BACKGROUND The trapeziometacarpal joint is subjected to high compressive forces during powerful pinch and grasp tasks due to muscle loading. In addition, muscle contraction is important for stability of the joint. The aim of the present study is to explore if different muscle activation patterns can be found between three functional tasks. METHODS Isometric forces and fine-wire electromyograp...

GRAY, SARAH, D., AND NORMAN C. STAUB. Resistance to bloodJEow in leg muscles of dog during tetanic isometric contraction. Am. J. Physiol. 213(3): 677-682. 1967.~We have reinvestigated the effects of tetanic, isometric leg muscle contraction in anesthetized dogs on the resistance to blood flow. In 19 of 20 dogs vascular resistance increased during the contraction. There appear to be two phases o...

BACKGROUND The Advanced Throwers Ten Exercise Program incorporates sustained isometric contractions in conjunction with dynamic shoulder movements. It has been suggested that incorporating isometric holds may facilitate greater increases in muscular strength and endurance. However, no objective evidence currently exists to support this claim. HYPOTHESIS/PURPOSE The purpose of this research wa...

The extra heat liberation accompanying muscular shortening, the force-determined shortening heat, is defined as the difference between the heat produced when shortening occurs and that produced in an isometric contraction developing the same amount of force and performing the same amount of internal work. Based on this definition, the initial energy production in twitches and tetanic contractio...

background : previous studies have investigated different effects of muscle fatigue on body systems. however, there are no reports on the effect of fatigue protocol and its level on musculotendinous stiffness (mts) of the tricep-surae. this study was designed to compare the effects of 2 levels of submaximal fatigue contraction on mts of triceps-surae. methods: twenty female students by simple r...

Oscillatory activity of the sensorimotor cortex shows coherence with muscle activity within the 15- to 35-Hz frequency band (β-band) during weak to moderate sustained isometric contraction. We aimed to examine the acute changes in this corticomuscular coupling due to muscle fatigue and its effect on the steadiness of the exerted force. We quantified the coherence between the electroencephalogra...

[Purpose] This study attempted to identify how genu varum or valgum affects the electromyographic activities of the vastus medialis, vastus lateralis, and rectus femoris during knee isometric contraction. [Subjects] Fifty-two healthy young adults were enrolled in this study. They were enrolled and classified into three groups by knee alignment conditions: the genu varum, genu valgum, and contro...

[Purpose] This study investigated the changes in the slope of EMG-time curves (relationship) at the maximal and different levels of dynamic (eccentric and concentric) and static (isometric) contractions. [Subjects and Methods] The subject was a 17 year-old male adolescent. The surface EMG signal of the dominant arm's biceps brachii (BB) was recorded through electrodes placed on the muscle belly...

Simple devices are described that can facilitate student experiments on mechanical and electrical aspects of muscle contraction, for example, of isolated preparations such as frog gastrocnemius and sartorius muscles and gut. The system includes a general-purpose preparation bath that was previously described for electrophysiological observations with suction electrodes [D.M. Easton. Am.J. Physi...