Influence of fascicle strain and corticospinal excitability during eccentric contractions on force loss.

New Findings: What is the central question of this study? Do neural and/or mechanical factors determine the extent of muscle damage induced by eccentric contractions? What is the main finding and its importance? The extent of muscle damage induced by eccentric contractions is related to both mechanical strain and corticospinal excitability measured at long muscle lengths during eccentric contractions.

Abstract: In this study, we investigated whether the mechanical and neural characteristics of maximal voluntary eccentric contractions would determine the extent of change in postexercise maximal voluntary isometric contraction (MVC) torque and muscle soreness. Eleven men performed 10 sets of 15 isokinetic (45 deg s ) maximal voluntary eccentric knee extensions.

Muscle length effect on corticospinal excitability during maximal concentric, isometric and eccentric contractions of the knee extensors.

What is the central question of this study? Does sensory input from peripheral mechanoreceptors determine the specific neural control of eccentric contractions? How corticospinal excitability (i.e. muscle responses to motor cortex stimulation) is affected by muscle length has never been investigated during eccentric contractions.

Asymmetry in Determinants of Running Speed During Curved Sprinting.

This study investigates the potential asymmetries between inside and outside legs in determinants of curved running speed. To test these asymmetries, a deterministic model of curved running speed was constructed based on components of step length and frequency, including the distances and times of different step phases, takeoff speed and angle, velocities in different directions, and relative height of the runner's center of gravity. Eighteen athletes sprinted 60 m on the curved path of a 400-m track; trials were recorded using a motion-capture system.

Degree of agreement between impulse and magnitude of momentum change for different types of movements.

This study aims to investigate the degree of agreement between the impulse and the magnitude of momentum change (MMC) for various types of movements. Six males performed five successful trials for four movements: straight jogging (SJo), 90° open cross cutting (OC), running jump for height (RJu), and curved jogging with a 5-m radius (CJo). Impulse and MMC were respectively measured using two forceplates and a 3D motion capture system with 10 infrared cameras.