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1.
EPJ Data Sci ; 11(1): 56, 2022.
Article in English | MEDLINE | ID: mdl-36466084

ABSTRACT

Researchers have studied political ideology and polarization in many different contexts since their effects are usually closely related to aspects and actions of individuals and societies. Hence, being able to estimate and measure the changes in political ideology and polarization is crucial for researchers, stakeholders, and the general public. In this paper, we model the ideology and polarization of 28 countries (the 27 EU member states plus the UK) using Facebook public posts from political parties' Facebook pages. We collected a three-year dataset from 2019 to 2021 with information from 234 political parties' Facebook pages and took advantage of the EU parliament elections of May 2019 to create our models. Our methodology works across 28 countries and benefits from being a low-cost running process that measures ideology and polarization at a high-resolution time scale. The results show our models are pretty accurate when validating them against 19 individual countries' elections as ground truth. Moreover, to make our results available to the research community, stakeholders, and individuals interested in politics, the last contribution of our paper is a website including detailed information about the political parties in our dataset. It also includes the temporal evolution of our ideology and polarization estimations. Therefore, our work delivers a novel tool that uses Facebook public data to create country metrics useful for different purposes. To the best of our knowledge, there is no prior work in the literature offering a solution that measures the ideology and polarization of all EU + UK countries.

2.
J R Soc Interface ; 19(190): 20220085, 2022 05.
Article in English | MEDLINE | ID: mdl-35611621

ABSTRACT

Culture has played a pivotal role in human evolution. Yet, the ability of social scientists to study culture is limited by the currently available measurement instruments. Scholars of culture must regularly choose between scalable but sparse survey-based methods or restricted but rich ethnographic methods. Here, we demonstrate that massive online social networks can advance the study of human culture by providing quantitative, scalable and high-resolution measurement of behaviourally revealed cultural values and preferences. We employ data across nearly 60 000 topic dimensions drawn from two billion Facebook users across 225 countries and territories. We first validate that cultural distances calculated from this measurement instrument correspond to traditional survey-based and objective measures of cross-national cultural differences. We then demonstrate that this expanded measure enables rich insight into the cultural landscape globally at previously impossible resolution. We analyse the importance of national borders in shaping culture and compare subnational divisiveness with gender divisiveness across countries. Our measure enables detailed investigation into the geopolitical stability of countries, social cleavages within small- and large-scale human groups, the integration of migrant populations and the disaffection of certain population groups from the political process, among myriad other potential future applications.


Subject(s)
Anthropology, Cultural , Culture , Humans
3.
SERIEs (Berl) ; 12(4): 687-708, 2021.
Article in English | MEDLINE | ID: mdl-34840619

ABSTRACT

We present a procedure to perform seasonal adjustment over daily sales data. The model adjusts daily information from the Immediate Supply of Information System for Value Added Tax declaration forms compiled by the Spanish Tax Agency. The procedure performs signal extraction and forecasting at the daily frequency, by means of an unobserved components model. The daily information allows a permanently updated monitoring of the short-term economic conditions of the Spanish economy.

4.
Int J Biometeorol ; 65(12): 2215-2227, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34313850

ABSTRACT

Phenology has been useful to better understand the climate-vegetation relationship, and it is considered an indicator of climate change impact. Phenological data have been generated through multiple remote sensing techniques and ground-based observations through professional or citizen science. The combination of both techniques is known as cross-scale phenological monitoring. However, no comparative analysis has been carried out to assess the advantages and disadvantages of each of these techniques to characterize the phenological cycle of forest ecosystem species. This work is a content-analysis-based review of scientific literature published between 2000 and 2018 related to cross-scale monitoring methods, to estimate the phenological variation in different forest ecosystems worldwide. For this study, 97 publications related to cross-scale phenological monitoring were selected. We found that 71% of the articles aimed to corroborate the data generated through satellite imagery using surface data from either phenocams, flux towers, or from citizen science networks. More publications were published by authors in the USA (30%), Canada (8%), and China (7%). The most commonly used vegetation index was the normalized difference vegetation index (65%). Some deficiencies in the evaluation of the phenological phases of autumn when compared with surface observations were found. Flux towers and phenocams were included as alternatives for ground-based monitoring. Cross-scale phenological monitoring has the potential to characterize the phenological response of vegetation accurately due to data combinations at two different observation scales. This work contributes to specifying the methodologies used in gathering phenological parameters of the world's forest ecosystems.


