Search results for "Muscle"
showing 10 items of 3397 documents
PGC-1 isoforms and their target genes are expressed differently in human skeletal muscle following resistance and endurance exercise
2015
The primary aim of the present study was to investigate the acute gene expression responses of PGC-1 isoforms and PGC-1a target genes related to mitochondrial biogenesis (cytochrome C), angiogenesis (VEGF-A), and muscle hypertrophy (myostatin), after a resistance or endurance exercise bout. In addition, the study aimed to elucidate whether the expression changes of studied transcripts were linked to phosphorylation of AMPK and MAPK p38. Nineteen physically active men were divided into resistance exercise (RE, n = 11) and endurance exercise (EE, n = 8) groups. RE group performed leg press exercise (10 9 10 RM, 50 min) and EE walked on a treadmill (~80% HRmax, 50 min). Muscle biopsies were ob…
Strength and muscle mass loss with aging process. Age and strength loss.
2014
Background aging process is associated with changes in muscle mass and strength with decline of muscle strength after the 30(th) life year. The aim of this study was to investigate these changes in muscle mass and strength. Patients & methods for this analysis 26 participants were subdivided in two groups. Group 1 comprises participants aged 40 years (n=12). We assessed anthropometrics, range of motions, leg circumferences and isometric strength values of the knee joints. Results besides comparable anthropometrics, circumferences and strength were higher in group 1 than in group 2. Circumference of upper leg (20 cm above knee articular space) showed for right leg a trend to a significant (m…
Twitch interpolation during equal-intensity voluntary and electrically-evoked isometric contractions of the quadriceps muscle
2005
It has been suggested that, during contractions triggered by electrical stimulation, motor units are recruited in a reversed sequence compared to voluntary contraction. The classic view is that lar...
Resumption of Ventilation at the End of Obstructive Sleep Apneas is not Determined by Diaphragmatic Fatigue
1988
In patients affected by obstructive sleep apnea syndrome (OSAS) a progressive increase of the force developed by the respiratory muscles is usually observed during the occlusive phase before upper airway patency is resumed (Onal and Lopata, 1986).
Preliminary study of the neuromuscular activation during barefoot and shod running
2015
El objetivo del presente estudio preliminar fue comparar la actividad muscular de los músculos tibial anterior, peroneo lateral largo, gastrocnemio medial y gastrocnemio lateral entre la carrera con y sin calzado, y la influencia de la fatiga. 7 participantes realizaron una carrera de fatiga de 20 minutos al 75% de su velocidad aeróbica máxima en cinta con 1% de pendiente. Se midió la actividad mioeléctrica de los músculos antes mencionados tanto antes como después de la prueba de fatiga en dos condiciones: con calzado y sin calzado. Los resultados mostraron una mayor actividad del tibial anterior durante la carrera en fatiga descalzo respecto a la carrera calzado y una mayor actividad del …
Internal jugular vein entrapment in a multiple sclerosis patient.
2012
We describe a multiple sclerosis patient presenting with compression of the internal jugular vein caused by aberrant omohyoid muscle. Previously this patient underwent balloon angioplasty of the same internal jugular vein. Ten months after this endovascular procedure, Doppler sonography revealed totally collapsed middle part of the treated vein with no outflow detected. Still, the vein widened and the flow was restored when the patient’s mouth opened. Thus, the abnormality was likely to be caused by muscular compression. Surgical exploration confirmed that an atypical omohyoid muscle was squeezing the vein. Consequently, pathological muscle was transected. Sonographic control three weeks af…
Effects of wrist oscillations on contralateral neurological postural tremor using a new myohaptic device ('wristalyzer')
2007
Upper limb postural tremor consists of distinct oscillations, mainly mechanical-reflex and central-neurogenic. These oscillations are superimposed upon a background of irregular fluctuations in muscle force. Muscle spindles play key-roles in the information flow to supra-spinal and spinal generators. Oscillations were delivered using a new generation portable myohaptic device, called 'wristalyzer', which takes into account the ergonomy of upper limbs allowing a fine adjustment to each configuration of upper limb segments. The nominal torque of the device is 4 Nm, with a maximal rotation velocity of 300 degrees/s and a range of motion of +45 to -45 degrees. Reliability was assessed in basal …
The Stretch-Shortening Cycle
2006
Neuromuscular fatigue has traditionally been examined using isolated forms of either isometric, concentric or eccentric actions. However, none of these actions are naturally occurring in human (or animal) ground locomotion. The basic muscle function is defined as the stretch-shortening cycle (SSC), where the preactivated muscle is first stretched (eccentric action) and then followed by the shortening (concentric) action. As the SSC taxes the skeletal muscles very strongly mechanically, its influence on the reflex activation becomes apparent and very different from the isolated forms of muscle actions mentioned above. The ground contact phases of running, jumping and hopping etc. are example…