Are trunk stability and endurance determinant factors for whole-body dynamic balance in physically active young males? A multidimensional analysis.

OBJECTIVES: Determine if (a) a better trunk stability and endurance are associated with an improved whole-body dynamic balance, and if (b) the assessment tests can be interchanged within each capability. METHODS: Sixty-three physically active young males performed three trunk stability (i.e., the lumbopelvic stability, the unstable sitting and the sudden loading sitting tests), three trunk muscle endurance (i.e., the Biering-Sørensen, the side bridge and the front bridge tests) and four whole-body dynamic balance (i.e., the tandem and the single-leg stance, the Y-Balance, and the single-leg triple hop tests) tests two times. After assessing the reliability of the variables, a Pearson correlation analysis was performed. RESULTS: The correlations between trunk stability and endurance tests with dynamic balance tests were non-significant except for the unstable sitting test with both the tandem (r = 0.502) and the single-leg stance (r = 0.522) tests. Moreover, no relationships were observed between the trunk stability and the trunk muscle endurance tests. Interestingly, no relationships were found between most tests within each capability (i.e., trunk stability, trunk endurance, and dynamic balance) except: (i) the front bridge stability test and the back (r = 0.461) and the side (r = 0.499) bridge stability tests; (ii) the two side bridge endurance tests (r = 0.786); (iii) the tandem and the single-leg stance tests (0.439 ≤ r ≤ 0.463); (iv) the Y-Balance and the single-leg triple hop tests (0.446 ≤ r ≤ 0.477). CONCLUSION: Better trunk function does not seem to be a relevant factor for dynamic balance in young active males. In this population, specific measures are needed as the test interchangeability is questioned.

Core stability: evaluación y criterios para su entrenamiento / / Core stability: avaliação e critérios para treinamento / Core stability: evaluation and training criteria

El objetivo de este trabajo fue revisar las características de los métodos utilizados para valorar la estabilidad de la zona central del cuerpo (core stability), así como las características más importantes de los programas de ejercicios de estabilización del tronco. Los resultados de la revisión indican que métodos biomecánicos, como la aplicación controlada de cargas o descargas súbitas, el paradigma del asiento inestable y la modelación matemática, han permitido analizar el efecto de numerosos factores sobre la estabilidad del raquis. Por otro lado, los test de campo utilizados habitualmente para valorar la core stability (test de condición muscular, test de equilibrio corporal en apoyo monopodal, test de control postural del raquis lumbar y la pelvis, etc.) presentan limitaciones importantes, principalmente debido a la falta de estudios sobre la validez de estas medidas. Finalmente, existe una gran cantidad de información en relación con la eficacia y la seguridad de los ejercicios de estabilización, pero carecemos de información suficiente sobre otras características de la carga de entrenamiento (AU)

The aim of this study was to review both the characteristics of the tests used to assess core stability and the most important features of trunk stabilization exercise programs. The results of this review suggest that biomechanical methods such as sudden and controlled trunk loading and unloading, unstable sitting paradigm and mathematical modeling, have allowed us to analyze the effect of several factors on spine stability. In addition, field tests commonly used to assess core stability (muscle condition tests, single leg stance balance tests, postural control of lumbar spine and pelvis tests, etc.) have important limitations, mainly due to the absence of studies on the validity of these measurements. Finally, there is a lot of information regarding the effectiveness and safety of the stabilization exercises, but we lack enough information on other training load characteristics (AU)

O objetivo desse trabalho foi revisar as características dos métodos utilizados para avaliar a estabilidade da zona central do corpo ("core estability"), assim como as características mais importantes dos programas de exercícios de estabilização do tronco. Os resultados da revisão indicam que métodos biomecânicos como a aplicação controlada de cargas ou descargas súbitas, o paradigma do assento estável e a modelação matemática, tem permitido analisar o efeito de numerosos fatores sobre a estabilidade da coluna. Por outro lado, os testes de campo utilizados habitualmente para avaliar a estabilidade do core (teste de condição muscular, teste de equilíbrio corporal em apoio monopodal, teste de controle postural da coluna lombar e da pelve, etc.) apresentam limitações importantes, principalmente devido a falta de estudos sobre a validade dessas medidas. Finalmente, existe uma grande quantidade de informação em relação à eficácia e à segurança dos exercícios de estabilização, mas carecemos de informação suficiente sobre outras características da carga de treinamento

