Relation between VT1, VT2, and VO2max with the Special Wrestling Fitness Test in Youth Wrestlers: A Short Report.

This study investigated the relationship between peak oxygen uptake and ventilatory threshold 1 (VT1) and 2 (VT2) with the Special Wrestling Fitness Test variables. Thirteen wrestlers (male: six; female: seven) of Olympic freestyle wrestling were assessed. The Pearson's correlation coefficient (p < 0.05) was used to establish the relationship between variables. A positive correlation was found between VT1 with throws in set B (r = 0.77; p = 0.002; 95%CI = 0.37-0.93), total throws (r = 0.73; p = 0.004; 95%CI = 0.30-0.91), heart rate recovery (r = 0.58; p = 0.036; 95%CI = 0.05-0.86), and test index (r = -0.60; p = 0.031; 95%CI = -0.86-0.07); between VT2 and throws in set B (r = 0.57; p = 0.043; 95%CI = 0.01-0.86); and between peak oxygen uptake with throws in set B (r = 0.77; p = 0.002; 95%CI = 0.39-0.93), throws in set C (r = 0.64; p = 0.02; 95%CI = 0.12-0.89), and total throws (r = 0.72; p = 0.006; 95%CI = 0.28-0.91). In conclusion, the peak oxygen uptake and ventilatory thresholds correlated with specific Special Wrestling Fitness Test variables.

How were modified the human anatomy study habits during and after confinement by the COVID-19 pandemic? / ¿Cómo se modificaron los hábitos de estudio en anatomía humana durante y después del confinamiento por la pandemia del COVID-19?

SUMMARY: During 2020 and 2021 the anatomy subject was developed by online classes. In 2022, face-to-face teaching activities were resumed. The objective was to compare the autonomous study habits of two student generations that coursed the Human Anatomy subject in online and face-to-face mode. Two groups of students were asked to fill-out an online questionnaire. Online Generation (OL) (n=185) and Face-to-face Generation (FF) (n=154). The difference between both groups was the learning activities. OL received only online classes, and FF received theoretical classes and laboratory activities in face-to-face sessions. The most of OL subjects had greater clarity about the contents (71.9 %) and the depth (50.8 %) that they should study them, in contrast with FF (58.4 %, p = 0.0124 and 24.7 %, p < 0.0001 respectively). In OL, 47 % spent more than 4 hours weekly studying human anatomy, whereas in FF 68.2 % (p<0.0001). In both groups, the most important resource was the Video Recorded Classes (90.8 % in OL, and 83.1 % in FF). For OL, the three priority resources were exclusively electronic: 1) Video Recorded Classes, 2) Apps on smartphone or tablets, and 3) Apps on laptop or computer. FF generation prioritized: 1) Video Recorded Classes, 2) Anatomy Atlas, and 3) Class Slides. During the COVID-19 pandemic, the students that received only online classes were able to plain their study time in a better way than whose were in face-to-face classes. However, they spent less time to study the topics. In addition, it was possible to determine that students prefer digital resources (video classes recorded and apps in smartphone or computer) over traditional resources such as textbook and anatomy atlas. It proposes to consider these results in the Human Anatomy subjects design, in virtual or face-to-face mode.