Subject(s)
Ecosystem , Forests , Climate Change , Satellite Imagery , Seasons
5.
Telemat Inform ; 64: 101692, 2021 Nov.
Article in English | MEDLINE | ID: mdl-36567816

ABSTRACT

In this paper we refer to the Open Web to the set of services offered freely to Internet users, representing a pillar of modern societies. Despite its importance for society, it is unknown how the COVID-19 pandemic is affecting the Open Web. In this paper, we address this issue, focusing our analysis on Spain, one of the countries which have been most impacted by the pandemic. On the one hand, we study the impact of the pandemic in the financial backbone of the Open Web, the online advertising business. To this end, we leverage concepts from Supply-Demand economic theory to perform a careful analysis of the elasticity in the supply of ad-spaces to the financial shortage of the online advertising business and its subsequent reduction in ad spaces' price. On the other hand, we analyze the distribution of the Open Web composition across business categories and its evolution during the COVID-19 pandemic. These analyses are conducted between Jan 1st and Dec 31st, 2020, using a reference dataset comprising information from more than 18 billion ad spaces. Our results indicate that the Open Web has experienced a moderate shift in its composition across business categories. However, this change is not produced by the financial shortage of the online advertising business, because as our analysis shows, the Open Web's supply of ad spaces is inelastic (i.e., insensitive) to the sustained low-price of ad spaces during the pandemic. Instead, existing evidence suggests that the reported shift in the Open Web composition is likely due to the change in the users' online behavior (e.g., browsing and mobile apps utilization patterns).

6.
Arch Esp Urol ; 73(5): 447-454, 2020 Jun.
Article in Spanish | MEDLINE | ID: mdl-32538816

ABSTRACT

INTRODUCTION: The COVID-19 pandemic poses significant challenges in the area of kidney donation and transplantation. The objective of this article is to establish general recommendations for surgical teams to manage the kidney transplant program duringthe COVID-19 era. MATERIAL AND METHODS: This document is based on the scientific evidence available on the infection caused by SARS-CoV-2 and the experience of authors during the COVID-19 pandemic. A web and Pubmed search was performed using the keywords "SARS-CoV-2"," COVID-19", "COVID Urology", "COVID-19 surgery", and "kidney transplantation." A modified nominal group technique was used. RESULTS: When health system saturation occurs, kidney transplants should be deferred, except in patients with low transplant possibilities and an optimal kidney available, combined transplants or life-threatening situations. Screening for the SARS-CoV-2 virus should be done in all those donors and recipients with clinical symptoms consistent with COVID-19, who have visited or live inhigh-risk areas, or who have been in close contact with confirmed cases of COVID-19. Donation and transplantation will not proceed in confirmed cases of COVID-19. Surgeries should be based on general recommendations in the COVID-19 era and will be efficient, short, and focused on those with the shortest hospital stay. In emergencies, protective measures will be taken with persona lprotection equipment. Surgical staff will be only the strictly necessary, and permanence in the OR should be minimized. Transplant urology consultations will be conducted by teleconsultation when possible. CONCLUSION: The safety of potential donors and recipients must be guaranteed, adopting individual protection measures and screening for SARS-CoV-2. Kidney transplant surgery must be efficient in terms of health, human resources, and clinical benefit. All non-urgent transplant activities should be delayed until the improvement of the local condition of each center.


INTRODUCCIÓN: La epidemia de COVID-19 plantea importantes retos en el ámbito de la donación y el trasplante renal. El objetivo de este artículo es establecer unas recomendaciones generales dirigidas a los equipos quirúrgicos de trasplante renal durante la era COVID-19. MATERIAL Y MÉTODOS: El documento se basa en la evidencia científica disponible sobre la infección causada por SARS-CoV-2 y la experiencia de los autores en la pandemia COVID-19. Se realizó una búsqueda web y en PubMed utilizando las palabras clave "SARSCoV-2", "COVID-19", "COVID Urology", "COVID-19 surgery" y "kidney transplantation". Se ha utilizado una técnica de grupo nominal modificada.RESULTADOS: En momentos de saturación del sistema sanitario, se deberán diferir los trasplantes renales, salvo en pacientes con bajas posibilidades de trasplante y un riñón óptimo disponible, trasplantes combinados o pacientes en situación de urgencia vital. Se deberá hacer cribado del virus SARS-CoV-2 en todos aquellos donantes y receptores que tengan sospecha clínica, hayan estado en zonas de alto riesgo o hayan compartido proximidad con casos confirmados de COVID-19. Nos e procederá con la donación ni con el trasplante en casos confirmados de COVID-19. Las cirugías deberáns er eficientes, cortas y centradas en las que menor estancia hospitalaria conlleven. En casos de urgencia, se extremarán las medidas de protección con equipos de protección individual. El personal quirúrgico será el menor posible y se minimizarán las estancias en quirófano. Las consultas urológicas de trasplante sin riesgo serán realizadas telemáticamente cuando sea posible. CONCLUSIÓN: La cirugía de trasplante renal debe ser eficiente en cuanto a recursos sanitarios, humano sy beneficio clínico. Se debe garantizar la seguridad de los potenciales donantes y receptores, adoptando medidas de protección individual y realizando cribado para SARS-CoV-2.


