Título: | Adaptación, validación y aplicación de una nueva tecnología para valorar la biomecánica de la carrera de resistencia |
Autores: | Ogueta-Alday, Ana |
Fecha: | 2014 |
Publicador: | Universidad de León (España) |
Fuente: |
Ver documento |
Tipo: | text (thesis) |
Tema: |
Leg-stiffness Umbral aeróbico Carrera de resistencia Rendimiento |
Descripción: |
Long-distance running performance depends on several factors such as physiology
(VO2max, anaerobic threshold, running economy, age, gender, muscle fibre composition,
fatigue and ethnicity), environment (air/wind, temperature, humidity, altitude and slope),
psychology (intervention, focus of attention and music), training (endurance, resistance,
heat acclimation and altitude training) and biomechanics (anthropometry, “legstiffness”,
flexibility, foot strike pattern and spatio-temporal parameters). Nowadays,
the real influence of some of these variables is still unknown. In particular, the influence
of some biomechanical parameters such as foot strike pattern and/or spatio-temporal
parameters on running economy, their relationship with physiological parameters and
the impact on running performance are controversial topics of discussion. It is possible
that the technological limitations of the measuring instruments have generated this
discrepancy.
The present Thesis would try to explain these issues by the following aims: 1- adapt
and validate a new method to measure spatio-temporal variables (i.e. contact and flight
times, step rate and length) during treadmill running, which would allow to register
automatically a high and representative number of steps of both feet, 2- analyze the
influence of foot strike pattern (rearfoot vs midfoot/forefoot) on running economy and
other biomechanical variables, 3- examine simultaneously the influence of
anthropometric, physiological and biomechanical variables on running performance.
The validation of the new method (SportJump System Pro; a contact laser platform
inserted in a treadmill and connected to a specific software) was performed with 15
runners, who completed 7 sets of running between 10 and 22 km·h-1
. Contact and flight
times were registered with a high-speed video camera (gold standard method) and the
new method. The new technology overestimated the contact time and underestimated
the flight time at every running speed. However, these differences between both
methods did not depend on runners’ foot strike pattern or mass, and they were corrected
according to running speed. In conclusion, the new method was validated, being reliable
and sensitive for detecting small changes in running spatio-temporal parameters, being
the analysis tool used in next experimental phases of this Thesis.
The analysis of the influence of foot strike pattern on running economy and
biomechanical variables was performed by comparing biomechanical and physiological Abstract
variables of 10 rearfoot and 10 midfoot/forefoot well-trained runners with a similar
level of performance in a half-marathon. No differences were observed in VO2max,
aerobic and anaerobic thresholds. Nevertheless, rearfoot strikers were between 5.0 and
9.3% more economical than midfoot/forefoot strikers at submaximal speeds. Step rate
and length were not different between groups, but rearfoot strikers showed longer
contact time and shorter flight time than midfoot/forefoot strikers at all running speeds.
Thus, the differences in contact and flight time could explain running economy
differences.
Finally, the influence of anthropometric, physiological and biomechanical variables
on running performance was examined analyzing 48 runners of different level. They
were divided into 4 groups according to their performance level in a half-marathon.
Significant differences between groups and correlations with performance were
observed in training-related (experience and km per week), anthropometrics (mass,
body mass index and sum of six skinfolds), physiological (VO2max, aerobic and
anaerobic thresholds and running economy) and biomechanical variables (foot strike
pattern). Higher level runners showed shorter contact time than lower level runners at
the same running speed. However, this was due to the higher percentage of
midfoot/forefoot runners in the best group of runners. Taking into account runners’ foot
strike pattern and speed, these differences disappeared. Step rate and length were not
different between groups at the same running speed. Therefore, running spatio-temporal
variables (contact and flight time, step rate and length) were not sensitive to
performance.
To sum up, the adaptation and validation of the new method to measure running
spatio-temporal parameters allowed us to obtain the following conclusions: 1- rearfoot
strikers are more economical than midfoot/forefoot strikers at submaximal running
speeds, 2- midfoot/forefoot strikers have an approximately 10% shorter contact time
than rearfoot strikers, which could be beneficial at high running speeds (> 20 km·h-1
), 3-
running spatio-temporal parameters (contact and flight time, step rate and length) seem
not to be sensitive to performance level. El rendimiento en carreras de larga distancia depende de una serie de factores fisiológicos, ambientales, psicológicos, ligados al entrenamiento, y biomecánicos. A día de hoy existe un gran desconocimiento sobre la verdadera influencia de alguno de ellos. La presente Tesis pretende adaptar y validar el nuevo método SportJump System Pro (Plataforma de contacto láser insertada en un tapiz rodante y conectada a un software específico) para registrar las variables espacio-temporales durante la carrera en tapiz rodante, lo que permitirá analizar automáticamente un alto y representativo número de pasos con ambos pies; analizar la influencia del patrón de pisada (talonador vs planta entera/antepié) en la economía de carrera y otras variables biomecánicas; y examinar simultáneamente la influencia de las variables antropométricas, fisiológicas y biomecánicas en el rendimiento. Gracias a la adaptación de este nuevo métodos se ha podido concluir que los corredores talonadores son más económicos que los de planta entera/antepié a velocidades de carrera submáximas; que los corredores planta entera/antepié presentan aproximadamente un 10% menos de tiempo de contacto que los corredores talonadores; y las variables espacio-temporales de la carrera (tiempo de contacto, frecuencia y amplitud de zancada) no parecen ser sensibles al nivel de rendimiento |
Idioma: | spa |