To examine individual or combined effects of static stretch and explosive contraction on quadriceps spinal-reflex excitability (the peak Hoffmann’s reflex normalized by the motor-response) latency times motor-response. Fourteen healthy young males randomly experienced four conditions (stretch, contraction, + control—no intervention). For condition, three sets a 30 s hold using modified Thomas t...

The static and dynamic components of the tonic stretch reflex and shortening reactions have been studied in 10 patients with athetosis. EMG activity could be recorded only from the biceps muscle when the patient was at rest. The dynamic stretch reflex increased with the velocity of stretching in all muscles examined except the biceps. The biceps stretch reflex was found to be inhibited by incre...

An increase in mechanical load in the heart causes cardiac hypertrophy, either physiologically (heart development, exercise and pregnancy) or pathologically (high blood pressure and heart-valve regurgitation). Understanding cardiac hypertrophy is critical to comprehending the mechanisms of heart development and treatment of heart disease. However, the major molecular event that occurs during ph...

Previously we have shown that gradual changes in the structure of elastin during an elastase treatment can lead to important transition stages in the mechanical behavior of arteries. However, in vivo arteries are constantly being loaded due to systolic and diastolic pressures and so understanding the effects of loading on the enzymatic degradation of elastin in arteries is important. With biaxi...

Smooth muscle cells (SMC) are the major cellular component of the blood vessel wall and are continuously exposed to cyclic stretch due to pulsatile blood flow. This study examined the effects of a physiologically relevant level of cyclic stretch on rat aortic vascular SMC proliferation. Treatment of static SMC with serum, platelet-derived growth factor, or thrombin stimulated SMC proliferation,...

AIMS Vascular smooth muscle cell (VSMC) phenotypic modulation plays a pivotal role in atherothrombotic diseases. Thrombin generation at the surface of VSMCs and activation of integrin mechanotransduction pathways represent potential mechanisms. Here, we examine whether mechanical stretch increases thrombin generation on cultured rat aortic VSMCs. METHODS AND RESULTS The integrin α(v)β(3) anta...

During exercise, muscle mechanoreflex-mediated sympathoexcitation evokes renal vasoconstriction. Animal studies suggest that prostaglandins generated within the contracting muscle sensitize muscle mechanoreflexes. Thus we hypothesized that local prostaglandin blockade would attenuate renal vasoconstriction during ischemic muscle stretch. Eleven healthy subjects performed static handgrip before ...

AIM Mechanical forces are important regulators of cell and tissue phenotype. We hypothesized that mechanical loading and boundary conditions would influence neovessel activity during angiogenesis. METHODS AND RESULTS Using an in vitro model of angiogenesis sprouting and a mechanical loading system, we evaluated the effects of boundary conditions and applied loading. The model consisted of rat...

Several studies utilizing adult subjects have indicated that static stretching may reduce subsequent strength and power production, possibly for as long as an hour following the stretch. This observation has not been evaluated in children, nor in athletes accustomed to performing static stretches during strength/ power type training sessions. The purpose of this investigation was to determine i...