Durante 2020 y 2021, la asignatura de anatomía fue desarrollada exclusivamente en modalidad online. En 2022 se retomaron las clases presenciales. El objetivo de este estudio fue comparar los hábitos de estudio autónomo de dos generaciones de estudiantes de anatomía. Dos grupos de estudiantes completaron un cuestionario online: Generación Online (OL) (n=185) y Generación Presencial (FF) (n=154). La principal diferencia entre ellos fue que OL recibió clases exclusivamente en modalidad online y FF exclusivamente presencial. La mayoría de los sujetos de OL tuvieron mayor claridad acerca de los contenidos (71,9 %) y la profundidad con que debían estudiarlos (50,8 %) en contraste con FF (58,4 %, p = 0,0124 and 24,7 %, p < 0,0001, respectivamente). En OL, el 47 % empleó más de 4 horas semanales de estudio, mientras en FF fue el 68,2 % (p<0.0001). En ambos grupos, el recurso más importante empleado fue la clase grabada (90,8 % en OL y 83,1 % en FF). Para OL la prioridad en el uso de los recursos de estudio fueron 1) Videoclase grabada, 2) Aplicación en teléfono o tablet y 3) Aplicación en computador. Para FF el orden de prioridad fue 1) Videoclase grabada, 2) Atlas de Anatomía y 3) Diapositivas de clases. Durante la pandemia de COVID-19, los estudiantes que recibieron exclusivamente clases online planearon su tiempo de estudio de mejor manera que quienes tuvieron clases presenciales y emplearon menos tiempo de estudio. Además, fue posible determinar que los estudiantes prefieren recursos de información digital (Videoclase Grabada y aplicaciones para teléfono celular o computador) por sobre los recursos tradicionales tales como texto y atlas de anatomía. Se propone considerar estos resultados en el diseño de los programas de asignatura de Anatomía Humana, a impartir en modalidad online o presencial.

Train at home, but not alone: a randomised controlled multicentre trial assessing the effects of live-streamed tele-exercise during COVID-19-related lockdowns.

OBJECTIVE: Public life restrictions associated with the COVID-19 pandemic caused reductions in physical activity (PA) and decreases in mental and somatic health. Considering the interplay between these factors, we investigated the effects of digital home exercise (DHE) during government-enforced lockdowns. METHODS: A multicentre randomised controlled trial was performed allocating healthy individuals from nine countries (N=763; 523 female) to a DHE or an inactive control group. During the 4-week main intervention, DHE members engaged in live-streamed multicomponent home exercise. Subsequently, both groups had access to prerecorded workouts for an additional 4 weeks. Outcomes, assessed weekly, included PA level (Nordic Physical Activity Questionnaire-Short), anxiety (Generalized Anxiety Disorder Scale-7), mental well-being (WHO-5 Questionnaire), sleep quality (Medical Outcome Study Sleep Scale), pain/disability (Chronic Pain Grade Scale) and exercise motivation (Self-Concordance Scale). Mixed models were used for analysis. RESULTS: Live-streamed DHE consistently increased moderate PA (eg, week 1: 1.65 times more minutes per week, 95% CI 1.40 to 1.94) and vigorous PA (eg, week 1: 1.31 times more minutes per week, 95% CI 1.08 to 1.61), although the effects decreased over time. In addition, exercise motivation, sleep quality and anxiety were slightly improved for DHE in the 4-week live streaming period. The same applied to mental well-being (mean difference at week 4: +0.99, 95% CI 0.13 to 1.86), but an inverted trend was observed after live streaming was substituted by prerecorded exercise. CONCLUSIONS: Live-streamed DHE represents an efficacious method to enhance PA and selected markers of health during pandemic-related public life restrictions. However, research on implementation is warranted to reduce dropout rates. TRIAL REGISTRATION NUMBER: DRKS00021273.

Drastic Reductions in Mental Well-Being Observed Globally During the COVID-19 Pandemic: Results From the ASAP Survey.