Subject(s)
Coronavirus Infections , Kidney Transplantation , Pandemics , Pneumonia, Viral , Betacoronavirus , COVID-19 , Coronavirus Infections/epidemiology , Humans , Pneumonia, Viral/epidemiology , SARS-CoV-2 , Spain/epidemiology
7.
Arch. esp. urol. (Ed. impr.) ; 73(5): 447-454, jun. 2020. tab
Article in Spanish | IBECS | ID: ibc-189703

ABSTRACT

INTRODUCCIÓN: La epidemia de COVID-19 plantea importantes retos en el ámbito de la donación y el trasplante renal. El objetivo de este artículo es establecer unas recomendaciones generales dirigidas a los equipos quirúrgicos de trasplante renal durante la era COVID-19. MATERIAL Y MÉTODOS: El documento se basa en la evidencia científica disponible sobre la infección causada por SARS-CoV-2 y la experiencia de los autores en la pandemia COVID-19. Se realizó una búsqueda web y en PubMed utilizando las palabras clave "SARSCoV-2", "COVID-19", "COVID rology", "COVID-19 surgery" y "kidney transplantation". Se ha utilizado una técnica de grupo nominal modificada. RESULTADOS: En momentos de saturación del sistema sanitario, se deberán diferir los trasplantes renales, salvo en pacientes con bajas posibilidades de trasplante y un riñón óptimo disponible, trasplantes combinados o pacientes en situación de urgencia vital. Se deberá hacer cribado del virus SARS-CoV-2 en todos aquellos donantes y receptores que tengan sospecha clínica, hayan estado en zonas de alto riesgo o hayan compartido proximidad con casos confirmados de COVID-19. Nos e procederá con la donación ni con el trasplante en casos confirmados de COVID-19. Las cirugías deberáns er eficientes, cortas y centradas en las que menor estancia hospitalaria conlleven. En casos de urgencia, se extremarán las medidas de protección con equipos de protección individual. El personal quirúrgico será el menor posible y se minimizarán las estancias en quirófano. Las consultas urológicas de trasplante sin riesgo serán realizadas telemáticamente cuando sea posible. CONCLUSIÓN: La cirugía de trasplante renal debe ser eficiente en cuanto a recursos sanitarios, humano sy beneficio clínico. Se debe garantizar la seguridad de los potenciales donantes y receptores, adoptando medidas de protección individual y realizando cribado para SARS-CoV-2


INTRODUCTION: The COVID-19 pandemic poses significant challenges in the area of kidney donation and transplantation. The objective of this article is to establish general recommendations for surgical teams to manage the kidney transplant program during the COVID-19 era. MATERIAL AND METHODS: This document is based on the scientific evidence available on the infection caused by SARS-CoV-2 and the experience of authors during the COVID-19 pandemic. A web and Pubmed search was performed using the keywords "SARS-CoV-2", "COVID-19", "COVID Urology", "COVID-19 surgery", and "kidney transplantation." A modified nominal group technique was used. RESULTS: When health system saturation occurs, kidney transplants should be deferred, except in patients with low transplant possibilities and an optimal kidney available, combined transplants or life-threatening situations. Screening for the SARS-CoV-2 virus should be done in all those donors and recipients with clinical symptoms consistent with COVID-19, who have visited or live in high-risk areas, or who have been in close contact with confirmed cases of COVID-19. Donation and transplantation will not proceed in confirmed cases of COVID-19. Surgeries should be based on general recommendations in the COVID-19 era and will be efficient, short, and focused on those with the shortest hospital stay. In emergencies, protective measures will be taken with personal protection equipment. Surgical staff will be only the strictly necessary, and permanence in the OR should be minimized. Transplant urology consultations will be conducted by teleconsultation when possible. CONCLUSION: The safety of potential donors and recipients must be guaranteed, adopting individual protection measures and screening for SARS-CoV-2. Kidney transplant surgery must be efficient in terms of health, human resources, and clinical benefit. All non-urgent transplant activities should be delayed until the improvement of the local condition of each center


Subject(s)
Humans , Coronavirus Infections/prevention & control , Pneumonia, Viral/prevention & control , Pandemics , Health Priorities , Evidence-Based Medicine , Patient Safety/standards , Kidney Transplantation/standards , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Tissue Donors , Practice Guidelines as Topic , Spain
8.
PLoS One ; 15(3): e0230877, 2020.
Article in English | MEDLINE | ID: mdl-32214390

