ADVANCED APPLICATIONS OF MOTION ANALYSIS IN SPORTS BIOMECHANICS

Motion analysis is utilized to capture various raw linear positional data of markers placed on a body performing a movement sequence in sport. The application of motion analysis involves biomechanical modeling to calculate various kinematic and kinetic derived variables to understand the principles of motion. Since biomechanists are recruited as consultants to teams and coaches in sport teams, it is essential that they apply motion analysis to not only evaluate individual performance, but suggest methods of optimizing technique for enhanced performance and injury risk reduction. This presentation will show how advanced applications of motion analysis can lead to the biomechanical enhancement of sports performance

How the Criminal Law in Australia Has Failed to Promote the Right to Life for Unborn Children: A Need for Uniform Criminal Laws on Abortion across Australia

This article contends that human life has an intrinsic value from the moment of its conception based on its potential use to the community. This value to the community demands protection from the state. However, there is also a need to balance this aim against the legitimate health interests of pregnant women. Abortions should be permitted only in circumstances where the abortion is necessary to preserve the pregnant woman from any serious danger to her physical or mental health. This article shows that the lack of uniformity in Australia’s criminal law in the area of abortion plays a part in unduly undermining the right to life of unborn children. Accordingly, there is a need for effective uniform criminal laws throughout Australia that properly protect the right to life of unborn children and are duly sensitive to the valid health interests of pregnant women that give rise to circumstances justifying abortion

ANGULAR IMPULSE MOTION-EFFECTS ON FRONT-LEG TECHNIQUE IN CRICKET BOWLING

The purpose of this study was to analyse the joint angular impulse-effect on knee joint extension-flexion angle on a sample of bowlers, determining whether front-leg technique is predominantly dependent on local joint torques or non-local cumulative effects generated elsewhere in the kinetic link chain. Elite young fast bowlers (n=13) were recruited for a motion analysis of their bowling actions in a biomechanics laboratory. Their fast bowling actions were classified according to front-leg technique and their changes in front knee extension-flexion angle related to corresponding joint angular impulse motion-effects. The majority of bowlers (61.5%) bowled with a bent-leg lever. Only 3.4% of knee extension-flexion periods were subject to an active angular impulse motion-effect. This result implies that knee extension-flexion angle in fast bowlers is also dependent on motions occurring away from knee joint, remotely located in the kinetic link chain

MECHANICS OF THE FRONT ARM TECHNIQUE IN CRICKET FAST BOWLING

The purpose of this study was to analyse the kinetics of front arm motion in fast bowling. A sample of 34 fast bowlers was divided into four speed groups. A three-dimensional (3-D) motion analysis system was used to track and analyse the motion trajectory of forty-eight reflective markers placed on each subject to determine the kinematics of segment joint centres. Ground reaction forces were measured with a force platform. These data were used as input to a 3-D 15-segment inverse solution model of the human body, which used a Newton-Lagrange multiplier iterative method to generate the kinetics equations of motion. The calculations show that the front upper arm torques are time-varying cyclic, challenging the coaching notion recommending fast bowlers to pull the front elbow down as fast as possible into the front hip

Cricket bowling: A two-segment Lagrangian model

In this study, a Lagrangian forward solution of the bowling arm in cricket is made using a two-segment rigid body model, coupled with projectile equations for the free flight of the ball. For given initial arm positions and constant joint torques, the equations are solved numerically to determine the ball speed and arm angle at release so that the ball can land on a predetermined position on the pitch. The model was driven with kinematic data from video obtained from an elite bowler. The model can be analysed in order to study the biomechanics of the bowling arm as well as to quantify the effects of changing input parameters on the trajectory and speed of the ball

TEACHING OPTIMAL SWING MECHANICS

An optimal golf swing technique has been proposed that produces a powertul and accurate stroke while minimising the stress on the shoulders and back. However, the teaching of this technique requires specialist knowledge and training to deal with players of different abilities -from the social player to the professional. Teaching methods have been developed that differ considerably from those normally recommended in conventional golf instructio

BOWLING ARM MECHANICS IN CRICKET

The purpose of this study was to identify the biomechanics of the bowling arm in fast bowlers in cricket. A sample of 34 fast bowlers was divided into four speed groups. A 3D motion analysis system was used to track and analyse the motion trajectory of forty-eight reflective markers placed on each subject to determine the kinematics of segment joint centres. Ground reaction forces were measured with a force platform. These data were used as input to a 3D 15-segment inverse solution model of the human body, which used a Newton-lagrange multiplier iterative method to generate the dynamic equations of motion. The calculations show that the bowling arm segments undergo a sequence of active and controlled motion during the power phase, which tends to vary bowling speed