INTRODUCTION Spinal manipulation therapy (SMT) is characterized by specific kinetic and kinematic parameters that can be modulated. The purpose of this study is to investigate fundamental aspects of SMT dose-physiological response relation in humans by varying SMT impulse duration. METHODS Twenty healthy adults were subjected to four different SMT force-time profiles delivered by a servo-cont...

PURPOSE To investigate the intersession reliability of selected kinematic and kinetic variables during countermovement vertical jumps (CMJs). METHODS Thirty-five men and 35 women performed CMJs on a force platform during four testing sessions each separated by 1 wk. Kinematic variables included time in the air (TIA), take-off velocity (TOV), total vertical displacement of the center of mass (...

Chromosome segregation machinery is controlled by mechanochemical regulation. Tension in a mitotic spindle, which is balanced by molecular motors and polymerization-depolymerization dynamics of microtubules, is thought to be essential for determining the timing of chromosome segregation after the establishment of the kinetochore-microtubule attachments. It is not known, however, whether and how...

impulse buying is a significant aspect of consumer behavior and a critical concept in the marketplace. dramatic increases in consumption and possibility of credit buying all over the world has provided appropriate situations for impulse buying, however there is little information about impulse buying in eastern and in transition societies and economies. the purpose of this study is to develop a...

BACKGROUND We examined the effect of four weeks of β-alanine supplementation on isometric endurance of the knee extensors at 45% maximal voluntary isometric contraction (MVIC). METHODS Thirteen males (age 23 ± 6 y; height 1.80 ± 0.05 m; body mass 81.0 ± 10.5 kg), matched for pre-supplementation isometric endurance, were allocated to either a placebo (n = 6) or β-alanine (n = 7; 6.4 g·d-1 over...

The purpose of this brief review is to explain the mechanical relationship between impulse and momentum when resistance exercise is performed in a purposefully slow manner (PS). PS is recognized by ~10s concentric and ~4-10s eccentric actions. While several papers have reviewed the effects of PS, none has yet explained such resistance training in the context of the impulse-momentum relationship...

This study aimed to investigate whether high peak ground reaction forces and high average loading rates are necessary to bowl fast. Kinematic and kinetic bowling data were collected for 20 elite male fast bowlers. A moderate non-significant correlation was found between ball speed and peak vertical ground reaction force with faster bowlers tending to have lower peak vertical ground reaction for...

Sacral marker and pelvis reconstruction methods have been proposed to approximate total body center of mass during relatively low intensity gait and hopping tasks, but not during a maximum effort vertical jumping task. In this study, center of mass displacement was calculated using the pelvic kinematic method and compared with center of mass displacement using the ground-reaction force-impulse ...

Dynamics and Impact Control of a Flying Soccer Ball Jae Yeon Choi and Byung-Ju Yi School of Electrical Engineering and Computer Science, Hanyang University, Ansan 426-791 (Received 12 August 2008, in nal form 31 October 2008) This paper deals with the dynamics and the impact control of a soccer ball driven by a kicking robot. The trajectory of the ball is a function of its initial velocity, lau...

We report on 2D collision experiments with 9 thin Delrin disks with variable axisymmetric mass distributions. The disks floated on an air table, and collided at speeds of about 0.5 to 1.0 m/s with a flat-walled stationary thick steel plate clamped to the table. The collision angle was varied. The observed normal restitution was roughly independent of angle, consistent with other studies. The fr...