DO SPORT COMPRESSION STOCKINGS IMPROVE COMFORT AND ACCELEROMETRY PARAMETERS IN RUNNERS?

In this study, we analysed accelerometry data from runners foot strikes with and without sport compression stockings. Also, we measured comfort perceived with these garments due its importance to a succesful performance. Ten male runners (n=10) exerted two laboratory test condition in different days: a) without compression stockings and b) with one kind of compression in each leg. Accelerometry data were registered using sensors in tibia and head. Also participants filled out a comfort test in stockings’ condition. Medium compression (MC) impacts attenuation was lower than no compression (NC) condition (p\u3c0,05). General comfort perceived was 66%. In conclusion, compression stockings demonstrated a protective effect against impacts and were perceived as comfortable

COMPRESSION PROFILE OF SPORT COMPRESSION STOCKINGS IN RUNNERS

The purpose of this study was to determine the interface pressure applied using two compressive stockings: medium compression (MC) and strong compression (SC); in three conditions: before, during and after running test. Ten male runners (n=10) exerted two laboratory test condition in different days: a) without compression stockings and b) with one kind of compression in each leg. Interface pressure was registered using PicoPress® device. In both compression conditions, the interface pressure was higher in proximal than distal sensors (MC p\u3c0,05; SC p\u3c0,001). Similar results were taken in dynamic condition, and lower level compression was observed after running test. In conclusion, compressive forces were higher in proximal compared to distal leg area. This is contradictory to the gradual decreasing compression principle

Clustering classification of cyclists according to the acute fatigue outcomes produced by an ultra-endurance event

This study aimed to analyze the differences between clusters obtained by the acute effect of fatigue after an ultra-endurance event in the internal and external load of cyclists. 26 volunteers participated in the study, and they were divided into the experimental group (N = 18; height: 177 ± 8 cm; body mass: 78.6 ± 10.3 kg) and the control group (N = 8; height: 176 ± 10 cm; body mass: 78.0 ± 15.7 kg). The experimental group completed a 12 h non-stop cycling event. Jump height, lactate, plasma antioxidant capacity, pain perception and fatigue perception were measured before and after the event. Cyclists of the experimental group were classified considering their training characteristics (recreational vs. competitive) and by conducting a non-supervised K-means clustering. The differentiation of cyclists according to training characteristics resulted in a lower distance covered by recreational than competitive cyclists (279.4 ± 39.7 km vs. 371.0 ± 71.7 km; ES ≥ 0.8; p 0.05). The clustering analysis provided two clusters. Cluster 2 suffered a greater jump height reduction (-3.3 ± 1.6 vs. 1.2 ± 0.8; ES ≥ 0.8; p < 0.001) and increased pain and fatigue perception (ES ≥ 0.5; p < 0.05) after the race than Cluster 1. In conclusion, counter-movement jump can differentiate the fatigue produced by a cycling ultra-endurance event and therefore, this non-invasive technique is useful in fatigue monitoring and recovery planification

Impact acceleration during prolonged running while wearing conventional versus minimalist shoes.

Purpose: In recent years a sub-group of minimalist runners have emerged who aim to perform physical exercise more naturally in an attempt to reduce running-related injuries. Here we aimed to determine the effect that running with minimalist footwear in a prolonged run has on footimpact accelerations. Method: Seventeen runners ran with minimalist and conventional shoes (MS and CS, respectively) in two separate sessions; the participants had experience with both footwear types. We measured the length and frequency of each stride, as well as the tibial and head impact acceleration every 5 minutes during a prolonged run (30 minutes at 80% of each individual's maximum aerobic speed). Results: There were significant differences in the acceleration rate in the tibia (CS: 516.1 ± 238.47 G/s and MS: 786.6 ± 238.45 G/s; p = .009) and head (CS: 73.3 ± 23.65 G/s and MS: 120.7 ± 44.13 G/s; p = .000). Our data indicate that the type of footwear increased the stride frequency and decreased length and that the impact acceleration is increased with MS compared to CS (p < .05 in both cases). However, the effect of prolonged run was not significantly different between CS and MS (p < .05). Conclusions: The peak tibia acceleration and headtibia acceleration rate indicate that the use of MS may be related to a higher risk of injury. These differences remained independently of the runners' fatigue stat

