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THE EFFECT OF WIDE PREPARATORY STANCE ON DIVING SAVE PERFORMANCE IN FEMALE GOALKEEPERS
Get PDFThe purpose of this study was to investigate the effect of a wider preparatory stance on diving save performance in female goalkeepers. Five national-level goalkeepers performed dives from preferred and wide (75% of leg length) preparatory stance. Repeated measures ANOVA showed no effect of preparatory stance on dive time. Statistical parametric mapping 2-way repeated measures ANOVA was performed on the centre of mass (CoM) velocity, legs contributions, and contralateral power curves. It was found that the wider stance width required more contribution from the contralateral and less from the ipsilateral push-off, but this effect did not manifest in an improved CoM velocity or contralateral power generation. Coaches are recommended to evaluate the physiological and biomechanical differences before translating research findings between gender
ASYMMETRY IN THE APPLICATION OF INWARD GROUND REACTION FORCE DURING CURVED SPRINTING ON ATHLETIC TRACK
Get PDFWe assessed the factors influencing the application of inward GRF during the left and right contact phases in curved sprinting. This study resulted no significant differences in inward impulse and mean inward GRF between the two contact phases. The symmetry index in inward GRF depended on the magnitude of both inward GRFs during the left and right contact phases. Based on the significant correlation between mean inward GRF and hip abduction torque, we propose that large inward GRF is influenced by the absence of inward pushing during the left contact phase, whereas it is influenced by outward pushing during the right contact phase. The left contact phase seems to involve a shift in the action direction of ankle plantarflexion, as mean inward GRF exhibited a significant correlation with ankle plantarflexion
THIGH MUSCLE ACTIVITY IN EXPERIENCED FEMALE HANDBALL PLAYERS DURING PREPLANNED AND UNPLANNED SIDESTEP CUTS
Get PDFThe purpose of this study was to assess if there is a difference in the thigh muscle activation patterns between a preplanned and unplanned sidestep cut performed by n = 31 experienced female handball players. Electromyogram vector fields containing the muscle activity of the vastus medialis, vastus lateralis, semitendinosus, and biceps femoris from 100 ms before ground contact until toe-off were created and compared using Statistical Parametric Mapping. Results show lower activity in the unplanned cut. When comparing individual muscles, vastus medialis was the only muscle showing differences between tasks, with the unplanned task eliciting lower activity right before initial ground contact. The findings of this study indicate that the knee joint might be more vulnerable to external knee joint moments in unplanned cutting tasks due to lower muscle pre-activity
ADVANCING AQUATIC MOTION TRACKING THROUGH MULTI-SENSOR DATA FUSION SURFING THE GIANT WAVES OF NAZARÉ – STUDY CASE
Get PDFAs we delve into the diverse applications of motion tracking from Space to Air and Land, we encounter distinct challenges and opportunities. However, the most significant arise in the aquatic domain, particularly in the maritime environment. The unique characteristics of water behaviour demand novel solutions for accurately tracking and interpreting movement in this dynamic environment. An outstanding outcome of my Sports Sciences PhD was the Fluid Flow Sensor. This groundbreaking multi-sensor innovation enables tracking data considering water flow, expanding research horizons of analytics in water sports. Notably, the technology showcased its exceptional potential through a successful pilot study during a surfing session in the extreme conditions of Nazaré Giant Waves (Portugal), illustrating its remarkable capabilities for advancing research in water sports and related fields
RUNNERS FATIGUE EARLIER ON A TREADMILL VERSUS OVERGROUND: KINEMATIC EVALUATION OF A RUN-TO-EXHAUSTION
Get PDFRunning biomechanics can be different between treadmill and overground, especially with fatigue during a run-to-exhaustion. The aim of this study was to investigate impact variables and kinematics of participants running an identical treadmill and overground fatigue protocol. Runners ran to exhaustion 9 minutes earlier on the treadmill compared to overground, with similar heart rate and rate of perceived exhaustion. Only peak sternal acceleration was significantly different between conditions, but only in the fatigue state. Environmental factors in a lab, such as air flow absence, may affect the aerobic capacity during running. No clear biomechanical differences suggest that a similar state of fatigue was reached, only getting there faster on the treadmill
