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KINEMATIC DIFFERENCES BETWEEN SPRINTING AND THE HURDLE JUMP EXERCISE – A PRELIMINARY ANALYSIS
Get PDFThe hurdle jump is a commonly prescribed plyometric exercise for sprint athletes. The purpose of this study was to assess the lower body kinematic differences between maximal velocity sprinting and hurdle jumps performed over a range hurdle heights. Six competitive male sprinters performed maximum effort sprints over 50 m and hurdle jumps over 0.60, 0.75 and 0.90 m. Ground contact times, ankle, knee, and hip angles were collected during the ground contact phase of all trials. Significantly lower peak dorsiflexion angles and lower mean ground contact times were found in sprinting compared to all three hurdle jump conditions (all p \u3c 0.015). The hurdle jump exercise may be a suitable exercise for sprint athletes due to the greater demand imposed on the athlete relative to maximum velocity sprinting. Coaches are advised to monitor ground contact times to ensure the intensity of the exercise is not excessive
COMPARISON OF SUCCESS AND FAILURE IN SOCCER VOLLEY KICKING
Get PDFThe purpose of this study was to describe kinematic variables that can distinguish between successful (straight to the goal) and failed (over the goal) soccer volley kicking. To mimic the situation of the volley kicking, the ball was set on a paper pipe. The kicking motions of both successful and failed trials were captured from ten male university soccer players using an optical motion capture system at 500 Hz. As a result, foot–ball impact points on the ball in failed trials were concentrated around the bottom part of the ball, and the kicking motion in failed trials were characterized as: 1) smaller hip internal rotation during the back-swing, 2) more upright foot posture at ball impact and 3) more downward leg swing just before ball impact. Furthermore, it was suggested that there were several patterns of failed trials depending on the subjects
DOES ATHLETIC BACKGROUND INFLUENCE TRUNK NEUROMUSCULAR CONTROL DURING CUTTING MANEUVERS?
Get PDFThe purpose of this study was to evaluate the effect of sports specificities on trunk neuromuscular control during cutting maneuvers. Male handball players and karatekas performed unanticipated cuttings, while trunk kinematics and muscles activation were measured. No significant difference in 3D trunk kinematics at initial contact between groups has been noted. Trunk peak angle values during weight acceptance were also comparable between groups. Trunk muscles co-contraction ratios during pre-activation and weight acceptance did not differ between handball players and karatekas. The lack of neuromuscular activity difference made sense with regards to the kinematic results. However, the use of muscles co-contraction ratios provided some information to further understand trunk control during cutting maneuvers. To conclude, high-level training, whatever the athletic background, seems to allow some skill transfer on unusual tasks, like cutting maneuvers
SEX-BASED ANALYSIS OF THE BIOMECHANICS OF PITCHING
Get PDFThis study assessed sex-based differences in the lower extremity kinetics and ball velocity during pitching. Fifteen men baseball players and fifteen women softball players threw fastballs on two force platforms, to assess propulsive and landing biomechanics. Doppler radar was used to assess ball velocity. Kinetic and kinematic data comparing men and women were analyzed with independent samples t-test. Paired samples t-test were used to assess difference between the propulsive and landing phases. Pearson’s bivariate correlations were used to assess the relationship between study variables and ball velocity. Few sex-based difference in the magnitude and rate of propulsive force development exist. Sex based differences (p \u3c 0.05) were found for all but one landing phase variable. None of the biomechanical variables assessed were related to ball velocity
SPRINT MECHANICAL PROPERTIES OF PROFESSIONAL SOCCER PLAYERS DURING A MATCH SIMULATION
Get PDFThe purpose of this study was to identify soccer-specific changes of mechanical properties in sprinting during a simulated soccer match. Professional soccer players (n=15) completed six sprint measurements before, during and after a simulated soccer game (i.e. Copenhagen Soccer Test). Mechanical properties (theoretical maximal sprinting velocity (V0), theoretical maximal horizontal force (F0), maximal horizontal sprinting power (Pmax) and the 20-metre sprint time were computed from continuous velocity data captured from a laser device. The results suggest that soccer-specific fatigue affects V0 more than F0. Furthermore, there is an inactivity-induced sprint performance loss because of the half-time break. However, at the end of the game, professional players can achieve similar sprint times as in the first half. These results could be useful for effective training planning and optimizing sprint performance during a match
COMPARISON OF THE BILATERAL AND UNILATERAL BARBELL HIP THRUST
Get PDFThe purpose of this study was to quantify the kinetics and kinematics of the unilateral (UL) barbell hip thrust and compare UL biomechanics with the bilateral (BL) barbell hip thrust. Ten resistance trained males performed three sets of three repetitions UL and BL at 10 repetition maximum intensity. The biomechanics of each lift were analysed using 3D motion capture and force plates that were floor mounted and instrumented in to a bespoke rig. Joint kinetics and kinematics were calculated in the sagittal, frontal and transverse planes. It was concluded that UL loaded the hip joint to a greater extent than the BL across all three planes. The current study offers novel insight to the biomechanical demand of the unilateral hip thrust and has implications for exercise selection within the physical preparation of athletes
ISOKINETIC STRENGTH PROFILE OF FEMALE SOCCER PLAYERS: BETWEEN LIMB COMPARISONS.
Get PDFThe purpose of this study was to provide an isokinetic strength profile of female soccer players and examine whether limb preference influences bilateral and reciprocal knee joint muscle balance. Gravity corrected isokinetic (60°·s-1) concentric and eccentric moment-angle profiles of both limbs were collected from 25 female soccer players from the 2nd tier of English women’s soccer. Bilateral muscle imbalances were present, but limb preference only had small effects on muscle strength asymmetry and reciprocal muscle balance ratios. Trivial to small non-significant differences between preferred and non-preferred limbs were observed throughout isokinetic range for each muscle group in each mode, suggesting that injury mitigation strategies for female soccer players should focus on developing global knee extensor and flexor strength, rather than on regional strength deficits
THE RELATIONSHIP BETWEEN ACHILLES TENDON DIMENSIONS AND FOOT STRIKE INDEX IN REARFOOT AND NON-REARFOOT RUNNERS
Get PDFThe purpose of this study was to describe the relationship between Achilles tendon dimensions and foot strike index in rearfoot and non-rearfoot runners. 107 recreational runners were divided into a group of rearfoot (n = 88) and a group of non-rearfoot runners (n = 19). Achilles tendon dimensions were measured by a combination of ultrasonography imaging and kinematic analysis. To analyse the footfall pattern, each participant performed 8 successful trials of running at their stated self-preferred endurance speed. Partial correlation was used for statistical analysis. Runners in the group of non-rearfoot runners, whose footfall pattern is more over forefoot, have a longer and thinner Achilles tendon