Efecto a corto plazo de un programa de estiramientos en la extensibilidad isquiosural y disposición sagital del raquis en estudiantes de Educación Secundaria

Hamstring shortness and postural deformities are frequent in adolescents. For this reason, the purpose of this study was to analyse the influence of a short-term stretching program in hamstring extensibility and sagittal spinal curvatures in high school students. Sixty-two male high school students aged 14-17 years old performed a 70 seconds hamstring stretching program (3 exercises) twice a week for five weeks during their physical education classes. Hamstring extensibility was measured by the straight leg raise test and sit-and-reach test. Thoracic and lumbar curves and pelvic inclination were measures in relaxed standing and in the sit-and-reach test. These measures were assessed before (pre-test) and after (post-test) the intervention program. Significant increases in the sit-and-reach score (d= 0.23) and in the straight leg raise angle (d= 0.85-0.90) were found. Sagittal spinal curvatures in standing showed no differences between pre- and post-test. In the maximal trunk flexion position during the sit-and-reach was detected a lower thoracic kyphosis and posterior pelvic tilt (p < 0.05) in post-test although with a low size effect (d=0.02-0.22). A hamstring muscle stretching program with a volume of 2 sessions per week (70 seconds each session), for 5 weeks, improves hamstring extensibility in adolescents and slightly reduces the thoracic bending and posterior pelvic tilt in trunk flexion postures with extended kneesDebido a la frecuencia de casos con una reducida extensibilidad isquiosural y alteraciones posturales en adolescentes, el objetivo de este estudio fue analizar la influencia de un programa de estiramientos, de corta duración, en la extensibilidad isquiosural y disposición sagital del raquis en estudiantes de Educación Secundaria. A sesenta y dos adolescentes varones (14-17 años) se les midió la extensibilidad isquiosural (test sit-and-reachy test de elevación de la pierna recta) antes (pre-test) y después (post-test) de un programa escolar de 5 semanas (2 sesiones semanales), compuesto por tres estiramientos de la musculatura isquiosural, con una duración total por sesión de 70 segundos. También se valoró la disposición sagital del raquis torácico, lumbar e inclinación pélvica en bipedestación relajada y en el sit-and-reach. Se encontró un aumento significativo en la distancia alcanzada en el test sit-and-reach (d= 0,23) y en el ángulo de flexión co-xofemoral en el test de elevación de la pierna recta (d= 0,85-0,90). La disposición sagital del raquis en bipedesta-ción no mostró diferencias entre el pre- y post-test. En la posición de máxima flexión del sit-and-reach, hubo una menor cifosis torácica y menor retroversión pélvica (p < 0,05) en el post-test, aunque con un tamaño del efecto bajo (d=0,02-0,22). Un programa de estiramientos de la musculatura isquiosural realizado en las dos clases semanales de Educación Física (70 segundos de estiramiento en cada clase), durante 5 semanas, mejora la extensibilidad isquiosural de adolescentes y reduce, ligeramente, la flexión torácica y la retroversión pélvica en la posición de máxima flexión del tronco con rodillas extendidaActividad Física y Deport

The Relationship Between Hamstring Muscle Extensibility and Spinal Postures varies with the degree of knee extension

The aim was to determine the relationship between hamstring muscle extensibility and sagittal spinal curvatures and pelvic tilt in cyclists while adopting several postures. A total of 75 male cyclists were recruited for this study (34.79 ± 9.46 years). Thoracic and lumbar spine and pelvic tilt were randomly measured using a Spinal Mouse. Hamstring muscle extensibility was determined in both legs by a passive knee extension test. Low relationships were found between hamstring muscle extensibility and spinal parameters (thoracic and lumbar curvature, and pelvic tilt) in standing, slumped sitting, and on the bicycle (r = .19; P > .05). Significant but low relationships were found in maximal trunk flexion with knees flexed (r = .29; P < .05). In addition, in the sit-and-reach test, low and statistically significant relationships were found between hamstring muscle extensibility for thoracic spine (r = –.23; P = .01) and (r = .37; P = .001) for pelvic tilt. In conclusion, hamstring muscle extensibility has a significant relationship in maximal trunk flexion postures with knees flexed and extended, but there are no relationships while standing or on the bicycle postures.Actividad Física y Deport