Most countries affected by the COVID-19 pandemic have repeatedly restricted public life to control the contagion. However, the health impact of confinement measures is hitherto unclear. We performed a multinational survey investigating changes in mental and physical well-being (MWB/PWB) during the first wave of the pandemic. A total of 14,975 individuals from 14 countries provided valid responses. Compared to pre-restrictions, MWB, as measured by the WHO-5 questionnaire, decreased considerably during restrictions (68.1 ± 16.9 to 51.9 ± 21.0 points). Whereas 14.2% of the participants met the cutoff for depression screening pre-restrictions, this share tripled to 45.2% during restrictions. Factors associated with clinically relevant decreases in MWB were female sex (odds ratio/OR = 1.20, 95% CI: 1.11-1.29), high physical activity levels pre-restrictions (OR = 1.29, 95% CI 1.16-1.42), decreased vigorous physical activity during restrictions (OR = 1.14, 95% CI: 1.05-1.23), and working (partially) outside the home vs. working remotely (OR = 1.29, 95% CI: 1.16-1.44/OR = 1.35, 95% CI: 1.23-1.47). Reductions, although smaller, were also seen for PWB. Scores in the SF-36 bodily pain subscale decreased from 85.8 ± 18.7% pre-restrictions to 81.3 ± 21.9% during restrictions. Clinically relevant decrements of PWB were associated with female sex (OR = 1.62, 95% CI: 1.50-1.75), high levels of public life restrictions (OR = 1.26, 95% CI: 1.18-1.36), and young age (OR = 1.10, 95% CI: 1.03-1.19). Study findings suggest lockdowns instituted during the COVID-19 pandemic may have had substantial adverse public health effects. The development of interventions mitigating losses in MWB and PWB is, thus, paramount when preparing for forthcoming waves of COVID-19 or future public life restrictions.

A Pandemic within the Pandemic? Physical Activity Levels Substantially Decreased in Countries Affected by COVID-19.

Governments have restricted public life during the COVID-19 pandemic, inter alia closing sports facilities and gyms. As regular exercise is essential for health, this study examined the effect of pandemic-related confinements on physical activity (PA) levels. A multinational survey was performed in 14 countries. Times spent in moderate-to-vigorous physical activity (MVPA) as well as in vigorous physical activity only (VPA) were assessed using the Nordic Physical Activity Questionnaire (short form). Data were obtained for leisure and occupational PA pre- and during restrictions. Compliance with PA guidelines was calculated based on the recommendations of the World Health Organization (WHO). In total, n = 13,503 respondents (39 ± 15 years, 59% females) were surveyed. Compared to pre-restrictions, overall self-reported PA declined by 41% (MVPA) and 42.2% (VPA). Reductions were higher for occupational vs. leisure time, young and old vs. middle-aged persons, previously more active vs. less active individuals, but similar between men and women. Compared to pre-pandemic, compliance with WHO guidelines decreased from 80.9% (95% CI: 80.3-81.7) to 62.5% (95% CI: 61.6-63.3). Results suggest PA levels have substantially decreased globally during the COVID-19 pandemic. Key stakeholders should consider strategies to mitigate loss in PA in order to preserve health during the pandemic.

Propuesta de modelo técnico de pateo en fútbol: Una revisión sistemática de variables cinemáticas y cinéticas / Proposal of a Technical Model of Soccer Kicking: A Systematic Review of Kinematic and Kinetic Variables

Resumen Este artículo presenta una visión propositiva de la bibliografía actual en la técnica de pateo en fútbol. Los objetivos de la investigación son: (i) identificar las variables cinéticas y cinemáticas potenciales utilizadas en los análisis de la técnica y (ii) determinar los valores de variables cinéticas y cinemáticas en relación con la técnica de pateo en fútbol. Se revisaron las siguientes bases de datos; PubMed y Taylor and Francis online, para obtener artículos seleccionados desde 2000-2017. Se utilizó la metodología PRISMA®; se incluyeron artículos con participantes adultos o juveniles sobre la mecánica de pateo en fútbol a través de variables biomecánicas. Los artículos incluidos fueron 29, posteriormente se elaboró un modelo técnico compuesto por cuatro fases: preparación, balanceo, impacto y seguimiento. Una perspectiva biomecánica con base en la técnica podría ofrecer una estrategia prometedora para mejorar, a partir del entrenamiento y análisis de la técnica, el rendimiento en fútbol además de proveer antecedentes para la prevención de lesiones.

