Immediate Effect of Trunk Flexion And Extension Isometric Exercise Using An External Compression Device On Electromyography of The Hip Extensor And Trunk Range of Motion Of Healthy Subjects

Background: Low back pain (LBP) is a very common symptom experienced by individuals across all age groups. Previous study established that using a device known as Active Therapeutic Movement version 2 (ATM®2) has been developed to improve pain and joint range of motion (ROM) in patients with LBP. However, no study has examined the physiological change in the muscle through ATM®2-based exercise thus far. This study aimed to determine the immediate effects of ATM®2 exercise on the contraction timing, back extension endurance, muscle fatigue, and trunk ROM of lumbar and lower limb muscles in healthy subjects.Methods: Thirty-six healthy subjects (mean age=23.16±2.3) volunteered to participate in this study. Subjects were instructed to perform ROM test using sit and reach test, back extensor endurance test using Biering-Sorensen test, erector spinae (ES), lumbar multifidus (LM) fatigue and onset time of Gluteus maximus (GM) in prone hip extension using electromyography before and after trunk flexion and extension isometric exercises.Results: The ROM in trunk flexion showed a significant increase by 7.9% after exercise compared to that before exercise (p<0.05). Relative GM contraction onset timing significantly decreased after exercise (p<0.05). The result of the Sorensen test after exercise showed a trend of increase in duration time. Muscle fatigue in the LM, however, showed a significant increase (p<0.05), whereas muscle fatigue in the ES was reduced without statistical significance.Conclusions: The results base on this study showed a significant increase in the trunk ROM after trunk flexion and extension isometric exercise using an external compression device, while the relative contraction onset timing in the GM significantly reduced. Furthermore, the muscle endurance test after exercise showed a trend of increase in the duration time with a decreasing trend in muscle fatigue in the ES. Exercise based on ATM®2 is an effective exercise protocol with an effect on biomechanics of healthy subjects. This exercise may be suitable in clinical practice for patients with LBP, for which long-term effects can be expected.

COMPARISON OF LUMINOUS FLUX MAINTENANCE METHODS, CONTINOUS VS. ON/OFF CYCLES

This paper will present preliminary results from a research project comparing two methods for estimating the lifetime of LED products, LM-84 (6000 h test) and the new EU endurance test (3600h test) including on/off cycling, that will be required by EU from 2021. Beside the luminous flux development for the sources tested, their colorimetric results will also be examined as a function of time. Preliminary results for two series of LED products will be presented. For one series, the 3600h test have been completed, for the remaining series only results from the 6000h test is available. Results of the luminous flux and colour maintenance will be presented. Initial examinations shows good agreement between the two tests methods for the first series of LED products measured.

Relationship Between Yo-Yo Intermittent Endurance Test-Level 1 and Match Running Performance in Soccer: Still on the Right Path?

Introduction. The Yo-Yo Intermittent Endurance Test-Level 1 (Yo-Yo IR1) is considered a valuable measurement tool in assessing specific soccer endurance. However, there is a lack of recent research validating this test with regard to match running performance (MRP) in elite-level soccer. Material and Methods. The aim of this study was to evaluate the validity of Yo-Yo IR1 in predicting MRP during elite-level soccer matches. The participants were soccer players who competed in the highest-level Croatian soccer league (23.57 ± 2.84 years, 181.9 ± 5.17 cm, 78.36 ± 4.18 kg), and they were all tested using Yo-Yo IR1 in the middle of the season 2019/2020. The players’ MRP (n = 71) was measured using the Global Positioning System over one-half season, and included the total distance covered, the distance covered in different speed zones, accelerations and decelerations. The association between MRP and Yo-Yo IR1 was identified with Pearson’s correlation. Results. The results indicated that central midfielders and fullbacks achieved significantly higher results in Yo-Yo IR1 than forwards and central defenders (F-test: 29.80; p < 0.01; large effect size). Higher results in Yo-Yo IR1 were correlated with the match amount of (i) the total distance covered (r = 0.65); (ii) high-speed running (r = 0.42); (iii) high-intensity distance covered (r = 0.36); (iv) total accelerations (r = 0.37); and total decelerations (r = 0.42). Conclusions. The established associations between Yo-Yo IR1 and MRP in this study confirmed the validity of Yo-Yo IR1 in predicting MRP in professional soccer today.

