José María Muyor

IMAGEN CORPORAL; REVISIÓN BIBLIOGRÁFICA

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 intervention programs and prevention, and the body image. METHODS It was searched in Medline, Isi Web of knowledge 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 preoccupation 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.

Influence of Hamstring Muscles Extensibility on Spinal Curvatures and Pelvic Tilt in Highly Trained Cyclists

Influence of Hamstring Muscles Extensibility on Spinal Curvatures and Pelvic Tilt in Highly Trained Cyclists The purpose of this study was to determine the influence of hamstring muscles extensibility in standing, maximal trunk flexion with knees extended and on the bicycle in lower handlebar-hands position of highly trained cyclists. Ninety-six cyclists were recruited for the study (mean ± SD, age: 30.36 ± 5.98 years). Sagittal spinal curvatures and pelvic tilt were measured in the standing position, maximal trunk flexion with knees extended (sit-and-reach test) and while sitting on a bicycle in lower handlebar-hand position using a Spinal Mouse system. Hamstring muscles extensibility was determined in both legs by passive straight leg raise test (PSLR). The sample was divided into three groups according to PSLR angle: (1) reduced extensibility (PSLR < 80º; n = 30), (2) moderate hamstring extensibility group (PSLR = 80º; - 90º; n = 35), and (3) high hamstring extensibility (PSLR = > 90º; n = 31). ANOVA analysis showed significant differences among groups for thoracic (p < 0.001) and pelvic tilt (p < 0.001) angles in the sit-andreach test. No differences were found between groups for standing and on the bicycle position. Post hoc analysis showed significant differences in all pairwise comparisons for thoracic angle (p < 0.01) and pelvic angle (p < 0.001) in the sit-and-reach test. No differences were found in lumbar angle in any posture. In conclusion, the hamstring muscles extensibility influence the thoracic and pelvic postures when maximal trunk flexion with knees extended is performed, but not when cyclists are seated on their bicycles

Acute Effects of Hamstring Stretching on Sagittal Spinal Curvatures and Pelvic Tilt

Acute Effects of Hamstring Stretching on Sagittal Spinal Curvatures and Pelvic Tilt The aim of this study was to determine acute effects of hamstring stretching in thoracic and lumbar spinal curvatures and pelvic tilt. Fifty-five adults (29.24 ± 7.41 years) were recruited for this study. Subjects performed a hamstring stretching protocol consisting of four exercises. The session consisted of 3 sets of each exercise and subjects held the position for 20 seconds with a 30-second rest period between sets and exercises . Thoracic and lumbar spinal angles and pelvic tilt were measured with a SpinalMouse in relaxed standing, sit-and-reach test and Macrae & Wright position. Hamstring extensibility was determined by active straight leg raise test and sit-and-reach score. All measures were performed before and immediately after the hamstring stretching protocol. Active straight leg raise angle and sit-and-reach score significantly improved immediately after the stretching protocol (p<0.001). Greater anterior pelvic tilt (p<0.001) and lumbar flexion (p<0.05) and a smaller thoracic kyphosis in the sit-and-reach (p<0.001) were found after the stretching protocol. However, stretching produced no significant change on spinal curvatures or pelvic tilt in standing and maximal trunk flexion with knees flexed. In conclusion, static stretching of the hamstring is associated to an immediate change in the sagittal spinal curvatures and pelvic position when performing trunk flexion with knees extended, so that allowing for greater lumbar flexion and anterior pelvic tilt and lower thoracic kyphosis. Hamstring stretching is recommended prior to sport activities involving trunk flexion with the knees straight.