ABSTRACT

Foot orthoses are one of the most used strategies by healthy runners in injury prevention and performance improvement. However, their effect on running kinematics throughout an intense prolonged run in this population is unknown. Moreover, there is some controversy regarding the use of custom-made versus prefabricated foot orthoses. This study analysed the effect of different foot orthoses (custom-made, prefabricated and a control condition) on spatio-temporal and angular (knee flexion and foot eversion) kinematic parameters and their behaviour during an intense prolonged run. Twenty-four recreational runners performed three similar tests that consisted of running 20 min on a treadmill at 80% of their maximal aerobic speed, each one with a different foot orthosis condition. Contact and flight time, and stride length and stride rate were measured every 5 min by an optical measurement photoelectric cell system. Knee flexion and foot eversion kinematic parameters were measured by two high-speed cameras. No significant differences were found between the different foot orthoses in any of the time points studied and between the interaction of foot orthosis and behaviour over time, in any of the variables studied (P > 0.05). The use of custom-made and prefabricated foot orthoses during an intense prolonged run does not produce changes in spatio-temporal and kinematic parameters in healthy runners. These results suggest that a healthy runner maintains its ideal movement pattern throughout a 20 minute prolonged run, regardless the type of foot orthosis used.


Subject(s)
Foot Orthoses , Mechanical Phenomena , Running , Adult , Biomechanical Phenomena , Equipment Design , Female , Humans , Male , Time Factors
9.
Proc Natl Acad Sci U S A ; 115(27): 6958-6963, 2018 07 03.
Article in English | MEDLINE | ID: mdl-29921703

ABSTRACT

Online social media are information resources that can have a transformative power in society. While the Web was envisioned as an equalizing force that allows everyone to access information, the digital divide prevents large amounts of people from being present online. Online social media, in particular, are prone to gender inequality, an important issue given the link between social media use and employment. Understanding gender inequality in social media is a challenging task due to the necessity of data sources that can provide large-scale measurements across multiple countries. Here, we show how the Facebook Gender Divide (FGD), a metric based on aggregated statistics of more than 1.4 billion users in 217 countries, explains various aspects of worldwide gender inequality. Our analysis shows that the FGD encodes gender equality indices in education, health, and economic opportunity. We find gender differences in network externalities that suggest that using social media has an added value for women. Furthermore, we find that low values of the FGD are associated with increases in economic gender equality. Our results suggest that online social networks, while suffering evident gender imbalance, may lower the barriers that women have to access to informational resources and help to narrow the economic gender gap.


Subject(s)
Interpersonal Relations , Models, Theoretical , Sexism , Social Media , Female , Humans , Male
10.
Gait Posture ; 59: 292-297, 2018 01.
Article in English | MEDLINE | ID: mdl-28754421

ABSTRACT

The characteristics of a treadmill and the environment where it is based could influence the user's gaze and have an effect on their running kinematics and lower limb impacts. The aim of this study was to identify the effect of visual focus on spatio-temporal parameters and lower limb kinematics during treadmill running. Twenty six experienced runners ran at 3.33ms-1 on a treadmill under two visual conditions, either looking ahead at a wall or looking down at the treadmill visual display. Spatio-temporal parameters, impact accelerations of the head and tibia, and knee and ankle kinematics were measured for the final 15s of a 90s bout of running under each condition. At the end of the test, participants reported their preference for the visual conditions assessed. Participants' stride angle, flight time, knee flexion during the flight phase, and ankle eversion during contact time were increased when runners directed visual focus toward the wall compared to the treadmill display (p<0.05). Whilst head acceleration was also increased in the wall condition (p<0.05), the other acceleration parameters were unaffected (p>0.05). However, the effect size of all biomechanical alterations was small. The Treadmill condition was the preferred condition by the participants (p<0.001; ESw=1.0). The results of the current study indicate that runners had a greater mass centre vertical displacement when they ran looking ahead, probably with the aim of compensating for reduced visual feedback, which resulted in larger head accelerations. Greater knee flexion during the flight phase and ankle eversion during the contact time were suggested as compensatory mechanisms for lower limb impacts.


Subject(s)
Fixation, Ocular , Gait/physiology , Lower Extremity/physiology , Running/physiology , Acceleration , Adult , Biomechanical Phenomena , Exercise Test , Humans , Male , Time and Motion Studies , Young Adult
11.
Appl Opt ; 56(19): 5559-5565, 2017 Jul 01.
Article in English | MEDLINE | ID: mdl-29047517

ABSTRACT

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 research.