Sprint kayaking and canoeing performance prediction based on the relationship between maturity status, anthropometry and physical fitness in young elite paddlers

This study aimed to identify the maturity-related differences and its influence on the physical fitness, morphological and performance characteristics of young elite paddlers. In total, 89 kayakers and 82 canoeists, aged 13.69 ± 0.57 years (mean ± s), were allocated in three groups depending on their age relative to the age at peak height velocity (pre-APHV, circum-APHV and post-APHV) and discipline (kayak and canoe). Nine anthropometric variables, a battery of four physical fitness tests (overhead medicine ball throw, countermovement jump, sit-and-reach test and 20 m multistage shuttle run test) and three specific performance tests (1000, 500 and 200 m) were assessed. Both disciplines presented significant maturity-based differences in all anthropometric parameters (except for fat and muscle mass percentage), overhead medicine ball throw and all performance times (pre > circum > post; P < 0.05). Negative and significant correlations (P < 0.01) were detected between performance times, chronological age and anthropometry (body mass, height, sitting height and maturity status), overhead medicine ball throw and sit and reach for all distances. These findings confirm the importance of maturity status in sprint kayaking and canoeing since the more mature paddlers were also those who revealed largest body size, physical fitness level and best paddling performance. Additionally, the most important variables predicting performance times in kayaking and canoeing were maturity status and chronological age, respectively.Actividad Física y Deport

Valoración del raquis torácico, lumbar e inclinación pélvica en ciclistas de categoría élite y máster 30

El objetivo principal del estudio fue evaluar la disposición sagital del raquis torácico, lumbar e inclinación pélvica en bipedestación y sobre la bicicleta, en ciclistas de las categorías élite y máster 30. Un total de 45 ciclistas élite (media de edad: 22,71  ±  3,23 años) y 45 ciclistas máster 30 (media de edad: 34,40  ±  2,87 años) fueron evaluados con el sistema Spinal Mouse® en bipedestación y sobre la bicicleta en los diferentes agarres del manillar: transversal, de manetas y bajo. En bipedestación, los valores angulares medios para el raquis torácico, lumbar e inclinación pélvica fueron de 47,96  ±  7,23°; -27,62  ±  6,97° y 14,29  ±  5,49°; y de 47,82  ±  9,32°, –26,58°  ±  5,97° y 12,07  ±  4,77°, para los ciclistas élite y máster 30, respectivamente. En ambas categorías, se observó una elevada frecuencia de casos con hipercifosis torácica en bipedestación (57,80 % en élite y 53,40 % en máster 30). Sobre la bicicleta, los ciclistas élite y máster 30 mostraron una reducción significativa de la cifosis torácica con respecto a la bipedestación. En cuanto al raquis lumbar se dispuso en una postura de inversión. En conclusión, la frecuente hipercifosis torácica en bipedestación, en ambas categorías de ciclistas, podría estar más relacionada con otros factores que con la postura adoptada sobre la bicicleta

Morphological and physical fitness profile of young female sprint kayakers.