COMPARING JUMP HEIGHT ESTIMATED FROM A VIRTUAL REALITY HEAD-MOUNTED-DISPLAY AND A FORCE PLATE
Get PDFThis study aims to determine the accuracy in measuring jump height by using a head-mounted display (HMD) compared to a force plate and a standard optical motion capture system. A total of 178 counter movement jumps were recorded. Results reveal a high correlation (r = 0.86) between HMD and force plate measurements, with a significant bias of 6.7 cm. Regarding the HMD’s spatial tracking ability, results demonstrated a very high correlation (r=0.99) and a minimal bias of 0.3 cm compared to motion capture. Our preliminary data suggest that varying head orientation during jumping potentially influence jump height measured via an HMD. Results underscore the idea of using HMD for jump assessment, but more specific algorithms are needed for accurately assess of jump height solely by an HMD
ANALYSIS OF SPRINT RELATED PERFORMANCE INDICATORS IN PROFESSIONAL YOUTH SOCCER ACROSS AGE GROUPS & POSITIONS
Get PDFThe aim of this study was to evaluate the playing intensity distribution among 51 highly trained young elite soccer players across different age groups and position profiles during competitive matches. We recorded and analyzed championship matches of the U15, U16 and U18 youth teams from AKA St. Pölten, focusing on kinematic and physiological parameters during halftime assessments and throughout the entire match duration. The final goal of this research is to equip soccer coaches with valuable insights to accurately prescribe training intensities aligned with competitive scenarios, thereby enhancing overall training control
DOES THE ALIGNMENT OF THE FORCE VECTOR AND THE CENTRE OF MASS TRAJECTORY AFFECT TUMBLE TURN PERFORMANCE?
Get PDFWe examined the hypothesis that the exit velocity (Vout) during the freestyle tumble turn depends on the alignment of the force vector with the body centre of mass trajectory. Seven swimmers performed a total of 21 turns while video and force data were gathered. We calculated the angle from the centre of pressure to the body centre of mass (COM) and determined its difference with the angle of the push-off force vector during wall contact. This difference was then correlated with Vout, yielding a non-significant result (-4.89 ± 2.48° with r = -0.11 (p = 0.63), thus refuting the hypothesis. However, there was a strong correlation between Vout and the impulse of the projection of the force vector on the COM vector (258 ± 75 N*s with r = 0.76 (p \u3c 0.001)), which requires further scrutiny
EFFECT OF MIDSOLE THICKNESS ON RUNNING ECONOMY, COMFORT AND EFFORT IN WELL-TRAINED RUNNERS
Get PDFBy the current rules, midsoles in running shoes cannot exceed 40 mm in thickness, but this limit seems arbitrary. We investigated the effect of midsole thicknesses beyond the current limits on running economy, perceived comfort and effort, and spatiotemporal variables. Sixteen well-trained runners completed twelve outdoor runs (1.2 km each) at 16 km·h−1 alternating between three different footwear (one entry-level shoe (EL) with 30mm thickness and two modern shoes with thickness of 40 mm and 50 mm). Both modern shoes showed lower O2 uptake and effort compared with EL, but no differences between the 40-mm and 50-mm shoes were detected. Comfort was lowest for the EL and 50-mm shoes. Gait parameters did not differ between footwear conditions. As higher midsole thickness does not provide clear advantages, current rules could be re-evaluated to prevent stifling innovation
UPPER LIMB MUSCLE ACTIVATION BETWEEN TWO DIFFERENT STANCES IN A TENNIS FOREHAND DRIVE: A PRELIMINARY STUDY
Get PDFThe purpose of this study was to compare the electromyography (EMG) activity and ball velocity between one forehand drive performed in quasi-static stance (QSS) in the cross-court direction (CC) and one forehand drive performed with a dynamic frontal weight transfer stance (DS) in the inside-out direction and the ball velocity between both stances. The EMG activity was recorded in five muscles of the upper limb in one high-performance tennis player. Six forehand drives in QSS in the CC direction and six in the IO direction were selected for analysis. Results demonstrate a higher activation of most of the selected muscles in the QSS except for the triceps brachii (TB), moreover, the QSS presented higher ball velocity. This study could present a deeper comprehension of the muscle activation intensity, thus, helping coaches and health professionals