Subject(s)
Foot/physiology , Pronation/physiology , Running/physiology , Skin Temperature/physiology , Thermography/methods , Adult , Female , Humans , Male , Time Factors
12.
J Hum Kinet ; 57: 221-231, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28713474

ABSTRACT

High plantar pressure has been associated with increased risk of injury. The characteristics of each physical activity determine the load on the lower limbs. The influence of Nordic Walking (NW) technique on plantar pressure is still unknown. The aim of this study was to analyze the differences between plantar pressure during NW with the Diagonal technique (DT) versus Alpha technique (AT) and compare them with the pressure obtained during normal walking (W). The normality and sphericity of the plantar pressure data were checked before performing a two-way repeated measures ANOVA in order to find differences between speeds (preferred, fast) and the gait (NW, W) as within-subject factors. Then, a t-test for independent measures was used to identify the specific differences between NW techniques. The strength of the differences was calculated by means of the effect size (ES). The results demonstrated that during NW with AT at preferred speed the pressure was lower under the Calcaneus, Lateral Metatarsal and Toes compared to the DT group (p = 0.046, ES = 1.49; p = 0.015, ES = 1.44; p = 0.040, ES = 1.20, respectively). No differences were found at the fast speed (p > 0.05). Besides the increase in walking speed during NW (p < 0.01), both technique groups showed lower pressure during NW compared to W under the Hallux and Central Metatarsal heads (F = 58.321, p = 0.000, ES = 2.449; F = 41.917, p = 0.012, ES = 1.365, respectively). As a practical conclusion, the AT technique may be the most effective of the NW techniques at reducing plantar pressure while allowing NW practitioners to achieve the physiological benefits of NW.

13.
Acta méd. costarric ; 59(2): 60-66, abr.-jun. 2017. tab, ilus
Article in Spanish | LILACS | ID: biblio-837725

ABSTRACT

ResumenAntecedentes:la albahaca (Ocium basilicum) es una hierba perteneciente a la familia laminaceae, caracterizada por sus bondades medicinales. Se ha referido su uso en la terapéutica del cáncer, vitíiigo, hipercolesterolemia y la diabetes mellitus.Objetivo:evaluar el efecto hipoglicemiante del extracto metanólico de la albahaca, su aislamiento y purificación de sus principales compuestos.Métodos:las hojas y tallos fueron colectadas en el sector la Hechicera, estado Mérida, Venezuela.Las muestras se maceraron en 20L de metanol al 70% v/v, dosificándose a dosis crecientes entre 1,0 y 2,0 g/kg, usando como modelo experimental, ratas macho de la cepa C57BL/6, con hiperglicemia inducida con aloxano monohidratado. Se incluyó un control positivo usando como agente hipoglucemiante la sitagliptina (400μg/kg). El extracto se sometió a fraccionamiento mediante cromatografía de columna abierta, cuyas fracciones (175 ml cada una) se asociaron por similitud estructural y fueron dosificadas a la población en estudio. Se obtuvieron muestras sanguíneas seriadas de la vena de la base de la cola y se procesaron siguiendo el método de la glucosa oxidasa-peroxidasa.Resultados:se demostró una disminución de la concentración de glucosa sanguínea a la dosis de 2,0 g/kg (<120 mg/dL). Los análisis estructurales se realizaron mediante pruebas cromatográficas, espectroscópicas, espectrométricas y químicas. Del estudio se aislaron e identificaron los siguientes compuestos: nandecilato de metilo (C20O2H40); behenato de metilo (C23O2H46) hexacosanoato de metilo(C27O2H54), así como 18-metoxicarbonil-3,4-didehidroibogamina, el flavonoides 5,7,3´-trihydroxi-3,6,4´-trimetoxiflavona, los cuales son reportados por primera vez en los análisis fitoquímicos para O. basilicum.Conclusión:estos hallazgos sustentan el potencial uso de la albahaca como alternativa considerable en el tratamiento hipoglucemiante.


AbstractBackground:Basil (Ocium basilicum) is an herb belonging to the family laminaceae, characterized by its medicinal benefits. Its use has been referred for the treatment of cancer, vitiligo, hypercholesterolemia, and diabetes mellitus.Objective:to evaluate the hypoglycemic effect of the methanol extract of basil, isolation and purification of its main compounds.Methods:The leaves and stems were collected in the sector La Hechicera, Mérida, Venezuela State. Samples were macerated in 20L of methanol to 70% v/v, dosing to increaseddoses between 1.0 and2.0 g/kg, using as experimental model, male rats of the C57BL/6 strain with hyperglycemia induced with alloxan monohydrate. A positivecontrol was included using as a hypoglycemic agent sitagliptin (400μg/kg). The extract was submitted to fractionation by open column chromatography,, whose fractions (175 ml each) were partnered by structural similarity and were dosed to the population under study. Serial blood samples from the base of the tail vein were obtained and were processed using the method of the glucose oxidase-peroxidase.Results:they showed a decrease of the concentration of blood glucose at a dose of 2.0 g/kg (< 120 mg/dL). Structural analyses were conducted using chromatographic, spectroscopic, spectrometric and chemical tests. They were isolated from the study and the following compounds were identified: nandecilato of methyl (C20O2H40); methyl behenate (C23O2H46), methyl hexacosanoate (C27O2H54) as well as 18-methoxycarbonyl-3, 4-didehidroibogamina, 5,7,3´-trihydroxi-3,6,4´- trimetoxiflavona flavonoid, which are reported for the first time in the phytochemical analysis for O. basilicum.Conclusion:These findings support the potential use of Basil as a weed of traditional medicine in the hypoglycemic treatment.


