Efectos del entrenamiento en slackline sobre la resistencia del core y el equilibrio dinámico

Slackline challenges balance by walking on a tensioned strap, where the trunk muscles help to maintain or regain balance. This study aimed to compare a cohort of individuals who regularly practiced slackline and physically inactive individuals on core endurance (CE) and dynamic balance (DB) and to determine whether CE is associated with years of slackline practice. Nine individuals (7 men) who practiced slackline regularly (SG; age= 24.5±3.6 years) and nine physically inactive individuals (7 men) (CG; age= 23.2±3.3 years) were compared. CE was assessed with the McGill battery (trunk flexor, extensor, and side-bridge test) and the plank test. DB was measured with the modified star excursion balance test in stable and unstable conditions. The SG maintained a 36.2% and 45% longer time in left lateral bridge (p=.049) and plank (p=.031), respectively, compared to the CG. The distance achieved in the stable DB test was similar between groups, but in unstable condition was 37.8% greater (p=.016) in SG in both legs and 46.6% greater in the non-dominant leg (p=.039) compared to CG. The SG showed a correlation between years of slackline practice and flexor (r=.674; p=.046), right lateral (r=.765; p=.016) and left (r=.730; p=.026) trunk endurance. In conclusion, those who practice slackline maintain a longer time in the plank and left lateral bridge test and achieve a higher reach distance in unstable DB compared to physically inactive individuals who do not practice slackline.El slackline desafía el equilibrio al caminar sobre una cinta en tensión, donde los músculos del tronco ayudan a mantener o recuperar el equilibrio. El objetivo de este estudio fue comparar individuos que practicaban slackline e individuos inactivos fisicamente (IF) en resistencia del core (RC) y equilibrio dinámico (ED), y conocer si la RC se asocia a los años de practica de slackline. Nueve individuos (7 hombres) que practicaban slackline regularmente (GS; edad= 24.5±3.6 años) y nueve individuos IF (7 hombres) (GC; edad= 23.2±3.3 años) fueron comparados. La RC se evaluó con la bateria de McGill (prueba de flexores y extensores de tronco y puente lateral) y la prueba de la plancha. El ED se midió con la prueba de excursión de la estrella modificada en condiciones estables e inestables. El GS mantuvo un tiempo 36.2% y 45% mayor en puente lateral izquierdo (p=.049) y plancha (p=.031) respectivamente comparado con el GC. La distancia alcanzada en la prueba de ED estable fue similar entre grupos, pero en condición inestable fue 37.8% mayor (p=.016) en GS en ambas piernas y 46.6% mayor en la pierna no dominante (p=.039) comparado al GC. El GS mostró una correlación entre años de práctica de slackline y resistencia flexora (r=.674; p=.046), lateral derecha (r=.765; p=.016) e izquierda (r=.730; p=.026) de tronco. En conclusión, quienes practican slackline mantienen un tiempo mayor la prueba de la plancha y puente lateral izquierdo y logran un mayor alcance en ED inestable comparados con individuos IF que no lo practican

Muscle Quality and Functional and Conventional Ratios of Trunk Strength in Young Healthy Subjects: A Pilot Study

Background: The trunk strength conventional ratio (CR) has been evaluated. However, the functional ratio and the ratio of strength to body weight (BW) or muscle mass (MM) have been poorly explored. Relative strength is a measure of muscle quality. Objectives: To analyze the trunk strength ratio normalized by BW and MM and compare the trunk's conventional and functional ratios collected in isokinetic and isometric conditions. Methods: Twenty-seven healthy males (21.48 +/- 2.08 years, 70.22 +/- 7.65 kg) were evaluated for trunk isometric and isokinetic strength using a functional electromechanical dynamometer. Results: The extensor's strength was greater than the flexors, with a CR of 0.41 +/- 0.10 to 0.44 +/- 0.10. Muscle quality was higher in eccentric contraction and high velocity for flexors and extensors. The functional flexor ratio (FFR) ranged between 0.41 +/- 0.09 and 0.92 +/- 0.27. The functional extensor ratio (FER) ranged between 2.53 +/- 0.65 and 4.92 +/- 1.26. The FFR and FER showed significant differences between velocities when considering the peak strength (p = 0.001) and mean strength (p = 0.001). Conclusions: Trunk extensors were stronger than the flexors; thus, the CR was less than one. Muscle quality was higher at a high velocity. Unlike CR, FFR and FER behaved differently at distinct velocities. This finding highlights the need to explore the behavior of the functional ratio in different populations.DGI-University Andres Bello DI-08-CBC/22FEDER/Ministry of Science, Innovation, and Universities-State Research Agency RTI2018-099723-B-I0

