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COMPARISON OF THE SWIMMING START PERFORMANCE BETWEEN INDIVIDUAL AND RELAY FREESTYLE RACES
Get PDFThe aim of the present study was to compare the swimming start performances between individual and relay events in freestyle races. Competitors who took part in both the individual 100m freestyle and the 4×100m freestyle relay races during the LEN 2017 European Junior Championships were analysed in the present study. The results indicated that swimmers performed 6.92% faster 15m start time in relay race versus the individual freestyle race and the difference seemed to be due to the longer reaction time from the race beginning. Coaches and swimmers would be suggested to try to optimize their relay starting performance in order to take more benefit on flight, underwater and swimming phases compare to individual start
BIOMECHANICS IN THE 4HAIE STUDY: AIR POLLUTION AND MUSCULOSKELETAL HEALTH - AN UPDATE
Get PDFThe overall purpose of the 4HAIE study was to assess the influence of the interaction between air pollution and biomechanical, physiological and psychosocial factors on the incidence of injuries, health and well-being. A total of 1,500 active runners and inactive controls aged 18-65 will be recruited. Herein, we describe the biomechanical study design with data examples to investigate musculoskeletal and neuro-mechanics health in different air quality regions
EFFECT OF WEARABLE FITNESS WATCH ON PHYSICAL ACTIVITY IN SCHOOL CHILDREN WITH OVERWEIGHT
Get PDFOverweight and obesity in children and adolescents is a significant health problem, and lack of physical activity may be a factor related to obesity. In this study, we explored the wearable fitness watch to monitor the physical activity promoted situation of overweight and obese schoolchildren. Participants were overweight schoolchildren divided into two groups, the study group (n=41) and the control group (n=44). In the control group, the wearable fitness watch only displays the time. In the study group, each week, participants set up the goal, which increases the steps by 10% from baseline steps to reach 10,000 steps. The ANOVA is adopted to analyze the parameters such as the average daily number of steps, moderate to vigorous physical activity (MVPA). The results indicated the study group increase and improved daily walking steps and MVPA accumulation time in 8 weeks. The wearable fitness watch can help to promote the physical activity of overweight children
KINEMATIC PARAMETERS FOR LARGE TRUNK TWIST TORQUE OUTPUTS DURING THE BAR TWIST EXERCISE
Get PDFThis study aimed to clarify the kinematic characteristics for large trunk twist torque outputs during a bar twist exercise, focusing on the angle and angular velocity of the trunk twist. Twenty-one healthy male college athletes performed the bar twist exercise. Kinematic and kinetic data were recorded using the Vicon system (250 Hz) and two force platforms (1000 Hz). The participants were divided into two groups based on the maximal trunk twist torque of an individual compared to the mean value of the all participants. The results revealed that participants who had a large trunk twist torque output showed a large trunk twist angle against the direction of rotation and a large negative trunk twist angular velocity. Therefore, during bar twist training, a maximal trunk twist angle and a large negative angular velocity at the countermovement motion could be effective in obtaining large trunk twist torque
MEASURING AND ANALYZING THE ANGULAR MOMENTUM PRODUCED IN THE APPLICATION OF THE JUDO THROWING TECHNIQUE OSOTO-GARI
Get PDFThe purpose of this study was to analyze the angular momentum in the judo throwing technique osoto-gari. Ten male judo athletes participated in this study. The kinematic and kinetic data were collected using a three-dimensional motion capture system and two force plates. We analyzed the resultant angular momentum of a system that includes both the thrower and the faller. The counterclockwise angular momentum continuously increased during the throwing phase, indicating the torque was always acting toward the throwing direction. Our results demonstrated that the torque was associated with the horizontal GRF during the early swing phase and it was associated with the Y-axis moment arm during the late throwing phase
A COMPARISON OF THREE METHODS FOR ESTIMATING VERTICAL GROUND REACTION FORCES IN RUNNING