Subject(s)
Rats , Hyperglycemia , Hypoglycemic Agents/therapeutic use , Mice, Obese/blood , Ocimum basilicum/chemistry
14.
Res Q Exerc Sport ; 88(2): 223-229, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28362217

ABSTRACT

PURPOSE: Graduated compressive stockings (GCS) have been suggested to influence performance by reducing muscle oscillations and improving muscle function and efficiency. However, no study to date has analyzed the influence of GCS on muscle activity during running. The objective of the study was to analyze the influence of GCS on the perception of comfort and muscle activation of the main muscles of the lower leg during running. METHOD: Thirty-six participants ran on a treadmill with (GCS) or without (control) GCS. The running tests consisted of a 10-min warm-up followed by a 20-min intense run at 75% of the athlete's maximal aerobic speed. Surface electromyography of the tibialis anterior, peroneus longus, gastrocnemius lateralis (GL), and gastrocnemius medialis (GM) were recorded every 5 min during the run and analyzed using a non-linearly scaled wavelet analysis. Perception of comfort of the GCS was measured before and after the run. RESULTS: The GCS were reported as comfortable garments and reduced GL activity at Minute 0 (p < .05, [Formula: see text]= .245) and Minute 5 (p < .05, [Formula: see text]= .326) and GM activity at Minute 0 (p < .05, [Formula: see text]= .233) compared with running without garments, but their effect was temporary and disappeared after 5 min of running. CONCLUSION: Even though GCS reduced gastrocnemius muscle activity during the initial minutes of running, it is hypothesized that the GCS could have lost their initial levels of compression after some minutes of exercise, thereby reducing their influence on muscle activation. However, this hypothesis needs to be further investigated.


Subject(s)
Muscle, Skeletal/physiology , Running/physiology , Stockings, Compression , Adult , Electromyography , Female , Humans , Leg/physiology , Male , Muscle Fatigue/physiology , Perception
15.
PLoS One ; 12(2): e0173179, 2017.
Article in English | MEDLINE | ID: mdl-28245273

ABSTRACT

Each time the foot contacts the ground during running there is a rapid deceleration that results in a shock wave that is transmitted from the foot to the head. The fatigue of the musculoskeletal system during running may decrease the ability of the body to absorb those shock waves and increase the risk of injury. Insoles are commonly prescribed to prevent injuries, and both custom-made and prefabricated insoles have been observed to reduce shock accelerations during running. However, no study to date has included a direct comparison of their behaviour measured over the same group of athletes, and therefore great controversy still exists regarding their effectiveness in reducing impact loading during running. The aim of the study was to analyse the acute differences in stride and shock parameters while running on a treadmill with custom-made and prefabricated insoles. Stride parameters (stride length, stride rate) and shock acceleration parameters (head and tibial peak acceleration, shock magnitude, acceleration rate, and shock attenuation) were measured using two triaxial accelerometers in 38 runners at 3.33 m/s before and after a 15-min intense run while using the sock liner of the shoe (control condition), prefabricated insoles and custom-made insoles. No differences in shock accelerations were found between the custom-made and the control insoles. The prefabricated insoles increased the head acceleration rate (post-fatigue, p = 0.029) compared to the control condition. The custom-made reduced tibial (pre-fatigue, p = 0.041) and head acceleration rates (pre-fatigue and post-fatigue, p = 0.01 and p = 0.046) compared to the prefabricated insoles. Neither the stride nor the acceleration parameters were modified as a result of the intense run. In the present study, the acute use of insoles (custom-made, prefabricated) did not reduce shock accelerations compared to the control insoles. Therefore, their effectiveness at protecting against injuries associated with elevated accelerations is not supported and remains unclear.


