Search results for "Muscle"
showing 10 items of 3397 documents
Electromechanical delay in skeletal muscle under normal movement conditions.
1979
Electromechanical delays (EMD), the time from onset of EMG activity to change in acceleration or deceleration of the forearm, were studied in concentric and eccentric contractions of biceps and triceps brachii muscles. Horizontal flexion and extension movements were performed at varying speeds by 10 subjects. EMD time in concentric contractions for biceps was 41 +/- 13 ms and for triceps was 26 +/- 11 ms and was not influenced by the velocity of the movement. In eccentric contractions at the slow velocity the biceps EMD time was 38 +/- 13 ms and shortened to 28 +/- 10 ms at the faster velocity. The eccentric triceps EMD, however, was not significantly altered by movement velocity and averag…
Different short-term modulation of cortical motor output to distal and proximal upper-limb muscles during painful sensory nerve stimulation
2004
The pattern of upper-limb muscle activation following painful stimulation has not been clarified in detail. We investigated the short-term inhibitory and excitatory effects of painful electrical digital stimulation on the motoneuron pools of distal and proximal upper-limb muscles. Transcranial magnetic stimulation (TMS) was used as test stimulus, and painful digital nerve stimulation as conditioning stimulus for motor evoked potential (MEP) recordings over the abductor digiti minimi (ADM), abductor pollicis brevis (APB), biceps brachii (BB), and deltoid muscles. Inhibition of the conditioned MEP response was most prominent in the distal muscles, whereas BB and deltoid muscles were only weak…
Studies on the subcellular pathophysiology of sublethal chronic cell injury.
1974
Summary This paper summarizes some of the important subcellular events occurring after chronic sublethal cell injury. Chronic cell injury is defined as the result of injurious stimuli which permit cell survival though in altered steady states for protracted periods of time. The importance of ultrastructural and biochemical studies of these phenomena is emphasized. Among the phenomena discussed are alterations in lysosomes, cellular hypertrophy, fatty metamorphosis, alterations in microfilaments and microtubules, alterations in mechanisms of transcription and replication, disturbances in the cell surface and transport across the cell membrane, and alterations in intracellular transport.
Economic aspects of different muscle relaxant regimens.
2000
Objective At a time of cost reduction in medical care efforts to manage the ever-increasing costs of new pharmaceutical drugs become increasingly important. Costs of four different muscle relaxant regimens including the new intermediate-acting neuromuscular blocking drugs (NMBD) cisatracurium and rocuronium will be analyzed. Methods Eighty patients undergoing laparoscopic cholecystectomy were prospectively studied. All patients received standardized general anaesthesia with desflurane/fentanyl. Muscle relaxation was achieved with atracurium, cisatracurium, vecuronium, or rocuronium with 20 patients in each group. Intraoperatively muscle relaxants were added to maintain two twitches of the t…
Repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex (DLPFC) during capsaicin-induced pain: modulatory effects o…
2009
Evidence by functional imaging studies suggests the role of left DLPFC in the inhibitory control of nociceptive transmission system. Pain exerts an inhibitory modulation on motor cortex, reducing MEP amplitude, while the effect of pain on motor intracortical excitability has not been studied so far. In the present study, we explored in healthy subjects the effect of capsaicin-induced pain and the modulatory influences of left DLPFC stimulation on motor corticospinal and intracortical excitability. Capsaicin was applied on the dorsal surface of the right hand, and measures of motor corticospinal excitability (test-MEP) and short intracortical inhibition (SICI) and facilitation (ICF) were obt…
Facilitatory effects of 1 Hz rTMS in motor cortex of patients affected by migraine with aura
2004
We previously showed paradoxical facilitatory effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) on striate and extrastriate cortex of patients suffering migraine with aura. In this study we evaluated the effects of 1 Hz rTMS on the excitability of inhibitory and facilitatory circuits of motor cortex to explore whether the abnormal pattern of excitability extends beyond the sensory cortex also involving motor areas in migraine with aura. Nine patients affected by migraine with aura and eight healthy controls entered into the study. The hot spot for activation of the right abductor pollicis brevis (APB) was checked by means of a figure-of-eight coil and motor thresh…
Minimal Stabilization Time for Ultra-short Heart Rate Variability Measurements in Professional Soccer
2020
The main aims of this study were: 1) to compare 1-minute RMSSD measurements using different stabilization times between them and also with the criterion; and 2) to determine the agreement between every 1-minute RMSSD measurement with the criterion in professional soccer players. Seven hundred eighteen HRV measurements from professional soccer players were taken. HRV was calculated from 5 to 10 minutes (criterion) and from 1-minute windows with different pre-stabilization times. Friedman and post-hoc tests were applied to compare 1-minute and criterion measurements. Effect size was considered to describe magnitude of change. To determine agreement, Spearman’s correlation was applied, and Bla…
Neuromuscular electrophysiological disorders and muscle atrophy in mechanically-ventilated traumatic brain injury patients: New insights from a prosp…
2018
International audience; Erratum inCorrigendum to "Neuromuscular electrophysiological disorders and muscle atrophy in mechanically-ventilated traumatic brain injury patients: New insights from a prospective observational study" [J Crit Care 44 (2018) 87-94]. [J Crit Care. 2019]AbstractPURPOSE:It is unclear whether the muscular changes in mechanically-ventilated traumatic brain injury patients (TBI) are only associated with disuse or additionally to neuromuscular electrophysiological disorders (NED). The correlation between muscle atrophy and NED may affect functional outcomes and rehabilitation programs significantly.MATERIAL AND METHODS:An observational study was performed to investigate th…
Comparison of training and anthropometric characteristics between recreational male half-marathoners and marathoners
2013
Zillmann, Teresa | Knechtle, Beat | Ruest, Christoph Alexander | Knechtle, Patrizia | Rosemann, Thomas | Lepers, Romuald; International audience; ''Participation in endurance running such as half-marathon (21-km) and marathon (42-km) has increased over the last decades. We compared 147 recreational male half-marathoners and 126 recreational male marathoners to investigate similarities or differences in their anthropometric and training characteristics. The half-marathoners were heavier (P < 0.05), had longer legs (P < 0.001), thicker upper arms (P < 0.05), a thicker thigh (P < 0.01), a higher sum of skinfold thicknesses (P < 0.01), a higher body fat percentage (P < 0.05) and a higher skelet…
Effects of vasopressin on human renal arteries
1996
The effects of vasopressin were studied in isolated rings from branches (2-3 mm in external diameter) of human renal arteries obtained from 18 patients undergoing nephrectomy for non-obstructive neoplasia. In arterial rings under resting tension, vasopressin produced concentration-dependent and endothelium-independent contractions with an EC 50 of 9.1 x 10 -10 mol L -1 . The vasopressin V 1 receptor antagonist d(CH 2 ) 5 Tyr(Me)AVP (10 -6 mol L -1 ) displaced the control curve to vasopressin 564-fold to the right in a parallel manner. In precontracted arterial rings and previously treated with the V 1 antagonist (10 -6 mol L -1 ) vasopressin caused endothelium-independent relaxation. The re…