ISBS (International Society of Biomechanics in Sports): Conference Proceedings Archive
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A CASE STUDY OF THE KICKING FOOT AND STANCE IN ROUNDHOUSE KICK: CONTROL AND COMBAT SITUATIONS
Get PDFOnce this work is part of a long term study, the aim was to show the preliminary results of the comparison of the kicking foot and stance in the roundhouse kick according to the onset condition (control vs. combat situation). One black belt athlete participated on this study. A motion capture system of 18 cameras (Optitrack© 360Hz) was used for the kinematic data acquisition. In order to obtain the maximum height and speed, execution and movement time of the kicking foot we used one marker. In order to represent the stance positions we used five markers. The preliminary analyses suggest that there are differences between control and combat situations: 1.the maximum height was smaller in combat situation since the athlete prefers to kick in the trunk of the opponent and 2.the stance positions highlight the influence of the movements of the opponent in combat
A COMPARISON OF STROKE CHARACTERISTICS BETWEEN TEAM BOAT (K2) AND INDIVIDUAL (K1) SPRINT KAYAKING
Get PDFThe purpose of this study was to compare the stroke characteristics of sprint kayakers in team boat (K2) versus individual (K1) 200-m racing. This case study centred on two male 200-m specialists from a national sprint kayak team. High-speed (120 Hz) videos were recorded from the sagittal view during an important selection time trial. Thereafter, video analysis was performed to identify stroke characteristics for each paddler in both K2 and K1, including stroke rate and a four-phase stroke breakdown of entry, pull, exit and aerial sub-phases. Results showed that the kayakers’ stroke profile were more similar when comparing between K2 and K1 for the same person, rather than within both paddlers during the K2. It is likely that sprint kayakers have individually preferred stroke profiles but it is not clear how these profiles may be adapted for successful team boat performance
CHANGES IN MOVEMENT REGULARITY DURING LEARNING OF A NOVEL DISCRETE TASK
Get PDFSample entropy and surrogate methods were employed to investigate changes in regularity of movement profiles during the learning of a novel discrete task under contextual interference conditions by two groups. The contextual interference effect was confirmed. Surrogate methods were used to show the presence of deterministic dynamics in observed data. Trends of decreased and increased movement regularity for groups 1 and 2 respectively were observed. The relative stage of learning and the ability to operate within an acceptable range of variability/complexity may explain these trends. Entropy estimates as a measure of regularity may provide important information about the learning of discrete tasks
THE APPLICATION OF FUNCTIONAL DATA ANALYSIS TECHNIQUES FOR CHARACTERIZING DIFFERENCES IN ROWING PROPULSIVE-PIN FORCE CURVES
Get PDFThe pattern of propulsive force (measured at the pin), represented by force-time and forceangle graphs, typically differs among rowers. How the pattern differs according to competition level and gender has not been identified. Functional data analysis (FDA) techniques were used on force-time and force-angle data to identify the main modes of variance in curves representing thirty eight rowers of different competition levels (domestic, underage international and open international) and different gender. Stepwise discriminant function analysis showed strong classification of rowers using force-time and force-angle graphs and strong classification of female rowers. Male rowers, Underage rowers and Open International rowers showed weaker classification. Despite this, FDA provided useful information for the assessment of rowing performance
THE EFFECT OF LIMB PREFERENCE ON KNEE MECHANICS DURING A FATIGUED UNANTICIPATED SIDESTEPPING MANOEUVRE
Get PDFFatigue may adversely affect knee kinetics and kinematics during the sidestepping manoeuvre. There is a lack of research examining the effect of limb preference on knee mechanics during fatigued unanticipated sidestepping. Twelve female collegiate soccer and field hockey players performed right and left unanticipated sidestepping prior to and following completion of a fatigue protocol. Magnitude based inferences were used to assess the impact of limb preference on knee mechanics during initial contact, weight acceptance, peak push-off, and final push-off of the sidestep. The preferred limb was more likely to experience increased coronal plane loading, whereas the non-preferred limb is more likely to experience increased transverse plane loading during fatigued, unanticipated sidestepping
VARIATIONS IN PITCHING PERFORMANCE DURING A MAJOR LEAGUE BASEBALL GAME: WHAT CAN WE LEARN FROM BALL TRACKING DATA?
Get PDFThe aim of this study was to identify changes in pitching characteristics during nine innings of professional (MLB) baseball. Ball tracking data were obtained for 1,514,304 pitches thrown by 129 pitchers during the 2008–2014 MLB seasons and compared across the nine innings using linear mixed model analyses. Earlier innings contained significantly more hard (i.e., fast-type) pitches. A significant decrease in pitch speed and release height emerged before the sixth inning. These data revealed that aspects of a starting pitcher’s performance significantly change as early as the second or third inning of an MLB game, although these do not influence his effectiveness. Coaches may use these data to inform their decision to relieve a starting pitcher and/or direct in-game strategies to exploit trends in pitcher performance
INERTIAL MEASUREMENT UNIT IN BIOMECHANICS AND SPORT BIOMECHANICS: PAST, PRESENT, FUTURE
Get PDFThe current technologies and methodologies used for physical activity monitoring and ambulatory motion analysis are based on the Inertial Measurement Unit (IMU). Perspectives and issues met with when performing physical activity monitoring and ambulatory motion analyses with this type of device are presented here
RUNNING ECONOMY IS A MULTIFACTORIAL PHENOMENON
Get PDFThe purpose of this review was to describe economy of human locomotion, especially in running. Several factors such as age, sex, air resistance, body temperature, body weight, maximal aerobic capacity, muscle fibre distribution, vertical oscillation of the body, ground reaction forces and their directions, tendomuscular structure, training status, and fatigue have been demonstrated to affect running economy (RE). Although there exist interindividual differences in RE, training, especially strength and power training, improves RE to a certain degree. On the contrary, RE decreases in fatiguing conditions, but negative influences on RE can be minimizd by optimal training
GIVING THE FORCE DIRECTION: ANALYSIS OF SPEED SKATER PUSH OFF FORCES WITH RESPECT TO AN INERTIAL COORDINATE SYSTEM.
Get PDFPush-off in speed skating requires an extensive motion strategy. During speed skating the skater continuously changes the lean and steering angle of the skate and therewith the direction of push-off, The forces in an inertial coordinate system can give insight into what amount of the push-off force is directed into the forward motion. In this paper we present the preliminary results of a study on the global forces in speed skating. From a mechanical viewpoint, increasing the lean angle of the skate seems beneficial at the end of the stroke, but detrimental at the start of the stroke. Furthermore the necessity of the lateral force on the skate in the overall force production is a variable of interest for further investigation, since dynamically it has a disadvantageous effect on the forward motion
THE CHARACTERISTICS OF STRIDE LEG GROUND REACTION FORCE BETWEEN DIFFERENT STRIDE TVPES BASEBALL PITCHERS WHILE PITCHING
Get PDFThe purpose of current study was to compare the ground reaction forms (GRF) of the stride leg in baseball pitchers using two different pitching stride techniques. Fourteen college pitchers volunteered as participants and made maximum effort pitches on an indoor mound toward a 8 m away target. The ball velocity were measured by a radar gun, the GRF were measured by a forceplate, and the trajectory of pelvis center were measured by a motion analysis system to classify pitcher\u27s strides as tall-and-fall (TF) or dip-and-drive (DD). There were no significant difference between two groups in ball velocity and stride leg GRF during pitching, and the ball velocity were significantly correlated with the vertical GRF of stride leg at ball release in TF group. It suggested that the different pitching technique might be used for different stride types