Influence of accelerometer signal filtering on automatic detection of gait impact parameters

[EN] Filtering the signal recorded by an accelerometer is essential to remove noise recorded by the sensor, but in order to calculate gait parameters properly, the choice of a suitable cutoff frequency of the filter is critical. This paper evaluates the influence of the filter cutoff frequency in the calculation of the parameters: vertical peak tibial acceleration and acceleration rate. The accelerometer signal filtering with low-pass filter with cutoff frequency below 50 Hz gives good results in the calculation of peak tibial acceleration but produces estimations of the acceleration rate below its real valueThis work has been sponsored by the Generalitat Valenciana: application 09.02.03.542.50.7 budget line T4015 grant from the “Conselleria de Educación, Cultura y Deporte”, aid for conducting R & D for emerging research groups corresponding to the call set out in Annex IX, the Order 64/2014, of July 31, the “Conselleria de Educación, Cultura y Deporte” (DOCV no. 7.332, of August 5, 2014). Record GV /2015/067.Camacho García, A.; Llinares Llopis, R.; Lucas-Cuevas, Á.; Pérez Soriano, P. (2016). Influence of accelerometer signal filtering on automatic detection of gait impact parameters. International Journal of Advancements in Digital Signal Processing. 3(1). http://hdl.handle.net/10251/94462S3

Effects of central and peripheral fatigue on impact characteristics during running

Fatigue and impact can represent an injury risk factor during running. The objective of this study was to compare the impact transmission along the locomotor system between the central and peripheral fatigued states during running. Tibial and head acceleration as well as shock attenuation in the time- and frequency-domain were analyzed during 2-min of treadmill running in the pre- and post-fatigue state in eighteen male popular runners (N = 18). The impact transmission was measured before and after a 30-min central fatigue protocol on the treadmill or a peripheral fatigue protocol in the quadricep and hamstring muscles using an isokinetic dynamometer. The time-domain acceleration variables were not modified either by peripheral or central fatigue (p > 0.05). Nevertheless, central fatigue increased the maximum (p = 0.006) and total (p = 0.007) signal power magnitude in the high-frequency range in the tibia, and the attenuation variable in the low- (p = 0.048) and high-frequency area (p = 0.000), while peripheral fatigue did not cause any modifications in the frequency-domain variables (p > 0.05). Furthermore, the attenuation in the low (p = 0.000)- and high-frequency area was higher with central fatigue than peripheral fatigue (p = 0.003). The results demonstrate that central fatigue increases the severity of impact during running as well as the attenuation of low and high components

Relationship between foot eversion and thermographic foot skin temperature after running

[EN] The main instruments to assess foot eversion have some limitations (especially for field applications), and therefore it is necessary to explore new methods. The objective was to determine the relationship between foot eversion and skin temperature asymmetry of the foot sole (difference between medial and lateral side), using infrared thermography. Twenty-two runners performed a running test lasting 30 min. Skin temperature of the feet soles was measured by infrared thermography before and after running. Foot eversion during running was measured by kinematic analysis. Immediately after running, weak negative correlations were observed between thermal symmetry of the rearfoot and eversion at contact time, and between thermal symmetry of the entire plantar surface of the foot and maximum eversion during stance phase (r = −0.3 and p = 0.04 in both cases). Regarding temperature variations, weak correlations were also observed (r = 0.4 and p < 0.05). The weak correlations observed in this study suggest that skin temperature is not related to foot eversion. However, these results open interesting future lines of researchSIDirección General de Investigación Científica y 397 Técnica (DGICT) (DEP2013-48420-P); Ministerio de 398 Educación, Cultura y Deporte (MECD) (Doctoral 399 Fellowship (FPU))

History of Swimming II: Since Reinassence to the appearence and consolidation of current competitive strokes

