ISBS (International Society of Biomechanics in Sports): Conference Proceedings Archive
Not a member yet
5464 research outputs found
Sort by
THE EFFECTS OF COMPRESSION SHORTS ON MUSCLE OSCILLATION AND LONG JUMP PERFROMANCE
Get PDFCompression garments were used to explore their effect on athletic performance and muscle oscillation during a 3-step long jump task. The study consisted of a 3 dimensional kinematic analysis (Vicon Motus 9.2) with force data collected by a Kistler force platform. Ten male subjects performed 6 jumps under 2 conditions, bare leg (control condition) and with the compression shorts. Two-tailed paired samples T-test were conducted to discover significant changes in the measures of Muscle Oscillation (MO), Peak Vertical Ground Reaction Force (PVGRF), Peak Horizontal Ground Reaction Force (PHGRF) and Jump Length. The findings of the study suggest that long jump performance can be increased (.18m) while wearing compression shorts, although the legs ability to disperse force may be reduced by the garment
A KINEMATIC ANALYSIS OF THE BACKWARD 2.5 SOMERSAULTS WITH 1.5 TWISTS DIVE (5253B) FROM THE 3M SPRINGBOARD
Get PDFThe aim of this case study was to determine the practical application of 3D inertial measurement units and compare angular velocity profiles, key position angles and event timings for the backward 2½ somersaults with 1½ twists (5253B). One male diver performed 11 trials of the 5253B while 3D inertial measurement units (IMU) and high speed video were used to measure kinematic variables. Peak angular velocity about the somersault and twist axes were 900±11deg/s and -1435±28.deg/s, with highly consistent patterns displayed for total flight time
KINETIC ANALYSIS OF THE UPPER LIMBS IN BASEBALL TEE-BATTING UNDER LOW HITTING POINT HEIGHT CONDITION
Get PDFHitting low height balls is more difficult for baseball batters in comparison to hitting high and middle height balls. The purpose of this study was to investigate the kinetic features of the individual upper limb joints among different skill level players in baseball tee-batting under the low hitting point height condition. Twenty-three collegiate baseball players were instructed to hit three kinds of hitting point height balls. Kinematic and kinetic analyses were implemented together with a motion capture system and an instrumented bat. The findings indicate that highly skilled batters exert great extension torque of the barrel-side (top hand) shoulder joint in the first half of the forward swing period in order to hit low point height balls. It is speculated that the large initial flexion angle of the barrel-side shoulder joint can help to increase the torque and angular velocity of the shoulder joint
DEVELOPMENT AND EVALUATION OF A METHOD TO QUANTIFY RUGBY PLACE KICK PERFORMANCE FROM INITIAL BALL FLIGHT DATA
Get PDFThe purpose of this study was to develop and evaluate a method for quantifying rugby place kick performance using a metric that represents field-based performance but relies only on data typically available within a laboratory setting. A mathematical model was developed to predict the flight path of a rugby ball using equations of projectile motion and initial ball flight kinematics as inputs. The accuracy of the model predictions were then evaluated against empirical data collected from eight place kicks taken 22 m from the goalposts on a rugby pitch. The model estimated the position of the ball at the instant it reached the goalposts with a root mean square error of 0.65 m (2.9% of the range). It is intended that this method will provide an applied outcome measure that is relevant to players and coaches
KINETIC ASYMMETRY AND CENTER OF MASS DISPLACEMENT DURING JUMPS
Get PDFThe purpose of this study was to determine the role of kinetic asymmetry on center of mass displacement in both mediolateral (COMd ML) and anteroposterior directions (COMd AP). Seventeen collegiate baseball players underwent weight distribution (WtD), and unloaded and loaded static (SJ) and countermovement jumps (CMJ). Concurrent kinetic and kinematic data were collected during the evaluation. Independent samples t tests were run to evaluate differences in COMd between the most and least asymmetrical athletes. WtD was not able to differentiate between values of COMd AP, but did for loaded conditions of COMd ML. Peak force and rate of force development (RFD) asymmetry appear to influence COMd, and RFD asymmetry appears to show the most differentiability between groups in terms of COMd ML. Kinetic asymmetry may result in undesirable displacement of athletes’ COM during jumping
A CASE STUDY OF MAXIMUM VELOCITY SPRINT RUNNING PERFORMANCE AND TECHNIQUE CHANGES WITHIN AN ELITE TRAINING GROUP