Traditionally, physical and anthropometrical profiles of the most successful kayak athletes have been identified in male kayakers. This study attempted to identify the differences in morphology and fitness level of two performance-based groups of young elite female paddlers. Eighty-six female kayakers, aged 13.62 ± 0.57 years (mean ± SD) were allocated in two groups (Top-10 and Rest) depending on their ranking in the three Olympic distances (200, 500 and 1000 meters). All subjects underwent a battery of anthropometrical (heights, weight, girths and sum of skinfolds), physical fitness (overhead medicine ball throw, countermovement jump, sit-and-reach test and 20-m multistage shuttle run test) and specific performance assessments (200, 500 and 1000 meters). Best paddlers presented significantly greater anthropometrical values in muscle mass percentage, maturity status and chronological age (p < 0.05) whereas physical fitness comparison only revealed significant differences in countermovement jump (p < 0.05). Furthermore, aerobic power and muscle mass percentage appear to be crucial in achieving optimal performances at long (1000-m) and short duration races (200 and 500-m). These findings confirm the importance of a larger and compact morphology, as well as superior fitness level, for success in female kayakers. The current results not only identify the weak areas on body composition and physical fitness depending on the maturity status but also the development of specific training programs for FEMALES.Actividad Física y Deport

RATING OF PERCEIVED EXERTION AS A TOOL TO CONTROL INTENSITY IN INDOOR CYCLING ACTIVITY

A un total de 133 sujetos entre 22 y 64 años (38 hombres y 95 mujeres) pertenecientes a un centro deportivo privado, se les evaluó el porcentaje de la intensidad de la frecuencia cardiaca de reserva (%FCR) alcanzada y la percepción subjetiva del esfuerzo (RPE) durante una sesión real de ciclismo indoor. La intensidad media alcanzada y la RPE manifestada en la fase principal fue alta, tanto en hombres como en mujeres. Se encontró una significativa y baja correlación entre la RPE y la FC media de reserva obtenida en la fase principal de la sesión. En conclusión, el ciclismo indoor es una actividad de alta intensidad. La RPE de Borg no es un instrumento válido para el control de la intensidad en esta actividad.One hundred and thirty-three subjects between 22 and 64 years old (38 males and 95 females) from a private sport centre participated in this study. Mean percentage heart rate intensity (%HRR) and overall ratings of perceived exertion (RPE) were measured during an indoor cycling session. Mean %HRR and RPE shown during the main phase were considered as high intensity in male and females. The correlation value between %HHR and overall RPE was low but significant. In conclusion, indoor cycling is a high-intensity activity. Borg’s RPE is not a valid instrument for controlling the intensity of effort during indoor cycling activity.Actividad Física y Deport

Criterion-related validity of sit-and-reach and toe-touch tests as a measure of hamstring extensibility in athletes

The aims of this study were (a) to determine and compare the concurrent hamstring criterion- related validity of the sit-and-reach (SR) and toe-touch (TT) tests in different athletes (tennis players, kayakers, canoeists, and cyclists); (b) to determine the criterion-related validity of the pel- vic tilt assessed by the Spinal Mouse system as a measure of hamstring flexibility in athletes; and (c) to evaluate the influence of spinal posture, pelvic tilt, and hamstring muscle flexibility in the SR and TT scores. Twenty-four tennis players, 30 canoeists, 43 kayakers, and 44 cyclists were recruited. Passive straight leg raise (PSLR), SR, and TT tests were randomly performed. Spinal curvatures and pelvic tilt were evaluated with a Spinal Mouse system when the maximal trunk flexion was achieved in the SR and TT tests. Tennis players and cyclists showed moderate cor- relations between PSLR with respect to SR (b = 0.78 and b = 0.76, respectively) and TT (b = 0.77 and b = 0.74, respectively). Correlations were slightly lower in canoeists (SR, b = 0.64; TT, b = 0.75). Kayakers showed the lowest correlation values (SR, b = 0.53; TT, b = 0.57). Correlation values between PSLR and pelvic tilt angle in both the SR and TT tests were b , 0.70 in all the groups of athletes. Stepwise multiple regression analysis showed a high variance explained from pelvic tilt and lumbar spine in the SR score. In conclusion, the SR and TT tests can be appropriate measures to determine spine flexibility and pelvic tilt range of motion but not to evaluate the hamstring muscle flexibility in tennis players, canoeists, kayakers, and cyclists.Actividad Física y Deport