Subject(s)
Running/physiology , Shoes , Adult , Athletes , Exercise Test , Female , Humans , Male , Muscle Fatigue/physiology , Young Adult
16.
J Sports Sci ; 35(17): 1734-1738, 2017 Sep.
Article in English | MEDLINE | ID: mdl-27690754

ABSTRACT

Tibial accelerations have been associated with a number of running injuries. However, studies attaching the tibial accelerometer on the proximal section are as numerous as those attaching the accelerometer on the distal section. This study aimed to investigate whether accelerometer location influences acceleration parameters commonly reported in running literature. To fulfil this purpose, 30 athletes ran at 2.22, 2.78 and 3.33 m · s-1 with three accelerometers attached with double-sided tape and tightened to the participants' tolerance on the forehead, the proximal section of the tibia and the distal section of the tibia. Time-domain (peak acceleration, shock attenuation) and frequency-domain parameters (peak frequency, peak power, signal magnitude and shock attenuation in both the low and high frequency ranges) were calculated for each of the tibial locations. The distal accelerometer registered greater tibial acceleration peak and shock attenuation compared to the proximal accelerometer. With respect to the frequency-domain analysis, the distal accelerometer provided greater values of all the low-frequency parameters, whereas no difference was observed for the high-frequency parameters. These findings suggest that the location of the tibial accelerometer does influence the acceleration signal parameters, and thus, researchers should carefully consider the location they choose to place the accelerometer so that equivalent comparisons across studies can be made.


Subject(s)
Accelerometry/methods , Leg/physiology , Running/physiology , Acceleration , Adult , Biomechanical Phenomena , Humans , Male , Tibia
17.
J Strength Cond Res ; 31(8): 2255-2262, 2017 Aug.
Article in English | MEDLINE | ID: mdl-27787465

ABSTRACT

Cortell-Tormo, JM, García-Jaén, M, Chulvi-Medrano, I, Hernández-Sánchez, S, Lucas-Cuevas, ÁG, and Tortosa-Martínez, J. Influence of scapular position on the core musculature activation in the prone plank exercise. J Strength Cond Res 31(8): 2255-2262, 2017-Prone plank is a widely used exercise in core stability training. Research has shown that pelvic tilt plays an important role on the electromyographic (EMG) activation of core musculature. However, the influence of scapular position on EMG activation is currently unknown. Therefore, this study evaluated the influence of scapular position on the core muscles during a prone plank. Surface EMG of the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and erector spinae (ES) was collected in 15 participants (10 men and 5 women). Four variations of the prone plank were evaluated: scapular abduction with anterior (ABANT) and posterior (ABRET) pelvic tilt; and scapular adduction with anterior (ADANT), and posterior (ADRET) pelvic tilt. Individual muscle EMG and overall EMG for each plank exercise was analyzed. Joint positions were controlled with a 2D kinematic analysis. Ratings of perceived exertion (RPE) were also registered. The ADRET resulted in higher overall EMG activity compared with ABANT (p = 0.04) and ADANT (p = 0.04). Moreover, ADRET resulted in greater EMG activity compared with ADANT, ABANT, and ABRET for EO (p = 0.000; p = 0.000; p = 0.035), IO (p = 0.000; p = 0.000; p = 0.005), and ES (p = 0.019; p = 0.001; p = 0.014). Regarding RA, ADRET was significantly higher compared with ADANT (p = 0.002) and ABANT (p = 0.005). Finally, ADRET provoked a higher RPE compared with ABANT (p = 0.000), ABRET (p = 0.001), and ADANT (p = 0.015). These findings demonstrate the influence of the scapular and pelvic position on the EMG response of the core muscle groups analyzed in this study, and highlight the greater contribution of these muscles to the postural stabilizing demands during posterior pelvic tilt positions, particularly when the scapulae are in adduction.


Subject(s)
Abdominal Muscles/physiology , Exercise/physiology , Paraspinal Muscles/physiology , Scapula/physiology , Abdominal Oblique Muscles/physiology , Adult , Biomechanical Phenomena , Electromyography , Female , Humans , Male , Movement , Pelvic Floor/physiology , Rectus Abdominis/physiology , Young Adult
18.
J Sports Sci ; 35(14): 1459-1465, 2017 Jul.
Article in English | MEDLINE | ID: mdl-27490817

ABSTRACT

The aim of this study was to assess the influence of different bike positions on the perception of fatigue, pain and comfort. Twenty cyclists underwent three tests that involved cycling for 45 min at their individual 50% peak aerobic power output while adopting different positions on the bike. Participants performed the cycling tests adopting three positions defined by two parameters (knee flexion angle [20°, 30°, 40°] and trunk flexion angle [35°, 45°, 55°]) in random order. Angles were measured using a 2D motion analysis system during cycling and applying Fonda's correction factor. Perceptions of comfort, fatigue and pain were reported before the end of each test. The combination of 40° knee flexion and 35° trunk flexion was perceived as the most uncomfortable position. Moreover, greater knee flexion had a negative effect on trunk comfort, accompanied by greater levels of fatigue and pain perception in the anterior part of the thigh and knee. In conclusion, cyclists perceived the most comfortable position to be when the saddle height was within the recommended knee angle (30° calculated from the offset position or 40 ± 4.0° of absolute value). Upright trunk was found to be the most comfortable position for recreational cyclists, where aerodynamics is not so important. Cyclists' bike perceptions should be taken into account when it comes to choosing the most beneficial position, since this can play a role in injury prevention and enhance cycling performance.