Effect of stretching program in an industrial workplace on hamstring flexibility and sagittal spinal posture of adult women workers: A randomized controlled trial

OBJECTIVES To determine the effect of a stretching program performed in the workplace on the hamstring muscle extensibility and sagittal spinal posture of adult women. MATERIAL AND METHODS Fifty-eight adult women volunteers (mean age of 44.23 ± 8.87 years) from a private fruit and vegetable company were randomly assigned to experimental (n=27) or control (n=31) groups. The experimental group performed three exercises of hamstrings stretching of 20 seconds per exercise, three sessions a week for a period of 12 weeks. The control group did not participate in any hamstring stretching program. Hamstring flexibility was evaluated through the passive straight leg raise test and toe-touch test, performed both before and after the stretching program. Thoracic and lumbar curvatures and pelvic inclination were measured in relaxed standing and toe-touch test with a Spinal Mouse. RESULTS Significant increases (p < 0.01) in toe-touch score and straight leg raise angle (in both legs) were found in the experimental group during post-test, while the control group showed a non-significant decrease for both toe-touch score and straight leg raise test. A significant decrease in thoracic curve and significant increase in pelvic inclination were found in the toe-touch test for the experimental group (p <0.05). However, no significant changes were found in standing posture for any group. CONCLUSIONS Hamstring stretching exercises performed in the working place are effective for increasing hamstring muscle extensibility. This increase generates a more aligned thoracic curve and more anterior pelvic inclination when maximal trunk flexion is performed.

CRITERION-RELATED VALIDITY OF SIT-AND-REACH AND TOE-TOUCH TESTS AS A MEASURE OF HAMSTRING EXTENSIBILITY IN ATHLETES

Abstract Muyor, JM, Vaquero-Cristóbal, R, Alacid, F, and López-Miñarro, PA. Criterion-related validity of sit-and-reach and toe-touch tests as a measure of hamstring extensibility in athletes. J Strength Cond Res 28(2): 546–555, 2014—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 pelvic 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 correlations between PSLR with respect to SR (&bgr; = 0.78 and &bgr; = 0.76, respectively) and TT (&bgr; = 0.77 and &bgr; = 0.74, respectively). Correlations were slightly lower in canoeists (SR, &bgr; = 0.64; TT, &bgr; = 0.75). Kayakers showed the lowest correlation values (SR, &bgr; = 0.53; TT, &bgr; = 0.57). Correlation values between PSLR and pelvic tilt angle in both the SR and TT tests were &bgr; < 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.

Influence of hamstring extensibility on sagittal spinal curvatures and pelvic tilt in highly trained young kayakers

Abstract Objective: To evaluate the influence of hamstring extensibility on spinal and pelvic postures adopted by young paddlers in their kayaks. Methods: Sixty-eight young elite kayakers were recruited for the study (mean value 15.23, s=0.68 years). Thoracic and lumbar curvatures and pelvic position were evaluated with a Spinal Mouse system in standing position and in the boat (seated in the kayak with the paddle resting on their thighs, right entry position and left entry position). Hamstring muscle extensibility was determined in both legs by passive straight leg raise test (PSLR). The sample was divided into two groups with regard to straight leg raise angle (Group A, PSLR < 80°, n=32, and group B, PSLR ≥ 80°, n=32). Results: Paddlers with lower extensibility presented higher thoracic and lumbar flexion and a more posterior pelvic tilt in the kayak in all three positions. However, no significant differences were found between the groups when standing. Conclusion: The results suggest that lower hamstring extensibility is related to increased spinal flexion and posterior pelvic tilt, which can overload the spine during paddling training. A systematic and intensive stretching programme to improve hamstring muscle extensibility should be incorporated into the training activities of paddlers.

A comparison of the thoracic spine in the sagittal plane between elite cyclists and non-athlete subjects

AIM to evaluate and compare the angular disposition of the thoracic spine (at different postures) in elite cyclists and a group of individuals who do not exercise in a systematic manner. METHODS Sixty elite cyclists and sixty-eight sedentary individuals (control group), mean age: 21.91 (2.86) years participated in this study. Thoracic spine was measure with a Spinal Mouse® while relaxed standing, lying prone and sitting on the bicycle in three handlebar positions (upper, middle and lower handlebar). RESULTS The mean (SEM) thoracic kyphosis while standing was 48.17 (8.05°) and 42.68 (8.02°) in cyclists and control group, respectively (p< 0.001). The thoracic curve adopted in lying prone was 34.69 (8.28°) in cyclists and 30.96 (7.24°) in control group (p< 0.05). On the bicycle, cyclists showed lower thoracic kyphosis with respect to control group (p> 0.05). The thoracic spine was adopted more neutral in the posture sitting on bicycle than in relaxed standing, in both groups analyzed. CONCLUSION The posture adopted in cycling is not the only result of the higher thoracic curvature in cyclists when standing. It is necessary to include spinal postural awareness in the training plan and thoracic muscle resistance exercises that favour more aligned postures while standing.

