AN INVESTIGATION INTO THE RELEASE FACTOR EFFECTS OF HAMMER THROW

This study aimed to determine the relationship of release factors on the final hammer throw distance of American throwers as well to determine where differences in release factors between the years and throw distance groups (TDG). The video from 94 hammer throws (52 female throws and 42 male throws) were analyzed using 2-D to 3-D coordinates via DLT procedures. Analysis of the release factors of a throw revealed correlations with release velocity but not height and angle. Further analysis revealed that release height has decreased while vertical velocity and release angle have increased since 2016

OPTIMIZING EXERCISE SELECTION FOR POWER DEVELOPMENT IN ATHLETES USING VELOCITY-BASED TRAINING

The purpose of this study was to determine which lift and velocity range provide the highest levels of power and force production. 7 highly trained strength professionals performed 3 sets of paired powerlifting exercises: deadlift (DL) and back squat (SQ), power clean (PC) and hang clean (HC), and power clean (PC) and clean pull (CP). Velocity was also controlled for the lifts. Velocity ranges, 0.5-0.75 m/s, 0.75-1.0 m/s, and 1.0-1.3 m/s, were used. A 2 x 3 ANOVA with post-hoc test investigated the data. Lift choice mattered for average power, peak power, and force when controlling the velocity of movement

USING VERTICAL JUMP POWER AND STANDING LONG JUMP POWER TO DETERMINE MUSCLE IMBALANCE

The purpose of this investigation was to determine the relationship between a ratio between vertical jump (VJ) power and standing long jump (SLJ) power and knee injury risk by using the functional power outputs with information generated from knee isokinetic testing. Medical records along with strength and conditioning testing records of 13 female NCAA-I soccer athletes were examined. Correlation and linear regressions were run to find relationships. The medical records included the isokinetic knee flexion and extension testing. Data from VJ height and SLJ distance were taken from the strength and conditioning data. Using VJ and SLJ power results to determine tendency in muscle dominance would allow development of interventions tailored to decrease the imbalance

TECHNIQUE COMPARISON OF MALE AND FEMALE HAMMER THROWERS

Distinct anthropometric differences occur between the sexes throwing the hammer that affect technique. No literature statistically compares the differences between male and female hammer throwers. The aim of this study was to determine the hammer throwing technique differences occurring between genders. The performances of 16 male and female throwers at the 2003 World Athletic Final and 13 male and female throwers from the 2003 USA Track and Field Nationals were examined. The best throw of each athlete was digitized and analyzed using the Peak Motus 8.2 motion analysis system. Results revealed that athlete mass, athlete height, velocity at release, timing components, and centripetal force were different between sexes

EXAMINING THE RELABILITY AND VALIDITY OF THE FITBIT CHARGE 2™ TECHNOLOGY ON HEART RATE DURING TREADMILL EXERCISE

The purpose of this study was to determine the reliability and validity of the Fitbit® Charge 2™ compared to a 4-lead ECG to monitor heart rate during exercise. All participants completed a VO2Max test to determine the participants’ cardiorespiratory fitness and appropriate work loads for the intensity protocol. Participants wore a Fitbit® Charge 2™ on the wrist and a 4-lead ECG. 16 participants were assigned to testing conditions: GPS stride length/manual stride length and hold/no-hold on the handrails of the treadmill. The participants completed a walking protocol including light (60% of HRR) intensities while wearing both devices. Intraclass Correlation Coefficient (ICC) was used to analyze the results. The ECG is a reliable and valid means to monitor heart rate. The Fitbit® Charge 2™ demonstrated poor reliability and validity to monitor heart rate

AN INVESTIGATION INTO SEASONAL POWER CHANGES IN COLLEGIATE BASEBALL PITCHERS

This study aimed to investigate changes in power and fatigue of collegiate baseball pitchers throughout a season to determine injury risk. Isokinetic, mobility, and performance test records were reviewed for 18 male NCAA-I baseball athletes. Testing was performed during the offseason, season start, and end of non-conference play and included medicine ball throws, hop testing, and 3-speed isokinetic testing. Statistical analysis determined that the kneeling medicine ball throw, 6-m hop, and several isokinetic outcomes decreased throughout the season. Using a combination of medicine ball throws, hop testing, and isokinetic testing at specific times during a season may provide insight into the overall fatigue level and injury risk within baseball pitchers

Implementation of a process-based catchment model in a poorly gauged, highly glacierized Himalayan headwater

The paper presents a catchment modeling approach for remote glacierized Himalayan catchments. The distributed catchment model TAC^D, which is widely based on the HBV model, was further developed for the application in highly glacierized catchments on a daily timestep and applied to the Nepalese Himalayan headwater Langtang Khola (360 km²). Low laying reference stations are taken for temperature extrapolation applying a second order polynomial function. Probability based statistical methods enable bridging data gaps in daily precipitation time series and the redistribution of cumulated precipitation sums over the previous days. Snow and ice melt was calculated in a distributed way based on the temperature-index method employing calculated daily potential sunshine durations. Different melting conditions of snow and ice and melting of ice under debris layers were considered. The spatial delineation of hydrological response units was achieved by taking topographic and physiographic information from maps and satellite images into account, and enabled to incorporate process knowledge into the model. Simulation results demonstrated that the model is able to simulate daily discharge for a period of 10 years and point glacier mass balances observed in the research area with an adequate reliability. The simple but robust data pre-processing and modeling approach enables the determination of the components of the water balance of a remote, data scarce catchment with a minimum of input data

ASSOCIATIONS BETWEEN CLINICAL AND PERFORMANCE TESTS IN SOCCER ATHLETES

The purpose of this study was to determine the relationship between selected Functional Movement Screen (FMS™) scores, quadriceps and hamstrings strength, and vertical jump performance to see if there is consistency between clinical and performance testing. Records for twelve NCAA-I female soccer players were selected for this study. The isolated scores from the hurdle step and deep squat portions of the FMS™ test were extracted, left and right peak knee extension and flexion torques from isokinetic tests at 60, 180, and 300 °/sec, and vertical jump heights were recorded. Bivariate correlations and a multiple regression analysis were conducted to explore relationships among variables. The results from this study indicated that the FMS™ test was a poor predictor of vertical jump height, but peak extension and flexion torques were related to the vertical jump in a complex relationship

Прогнозирование временного сопротивления разрыву малоуглеродистой низколегированной арматурной стали на основе системы частных регрессионных моделей

Предложен способ декомпозиции многофакторной регрессионной модели прогнозирования механических свойств арматурного проката. Обоснована система частных регрессионных моделей прогнозирования временного сопротивления разрыву арматурного проката. Показано, что полученные результаты хорошо согласуются с экспериментальными данными