Abstract This article describes a propositive vision of the current literature on soccer kicking techniques. It aims to identify the potential kinetic and kinematic variables used in the analysis of the techniques, and to determine the values of kinetic and kinematic variables in relation to the kicking techniques in soccer. PubMed and Taylor & Francis online were reviewed to obtain selected articles from 2000 to 2017. PRISMA® methodology was implemented. Twenty-nine papers were selected; they considered kicking techniques in soccer young or adult participants through biomechanical variables. Then, a four-phase technical model was prepared: preparation, roll, impact, and follow-up phases. A technique-based biomechanical perspective can offer a promising strategy to improve, from training and technique analysis, the performance in football, in addition to providing a background for injury prevention.

Resumo Este artigo apresenta uma visão propositiva da bibliografia atual sobre a técnica do chute no futebol. Os objetivos da pesquisa são: (i) identificar as variáveis cinéticas e cinemáticas potenciais utilizadas na análise da técnica e (ii) determinar os valores das variáveis cinéticas e cinemáticas em relação à técnica de pontapés no futebol. As seguintes bases de dados foram revistas; PubMed e Taylor e Francis online, para artigos selecionados de 2000 a 2017. Foi utilizada a metodologia PRISMA®; foram incluídos artigos com participantes adultos ou juvenis sobre mecânica do chute de futebol através de variáveis biomecânicas. Os artigos incluídos foram 29, posteriormente foi desenvolvido um modelo técnico composto por quatro fases: preparação, balanceamento, impacto e acompanhamento. Uma perspectiva biomecânica baseada na técnica poderia oferecer uma estratégia promissora para melhorar, a partir do treinamento e da análise da técnica, o desempenho no futebol, bem como fornecer um pano de fundo para a prevenção de lesões.

The relation of foot morphology to performance in three vertical jumping tasks / Relación entre la morfología del pie y el rendimiento en tres saltos verticales

SUMMARY: The objective of this research is to relate the performance in three vertical jump events with morphological variables of the foot and stature. A total of 177 practitioners of 12 sporting events aged 24.5 ±8.0 years, with 71.01 ±13.00 kg of body mass, 1.71±0.09 m height, and BMI of 24.29±3.24 kg·m-2 were evaluated with an anthropometer in terms of foot length (FL), forefoot width (FW), navicular height (NH), and hindfoot width (HW). These variables were normalized to the height of the subjects. From the footprint record the arch index (AI) was obtained, which indicates the morphology of the medial longitudinal foot arch (MLFA). Performance was evaluated in three vertical jump events: countermovement jump (CMJ), squat jump (SJ), and drop jump (DJ), recording the height reached. FL, FW and HW show a weak positive correlation (r<0.4; p<0.05) with the heights achieved in the three types of jump. The stature is strongly associated with FL, FW and HW (r=0.8; r=0.7 and r=0.6; respectively; p<0.05) and with the height in CMJ, SJ, and DJ (r=0.37; r=0.41 and r=0.32, respectively, p<0.05). The only normalized morphological foot variable that maintained consistency in the correlations analysis was the normalized foot length (NFL) with CMJ (r = 0.2, p<0,05). The subjects whose left foot length was equivalent to 14 % of the stature jumped 27.94 ±6.63 cm, those with 15 % jumped 30.96 ±7.4 cm, and those with 16 % jumped 31.03 ±7.8 cm. FL, FW, HW, and stature are moderately correlated with performance in vertical jump events. However, after discarding the stature of the subjects, only the foot length maintained its relation with performance in CMJ.