Chemometric Approach to Assess Response Correlation and its Classification in simplex centroid design for Pre-Optimization stage of Catechin-SNEDDS

Catechins are isolated from tea leaves and shown to have pharmacological activities. However, the permeability and absorption capacity of the digestive tract is low, thus affecting the value of bioavailability. Self-nano emulsifying drug delivery system (SNEDDS) is formulated as a breakthrough in nano delivery to increase the value of bioavailability and stability in a model of natural compounds, namely catechins. This study applies chemometrics to the simplex centroid design (SCD) to analyze the catechin-SNEDDS pre-optimization design. The factors defined include oleic acid, croduret 50-SS, and propylene glycol. Evaluation parameters include emulsification time, percent transmittance (%T), freeze-thaw, and endurance test. The results showed a formula that met the requirements at the time of emulsification, stability, and %T. There were four clusters of results from the principal component analysis - cluster analysis (PCA-CA) in the SCD formula. The evaluation between responses in the SCD optimization design is indicated to have a positive correlation. Analysis using multivariate chemometric can describe the characteristics of each formula and the response based on the parameters used, which refers to the similarity, grouping, and correlation of each formula and response. The PCA-CA technique can group formulas from SCD in similar clusters and provide important information regarding response patterns or correlations.

Physical Fitness in Preschool Children

Introduction. The level of mental and motor development as well as physical fitness and perceptual-motor performance should guarantee success in adapting to the new school environment. The aim of the research. The aim of the research was to determine physical fitness in preschool children of both genders aged from 4 to 7 years. Material and methods. The study included 275 children at the chronological age of 4 to 7 years including 134 girls and 141 boys. In order to assess physical fitness, the authors used the Wrocław Physical Fitness Test for preschool children completed by the endurance test Results. Final physical fitness results showed that six-year-old boys were the fittest and less fit were girls at the age of seven. The least fit were boys and girls at the age of four. Conclusions The Wrocław Physical Fitness Test and the endurance test revealed that the experimental group of children aged between four and seven years from the Western Pomerania region represented a satisfactory physical fitness level. It should be noted that this level was significantly lower than the ones obtained in tests conducted by other authors in 2006, 1996, 1972, and 1967. The represented fitness level, especially the level of endurance, may result in adaptation disorders during the school shock period. The phenomenon of sexual dimorphism at preschool age is demonstrated by significantly better physical fitness in boys at the age of five and six and balanced fitness at the age of seven. Positive development of physical fitness is not supported by ongoing lifestyle pre-orientation. It is recommended to complete primary school admission criteria for the first form by physical fitness standards, including endurance.

Research on testing method of solid-state disk used in intelligent security field

This paper summarizes the specific requirement of SSD in intelligent security field and comparison of related lifespan and endurance test method.

Categorization of Different Clamp Types Used For The Endurance Test of Human Grafts – A Systematic Review

BackgroundThe use of tendon allografts for orthopedic repair has gained wide acceptance in recent years, most notably in anterior cruciate tendon reconstruction. Multiple studies support the use of tendon allografts and the benefits of its use are well accepted and understood. One of the important criteria of the use of tendon allografts is statistically similar histological and biomechanical properties to autographs. Five major scientific literature databases (Web of Science, Science Direct, Scopus, PloS ONE, Hindawi) and additional sources were used. ResultsThe objective of this systematic literature review is to investigate and categorize existing clamps used in the determination of the biomechanical properties (maximum load, maximum strength, modulus of elasticity, ultimate strain, stiffness) of tendons. Studies had to use an endurance test of tendons and clamps in detail. The database search and additional sources resulted in 274 records. 216 records eliminated during the screening for various reasons. The number of articles used in the final synthesis was 58. Search for publications dated between 1991 and Oct 31st, 2020. A variety of clamps for use during the endurance test of tendons were identified and categorized according to the temperature used during the measurement. The clamps are divided into three groups: room temperature, cooled or heated clamps.ConclusionsOn the basis of the systematic literature review, mechanical parameters determined by usage with cooled clamps proved to be more reliable than with those at room temperature and with heated clamps. The main advantage of the cooled clamps is that there is no limit to the type and length of the tendon. This study provides an overview of clamps and does not represent the modernity of any method.