Efectos de un programa de fortalecimiento funcional del CORE utilizando dinamometría electromecánica funcional sobre el dolor, incapacidad, fuerza y calidad muscular en sujetos con dolor lumbar agudo no específico

En base a los antecedentes expuestos, el objetivo principal de la presente Tesis Doctoral fue: Determinar los efectos de un programa de fortalecimiento funcional del tronco utilizando un DEMF sobre el dolor, incapacidad, fuerza y calidad muscular en sujetos con dolor lumbar no específico. Dada las restricciones temporales impuestas por la pandemia, solo podremos dar una respuesta parcial a este objetivo, para ello contamos con cuatro investigaciones publicadas en revistas indexadas en el Journal Citation Reports más un proyecto de investigación en desarrollo, cuyos objetivos fueron: (1) determinar la calidad de la evidencia de los artículos que evalúan la fuerza isocinética de tronco en sujetos con dolor lumbar agudo y sujetos sanos y establecer valores de referencia de fuerza isocinética de tronco en sujetos con dolor lumbar agudo (estudio 1); determinar la calidad de la evidencia y examinar la fiabilidad y el protocolo más fiable de la evaluación de la fuerza del tronco con un dinamómetro isocinético en pacientes con dolor lumbar (estudio 2); examinar la fiabilidad y determinar el protocolo más fiable de la evaluación de la fuerza de extensores de tronco utilizando un DEMF (estudio 3), y analizar la calidad muscular y comparar el ratio de fuerza de tronco convencional y funcional utilizando diferentes variables de fuerza recogidas en condiciones isocinéticas e isométricas (estudio 4). Además, determinar los efectos del entrenamiento isocinético del tronco sobre la intensidad del dolor, la incapacidad y la fuerza isocinética del tronco en pacientes con dolor lumbar no especifico (estudio 5).Based on the above background, the main objective of this Doctoral Thesis was: To determine the effects of a functional trunk strengthening program using a FEMD on pain, disability, strength, and muscle quality in subjects with non-specific low back pain. Given the temporal restrictions imposed by the pandemic, we will only be able to give a partial answer to this objective, for this we have four investigations published in journals indexed in the Journal Citation Reports plus a research project in development, whose objectives were: (1) determine the quality of evidence of articles evaluating isokinetic trunk strength in subjects with acute low back pain and healthy subjects and establish reference values of isokinetic trunk strength in subjects with acute low back pain (study 1); determine the quality of evidence and examine the reliability and most reliable protocol of trunk strength assessment with an isokinetic dynamometer in patients with low back pain (study 2); explore the reliability and determine the most reliable protocol of trunk extensor strength assessment using a FEMD (study 3), and analyze muscle quality and compare the ratio of conventional and functional trunk strength using different strength variables collected under isokinetic and isometric conditions (study 4). In addition, to determine the effects of isokinetic trunk training on pain intensity, disability, and isokinetic trunk strength in patients with non-specific low back pain (study 5).Tesis Univ. Granada.FEDER/Junta de Andalucía, España B-CTS-184-UGR20Universidad Andrés Bello, Chile DI-08-CBC/2

Isokinetic Trunk Strength in Acute Low Back Pain Patients Compared to Healthy Subjects: A Systematic Review