RESUMEN: El objetivo de esta investigación fue relacionar el rendimiento en salto vertical con variables morfológicas del pie y estatura. 177 practicantes de 12 disciplinas deportivas de 24,5 ±8,0 años; 71,01 ±13,00 kg; 1,71 ±0,09 m, e IMC de 24,29 ±3,24 kg•m-2 fueron evaluados con un antropómetro obteniendo longitud de pie (FL), ancho de antepié (FW), altura navicular (NH) y ancho de retropié (HW). Estas variables fueron normalizadas a la estatura. Se midió la huella plantar obteniendo el índice del arco (AI), el cual indica la morfología del arco plantar longitudinal medial (MLFA). El rendimiento fue evaluado en tres pruebas de salto: salto con contramovimiento (CMJ), sentadilla con salto (SJ) y salto desde caída (DJ), registrando la altura alcanzada. FL, FW y HW mostraron una débil correlación positiva (r<0,4; p<0,05) con la altura alcanzada en los tres saltos. La estatura se asocia con FL, FW y HW (r=0,8; r=0,7 y r=0,6; respectivamente; p<0,05) y con la altura en CMJ, SJ y DJ (r=0,37; r=0,41 y r=0,32, respectivamente, p<0,05). La única variable normalizada del pie que mantuvo consistencia en el análisis de correlaciones fue la longitud del pie normalizada (NFL) con CMJ (r=0,2; p<0,05). Los sujetos cuyo pie tiene una longitud equivalente al 14 % de la estatura saltaron 27,94 ±6,63 cm, los que equivalen al 15 % saltaron 30,96 ±7,4 cm y quienes tuvieron un pie equivalente a un 16 % de la estatura saltaron 31,03 ±7,8 cm. FL, FW, HW y la estatura se correlacionan moderadamente con el rendimiento en salto vertical. Sin embargo, después de descartar la estatura de los sujetos, solamente la longitud del pie mantiene su relación con el rendimiento en CMJ.

Plantar support adaptations in healthy subjects after eight weeks of barefoot running training.

BACKGROUND: Although the studies of barefoot running have intensified, it is still missing longitudinal work analyzing the effects of barefoot running on the phases of plantar support. The objective of this research was to analyze the modifications undergone by the Total Foot Contact (TFC) phase and its Flat Foot Phase (FFP) in subjects beginning the practice of barefoot running, in its acute and chronic effects. METHODS: A total of 28 subjects were divided into the Barefoot Group (BFGr) (n = 16) and the Shod Group (SHGr) (n = 12), evaluated before (Baseline) and after running for 20 min at 3.05 m·s-1 (Post 20 min Running), and at the end of a running training protocol with an 8-week long progressive volume (Post-8-week Training). The dynamic plantar support was measured with a baropodoscope. The duration of TFC (ms), the moment at which the FFP occurred, the maximum surface of TFC (MSTFC) (cm2), the FFP surface (SFFP) (cm2), the peak pressure of TFC (PP°TFC) (kg·cm-2), and the peak pressure of FFP (PP°FFP) (kg·cm-2) were recorded. The 3 × 2 ANOVA analysis was made to determine the effects and interactions that the condition produced (Shod/Barefoot), and the time factor (Baseline/Post 20 min Running/Post-8-week Training). RESULTS: The condition factor caused more significant effects than the time factor in all the variables. Duration of TFC in BFGr showed significant differences between the Baseline and Post-8-week Training (p = 0.000) and between Post-20-min Running and Post-8-week Training (p = 0.000), with an increasing trend. In the moment at which the FFP occurred a significant increase (p = 0.029) increase was found in Post-20 min Running (48.5%) compared to the Baseline (42.9%). In MSTFC, BFGr showed in Post-8-week Training values significantly higher than the Baseline (p = 0.000) and than Post-20-min Running (p = 0.000). SHGr presented a significant difference between the Baseline and Post-8-week Training (p = 0.040). SFFP in BFGr modified its values with an increasing trend (p = 0.000). PP°TFC in BFGr showed a significant decrease (p = 0.003) in Post-8-week Training (1.9 kg·cm-2) compared to the Baseline (2.4 kg·cm-2). In PP°FFP significant decreases were recorded in BFGr and between Post-8-week Training and Baseline (p = 0.000), and Post-8-week Training and Post 20 min Running (p = 0.035). CONCLUSIONS: The adaptation took place after the 8-week training. The adaptations to running barefoot were characterized by causing an increase of the foot's plantar support in TFC and in FFP, as well as a decrease of the plantar pressure peak in both phases. Also, there is an increased duration of the TFC and FFP, which may be related to an acquired strategy to attenuate the impacts of the ground's reaction forces.