Influencia de la Extensibilidad Isquiosural en la Morfología Sagital del Raquis e Inclinación Pélvica en Deportistas

El objetivo de este estudio fue determinar la influencia de la extensibilidad isquiosural en la morfologia sagital del raquis e inclinacion pelvica en deportistas jovenes. Metodos. Un total de 152 deportistas (media de edad: 16,22 ± 0,80 anos) participaron voluntariamente en este estudio. La morfologia sagital de las curvas toracica y lumbar, asi como la inclinacion pelvica, fueron evaluadas con un Spinal Mouse al realizar los test sit-and-reach, toe-touch y McRae & Wright. La extensibilidad isquiosural fue determinada mediante el test de elevacion de la pierna recta (EPR). En base al valor obtenido en el test EPR, la muestra fue dividida en tres grupos (Grupo A: EPR 88, n=50). Resultados. Los deportistas con menor extensibilidad isquiosural adoptaron posturas de mayor cifosis toracica y una mayor retroversion pelvica en los test sit-and-reach y toe-touch. No obstante, no se encontraron diferencias significativas entre grupos en el test McRae & Wright. Ademas, la extensibilidad isquiosural no tuvo influencia alguna en la morfologia sagital del raquis lumbar. Conclusiones. Una menor extensibilidad isquiosural esta relacionada con una mayor cifosis toracica y una mayor retroversion pelvica cuando se realizan movimientos de flexion maxima del tronco con rodillas extendidas. La extensibilidad isquiosural no afecta a la disposicion sagital del raquis lumbar en movimientos de flexion maxima del tronco.

Morphological characteristics of young elite paddlers

Morphological characteristics of young elite paddlers The aims of this study were to describe kinanthropometric characteristics of elite male and female young paddlers and to compare their proportionality with Olympic paddlers. One hundred and eighty seven young elite sprint paddlers (124 males and 63 females), aged 13 and 14 years, were assessed using a battery of 31 anthropometric dimensions. Somatotypes, Phantom Z-scores and corrected girths were calculated. Comparison between the 13 and 14 year old paddlers showed that 14 year old males had greater height, body weight, sitting height, arm span and upper body lengths, breadths and girths than their 13 year old counterparts, whereas 14 year old female paddlers only differed significantly from the 13 year olds in biacromial breadth and corrected arm girth. Mean somatotypes of male paddlers were best described as balanced mesomorphs, while female paddlers were centrals. Olympic paddlers had higher proportional dimensions in upper body girths, and biacromial breadth in both genders. The data provided in this study could be used as a guideline for talent identification in sprint canoeing and kayaking.

Concurrent validity of clinical tests for measuring hamstring flexibility in school age children.

The objectives were 1) to evaluate the hamstring muscle flexibility in children and adolescents; 2) to examine the relative contribution of the spinal curvatures, pelvic tilt and hamstring flexibility on the sit-and-reach (SR) score; and 3) to determine the validity of the sit-and-reach test through both active and passive hip flexion tests. 118 children and adolescents (aged 7-18 years; 60 males and 58 females) were tested for sit-and-reach (SR), passive straight leg raise (PSLR) and active straight leg raise (ASLR). The spinal curvatures and pelvic tilt were assessed during the SR test by means of the Spinal Mouse system. Females showed a statistically greater anterior pelvic tilt, distance reached in the SR test and hip flexion in both PSLR and ASLR tests than males. The pelvic tilt independently explained more than 60% of the variance (distance reached in the SR test) and in conjunction with lumbar flexion explained more than 80% of the variance. In conclusion, the pelvic tilt is the main determinant of SR test in school age children. The SR test can be considered an appropriate and valid test for evaluating pelvic tilt and lumbar flexion in school age children, but not to measure hamstring flexibility.