Background: The purpose of this systematic review was to: (I) determine the quality of evidence from studies assessing trunk isokinetic strength in subjects with acute low back pain (ALBP) compared to healthy subjects and (II) establish reference values of isokinetic trunk strength in subjects with ALBP. Methodology: Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statements were followed using keywords associated with trunk, strength and low back pain. Four databases were used: PubMed,Web of Science, Scopus and SPORTDiscus. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS). Results: A total of 1604 articles were retrieved, four included in this review. All were evaluated as high risk of bias (Rob). Due to the high Rob and the diversity of protocols, instruments and variables used, it was not possible to determine reference values for subjects with ALBP, we can only establish a range of flexion peak torque (PT) between 175.1 and 89.7 Nm at 60 /s and between 185 and 81.5 Nm at 120 /s, and for extension PT between 240.0 and 91.5 Nm at 60 /s and between 217.5 and 69.2 Nm at 120 /s in subjects with ALBP. Conclusions: Due to the low quality of the evidence and the diversity of protocols used when measuring trunk isokinetic strength, it is necessary to carry out new high-quality research to establish reference values of trunk strength in subjects with ALBPFEDER/Ministry of Science, Innovation and Universities-State Research Agency RTI2018-099723-B-I0

Efectos del entrenamiento en slackline sobre la resistencia del core y el equilibrio dinámico

Slackline challenges balance by walking on a tensioned strap, where the trunk muscles help to maintain or regain balance. This study aimed to compare a cohort of individuals who regularly practiced slackline and physically inactive individuals on core endurance (CE) and dynamic balance (DB) and to determine whether CE is associated with years of slackline practice. Nine individuals (7 men) who practiced slackline regularly (SG; age= 24.5±3.6 years) and nine physically inactive individuals (7 men) (CG; age= 23.2±3.3 years) were compared. CE was assessed with the McGill battery (trunk flexor, extensor, and side-bridge test) and the plank test. DB was measured with the modified star excursion balance test in stable and unstable conditions. The SG maintained a 36.2% and 45% longer time in left lateral bridge (p=.049) and plank (p=.031), respectively, compared to the CG. The distance achieved in the stable DB test was similar between groups, but in unstable condition was 37.8% greater (p=.016) in SG in both legs and 46.6% greater in the non-dominant leg (p=.039) compared to CG. The SG showed a correlation between years of slackline practice and flexor (r=.674; p=.046), right lateral (r=.765; p=.016) and left (r=.730; p=.026) trunk endurance. In conclusion, those who practice slackline maintain a longer time in the plank and left lateral bridge test and achieve a higher reach distance in unstable DB compared to physically inactive individuals who do not practice slackline.El slackline desafía el equilibrio al caminar sobre una cinta en tensión, donde los músculos del tronco ayudan a mantener o recuperar el equilibrio. El objetivo de este estudio fue comparar individuos que practicaban slackline e individuos inactivos fisicamente (IF) en resistencia del core (RC) y equilibrio dinámico (ED), y conocer si la RC se asocia a los años de practica de slackline. Nueve individuos (7 hombres) que practicaban slackline regularmente (GS; edad= 24.5±3.6 años) y nueve individuos IF (7 hombres) (GC; edad= 23.2±3.3 años) fueron comparados. La RC se evaluó con la bateria de McGill (prueba de flexores y extensores de tronco y puente lateral) y la prueba de la plancha. El ED se midió con la prueba de excursión de la estrella modificada en condiciones estables e inestables. El GS mantuvo un tiempo 36.2% y 45% mayor en puente lateral izquierdo (p=.049) y plancha (p=.031) respectivamente comparado con el GC. La distancia alcanzada en la prueba de ED estable fue similar entre grupos, pero en condición inestable fue 37.8% mayor (p=.016) en GS en ambas piernas y 46.6% mayor en la pierna no dominante (p=.039) comparado al GC. El GS mostró una correlación entre años de práctica de slackline y resistencia flexora (r=.674; p=.046), lateral derecha (r=.765; p=.016) e izquierda (r=.730; p=.026) de tronco. En conclusión, quienes practican slackline mantienen un tiempo mayor la prueba de la plancha y puente lateral izquierdo y logran un mayor alcance en ED inestable comparados con individuos IF que no lo practican

Cardiorespiratory Fitness, Physical Activity, Sedentary Time and Its Association with the Atherogenic Index of Plasma in Chilean Adults: Influence of the Waist Circumference to Height Ratio.