Modificaciones morfológicas del pie luego de ocho semanas de entrenamiento de carrera a pie descalzo / Foot morphological adaptations developed after eight weeks of barefoot running training

La carrera descalza ha sido ampliamente estudiada últimamente, pero poco se sabe de cambios anatómicos que produce en el pie. El objetivo de este estudio fue determinar estos cambios producidos de forma aguda y a largo plazo en sujetos que entrenan a pie descalzo. 29 sujetos divididos en dos grupos: Barefoot (BFGr) (n=17) y Shod (SGr) (n=12), realizaron un protocolo de efecto agudo consistente en correr durante 20 min sobre treadmill a 3.1 m/s y un protocolo de entrenamiento de 8 semanas de carrera de resistencia con aumento progresivo de volumen. BFGr realizó todas las sesiones a pie descalzo. Al finalizar cada protocolo se midió Foot Length (FL), Forefoot Width (FW), Hindfoot Width (HW), Navicular Height (NH), Arch Index (AI) y Maximum Surface (MS). Se efectuó ANOVA 3x2 para comprobar los efectos que el tiempo y la condición de calzado produjo. La condición de calzado produjo efectos significativos sobre todas las variables (FL: p=0.000, η2p=0.997; FW: p=0.000, η2p=0,997; HW: p=0.000, η2p= 0,994; NH: p=0.000, η2p=0.953; AI: p=0.000, η2p=0.898; MS: p=0.000, η2p=0.983) y el factor tiempo sobre AI (p=0.012, η2p=0.152) y MS (p=0.000, η2p=0.259). Hubo interacción significativa Tiempo x Condición en FW (p=0.036, η2p= 0.116) y NH (p=0.019, η2p= 0.143). MS aumentó luego del protocolo de efecto agudo (p=0.000) y a largo plazo (p=0.001) en BFGr. El porcentaje de sujetos con pie normal aumentó en BFGr y con pie plano aumentó en SGr. El entrenamiento de carrera a pie descalzo produce efectos, principalmente luego de un período de adaptación de 8 semanas, tendientes a un aumento armónico en la superficie de apoyo plantar con tendencia a una disminución relativa del área del mediopié, lo cual se tradujo en una disminución de sujetos con arco plantar de tipología plana.

Barefoot running has been studied extensively recently, but little is known of the anatomical changes that take place in the foot. The objective of this study was to determine the acute and chronic changes that are produced in subjects who train barefoot. 29 subjects divided into two groups, Barefoot (BFGr) (n=17) and Shod (SGr) (n=12), followed an acute effect protocol which consisted in running during 20 min on a treadmill at 3.1 m/s, and an eight-week long chronic effect protocol covering eight weeks of resistance running with progressively increasing volume. BFGr did all the sessions barefoot. At the end of each protocol Foot Length (FL), Forefoot Width (FW), Hindfoot Width (HW), Navicular Height (NH), Arch Index (AI), and Maximum Surface (MS) were measured. ANOVA 3x2 was run to verify the effects caused by time and the shod condition produced. Shod/ Unshod factor caused significant effects on all the variables (FL: p=0.000, η2p=0.997; FW: p=0.000, η2p=0,997; HW: p=0.000, η2p= 0,994; NH: p=0.000, η2p=0.953; AI: p=0.000, η2p=0.898; MS: p=0.000, η2p=0.983), and the time factor on AI (p=0.012, η2p=0.152) and MS (p=0.000, η2p=0.259). There was a significant Time x Condition interaction in FW (p=0.036, η2p=0.116) and NH (p=0.019, η2p= 0.143). MS increased after the acute (p=0.000) and the chronic (p=0.001) protocols in the BFGr. The percentage of subjects with normal feet increased in the BFGr and that with flat feet increased in SGr. Barefoot running training causes effects, mainly after an adaptation period of eight weeks, tending to a harmonic surface increase on the support plantar area, with a relative decrease of the midfoot area, which meant a decrease of subjects with plantar arch of flat type.

