CLUSTER ANALYSIS OF SPEED RUN, BOUNDING RUN AND SKIPPING EXERCISES

The purpose of this study is to find analogies and differences among 3 different skills: speed run and two special exercises (bounding run and skipping). Three correlation patterns have been created, each for one of the 3 skills, every pattern takes origin by multivariate analysis (cluster analysis), using the same 12 variables. All these variables (spatial, temporal and kinematic) are relative to the Center of Mass (COM). Eight athletes were analyzed and the system used to get the data was the Vicon Motion System (3D optoelectronics system). The analysis has shown that only few variables of the 3 patterns are correlated in the same way, these few variables must to be taken into consideration to develop the running performance through these special exercises

ON-BOARD AND PRE-FLIGHT MECHANICAL MODEL OF YURCHENKO ONE TWIST ON VAULT: IMPLICATIONS FOR PERFORMANCE

The aim of this study was to point out the biomechanical explanation of the judges’ detection of scores relative to the on-board and pre-flight phases of the Yurchenko vault with one twist on (table). In an attempt to identify the weakness of technique and then to diagnose the likely causes of a poor performance, an extensive analysis was undertaken using a deterministic model. The 4 female gymnasts performing YU vault one twist on during the 2006 Italian Championship for Clubs were filmed by three cameras operating at 100Hz. Spearman’s correlation coefficient was used to establish the strength of the relationship between the mechanical variables of the model and the judges` detection of points. Significant correlations indicated that the loss of credit depended mostly on angular variables. Firstly, low angular velocity of the center of mass (CM) at the impact of the board, then the small angular displacement of CM and high shoulder angular velocity produced on board and finally, a smaller hip extension and a larger shoulders extension at the take off from the board. In addition, other vertical variables determined a worst result: the lack of height of the CM at takeoff from the board, the decreased displacement of the CM on the board and the loss of the vertical velocity on the board

KINEMATIC AND DYNAMIC ANALYSIS OF SPRINT START

Aims of this study were the tuning of the methods for kinematic and dynamic analysis of sprint start and the assessment of their relevance for field practice. Data collection was performed by means of an Elite Motion Analysis System (two cameras,3D) at 100 Hzi and a Kistler force platform (type 9281b ) at 500 Hz. Three elite athletes participated in the study; each subject performed three trials. statistical analysis ( ONEWAY ANOVA - SPSSPC software package) was performed in order to highlight significant differences ( F>0.05 ) between the subjects. The start movement was divided into three temporal phases: release of the starting block, landing on first supported push off from platform. significant differences were observed with respect to hip horizontal linear velocity within these phases (F > 0.02-0.001-0.0003) between the subjects. In order to give a complete description of the movement pattern four groups of variables were selected: 1)LINEAR DISPLACEMENTS. Eighteen variables were studied ; thirteen of them show significant differences index of different positions on the starting blocks -and different movement pattern during push-of f . 2)ANGULAR DISPLACEMENTS. Thirty-five variables were selected; eighteen show significant differences. 3) LINEAR AND ANGULAR-VEMCITIES Of the 54 variables studied (20 linear var. and 34 angular var.) , 38 (13 linear var. and 15 angular var. ) shows significant differences. 4)DYNAMIC DATA. We studied 62 variables, 26 of which showed significant differences. Exit velocity from starting blocks is influenced by the force produced during the first support phase and by the kinematics of the body segments. The different results obtained by the athletes in hip horizontal velocity, can be explained with the significant differences observed with respect to kinematic and dynamic of the phases of start studied. Main variables that shows significant differences are: hip, knee and ankle peak angular velocities, duration of first support phase and joint moments during push-off from first support phase. These variables seems to be logically related with the index of performance,hip horizontal velocity

Inflammatory and Adipose Response in Solid Organ Transplant Recipients After a Marathon Cycling Race

