ISBS (International Society of Biomechanics in Sports): Conference Proceedings Archive
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JUMPING PERFORMANCES IN NATIONAL 2 WOMEN HANDBALL PLAYERS: EFFECT OF A 3-MONTH PLYOMETRIC TRAINING PROGRAM
Get PDFThis study investigates both jumping performances (in squat jump (SJ) and counter movement jump (CMJ)) and global lower limbs stiffness in women handball players and reports the effect of a 3-month plyometric training program (length: 45 min, once a week) on these parameters. Mean performance for SJ was 22.3±3.0 cm and for CMJ 29.3±4.1 cm. Lower limbs stiffness reached 21213±7510 N.m-1. There was no correlation between the different parameters. Eight players followed the plyometric program but six were finally evaluated because of injuries. No change was observed for CMJ but lower limbs stiffness and SJ height tend to increase. This suggests that a unique 45-min plyometric training session once a week during three months may not be enough to enhance jumping capacities and lower limbs stiffness in women handball players
TOWARD AN IDEAL PERFORMANCE OF CIRCLES ON POMMEL HORSE —CENTRIFUGAL FORCE AND MASS-CENTRE VELOCITY—
Get PDFTo advance mechanical understanding of circles on pommel horse, we analysed the centrifugal force and the kinematics of whole-body mass centre during circles performed by five high-scored and five low-scored gymnasts. Three-dimensional kinematic and kinetic data were recorded using a motion capture system and force plates set under a no-leg pommel horse. The results showed that the high-scored gymnasts kept a greater mass-centre velocity and centrifugal force during the single-hand support phases than the low-scored gymnasts. It also seemed to be a reasonable interpretation, however, that the double-hand support phases were more complicated and difficult from a mechanical standpoint. Even the high-scored gymnasts who participated in this study might have room for further improvement especially in the double-hand support phases
INVESTIGATING THE SEATED DOUBLE POLING CYCLE: IDENTIFYING BASELINE MEASURES FOR THE PREPARATION PHASE
Get PDFThe purpose of this study was to identify baseline measures (BM) for the preparation phase (PREP) within the linear stroking cycle for the sport of sledge hockey. The addition of this phase to seated double poling is unclear biomechanically; full arm extension to pick-plant. A validated solid-static prototype mimicking the average single-armed adult male with dynamic shoulder joint was used to determine BM in 3 dimensions and initial pick-impact forces (GRF). Results indicated that average peak GRF occurred prior to 5.0x10-3s post initial contact; Fy=179N, Fz=515N and Fx=573N. Evidence indicated PREP should initiate slightly below the horizon in order to produce the greatest non-contracting force for sledge propulsion. Isolated data provides insight to the biomechanics of the dynamic limb within PREP assisting with its importance to the complete cycle
KINEMATIC ANALYSIS ON SERVE TECHNIQUE OF WORLD’S ELITE FEMALE TENNIS PLAYER
Get PDFThe purpose of this study was to obtain the kinematic parameters on serve technique of WTA (Women\u27s Tennis Association) top two Serena Williams and Simona Halep. The study selected WTA top two players’ first serve in 2014 China Open, which was held in Beijing, China. This paper makes analysis on serve technique between two elite players through the method of three-dimensional video analysis. The kinematic technical feature has been obtained through this study, resulting in not only providing referential statistics for the technical training of the players, but also enriching the technical theory of tennis
BIOMECHANICAL STUDY OF MID-FLIGHT BODY SEGMENT ACTION AND ITS EFFECT ON HANG-TIME FOR VOLLEYBALL SPIKE JUMPS
Get PDFThis study examined pilot data exploring approaches to testing whether the existing explanation about the biomechanics of hang-time in a basketball jump shot proposed by Bishop and Hay (1979) is applicable for spike jumps in volleyball and to identifying possible additional factors that could have an influence on hang-time in volleyball. Kinematics of spike jumps of volleyball players (n=3) using a technique that would theoretically increase hang-time were compared to jumps using a technique that would theoretically decrease it. The results suggested that the mechanisms creating hang-time in volleyball spike jumps are not the same as those in a basketball jump shot. These results suggested that the leg contributions are different and that the motion of the trunk also contributes to hang-time
THE CONTRIBUTION OF THE FLIGHT PHASE IN ELITE RACE WALKING