Subject(s)
Bicycling/physiology , Muscle Fatigue/physiology , Pain/psychology , Perception , Sports Equipment/adverse effects , Adult , Biomechanical Phenomena , Equipment Design , Humans , Knee/physiology , Male , Pain/etiology , Posture/physiology , Thigh/physiology , Time and Motion Studies , Torso/physiology
19.
Eur J Sport Sci ; 16(8): 1145-52, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27346636

ABSTRACT

Runners tend to shift from a rearfoot to a forefoot strike pattern when running barefoot. However, it is unclear how the first attempts at running barefoot affect habitually rearfoot shod runners. Due to the inconsistency of their recently adopted barefoot technique, a number of new barefoot-related running injuries are emerging among novice barefoot runners. The aim of this study was therefore to analyse the influence of three running conditions (natural barefoot [BF], barefoot with a forced rearfoot strike [BRS], and shod [SH]) on muscle activity and impact accelerations in habitually rearfoot shod runners. Twenty-two participants ran at 60% of their maximal aerobic speed while foot strike, tibial and head impact accelerations, and tibialis anterior (TA), peroneus longus (PL), gastrocnemius medialis (GM) and gastrocnemius lateralis (GL) muscle activity were registered. Only 68% of the runners adopted a non-rearfoot strike pattern during BF. Running BF led to a reduction of TA activity as well as to an increase of GL and GM activity compared to BRS and SH. Furthermore, BRS increased tibial peak acceleration, tibial magnitude and tibial acceleration rate compared to SH and BF. In conclusion, 32% of our runners showed a rearfoot strike pattern at the first attempts at running barefoot, which corresponds to a running style (BRS) that led to increased muscle activation and impact accelerations and thereby to a potentially higher risk of injury compared to running shod.


Subject(s)
Foot/physiology , Leg/physiology , Muscle, Skeletal/physiology , Running/physiology , Acceleration , Adult , Biomechanical Phenomena/physiology , Humans , Young Adult
20.
Eur J Sport Sci ; 16(5): 609-17, 2016 Aug.
Article in English | MEDLINE | ID: mdl-26364906

ABSTRACT

Disinfection by-products (DBPs) are generated through the reaction of chlorine with organic and inorganic matter in indoor swimming pools. Different DBPs are present in indoor swimming pools. This study evaluated the effects of different chlorinated formations in oxidative stress and lung damage in 20 swimmers after 40 min of aerobic swimming in 3 indoor pools with different characteristics. Biological samples were collected to measure lung damage (serum-surfactant-associated proteins A and B), oxidative stress parameters (plasma protein carbonylation and malondialdehyde, and whole-blood glutathione oxidation), and swimming exertion values (blood lactate) before and after exercise. Free chlorine and combined chlorine in water, and chlorine in air samples were determined in all the swimming pools. Chlorination as disinfection treatment led to the formation of chloramines in water samples, mainly mono- and dichloramine. However, free chlorine was the predominate species in ultraviolet-treated swimming pool. Levels of total chlorine increased as a function of the swimming activity in chlorinated swimming pools. The lower quality of the installation resulted in a higher content of total chlorine, especially in air samples, and therefore a higher exposure of the swimmer to DBPs. However, the concentration level of chlorinated DBPs did not result in significant variation in serum-surfactant-associated proteins A and oxidative stress parameters in swimmers. In conclusion, the quality of the installation affected the DBPs concentration; however, it did not lead to lung epithelial damage and oxidative stress parameters in swimmers.


Subject(s)
Air Pollutants/analysis , Chlorine Compounds/analysis , Disinfectants/adverse effects , Oxidative Stress/drug effects , Swimming Pools , Water Pollutants, Chemical/analysis , Adult , Air Pollutants/adverse effects , Air Pollutants/chemistry , Chlorine Compounds/adverse effects , Chlorine Compounds/chemistry , Glutathione/blood , Glutathione Disulfide/blood , Humans , Lactic Acid/blood , Male , Swimming , Water/analysis , Water/chemistry , Water Pollutants, Chemical/adverse effects , Water Pollutants, Chemical/chemistry , Young Adult
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