Atherogenic index of plasma (AIP) is a novel biomarker related to cardiovascular disease (CVD). Cardiorespiratory fitness (CRF) and physical activity (PA) have an inverse relationship with the AIP, while sedentary time (ST) and fatness present a positive association. This study aimed to determine the combined and independent association of CRF, PA, and ST with the AIP, and additionally to establish the waist-to-height ratio (WHtR) mediation role. Data from the Chilean national health survey were used (4671 adults). A PACS (Physical Activity Cardiorespiratory Sedentary) score was created ranging from 0 to 3, indicating the number of positive recommendations met (PA, ST, and CRF). AIP was calculated (Log10 triglycerides/high-density lipoprotein-cholesterol). The combined analysis showed that compared to those with a PACS score of 0, those with a score of 1 or 2 did not present significantly reduced AIP values (adjusted by the WHtR); however, those with a score of 3 did (OR (odds ratio) = 0.50; 95% CI, 0.32 to 0.77;

Influence of Sex and Dominant Side on the Reliability of Two Trunk Rotator Exercises

Background: A method to assess the influence of sex and side testing on trunk rotator muscles has not been described. The purpose was to analyze the influence of sex and dominant and non-dominant sides (DS-NDS) on the reliability of two trunk rotator exercises and to study the relationship between the DS-NDS of two trunk rotator strength exercises. Methods: The reliability of the horizontal cable woodchop (HCW) and low cable woodchop (LWC) exercises was studied using a test-retest design with 51 physically active students. Isokinetic and isometric strength were assessed with a functional electromechanical dynamometer. Results: There were significant differences in reliability between male and female HCW and no significant differences in reliability between the average of the DS-NDS in HCW and LCW. There were no significant differences between the DS-NDS in the sex of HCW, and the strength of the two exercises showed no significant differences except for two conditions assessed. Very large to extremely large correlations were observed between sides in the strength of two exercises (r = 0.71–0.91). Conclusions: This test is handy for physical trainers or coaches to know the strength of the trunk rotators of their athletes.FEDER/Junta de Andalucia- Consejeria de Transformacion Economica, Industria, Conocimiento y Universidade B-CTS-184-UGR20program "Recualificacion del profesorado universitario. Modalidad Margarita Salas", Universidad de Granada/Ministerio de Universidades y fondos Next Generation de la Union Europe

Strength Assessment of Trunk Rotator Muscles: A Multicenter Reliability Study

Background: Trunk rotator strength plays an important role in sports performance and health. A reliable method to assess these muscles with functional electromechanical dynamometer has not been described. Therefore, the objectives of this paper were (I) to explore the reliability of different strength variables collected in isokinetic and isometric conditions during two trunk rotator exercises, and (II) to determine the relationship of isometric and dynamic strength variables collected in the same exercise. Methods: A repeated measures design was performed to evaluate the reliability of the horizontal cable woodchop (HCW) and low cable woodchop (LCW) exercises. Reliability was assessed using t-tests of paired samples for the effect size, the standard error of measurement, the coefficient of variation (CV) and the intraclass correlation coefficient (ICC). The Pearson’s (r) correlation coefficient was used to explore the association between isometric and isokinetic tests. Results: HCW exercise is more reliable than LCW exercise in assessing trunk rotator muscles. The strength manifestation that should be used is the average strength, and the most reliable evaluation was the HCW at 0.40 m·s−1 concentric (ICC = 0.89; CV = 10.21%) and eccentric (ICC = 0.85; CV = 9.33%) contraction and the dynamic condition that most correlated with the isometric was LWC at 0.50 m·s−1 (r = 0.83; p < 0.01). Conclusion: HCW is a reliable exercise to measure trunk rotator muscles