Search results for "Muscles"
showing 10 items of 616 documents
Effects of plantar flexor muscle fatigue induced by electromyostimulation on postural coordination
2007
International audience; The aim of the present study was to investigate the influence of a modification of an intrinsic capacity (plantar flexor strength) on the implementation of in-phase and anti-phase mode of coordination. Analysis of hip and ankle relative phases during fore-aft tracking task was done before and after an electromyostimulation fatigue protocol on the soleus muscles. Results showed participants used exclusively in-phase and anti-phase modes of coordination, with a sudden switch from one to the other with target frequency increase. Regarding tracking tasks, fatigue induces a decrease of performance for lower frequencies, and a significant decrease of switch frequency (−0.0…
Phosphomannosyl receptors of lysosomal enzymes of skeletal muscle in neuromuscular diseases.
1988
The phosphomannosyl receptor system is responsible for both the receptor-mediated endocytosis and the intracellular transport of lysosomal enzymes. In the present study this receptor system was examined in affected muscles of patients with various neuromuscular diseases. The total activity of beta-N-acetyl-glucosaminidase, a marker enzyme of lysosomal hydrolases, was significantly elevated in the patients with myopathies (polymyositis and muscular dystrophies) but only slightly increased in those with neurogenic muscle atrophies (amyotrophic lateral sclerosis, polyneuropathy or other neurogenic muscle disease). The increase was most prominent in the group of polymyositis. The content of pho…
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.
Ocular pseudomyasthenia: report of a case with a pineal region tumor.
1991
A case presenting with clinical features of ocular myasthenia and a false-positive edrophonium test is reported. Brain CT and MRI scan revealed a pineal region tumor histologically verified as germinoma. We recommend evaluating patients with clinical features of myasthenia gravis (MG) confined to the ocular muscles for intracranial mass lesions.
Magnetic resonance imaging of the pituitary gland in patients with secondary hypogonadism due to transfusional hemochromatosis
1999
To identify pituitary iron overload in patients with transfusional hemochromatosis causing secondary hypogonadism, we prospectively evaluated signal intensity abnormalities of the anterior lobe of the pituitary gland of 18 patients affected by transfusion-dependent thalassemia major and secondary hypogonadism. Magnetic resonance (MR) imaging is useful to assess pituitary iron overload in patients with transfusional hemochromatosis and secondary hypogonadism by detection of a significant decreased signal intensity of the anterior lobe of the pituitary gland on GRE T2*-weighted images. The decreased signal intensity of the anterior lobe of the pituitary gland on GRE T2*-weighted images was co…
Perceived physical exertion is a good indicator of neuromuscular fatigue for the core muscles
2019
Although several studies have assessed core training, specific prescription recommendations remain lacking. The purpose of the present study was to determine the association between the rate of perceived exertion (RPE) and neuromuscular fatigue of the core muscles during the prone bridging endurance test. Fifteen healthy and moderately active subjects participated. Neuromuscular fatigue was assessed with surface electromyography on the rectus abdominis (RA), external oblique, internal oblique, and lumbar erector spinae. Participants rated the RPE (Borg CR 10) every 5 s. The time to failure was 123.7 ± 58.1 s. From the midpoint of the time to failure, the RPE significantly increased (p 0.05…
Muscle metabolic profile and oxygen transport capacity as determinants of aerobic and anaerobic thresholds
1988
Aerobic and anaerobic thresholds determined by different methods in repeated exercise tests were correlated with cardiorespiratory variables and variables of muscle metabolic profile in 33 men aged 20–50 years. Aerobic threshold was determined from blood lactate, ventilation, and respiratory gas exchange by two methods (AerT1 and AerT2) and anaerobic threshold from venous lactate (AnTLa), from ventilation and gas exchange (AnTr) and by using the criterion of 4 mmol·l−1 of venous lactate (AnT4mmol). In addition to ordinary correlative analyses, applications of LISREL models were used. The 8 explanatory variables chosen for the regression analyses were height, relative heart volume, relative …
A new method for the evaluation of anaerobic running power in athletes.
1993
A new maximal anaerobic running power (MARP) test was developed. It consisted of n.20-s runs on a treadmill with a 100-s recovery between the runs. During the first run the treadmill speed was 3.97 m.s-1 and the gradient 5 degrees. The speed of the treadmill was increased by 0.35 m.s-1 for each consecutive run until exhaustion. The height of counter-movement jumps and blood lactate concentration ([la-]b) were measured after each run. Submaximal ([la-]b = 3 mmol.l-1 and 10 mmol.l-1) and maximal speed and power (W3mmol, W10mmol and Wmax, respectively) were calculated and W was expressed in oxygen equivalents according to the American College of Sports Medicine equation. Thirteen male athletes…
Enzyme activities in muscle and connective tissue of M. vastus lateralis in habitually training and sedentary 33 to 70-year-old men
1975
A cross-sectional study was carried out to examine the activities of certain enzymes representing aerobic and anaerobic energy metabolism as well as the biosynthesis of collagen of M. vastus lateralis in 23 male endurance athletes in habitual training, aged 33 to 70 years. 23 sedentary healthy men of corresponding ages were selected for the control group. The mean maximal oxygen uptake of the trained subjects was 53.6 ml · kg−1 · min−1 and that of the control subjects 36.3 ml · kg−1 · min−1. As compared to the control group the trained subjects had significantly higher values in the muscle malate dehydrogenase, succinate dehydrogenase and prolyl hydroxylase activities, whereas the opposite …
Lipid metabolism during exercise I: Physiological and biochemical characterization of normal healthy male subjects in relation to their physical fitn…
1978
On the basis of maximal oxygen uptake (\(\dot V\)O2 max) 18 normal, healthy men were divided into two groups of equal size: moderately trained subjects (MTR) each having \(\dot V\)O2 max below 65.0 ml·min−1·kg−1 body weight (54.0±8.3) and well trained subjects (WTR), whose \(\dot V\)O2 max exceeded 65.0 ml·min−1·kg−1 body weight (69.2±4.1). The WTR group had slightly (non significant, n.s.) higher percentage of slow twitch, oxidative (SO) fibers in M. vastus lateralis and higher (n.s.) activities of cytochrome c oxidase (CytOx), succinate dehydrogenase (SDH), 3-hydroxyacyl-CoA-dehydrogenase (HADH), and citrate synthase (CS), while lactate dehydrogenase (LDH) activity was lower (n.s.). In th…