279 research outputs found
RELATIONSHIPS BETWEEN HITTING TECHNIQUE AND BALL CARRY DISTANCE IN CRICKET
The aim of this study was to identify the technique parameters characterising batsmen who generate large carry distances, ball launch speeds, and bat speeds during a range hitting task in cricket. Kinematic data were collected for 20 batsmen, and a series of ball launch, impact, and technique parameters were calculated for each trial. A regression analysis found impact location relative to the sweetspot and bat speed together to explain 70% of the observed variation in ball speed. A further regression analysis found the maximum X-factor (the separation between the pelvis and thorax segments in the transverse plane), front elbow extension, and wrist uncocking during the downswing explained 66% of the observed variation in bat speed. These findings will be useful in coaching more effective hitters, and in assessing the mechanics of generating bat speed
The effects of different delivery methods on the movement kinematics of elite cricket batsmen in repeated front foot drives
The aim of this paper was to examine differences in delivery characteristics and the resulting response exhibited by ten elite
cricket batsmen when hitting repeated front foot drives against three different ball delivery methods; a bowling machine, a
Sidearmâ„¢ ball thrower and a bowler. Synchronous three-dimensional Vicon motion capture technology and high-speed video
were used to track batsman, bat and ball motion, and a range of discrete timing and kinematic variables were extracted from the
resulting biomechanical model. Results showed significant differences in speed and ball release-to-impact time between the
three delivery methods, thus questioning the validity of the bowling machine and Sidearmâ„¢ in the way they are currently used
as true representations of batting against a real life bowler. Findings from the timing and kinematics of the subjects’
movements suggest a different technical response is also exhibited when facing the different delivery methods; for example
batters were found to initiate movement earlier and have a lower maximum bat speed against the bowling machine, but initiate
and complete their front foot stride earlier as well as moving their COM further forward in the Sidearmâ„¢ trials.
© 2014 The Authors. Published by Elsevier Ltd
The effects of different delivery methods on the movement kinematics of elite cricket batsmen in repeated front foot drives
The aim of this paper was to examine differences in delivery characteristics and the resulting response exhibited by ten elite
cricket batsmen when hitting repeated front foot drives against three different ball delivery methods; a bowling machine, a
Sidearmâ„¢ ball thrower and a bowler. Synchronous three-dimensional Vicon motion capture technology and high-speed video
were used to track batsman, bat and ball motion, and a range of discrete timing and kinematic variables were extracted from the
resulting biomechanical model. Results showed significant differences in speed and ball release-to-impact time between the
three delivery methods, thus questioning the validity of the bowling machine and Sidearmâ„¢ in the way they are currently used
as true representations of batting against a real life bowler. Findings from the timing and kinematics of the subjects’
movements suggest a different technical response is also exhibited when facing the different delivery methods; for example
batters were found to initiate movement earlier and have a lower maximum bat speed against the bowling machine, but initiate
and complete their front foot stride earlier as well as moving their COM further forward in the Sidearmâ„¢ trials.
© 2014 The Authors. Published by Elsevier Ltd
THE EFFECT OF DELIVERY METHOD ON CRICKET BATTING UPPER-BODY KINEMATICS
The aim of this study was to determine the effect of delivery method on upper-body kinematics in cricketers playing a front foot drive and a back foot pull shot. Fourteen male cricketers were played both shots against a bowler, bowling machine, and SidearmTM ball thrower. The availability of pre-release visual cues appears to affect upper-body kinematics during the pull shot but not the drive other than at the back shoulder. The SidearmTM may represent a compromise between bowler and bowling machine when training the pull shot but coaches should consider differences in upper-body proximal-distal joint dominance
The relationships between impact location and post-impact ball speed, bat torsion, and ball direction in cricket batting
Three-dimensional kinematic data of bat and ball were recorded for 239 individual shots performed by twenty batsmen ranging from club to international standard. The impact location of the ball on the bat face was determined and assessed against the resultant instantaneous post-impact ball speed and measures of post-impact bat torsion and ball direction. Significant negative linear relationships were found between post-impact ball speed and the absolute distance of impact from the midline medio-laterally and sweetspot longitudinally. Significant cubic relationships were found between the distance of impact from the midline of the bat medio-laterally and both a measure of bat torsion and the post-impact ball direction. A ‘sweet region’ on the bat face was identified whereby impacts within 2 cm of the sweetspot in the medio-lateral direction, and 4.5 cm in the longitudinal direction, caused reductions in ball speed of less than 6% from the optimal value, and deviations in ball direction of less than 10° from the intended target. This study provides a greater understanding of the margin for error afforded to batsmen, allowing researchers to assess shot success in more detail, and highlights the importance of players generating consistently central impact locations when hitting for optimal performance
Energy downconversion between classical electromagnetic fields via a quantum mechanical SQUID ring
We consider the interaction of a quantum mechanical SQUID ring with a classical resonator (a parallel LC tank circuit). In our model we assume that the evolution of the ring maintains its quantum mechanical nature, even though the circuit to which it is coupled is treated classically. We show that when the SQUID ring is driven by a classical monochromatic microwave source, energy can be transferred between this input and the tank circuit, even when the frequency ratio between them is very large. Essentially, these calculations deal with the coupling between a single macroscopic quantum object (the SQUID ring) and a classical circuit measurement device where due account is taken of the nonperturbative behavior of the ring and the concomitant nonlinear interaction of the ring with this device
Towards a complete and continuous Wigner function for an ensemble of spins or qubits
We present a new quasi-probability distribution function for ensembles of spin-half particles or
qubits that has many properties in common with Wigner's original function for systems of continuous
variables. We show that this function provides clear and intuitive graphical representation of a
wide variety of states, including Fock states, spin-coherent states, squeezed states, superpositions
and statistical mixtures. Unlike previous attempts to represent ensembles of spins/qubits, this
distribution is capable of simultaneously representing several angular momentum shells
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