Get PDFAlthough race walkers are not permitted a visible flight phase, previous research has found that most competitors do experience very brief losses of contact. The purpose of this study was to assess the role of the flight phase in elite race walking. Seventeen international athletes race walked over two force plates recording at 1000 Hz. Video data were simultaneously recorded at 100 Hz and used to calculate kinematic variables such as step length. The mean flight time was 0.030 s (± .011) while the mean distance travelled during this phase was 0.12 m (± .05). It was calculated that without flight times, athletes would have slower mean velocities, particularly if mean cadence remained the same. However, the contribution of flight phases in race walking does not just allow for greater step lengths and faster speeds, but also more time for lower limb repositioning
PITCHING ACCURACY IN PROFFESSIONAL, HIGH SCHOOL AND JUNIOR HIGH SCHOOL PITCHERS
Get PDFThe purpose of this study was to investigate the differences in pitching accuracy among three different age groups. Professional (n=5), high school (n=8), and junior high school (n=11) pitchers were tested. To determine pitching accuracy, pitch locations relative to the catcher’s mitt were fitted to a bivariate normal distribution and a 90% confidence ellipse was obtained for each pitcher. Significant main effects were observed for age group in all of the parameters analysed, including: area, major radius and minor radius. There were significant differences in the minor and major radii of the 90% confidence ellipses between professional and junior high school players. The pitching accuracy of high school and professional players was also significantly greater than that of junior high school players. The superior pitching accuracy demonstrated by professional pitchers may be an important motor skill that is required to pitch at the professional level
KINETICS OF LOWER EXTREMITY DURING OVERGROUND HILL RUNNING IN FOREFOOT STRIKE RUNNERS
Get PDFThe aim of this study was to compare the lower extremity kinetics of forefoot strike (FFS) level ground running to those occurring during uphill and downhill running. Habitual FFS runners (n=5) completed overground trials during uphill and downhill conditions on a ramp set to 6? and 9? and during level running at a speed of 3 m/s ± 5%. Peak ground reaction forces (GRF), joint moment, and power absorption of lower limb were analyzed. GRF showed an absent impact transient in all conditions. Peak power absorptions did not change significantly during any of the hill running conditions compared to the level trial. Knee extension moment increased only during the 9? downhill condition. The findings suggest that running on hills with a FFS is characterized by an absent impact transient that is thought as a sign of less impact on the lower limb and may help to reduce injury risk
KINEMATICAL ANALYSIS OF FOREHAND STROKE TECHNIQUE OF EXCELLENT WOMEN’S TENNIS PLAYER SHARAPOVA
Get PDFForehand stroke is one of the most important and basic tennis techniques, with the highest rate of utilization. Good forehand stroke technique may serve as a powerful offensive weapon for a player, it can have a profound impact on the tennis game result and lay a solid foundation for learning other tennis techniques. In virtue of three-dimensional photograph analytical method, this research presents a kinematical analysis on key links of forehand stroke technique by Maria Sharapova, the champion of women\u27s singles in 2014 China Open, so as to obtain kinematical parameters of forehand stroke technique by the world excellent women’s tennis player, reveal kinematics characteristics of forehand stroke technique and offer theoretical instructions to coaches and athletes for proper understanding and mastery of such a technique during training
BIOMECHANICS OF TECHNIQUE SELECTION IN WOMEN’S ARTISTIC GYMNASTICS: FROM THEORY TO PRACTICE
Get PDFThis research aimed to determine effective technique selection for the female longswing through four themes: contemporary trend (T1), biomechanical conceptual (T2), musculoskeletal (T3) and energetic (T4) approaches. 3D video data at two elite competitions provided high ecologically validity. T1 identified the straddle Tkachev as the ideal vehicle with three distinct preparatory techniques (arch, pike, straddle) preceding it. Significant joint kinematic differences were not replicated in release parameters (T2) although joint kinetics highlighted greater physical demands in the pike (T3), with an energetics effectiveness score highlighting the arch as a technique promoting skill development (T4). Increasing knowledge and understanding allows coaches to optimise technique selection