Caracterización morfológica del arco plantar longitudinal medial del pie en una población chilena / Morphological characterization of the medial plantar longitudinal arch foot in a Chilean population

El arco plantar longitudinal medial del pie (APLM) es el componente más importante en estática y dinámica de la bóveda plantar. Su altura define pies normales, planos y cavos, estos últimos son factores predisponentes de lesiones. El objetivo de este estudio fue describir y relacionar en una población de estudiantes universitarios chilenos la prevalencia de pies normales, cavos y planos según índice de masa corporal (IMC), sexo y actividad física (AF) semanal y la distribución de asimetrías entre pies. Se estudió a 209 sujetos (128 hombres y 81 mujeres), estudiantes universitarios, cuya edad, estatura, peso e IMC fue de 20,4 años (±3,4); 1,68 m (±0,09); 67,6 Kg (±12,4) y 23,77 (±3,0) respectivamente. Por medio de cuestionario se determinó los hábitos de AF de la muestra. La impresión plantar se obtuvo mediante fotopodoscopía, la cual fue evaluada empleando el Arch Index (AI) de Cavanagh y Rodgers. Los hombres presentan mayor prevalencia de pie plano (31,3 % contra 11,1 %). Hay correlación positiva estadísticamente significativa entre AI e IMC en ambos sexos. Se obtuvo mayor correlación entre AI izquierdo y AF en hombres y mujeres con significancia estadística. El 31,25 % de los hombres y el 37,04 % de las mujeres presentaron asimetrías en APLM. Hombres con IMC normal tienen 64,20 % de pies asimétricos. Las mujeres que practican entre 6 y 10 horas de AF a la semana presentan 50,98 % de pies asimétricos. El IMC se relaciona con una disminución de la altura del APLM, se sugiere el control de esta variable en sujetos con diagnóstico de pie plano flexible y pie plano valgo. La práctica de AF se relaciona con aumento de la altura del APLM en hombres y mujeres y se sabe que también contribuye a disminuir el IMC, actuando en concordancia hacia estas dos variables.

The (MPLA) is the most important component in statics and dynamics of the vault plant. Its height defines normal, flat and cavus feet, which are predisposing factors for injuries. The objective of this research was to describe and relate in a population of Chilean university students the prevalence of normal, cavus and flat feet according to body-mass index (BMI), sex, and weekly physical activity (PA) and the distribution of asymmetries between feet. 209 subject were studied (128 men and 81 women), university students, whose age, height, weight and BMI was of 20.4 years (±3.4); 1,68 m (±0.09); 67.6 kg (±12.4) and 23.77 (±3.0) respectively. The PAs habits of the sample were determined by means of questionnaire. The footprint is obtained by photo-podoscopy, which was evaluated by the Arch Index (AI) of Cavanagh and Rodgers. Men have higher prevalence of flat foot (31.3 % against 11.1 %). There are both statistically significant positive correlations between AI and BMI in both sexes. Greater correlation between left AI and PA in both men and women was obtained with statistical significance. The 31.25 % of men and 37.04 % of women presented asymmetries in MPLA. Men with normal BMI have 64.20 % of asymmetric feet. Women that practice between 6 and 10 hours of PA a week presented 50.98 % of asymmetric feet. The BMI is related to a decrease of the height of MPLA, suggesting the control of this variable in subjects with flexible flat foot and valgus flat foot diagnosis. The practice of PA is related to the height of the MPLA increased in men and women and it is known that it also helps to reduce BMI, acting in accordance to these two variables.