Mathematical muscle models are required to better understand biomechanical behaviour and to develop strategies for simulation, motion synthesis or motor control during clinical restoration of movement for paralysed limbs through functional electrical stimulation (FES). A muscle model has to predict accurately the force output under physiological operating conditions. But very few models are abl...

Postnatal transitions in myosin heavy chain (MHC) isoform expression were found to be associated with changes in both isometric and isotonic contractile properties of rat diaphragm muscle (Diam). Expression of MHCneo predominated in neonatal Diam fibers but was usually coexpressed with MHCslow or MHC2A isoforms. Expression of MHCneo disappeared by day 28. Expression of MHC2X and MHC2B emerged a...

The active state describes the force developed in a muscle when the contractile elements are neither lengthening nor shortening. Recently it was suggested that perturbations used to measure the active state also alter the time-course of the active state. The present research was undertaken to assess quantitatively the effect of two such perturbations, isotonic shortening and quick release, on t...

BACKGROUND Few interventions reduce patellar tendinopathy (PT) pain in the short term. Eccentric exercises are painful and have limited effectiveness during the competitive season. Isometric and isotonic muscle contractions may have an immediate effect on PT pain. METHODS This single-blinded, randomised cross-over study compared immediate and 45 min effects following a bout of isometric and i...

Contraction of smooth muscle tissue involves interactions between active and passive structures within the cells and in the extracellular matrix. This study focused on a defined mechanical behavior (shortening-dependent stiffness) of canine tracheal smooth muscle tissues to evaluate active and passive contributions to tissue behavior. Two approaches were used. In one, mechanical measurements we...

BACKGROUND Reductions in detrusor shortening velocity and detrusor contractility have been observed in association with aging. The reasons for these changes are unclear. METHODS We examined the isometric and isotonic responses of detrusor, taken from the bladder body, to adenosine 5'-triphosphate (ATP), noradrenaline (NA), serotonin, and acetylcholine (Ach) in vitro, using bladders from young...

Smooth muscle cells of the frog iris sphincter contain rhodopsin and contract in response to light. The mechanism of light-evoked contraction was studied with particular attention paid to the role of calcium. The contractile proteins of the sphincter smooth muscle cell can be activated by an increase in intracellular calcium. Light-evoked contraction, however, is not accompanied by a measurable...

HYPOTHESIS Fibroblasts, not myofibroblasts, are responsible for wound contraction. Only myofibroblasts express a smooth muscle actin for which vanadate blocks its expression. Wound contraction in vanadate-treated rats will proceed normally in the absence of myofibroblasts. DESIGN Laboratory study using rats. METHODS Wound healing in rats receiving vanadate parenterally, an inhibitor of tyro...

The crude extract of Carthamus oxycantha (Co.Cr) was studied in vitro for its possible spasmogenic and spasmolytic activities. Segments of isolated rabbit jejunum 2-3 cm long were mounted in Tyrode’s solution and aerated with 95% oxygen in carbon dioxide. Isotonic responses were measured on Bioscience oscillograph. Isotonic responses were measured on Bioscience oscillograph. Co.Cr caused dose-d...