The muscle forces and stresses occurring during normal locomotor activity in kangaroo rats are compared with the peak isometric force developed by the same muscles in situ. Two methods were used simultaneously to determine the stresses (force/cross-sectional area) acting in the ankle extensors during steady-speed hopping and during jumps when animals were startled: a direct measurement using a ...

Linnamo, Vesa Motor unit activation and force production during eccentric, concentric and isometric actions Jyväskylä: University of Jyväskylä, 2002, 77 p. (Studies in Sport, Physical Education and Health, ISSN 0356-1070; 82) ISBN 951-39-1162-4 Finnish summary Diss. The aim of the present series of studies was to examine force and myoelectrical activity in human forearm flexors and knee extenso...

The aim of the present study was to investigate memory effects, force accuracy, and variability during constant isometric force at different force levels, using auditory biofeedback. Two types of transition trials were used: a biofeedback-no biofeedback transition trial and a no biofeedback-biofeedback transition trial. The auditory biofeedback produced a low- or high-pitched sound when partici...

The effects of the naturally occurring amino acid taurine (2-aminoethanesulphonic acid) on isometric force development were investigated using skinned muscle fibre preparations. In atrial and ventricular pig heart muscles, as well as in fibres of slow abdominal extensor muscle of crayfish, an increase of submaximal isometric force was observed in Ca2(+)-activated skinned fibre preparations at p...

Isometric force developed by skinned gizzard muscle fiber bundles and levels of phosphorylation and thiophosphorylation of the 20,000-dalton myosin light chain were determined. These data showed a highly non-linear relationship between isometric force and myosin light-chain phosphorylation. Maximum force was developed at approximately 0.2 mol of phosphate/mol of light chain as reported previous...

INTRODUCTION Losses in muscle mass and strength may affect an astronaut's safety; therefore, it is of utmost importance to optimize countermeasures to minimize atrophy and strength loss during spaceflight. The main purpose of this study was to determine if high force eccentric or isometric contractions performed by the plantar flexor group during hind limb suspension would preserve muscle mass ...

It has been observed consistently and is well accepted that the steady-state isometric force after active muscle stretch is greater than the corresponding isometric force for electrically stimulated muscles and maximal voluntary contractions. However, this so-called force enhancement has not been studied for submaximal voluntary efforts; therefore, it is not known whether this property affects ...

Isometric impulse frequencies associated with active tremor and force regulation were examined in 10 patients with idiopathic Parkinson's disease (PD) and in 10 older adults (OAs) who performed an isometric tracing task. The authors decoupled and analyzed the data to determine whether PD-related tremor in the thumb and in the index finger during isometric force control are related and whether P...

The decline in isometric force, swelling of sarcoplasmic reticulum and loss of desmin was measured in semimembranosus lateralis muscle of male Wistar rats immediately after a short series of brief (500 ms) maximal isometric contractions. For the active muscle, the series ended below (protocol A) and just over muscle optimum length (protocol AA). In one protocol, the muscle remained passive and ...

INTRODUCTION This study evaluates the complexity of force and surface electromyography (sEMG) during knee extension and flexion at low-level isometric contractions in individuals with different degrees of diabetic peripheral neuropathy (DPN). METHODS Ten control and 38 diabetic participants performed isometric contractions at 10%, 20%, and 30% of maximal voluntary contraction. Knee force and ...