The aim of this study was to quantify kinematic, kinetic and performance changes that occur in the serve throughout a prolonged tennis match play. Serves of eight male advanced tennis players were recorded with a motion capture system before, at mid-match, and after a 3-hour tennis match. Before and after each match, electromyographic data of 8 upper limb muscles obtained during isometric maxim...

To investigate the effect of teeth clenching on isokinetic knee extension at various velocities, isokinetic muscle strength during knee extension was measured in association with teeth clenching at 30, 60, 150, 300 and 450 degrees per second (deg/s) using the Cybex 6000 isokinetic dynamometer. The volunteer subjects were 9 healthy males (26.2•} 0.97 years). The peak torque per body weight and a...

BACKGROUND The extent to which fatigue is related to the velocity of shortening is still not fully understood. OBJECTIVES To examine the effects of fatigue induced by maximal intensity exercise at different velocities on subsequent torque-velocity relations in muscle. METHODS Ten men (mean (SD) age 25 (3) years; stature 1.78 (0.34) m; body mass 80.6 (14.5) kg) provided written informed cons...

Single-unit activity in area M1 was recorded in awake, behaving monkeys during a three-dimensional (3D) reaching task performed in a virtual reality environment. This study compares motor cortical discharge rate to both the hand's velocity and the arm's joint angular velocities. Hand velocity is considered a parameter of extrinsic space because it is measured in the Cartesian coordinate system ...

The present investigation studies the behavior of steady flow of visco-elastic liquid between two porous coaxial circular cylinders, where both the cylinders are rotating with different uniform angular velocities about the common axis. In addition, the inner cylinder has uniform velocity along the axis and the visco-elastic fluid, which is a Walters liquid B′, is allowed to flow in the annulus....

We investigated accuracy in discriminating between constant and variable angular velocities for orthographic projections of three-dimensional rotating objects. The reported judgments of "constant" or "variable" angular velocity were only slightly influenced by the projected angular velocities, but they were greatly affected by the variations of the deformation, a first-order component of the op...

OBJECTIVE To evaluate normal healthy persons without spasticity to observe normal findings of the elbow stretch reflex using a newly developed, portable, hand-driven spasticity-measuring system. METHOD Thirty normal persons without any disease involving the central or peripheral nervous system were enrolled in this study. The portable hand-driven isokinetic system is able to measure the joint...