BODY IMAGE; LITERATURE REVIEW

Introducción: En los países desarrollados existen en la actualidad unos estándares de belleza basados en modelos prodelgadez, que son interiorizados por los adolescentes y los jóvenes, sobre todo en el caso de las mujeres, suponiendo un factor de riesgo para el desarrollo de alte- raciones de la imagen corporal y su percepción. Objetivo: Analizar el estado actual de las investigaciones sobre la imagen corporal, las variables sociodemográficas que influyen sobre ella y su relación con la composición corporal, la realización de dietas, los trastornos de la conducta alimentaria, el deporte y los programas de intervención y prevención. Metodología: Se realizó una búsqueda bibliográfica en Medline, Isi Web of Knowlegde y Dialnet, así como una búsqueda manual entre las referencias de los estudios seleccionados y en diferentes bibliotecas. Resultados y discusión: Una mayor influencia sociocultural está asociada a una mayor percepción de la grasa corporal, a una mayor insatisfacción con la imagen corporal y a una menor valoración del autoconcepto físico general. Esto lleva a una gran cantidad de adolescentes y jóvenes a abusar de dietas restrictivas y a sufrir trastornos de la conducta alimentaria. Numerosos estudios han analizado la relación de la práctica deportiva con las alteraciones de la imagen corporal, encontrando resultados contradictorios. Por otra parte, es necesario crear herra- mientas objetivas para detectar las alteraciones y profundizar en el diseño de programas de prevención e interven- ción con el fin de evitar la distorsión de la imagen corporal, sobre todo en aquellas franjas de edad donde la población es más vulnerable a este fenómeno. Conclusiones: La excesiva preocupación sobre la imagen corporal trae como consecuencia la realización de dietas y alteraciones como los trastornos de la conducta alimentaria. Existen además otros factores que influyen sobre la imagen corporal y su percepción como es la realización de ejercicio físico, aunque los resultados sobre la relación de ambos factores son contradictorios. Por esto, es necesario profundizar más en el tema, creando herramientas para detectar las alteraciones y profundizar en el diseño de programas de prevención e intervención.Introduction: Nowadays, in developed countries there are standards of beauty based on pro-thin models, which are internalized by adolescents and young people especially in the case of women, assuming it as risk factor for developing changes in body image and perception. Objective: To analyze the current state of research in relation to body image, the sociodemographic variables that influence it, the relationship between body composition, conducting diets, eating disorders, sports and inter- vention programs and prevention, and the body image. Methods: It was searched in Medline, Isi Web of knowlegde and Dialnet as well as a manual search among the references of selected studies and in different libraries. Results and discussion: A increased socio-cultural influence is associated with a greater perception of body fat, greater body image dissatisfaction and lower self assessment of overall fitness. This leads to a lot of teenagers and young adults to abuse to the restrictive diets and to suffer eating disorders. Numerous studies have analyzed the relationship between sports practice with body image disturbance; there are conflictive results. Moreover it is necessary to design objective tools to detect changes and enhance the design of prevention and intervention programs in order to avoid distortion of body image, especially in those age ranges where the population is more vulnerable to this phenomenon. Conclusions: The excessive current preocupation about body image has resulted in the realization of diets and changes as eating disorders. There are other factors that influence body image and perception as the realization of physical exercise, although the results about the relationship between these factors are contradictory. Therefore, further work is needed on the issue by creating tools to detect changes and enhance the design of prevention and intervention programs.Actividad Física y DeportePsicologí