Get PDFThe purpose of this study was to compare different approaches for the estimation of biomechanical loads in running. A neural network, a biomechanical model, and a two-mass model were tested on the same data set. The predictions of the neural network were highly accurate for all considered running speeds (average RMSE, 0.11 BW). The biomechanical model returned statistically similar results (p=0.113, 0.14 BW), but with increasing RMS errors at high running speeds. Finally, the two-mass model estimates were independent of running speed, but were the least accurate (RMSE, 0.18 BW)
HOW HITTING THE HURDLE AFFECTS PERFORMANCE IN THE 110 M HURDLES
Get PDFThis study aimed to clarify the kinematic factors of hurdle hitting and its effect on the performance in 110-m Hurdles. Three male hurdlers volunteered. The trial which from start to the second hurdle was conducted about 20 times and these trials were recorded by motion capture system with 240 Hz. From all trials, 19 Non-Hitting Trials (NHT) and 33 Hitting Trials (HT) were classified. Kinematic variables and hitting grade, which is a value obtained by root mean square of the acceleration of hurdle’s bar, were calculated. As a result, the cause of hitting the hurdle was the low height of centre of mass (CoM) of the body at the take-off. Moreover, hitting grade was correlated with decrease in velocity by hurdle hitting during the hurdle clearance phase (r = 0.43). Furthermore, a decrease in running speed after landing at the first hurdle was also confirmed in HT trials
VALIDITY OF A TREADMILL-MOUNTED PHOTOELECTRIC SYSTEM FOR MEASURING SPATIOTEMPORAL PARAMETERS OVER A RANGE OF RUNNING SPEEDS
Get PDFThe purpose of this study was to determine the concurrent validity of a treadmill-mounted photoelectric system (Optojump) for measuring spatiotemporal parameters of runners at a range of running speeds (12-16 km/h). Ten participants ran for 20 s at each of three different speeds (12, 14 and 16 km/h) on a HP Cosmos Pulsar treadmill while spatiotemporal parameters were measured by both the Optojump and a high-speed camera (960 fps). The Optojump was placed on the sides of the treadmill as per the manufacturer protocols. Large timing errors for contact time (13.1%) and swing time (6.8%) were recorded, while excellent validity was shown for the other parameters of stride time, stride length and stride frequency (errors less than 0.6%). Increases in gait speed resulted in significantly lower error values for both contact time and swing time, but had no effect on the other variables. Early identification of initial contact and delayed identification of toe-off in the Optojump system due to placement on the slightly elevated sides of the treadmill are hypothesised to be the cause of the notable errors in contact time and swing time. However, these systematic errors do not negatively affect the other spatiotemporal parameters of stride time, stride length and stride frequency which are all still accurately measured by the Optojump in this set-u
MINI REVIEW: ASSESSING TECHNICAL SKILLS IN YOUTH ATHLETES USING SPORTS BIOMECHANICAL METHODS
Get PDFSince technical skills are suggested to play a crucial role in talent identification and development (TID) programs, sports biomechanical assessment methods could gain in importance within this field. This systematic mini review provides a brief overview of the biomechanical approaches used so far to assess technical skills and the respective findings in the context of TID. Our results show that few studies have used biomechanical approaches to identify or develop talented young athletes but those doing so found promising results. On the basis of those studies and given the advancements in technologies, we discuss possible obstacles and the potential of biomechanical assessment methods for motion and technique analysis in the context of talent research
ESTIMATING THE PEAK VERTICAL GROUND REACTION FORCE COMPONENT AND STEP TIME IN TREADMILL RUNNING USING MACHINE LEARNING - A PILOT STUDY
Get PDFThis study aims to investigate the efficacy of a stacking approach to estimate parameters in treadmill running. Nineteen participants ran on a treadmill at self-selected pace. Ground reaction force and kinematic data were collected. Stacking in machine learning was used to estimate the peak vertical ground reaction force and step time. Good agreement was observed in the test data set for predicted and measured values of the peak vertical ground reaction force component and step time where the ICC values were 0.85 and 0.99 respectively. This suggests stacking may be a feasible approach to estimate kinetic and kinematic parameters during treadmill running