A physical exercise program is one of the commonly used methods for improving an individual’s antioxidative capacity. However, an inappropriate physical exercise program would induce extra oxidative stress (OS), and the relationship between the details of a physical exercise protocol and the severity of intracellular OS is still unclear. A systematic review and meta-analysis of randomized controlled trials were conducted by searching PubMed, Medline, and Web of Science with the eligibility criteria: (1) participants over 18 years old; (2) physical exercise interventions; (3) 8-hydroxydeoxyguanosine, F2-isoprostanes, and protein carbonyls (PCs) as outcome measures; (4) published in English and peer-reviewed. 12 studies were included, and the data of 8 in them were pooled together. The agreement between authors reached a kappa value of 0.73. The results of the meta-analysis showed that: (1) the level of OS did not depend on the absolute intensity of physical exercise but on both the intensity and the volume of exercise; (2) high-intensity aerobic exercise (HIAE) and a combined protocol of HIAE and resistance training had the highest potential to induce large OS in unhealthy people; (3) the OS induced by moderate-to-high intensity aerobic exercise was significantly larger than that induced by ordinary life activities in healthy adults; (4) high-intensity interval training and moderate-intensity aerobic exercise had the lowest and sub-lowest probabilities to induce high intracellular OS for unhealthy adults. activities induce OS in various tissues in the human body, and the severity of OS depends on many factors of physical exercises as well as the health condition of an individual. A high-intensity and high-volume physical exercise program has the largest possibility of inducing severe OS, while a moderate-intensity aerobic exercise program and a high-intensity interval training program with a relatively low volume might be beneficial to the redox balance for unhealthy individuals. In conclusion, continuous aerobic exercise under moderate-intensity or high-intensity interval training could be recommended to enhance the body’s capacity for maintaining redox balance, especially for unhealthy individuals. The PROSPERO Registration Number is CRD42022349687.
1 August 2016 in International Journal of Sports Science & Coaching
The purpose of this study was to investigate the characteristics of center of pressure (COP) trajectory during table tennis topspin forehand loop between superior and intermediate players. Twenty-six male table tennis players with two different skilled level participated in this test. Novel Pedar insole plantar pressure measurement system was used to record COP displacement. Subjects were asked to perform crosscourt forehand loop against the topspin ball with maximal power. The motion was divided into two phases as backswing and forward swing. Compared to intermediate players, superior players showed significantly larger medial–lateral COP displacement at backward-end and significantly smaller anterior–posterior displacement at both backward and forward ends. In addition, the ratio of COP velocity between forward swing and backswing was much higher for superior subjects. Results indicated that superior players possessed better foot drive technique and ability of foot motion control during forehand loop. These characteristics are beneficial for coaches to develop special training schemes in improving forehand loop performance.
25 September 2017 in Journal of Medical and Biological Engineering
This study investigated the influence of human head impact on the severity of traumatic brain injury. Simulation of the dynamic impact of a human head was performed using FEM (finite element method) and employing HIC (Head Injury Criterion). The study of traumatic brain injury included impacts with the occiput, temporal, forehead, and parietal part of the head, and the impact velocity at the surface ranged from 1 to 7 m/s. The following characteristics were considered and analyzed in the simulation: duration of the impact, intracranial pressure, HIC, and change in accelerations at the center of gravity of the brain. The computed distribution of pressure values in the brain during an impact confirmed the theory of inertial intracranial brain displacement. The effect of a protective helmet aimed at reducing the severity of traumatic brain injury was investigated, and a method to determine rational helmet parameters was developed. In the case of the protected head, impact acceleration occurred over a longer period of time, which yielded a reduction in the brain load compared to the unprotected head. The developed method allows us to predict the severity of traumatic brain injury (TBI) in the protected/unprotected human head and to provide recommendations for the determination of rational parameters for manufacturing personal protective equipment for the head.
Nowadays, footwear serves an essential role in improving athletic performance and decreasing the risk of unexpected injuries in sports games. Finite element (FE) modeling is a powerful tool to reveal the biomechanical interactions between foot and footwear, and establishing a coupled foot-shoe model is the prerequisite. The purpose of this pilot study was to develop and validate a 3D FE coupled model of the foot and sports shoe complex during balanced standing. All major foot and shoe structures were constructed based on the participant’s medical CT images, and 3D gait analysis was conducted to define the loading and boundary conditions. Sensitivity analysis was applied to determine the optimum material property for shoe sole. Both the plantar and shoe sole areas were further divided into four regions for model validation, and the Bland–Altman method was used for consistency analysis between methods. The simulated peak plantar and sole pressure distribution showed good consistency with experimental pressure data, and the prediction errors were all less than 10% during balanced standing with only two exceptions (medial and lateral forefoot regions). Meanwhile, the Bland–Altman analysis demonstrated a good agreement between the two approaches. The sensitivity analysis suggested that shoe sole with Young’s modulus of 2.739 MPa presented the greatest consistency with the measured data in our scenario. The established model could be used for investing the complex biomechanical interactions between the foot and sports shoe and optimizing footwear design, after it has been fully validated in the subsequent works under different conditions.