Core stability. Concepto y aportaciones al entrenamiento y la prevención de lesiones / / «Core stability». Conceito e contribuições no treinamento e a prevenção de lesões / «Core stability». Concept and contributions to training and injury prevention

En este trabajo presentamos una revisión de la literatura científica sobre la estabilidad de la zona central del cuerpo (core stability) con el objeto de clarificar el significado de este concepto y su relación con el rendimiento y las lesiones deportivas. Los resultados de la revisión indican que el uso del término core stability es ambiguo, existiendo una gran confusión terminológica tanto en la literatura científica como en el ámbito profesional. Diversos estudios biomecánicos y epidemiológicos sugieren que el déficit en el control neuromuscular de la core stability está relacionado con el síndrome de dolor lumbar y lesiones de los miembros inferiores. Sin embargo, a pesar de que los ejercicios de core stability son elementos habituales dentro de los programas de entrenamiento deportivo, no existen evidencias suficientes para establecer una relación clara entre la práctica de estos ejercicios y la mejora del rendimiento en el deporte (AU)

In this work we present a scientific literature review on core stability with the aim of clarifying the meaning of this concept and its relation with sport performance and injury. The results of this review show that the use of the term core stability is ambiguous, as there is a great terminological confusion in both scientific literature and professional fields. Several biomechanical and epidemiological studies suggest that the neuromuscular control deficit of core stability is related to low back pain and lower limb injuries. Nevertheless, despite the fact that core stability exercises are key elements in sport training programs,there isnot enoughevidence to establisha clear relationbetweenthe practice ofthese exercises and the improvement in sport performance (AU)

Neste trabalho apresentamos uma revisão da literatura científica sobre a estabilidade da zona central do corpo (core stability), com o objetivo de esclarecer o significado do conceito e sua relação com o rendimento e lesões desportivas. Os resultados desta revisão indicam que o uso do termo core stability é ambíguo, existindo uma grande confusão terminológica tanto na literatura científica como no âmbito profissional. Diversos estudos biomecânicos e epidemiológicos sugerem que o déficit no controle neuromuscular da core stability está relacionado com a síndrome da dor lombar e lesões dos membros inferiores. No entanto, apesar dos exercícios de core stability serem elementos habituais dentro dos programas de treinamento desportivo, não existem evidências suficientes para estabelecer uma relação clara entre a prática dos exercícios e a melhora do rendimento no esporte (AU)

Short-term effect of crunch exercise frequency on abdominal muscle endurance.

Despite core exercise programs are broadly used to increase muscle function and to promote low back health, there is a lack of scientific evidence on some of the most important characteristics of trunk exercise programs, as for example training frequency. This study aimed to compare the short-term effect of training frequencies of 1, 2 and 3 days per week (d/wk) on abdominal muscle endurance in untrained adolescents. One hundred and eighteen high-school students (59 men and 59 women) with no previous experience in structured abdominal exercise programs were assigned randomly to groups that trained 1 d/wk (G1; N.=21), 2 d/wk (G2; N.=27), 3 d/wk (G3; N.=23), or to a control group (CG; N.=47) that did not train. The training groups performed crunch and cross-crunch exercises 1, 2 or 3 d/wk during six weeks. Before and after the training period, the bench trunk-curl test (BTC test) was carried out to assess abdominal muscle endurance. Men obtained higher BTC test scores than women before and after training. Training frequencies of 1, 2 and 3 d/wk provided a significant increase in BTC test scores; however, no significant differences between the three groups' scores were found after training. Therefore, a small dose of crunch exercise training (1 d/wk) may be sufficient stimulus to increase abdominal endurance in untrained male and female adolescents, at least during the first weeks of an abdominal exercise program, which seems a very relevant finding in terms of time-cost efficiency.