Search results for "ORC"
showing 10 items of 4623 documents
Neuromuscular fatigue induced by an isotonic heavy-resistance loading protocol in knee extensors.
2009
Abstract The main aim of this study was to assess neuromuscular fatigue during a typical high-load, low-repetition loading protocol. Muscle stimulations were used to assess maximum voluntary contraction, resting single- and double-pulse twitch characteristics, and superimposed double-pulse twitch force (used to calculate voluntary activation) before and after an acute knee extension loading protocol. In our participants, who had previous resistance training experience, the mean voluntary activation level was 96.2% in an unfatigued state. Maximum voluntary contraction (−11.8%), resting double-pulse twitch force (−10.6%), and voluntary activation (−2.1%) were markedly decreased as a consequen…
Neuromuscular Differences Between Endurance-Trained, Power-Trained, and Sedentary Subjects
2003
This study tested the hypothesis that neuromuscular characteristics of plantar flexor (PF) and knee extensor (KE) muscles explain differences of both performance in vertical jump and maximal voluntary isometric contraction (MVC) between endurance-trained (END, n = 9), power-trained (POW, n = 8), and sedentary subjects (SED, n = 8). Evoked twitch characteristics of PF and KE were measured. MVC, maximal voluntary activation (%VA) of KE, and performance in vertical jump were also measured. POW have higher maximal rate of twitch force development (MRFD) than SED and END for both PF (p < 0.05) and KE (p < 0.01); %VA and MVC were higher for POW and END than SED (p < 0.01). Higher performances wer…
Experience in the long term use of new antiarrhythmic drugs.
1985
Meinertz et a1. (1984) investigated the long term efficacy and tolerability of flecainide in patients with ventricular arrhythmias. 15 patients were studied, 8 women and 7 men, aged 19 to 74 (mean 58.7) years, with more than 30 ventricular premature complexes (VPCs) per hour, and ventricular arrhythmias of Lown grade IVA or IVB. 11 had coronary artery disease and 2 had idiopathic dilated cardiomyopathy. Patients were excluded on the basis of sustained ventricular tachycardia (VT) [defined as ~ 3 consecutive beats at a rate of> 100 beats/min]; myocardial infarction within the last 6 months; unstable angina; severe congestive heart failure; or conduction abnormalities. Previously unsuccessful…
The role of anticipatory postural adjustments during whole body forward reaching movements
1998
THE purpose of this study was to examine the role of anticipatory postural adjustments (APAs) in the execution of forward oriented whole body reaching movements. From the standing position, eight healthy subjects were asked to reach an object placed at 45 cm from the feet, at both naturally paced and fast speeds. Electromyographic signals of six antagonistic muscles were analysed in conjunction with centre of mass (CM) displacements, centre of foot pressure displacements and resultant ground reaction forces. Results revealed that APAs created necessary angular momentum of body segments for effective task execution. These results suggest that APAs can initiate movements conducted from a fixe…
Fertility in males after childhood, adolescent, and adult inguinal operations
2018
Abstract Background/purpose Inguinal hernia repair and orchidopexy are among the most common operations in boys. The impact on future fertility has not been conclusively defined. This study evaluates sperm quality after previous inguinal surgery. Methods Spermiograms of men with a desire to conceive children were analyzed. History of previous inguinal surgery (hernia repair, orchidopexy, varicocele ligation) was correlated with sperm quality. Other influential factors (age, BMI, chronic medication, tobacco use) were also tested. Results A total of 333 patients were included. Overall, 12.6% of the subjects had undergone previous inguinal surgery. Of these, 17 (43%) were inguinal hernia repai…
Electromyographic and patient-reported outcomes of a computer-guided occlusal adjustment performed on patients suffering from chronic myofascial pain
2014
Objectives: Muscular hyperactivity is a potential source of symptoms in patients with temporal-mandibular disorders. An adequate occlusal adjustment may relieve such symptoms. This study aims to measure the effect of shortening the protrusive disclusion time (DT) and balancing the center of occlusal forces (COF) on the EMG recordings and assess the pain reported by chronic patients one month after the computer-guided occlusal adjustment. Study Design: The sample studied comprised 34 patients suffering from chronic facial pain in which the EMG activity of both masseters was recorded by electromyography. By selective grinding we alleviated all the occlusal interferences during the mandibular …
Trismus resulting from central nervous system lesion.
1976
Three cases of unusual trismus are reported, occurring in patients with lesions of the central nervous system. On the basis of the clinical and electromyographical findings and observation of the course of the trismus this is interpreted as a symptom of a lesion of the brain stem, causing a dis-synergism of the masticatory muscles.
Job absenteeism and arterial hypertension: results of a hypertension control program.
1992
This study reports the findings of one of the stages of a programme for the detection and control of arterial hypertension, started in I980 in an automobile company with a workforce of 9,782. In the initial screening, 522 hypertensive males were found using epidemiological criteria and 206 of these fulfilled the criteria of definite hypertension. The objective of this study consisted of evaluating, 9 years after the start of the program, the indirect cost in terms of the reduction in the morbidity indicator-temporary work incapacity (TWI). Analysis is based on a comparison of the prevalence of hypertension in the population when the program was begun (6%) and in 1989 (9.8%). It can be obser…
Myoelectric Activation and Kinetics of Different Plyometric Push-Up Exercises
2011
The kinetic and myoelectric differences between 3 types of plyometric push-ups were investigated. Twenty-seven healthy, physically active men served as subjects and completed both familiarization and testing sessions. During these sessions, subjects performed 2 series of 3 plyometric push-up variations in a counterbalanced order according to the following techniques: Countermovement push-ups (CPUs) were push-ups performed with the maximum speed of movement; jump push-ups (JPUs) were similar to clapping push-ups; and fall push-ups (FPUs) required kneeling subjects to drop and then attempt to return to their initial position. Vertical ground reaction forces were determined by using a force pl…
Changes in muscle activity with increasing running speed.
2005
Electromyographic (EMG) activity of the leg muscles and the ground reaction forces were recorded in 17 elite male middle-distance runners, who performed isometric maximal voluntary contractions (MVC) as well as running at different speeds. Electromyograms were recorded from the gluteus maximus, vastus lateralis, biceps femoris, gastrocnemius and tibialis anterior. The results indicated that the averaged EMG (aEMG) activities of all the muscles studied increased (P < 0.05) with increasing running speed, especially in the pre-contact and braking phases. At higher speeds, the aEMG activities of the gastrocnemius, vastus lateralis, biceps femoris and gluteus maximus exceeded 100% MVC in these s…