Get PDFThe purpose of this study was to identify the effect of a structured training programme on sprint performance and technique in three individual experienced sprinters. Velocity, step length, step frequency, temporal variables and segment angles were gathered from 50 m maximal sprints before and after two high volume four-week training blocks. Participantspecific analyses revealed that athletes’ performance responded differently to training. Changes in velocity between sessions were attributable to different underlying variables across athletes, which matched with expectations based upon coaching observations. These findings have important implications for the design of sprint training programmes and for the timing of applied biomechanical data collection sessions for the purpose of analysis and feedback to coaches and athletes
AN INVESTIGATION OF FULL BODY KINEMATICS FOR STATIC AND DYNAMIC THROW-IN IN PROFICIENTPROFICIENT AND NON-PROFICIENTPROFICIENT SOCCER PLAYERS WHEN THEY TRIED TO HIT A SPECIFIC TARGET
Get PDFThe purpose of this study was to identify the kinetic differences between proficient and non-proficient players during one ability: Throw-in. Twelve players were recruited from the local university to perform the experiment. Many studies have been conducted to explain the biomechanics of this ability, however there is about a lack of research, investigating the comparison between proficient and non-proficient players. The hypotheses of this study were that a) peak knee flexion angles would be higher for dynamic style for proficient and less proficient subjects, and b) peak vertical ground reaction force (GRF) would be higher for the dynamic style. Our results showed a markedly difference in the peak flexion angles for proficient players. The results may be useful to develop training strategies to help to the players to achieve precise throws
CHANGES IN PRINCIPAL COMPONENT STRUCTURE OF COUNTERMOVEMENT JUMPS AFTER A VOLLEYBALL SEASON
Get PDFThe purpose of this study was to investigate changes in the principal component structure of countermovement jumps (CMJ) in female volleyball players over the course of a competitive season. Eleven NCAA Division I female volleyball players performed CMJs on a force plate before and after a competitive season. Discrete biomechanical variables were extracted from the force-time records of all CMJs and entered into a factor analysis. The analysis yielded two factors that could account for the biomechanical structure of the CMJs: a temporal and a force factor. Although no differences in factor scores were identified between pre- and post-season testing sessions, sub-group analysis highlighted large individual changes in temporal and force factor scores
RELEVANCE, RELIABILITY AND LIMITATIONS OF A DROP AND STICK LANDING ANALYSIS
Get PDFThe vertical force data from a drop and stick landing can be used to derive a number of variables. Previous studies have generally focused on the time to stabilization and peak force aspects, and issues related to reliability have been reported. This study investigated reliability for time to stabilisation, peak force, time to peak force, stiffness, rate of force dissipation, impulse and eccentric power (EP) among five professional elite surfing athletes. This data was also compared to data of aerial success in World Championship Tour competitions. The results revealed the best relationship between relative stiffness as well as eccentric power and completion rate of aerial manoeuvres. Further, eccentric power had the best reliability of the variables and may therefore be an interesting variable to study further
CORRELATIONS BETWEEN HEAD ROTATIONAL KINEMATICS AND BRAIN TISSUE STRAIN FOR LOW AND HIGH LEVEL FOOTBALL HELMET IMPACTS
Get PDFThis study examined the correlation between head angular velocity and acceleration with brain strain for low and high level impacts. Impacts at 2.4m/s (low) and 11m/s (high) were delivered to a American football helmeted Hybrid III headform using a centric/non-centric protocol. A finite element model calculated strain from headform accelerations. The lowlevel impact data were obtained from a previous subset eliciting angular responses occurring at 20g, therefore linear acceleration relationships were not examined. High correlations (r=>0.8) existed for non-centric conditions between strain with angular acceleration and velocity, while centric conditions had moderate relationships (r=0.50.68). This research demonstrates that kinematic-strain relationships are dependent on the impact event, and that a single variable may not represent strain under all conditi