5954 research outputs found
Sort by
KINEMATIC AND MUSCULAR STRATEGIES OF THE LOWER BACK DURING BACKWARD SOMERSAULT LANDING IN GYMNASTICS
Get PDFThe purpose of this study was to investigate the kinematics and muscle activity of the lower limbs and lumbar spine during the landing of a jump in female gymnasts. Sixteen adult gymnasts performed round-offs followed by a back somersault. Lumbar, hip, and knee joint angles at peak GRF and EMG activity of 4 lumbar spine muscles were recorded. The study reveals a large heterogeneity in the kinematic and muscular strategies used by the gymnasts. A more detailed investigation is required to gain a better understanding of the motor behaviors observed, with a view to potentially improving individualized monitoring during the season and reducing the incidence of injury
DISTAL JOINT KINETICS ARE ASSOCIATED WITH SHOT PUT PERFORMANCE
Get PDFShot put motion exhibits upper-limb “push type proximal-to-distal sequence”, which is a common motor task with the lower limb. In the lower limb, proximal muscle function is associated with motor performance. Here we show the strong correlation of the wrist torque and power with the flight distance in the motion of 13 male shot putters. For the shoulder, only the peak torque correlated with the flight distance, whereas for the elbow, flexion torque was exerted, and both torque and power did not correlate with the flight distance. We suggest that it is important for shot putters to strengthen both the torque and power exertion abilities in the wrist and to prioritise the torque exertion ability in the shoulder. We open a novel perspective for training strategies to maximise upper limb motor performance
VIDEO SKELETONIZATION AND AI: A NOVEL APPROACH FOR ANALYZING KINEMATICS IN TABLE TENNIS
Get PDFThis study introduces a simple yet effective system to measure table tennis player movements and relate them to the moment the ball hits the racket. The system accurately measures shoulder, elbow, hip and knee joint angles without hindering player movements, using only two GoPro Hero 10 cameras and the Mediapipe framework. Ten male participants were evaluated using synchronized cameras and a custom-trained YOLOv8 algorithm to pinpoint the moment of impact between the racket and the ball. This approach, avoiding participant-worn equipment, offers a streamlined solution for assessing table tennis movements, promising potential applications in sports analysis
THE RELATIONSHIP BETWEEN FOOT POSITION IN THE TAKE-OFF PHASE AND THE HEIGHT OF THE JUMP SHOT IN BASKETBALL
Get PDFThe purpose of this study was to identify the relationship between foot position in the take-off phase and the height of the jump shot. The research was conducted on 20 professional basketball players. Each participant performed 9 jump shots on a force plate in laboratory conditions. Jump shots were performed from three different foot positions in random order: 3 from a dominant staggered stance, 3 from a parallel stance, and 3 from a cross-dominant staggered stance. The height of the jump shots from a parallel stance (0.44 ± 0.05 m) were significantly greater than from a dominant staggered stance (0.43 ± 0.04 m) and from a cross-dominant staggered stance (0.43 ± 0.05 m). Therefore, the desirable dominant staggered stance consistent with the reference movement pattern did not prove to be more advantageous in terms of the height of the jump shot compared to other foot placements
FATIGUE-INDUCED ECCENTRIC HAMSTRING WEAKNESS AS A POSSIBLE RISK FACTOR FOR HAMSTRING INJURY IN SOCCER PLAYERS
Get PDFThe purpose of this study was to investigate how isokinetic strength parameters, which are possible risk factors for hamstring injury (HSI), change after fatigue elicited by a simulated soccer match. Eight male and four female amateur and semi-professional soccer players were included in the study. The Loughborough Intermittent Shuttle Test (LIST) was used to simulate a soccer match. Isokinetic strength testing of knee flexor and extensor muscles was performed prior to the simulated match, at half time break, and immediately after the match. After the LIST, eccentric hamstring peak torque was decreased by 14.3% (±11.7) and 14.80% (±13.87) on average, in the dominant and non-dominant leg, respectively. This might translate to an inability to decelerate the lower limb during running or kicking, which might increase the risk of HSI
EXPLORING THE ATTENUATION INTERACTION BETWEEN HORSE AND RIDER IN SITTING TROT USING INERTIAL MEASUREMENT UNITS