Con el Renacimiento resurge el arte de nadar en Europa y se publican los primeros textos dedicados a la Natación, destacando Colymbetes (1538) de Wynman, De Arte Natandi (1587) de Digby y, con posterioridad, L´Art de Nager (1696) de Thevenot. En el s.XVII surgirán dos escuelas antagónicas: la seguidora de G. Muts que preconizaba una fase inicial de ejercicios en seco y la Natación natural de O. de Bernardi y H. Ladebeck. En el s.XIX tres grandes motivos popularizan la Natación a todos los estratos sociales: (a) las grandes travesías a nado, especialmente la del canal de la Mancha, (b) la importancia que los militares vuelven a darle a la Natación en la formación de los soldados y (c) la aparición de los primeros clubs, piscinas y primeras competiciones. Con el espaldarazo definitivo que supuso la reaparición de los J.J.O.O., se llega a la situación actual, con cuatro estilos de competición que evolucionaron notablemente durante el s.XX. En las últimas décadas de dicho siglo, quedaron establecidos los modelos técnicos de nado de los cuatro estilos de competición.With the Renaissance, the art of swimming revived in Europe and the first texts dedicated to swimming were published, highlighting Colymbetes (1538) of Wynman, De Arte Natandi (1587) of Digby, and thereafter, L'Art de Nager (1696) of Thevenot. In the eighteenth century two opposig methods emerge: G. Muts method advocated an initial phase with dry land exercises and natural swimming method of O. de Bernardi and H. Ladebeck. In the nineteenth century three major reasons popularized swimming to all social strata: (a) large swimming trips, especially the English Channel, (b) the military significance of swimming and (c) the emergence of clubs, swimming pools and firsts championships. With the return of the Olympic Games, we get to the current situation, with four racing styles that evolved significantly over the twentieth century. In the last decades of this century were established the technical models of the four racing swimming stroke

Effects of Kinesiotape taping on plantar pressure and impact acceleration during walking

Objectives: The aim of this study was to analyse the plantar pressure pattern, contact time, stride rate and impact acceleration in the shank during walking with and without Kinesio Tape (KT®) placed on two muscle groups: Peroneus and Triceps surae. Methods: 29 subjects (12 men, 17 women) participated in the study. KT® was placed on the triceps surae and peroneus and participants walked at two different speeds (V1: 0.73 m/s; V2:1.30 m/s) with and without KT®. The pedobarographic system Biofoot IBV® 6.0 was used to analyse plantar pressure (mean peak pressure [kPa]) in 5 foot areas and the kinematic variables of the study (contact time [s]; stride rate [steps/min]). One uni-axial accelerometer (Sportmetrics®) was placed on the shank for the impact loading analysis. Results: No significant difference was observed on plantar pressure (p>0.05), and kinematics variables (p>0.05) between the KT® and noKT® conditions. However, results revealed a relationship of dependence between speed and plantar pressure and kinematics parameters, especially under the rearfoot and the medial part of the foot (p<0.005). Conclusion: The results suggest that application of KT® on peroneus and triceps surae does not have a direct effect on the kinematic pattern of healthy individuals during walking

Effects of the exercise in the cerebral blood flow and metabolism. A review

In recent years it has been shown that cerebral blood flow is affected by intense exercise, what may even lead to a reduction in the cognitive capacity. This statement is contrary to the traditional belief that cerebral blood flood remains constant and unaltered even when exercise is performed. During physical exercise of moderate intensity, cerebral blood flow increases in the cerebral areas responsible for movement. Moreover, recent studies have observed that cerebral blood flow decreases during high-intensity exercise as a consequence of a local hyperventilation and vasoconstriction of the areas with lower cerebral activity. Traditionally, the glucose has been considered as the main and unique source of energy for the brain. However, new studies are suggesting that as the intensity of exercise increases, the glucose uptake decreases in favour of an increase in the lactate uptake. Finally, Hyperthermia may also play a major role in the cerebral regulation system, since it can provoke central fatigue as well as hypoglycaemia