of motion in HTG was observed, but no other effects were observed on performance and dynamic stability after a local fatigue protocol depending on hamstring extensibility