Get PDFThe aim of this study was to explore how riders attenuate accelerations in sitting trot between their trunk and pelvis using IMUs. Fifteen female adult riders and their own horses were captured in sitting trot using IMUs affixed the rider’s trunk (approx. T12), and sacrum, and the horse’s girth. Horse-pelvis and trunk-pelvis attenuation were calculated from the resultant acceleration in the frequency domain. The root mean square of the horse’s acceleration per stride was averaged for the trial. Sensor fusion was performed to elicit rider pelvis and trunk pitch. Significant (pr2=-0.52) attenuation and trunk-pelvis attenuation and horse acceleration (r2=-0.58). Riders attenuate the horse’s accelerations between trunk and pelvis, scaling to horse acceleration, calling for further investigation of contributing factors
BIOMECHANICS OF BREATHING WITH THE USE OF A FACE MASK AT REST
Get PDFThe purpose of this study was to assess breathing patterns and the mechanics of individual breathing compartments (IBC) with and without a respirator (FFR) at rest. Twenty-one (11 M; 10 F) participants completed 10 min of breathing with or without FFR in a randomized order over two days. Three IBC were identified and measured through optoelectronic plethysmography: pulmonary rib cage, abdominal rib cage, and the abdomen. Simultaneously, data on inspiratory time, expiratory time, and respiratory frequency were gathered. The results indicated no significant differences in any of the parameters. This implies that the augmented respiratory effort due to the resistance of the FFR is uniformly distributed among the IBCs. Although there may be minimal immediate impacts of FFR on breathing patterns in healthy individuals during rest, long-term effects may vary
EFFECT OF CHANGING FOOT STRIKE PATTERN FROM REARFOOT TO FOREFOOT ON FOOT EXTERNAL EVERSION MOMENT
Get PDFWe aimed to illustrate the change in the foot external eversion moment of habitual rearfoot strike runners when they immediately change their foot strike pattern to an anterior foot strike pattern. Eighteen healthy males participated and were instructed to run with their habitual foot strike pattern and a modified (anterior) foot strike pattern. From the three-dimensional coordinates of running (250 Hz) and the ground reaction force (1000 Hz), the foot external eversion/inversion moments were calculated. During the stance phase of running, the modified foot strike running exhibited a significantly larger peak external eversion moment than the rearfoot strike running. Our results suggest that changing the foot strike pattern from a rearfoot to a forefoot may increase foot eversion moments and susceptibility to overuse running injuries
SYNERGISTIC CONTROL OF MUSCLE ACTIVITY DURING CHALLENGING LOCOMOTOR TASKS
Get PDFThis talk will explore the neuromotor control of challenging locomotor tasks using the concept of muscle synergies: modular sets of activation patterns that are common to functionally similar muscle groups and may exist to simplify movement control. I will argue that the structure of these synergies is largely conserved across different walking and running speeds, as well as in response to internal (e.g. aging) or external (e.g. uneven terrain) perturbations. The nervous system finely tunes the linear and nonlinear time characteristics of muscle synergies to cope with disturbances, rather than adjusting the relative muscle contributions, regardless of the nature of the perturbation. This suggests the existence of a common neural mechanism for managing various locomotor situations
Medial Prefrontal Cortex fNIRS Activity while Viewing Nature and Urban Scenes: The Search for Neurological Evidence of Nature\u27s Transcendent Self-Diminishment Effect
Get PDFPrior research suggests that exposure to nature increases prosociality. One of the theories as to why this happens is that nature can elicit self-diminishment which leads to the positive experience of paying less attention to oneself. To better understand the neural processes behind this, this study used functional near-infrared spectroscopy (fNIRS) to measure activity in the medial prefrontal cortex (mPFC) which is related to the self-concept. Participants were shown 12 images divided into four blocks separated by image types. Six were entirely natural scenes (three pleasant and three unpleasant), and six were entirely urban scenes (three pleasant and three unpleasant). After each image block participants took a brief questionnaire to measure their level of immersion. A Flanker task was used to separate the image blocks after each immersion questionnaire. There was no significant difference in HbT between nature and urban scenes, but a significant main effect of valence was found. Unpleasant stimuli compared to pleasant stimuli were associated with lower average HbT in the mPFC. This might suggest that negative images resulted in more correlates of self-diminishment, however, more research is needed to support this