Abstract Background Organ transplant recipients frequently have chronic inflammation, with a weighty impact on cardiovascular risk. These patients can benefit from exercise, although the role of intense training is unclear. We evaluated the effect of a 130-km cycling race on inflammatory cytokines and adiponectin levels in transplant recipients. Methods Circulating interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and adiponectin were assayed in 35 healthy subjects vs 19 transplant recipients (10 kidney, 8 liver, 1 heart), matched for sex, age, body mass index, and preparation workout. The determinations were performed before the race, at the end, and after 18 to 24 hours. Baseline values of 32 sedentary transplant recipients also were evaluated to explore the possible chronic impact of lifestyle. Results All cyclists had 6- to 8-fold increased IL-6 levels after the race that decreased, without returning to baseline, the day after. Conversely, serum TNF-α and IFN-γ showed a progressive increase starting during physical performance and enduring for the next 18 to 24 hours in healthy subjects, whereas they were unchanged over time in cyclists with transplants. In transplant recipients who did not perform exercise, all of the analytes were significantly higher in comparison to basal levels of physically active subjects. Conclusions Our data suggest that clinically stable and properly trained transplant recipients can safely perform and progressively benefit from exercise, even at a competitive level. The changes in inflammation parameters were temporary and parallel with those of the healthy subjects. The comparison with sedentary transplant recipients revealed an overall amelioration of inflammatory indexes as a possible effect of regular physical activity on systemic inflammation

Evaluation of Rapidity in Karate

Introduction Rapidity is an important ability of many sports, in karate it becomes a performance\u2019s conclusive factor and it is important to study this ability. The purpose of this study is to compare groups of karate apprentices with male and female Sport Science Faculty students using general and karate specific tests. We will try to underline the possible differences on reaction time between the expertise levels and also between genders. Methods The examined sample contains: 16 males (MS) and 14 females (FS) students, and 6 males (MK) and 5 females (FK) karate apprentices from two clubs. The average ages are (MS 22.4 yr; FS 21.5 yr; MK 20,8 yr; FK 20,4 yr). The average anthropometric data are: weight (Kg) MS 75.5; FS 54.5; MK 77,8; FK 55,8, height (cm) MS 177.8; FS 161.5; MK 178,8; FK 163,6), arm\u2019s length (cm) MS 62,8; FS 57,1; MK 61,7; FK 57,0. The following tests have been used for rapidity evaluation: 1) Drop test, following Lehman\u2019s indications, that appraises the contact time (seconds*10-3) on electric footboard on the ground, after a fall of 20 cm. 2) Tapping test to detect of two feet cyclic frequency (Hz). 3) Punch simplex test, that consists of voluntary execution of karate punch technique (gyaco-tzuki) recorded using a punch-bag fitted without stimulus. The punch-bag was hung so that the centre was set at the height of the subject\u2019s solar plexus (Layton). The measurement was made in seconds*10-2 from start with photocells and stop with shoot detector. 4) Punch reflex test, an execution of the same technique after a light stimulus. An independent samples T test was used to discover the significant differences between groups. Results Drop test, tapping test, punch simplex don\u2019t show significant differences between groups. The average values are: Drop test 0,160\ub10,022 s, Tapping test 11,6\ub11,3 Hz. Calculating the rapidity quotient, as proposed by Lehmann (QR=tap. freq./drop), the average value is 73,9\ub112,8. Punch simplex test 0,479\ub10,069 s. Punch reflex test 0,429\ub10,095 s. In this case there are significant differences between male experts (0,498 s) and students (0,374 s), and between male and female (0,493 s) students. Conclusions The results, particularly in the last test, show that students are faster than experts. Students\u2019 better results can be explained thanks to the atypical starting signal and the different movement execution in its preparatory phase. This conclusion agrees to Mori S. et al. statement. References Layton C., \u201cReaction movement time and sidedness in Shotokan Karate Students\u201d (Perceptual and Motor skill n\ub0 76 ,1993, p 765-766) Mori S., Ohtani Y.,Imanaka K., \u201cReaction time and anticipatory skills of karate athletes\u201d (Hum. Mov. Science. n\ub0 21, 2002, p. 231-230), Lehmann,F. \u201cZur Beziehung zwischenSchnelligkeit als neuromusk\ufclare Leistungss-voraussetzung und maximaler Laufgeschwindikeit im sprint Nachwuchstraining\u201d Leistungssport, 21,4, 1992 p. 13-19