THE EFFECTS OF THE PILATES METHOD ON HAMSTRING EXTENSIBILITY, PELVIC TILT AND TRUNK FLEXION

Introducción: el Pilates engloba un gran volumen de ejercicios de estiramiento de la musculatura isquiosural y de flexión máxima del tronco con rodillas extendidas. Objetivo: realizar una revisión sistemática sobre los efectos de la práctica de Pilates y de un período de desentrenamiento sobre la flexibilidad isquiosural, la inclinación pélvica y la flexión del tronco en flexión máxima del tronco con rodillas extendidas. Metodología: se analizaron todos los diseños experimentales o cuasi-experimentales redactados en inglés, español o portugués incluidos en las siguientes bases de datos: Pubmed, Sports Discus, ISI Web of Knowledge, Dialnet y Research Gate. Resultados y discusión: fueron analizados veintiún artículos. La mayoría utilizaron un diseño de pre-test-post-test con grupo control, siendo heterogéneos los programas de intervención aplicados. La muestra estaba compuesta principalmente por mujeres, jóvenes y mayores. Se encontró que la práctica de Pilates, con diferente volumen, incrementaba significativamente la extensibilidad isquiosural y la inclinación pélvica en flexión máxima del tronco. Para obtener una mayor inclinación del tronco fueron necesarios, al menos, tres días de entrenamiento semanal durante seis semanas. En los estudios que incluyen poblaciones de deportistas los resultados son contradictorios. Con el desentrenamiento se produce una disminución de la extensibilidad isquiosural y la flexión del tronco a partir de la segunda semana. Conclusiones: existen moderadas evidencias de que el Pilates es efectivo para aumentar la extensibilidad isquiosural, la inclinación pélvica y el grado de flexión del tronco en posiciones de flexión máxima en poblaciones sedentarias y activas recreacionales, así como para incrementar la flexibilidad isquiosural en deportistas.Introduction: Pilates includes a high volume of hamstring stretching and maximal trunk flexion with knees extended exercises. Objective: to perform a systematic review about Pilates practice effects and a detraining period on hamstring extensibility, pelvic tilt and trunk flexion in maximal trunk flexion with knees extended. Method: it was analysed all the experimental or quasi-experimental designs written in English, Spanish or Portuguese and included in the following databases: Pubmed, Sports Discus, ISI Web of Knowledge, Dialnet and Research Gate. Results and discussion: twenty-one papers were analysed. Most of them used a pre-test-post-test design with control group. The intervention programs applied were heterogeneous. Samples were composed mainly of women, both young and old. It was found that the Pilates practice, with different volume, significantly increased hamstring muscle extensibility and pelvic tilt in maximal trunk flexion. At least three training sessions peer week during six weeks were necessary in order to obtain a high trunk inclination. Studies which involved athletes showed contradictory results. By inducing a detraining period it was noticed a decrease in hamstring extensibility and trunk flexion from the second week. Conclusions: there is a moderate evidence that Pilates is an effective method to increase hamstring extensibility, pelvic tilt and the degree of trunk flexion in maximal flexion positions in sedentary and recreational active people and also to increase hamstring extensibility in athletes.Actividad Física y Deport

Kinematic Variables Evolution During a 200-m Maximum Test in Young Paddlers

The objective of this research was to determine the kinematic variables evolution in a sprint canoeing maximal test over 200 m, comparing women and men kayak paddlers and men canoeists. Speed evolution, cycle frequency, cycle length and cycle index were analysed each 50 m section in fifty-two young paddlers (20 male kayakers, 17 female kayakers and 15 male canoeists; 13-14 years-old). Recordings were taken from a boat which followed each paddler trial in order to measure the variables cited above. Kinematic evolution was similar in the three categories, the speed and cycle index decreased through the test after the first 50 m. Significant differences were observed among most of the sections in speed and the cycle index (p<0.05 and <0.01, respectively). Cycle length remained stable showing the lowest values in the first section when compared with the others (p<0.01). Cycle frequency progressively decreased along the distance. Significant differences were identified in the majority of the sections (p<0.01). Men kayakers attained higher values in all the variables than women kayakers and men canoeists, but only such variables as speed, cycle length and cycle index were observed to be significantly higher (p<0.01). Moreover, lower kinematic values were obtained from men canoeists. The study of the evolution of kinematic variables can provide valuable information for athletes and coaches while planning training sessions and competitions.Actividad Física y Deport