Children with secondary dystonia due to cerebral palsy (CP) often exhibit excess variability in their movements. To investigate the relationship between excess variability and single-joint control in these children, we compared their force variations during single-joint isometric tasks to age-matched controls. Subjects performed isometric biceps contractions at six target force levels scaled to...

It has been known that when a human moves its hand to a target, the trajectories becomes almost a straight line from the start point to the target. When a viscosity force field is loaded to the hand unexpectedly, it is pulled toward the force direction once and then goes back to the target. However, after the learning in the force field, the trajectory becomes a straight line again, and when th...

The purpose of the study was to determine the practice-induced adjustments in the motor-output variability and the agonist-antagonist activity that accompanied improvements in endpoint accuracy of goal-directed isometric contractions in young and old adults. Young and old adults performed 100 trials that involved accurately matching the peak of a force trajectory (25% maximum) to a target force...

A deterministic mechanical model based on physical tool parameters was used for estimating static and dynamic hand forces from kinematic measurements. We investigated the effects of target torque (25, 40, and 55 Nm) and threaded fastener joint hardness (35-, 150-, 300-, 500-, and 900-ms torque buildup time) on hand force. Estimated hand force was affected by target torque and joint hardness. Pe...

Continuous force output containing numerous intermittent force pulses is not completely smooth. By characterizing force fluctuation properties and force pulse metrics, this study investigated adaptive changes in trajectory control, both force-generating capacity and force fluctuations, as fatigue progresses. Sixteen healthy subjects (20-24 years old) completed rhythmic isometric gripping with t...

INTRODUCTION Left ventricular dysfunction is a frequent and potentially severe side effect of many tyrosine kinase inhibitors (TKI). The mode of toxicity is not identified, but may include impairment of mitochondrial or sarcomeric function, autophagy or angiogenesis, either as an on-target or off-target mechanism. METHODS AND RESULTS We studied concentration-response curves and time courses f...

The purposes of rhis study were to clarify the decreasing properties oC and to examine usefu1 measurernent tjmes fbr eyaluating muscle endurance in a comparison among various parameters using measuremcnt times of 1, 3 and 6mins and target values of 50, 75 and 100% MVC. Fifteen males and l5 femalcs participated in this study. All subjects carried out sustained isometric gripping under nine condi...

Generalized Parton Distributions (GPDs) provide information on the distribution of quarks in impact paarmeter space. For transversely polarized nucleons, these impact parameter distributions are transversely distorted and this deviation from axial symmetry leads on average to a net transverse force from the spectators on the active quark in a DIS experiment. This force when acting along the who...

The purpose of this study was to investigate the asymmetry of force fluctuation in the leg muscles during isometric knee extension and flexion. Twenty healthy males (21±2 years) performed the maximal voluntary isometric contraction (MVC) in knee extensor and flexor. On the basis of MVC measurement, the subjects performed sustained isometric knee extension and flexion for 15s at levels correspon...