Few studies have quantified lower limb muscle activity over 24 h using electromyographic signals (EMG). None have described the changes in EMG duration and intensity when data are analyzed with different thresholds. Continuous bilateral EMG recordings were made from vastus lateralis (VL) in 10 subjects (20-48 yr) for 24 h. Before and after this recording, voluntary quadriceps forces and VL EMG ...

Local muscle fatigue (1 min maximal voluntary contraction) and recovery were studied by means of surface and invasive EMG on elbow flexors to record the changes in muscle fiber conduction velocity (MFCV), median power frequency (MPF), integrated EMG (IEMG), and force. The main finding was a long-lasting "supernormal" MFCV during recovery, for at least 1 hour. After a normalization phase, the MF...

The assessment of cough threshold and intensity is important in respiratory medicine. We have developed a method for objectively and noninvasively assessing cough threshold and intensity of expiratory muscle efforts in response to inhalation of ultrasonically nebulized distilled water (UNDW). Thirty (83%) out of 36 volunteers studied coughed in response to UNDW inhalation. Cough threshold was t...

PURPOSE The present study was designed to examine the role of central and peripheral fatigue on 4000-m cycling time trial performance by comparing changes in power output and integrated electromyography (iEMG) in differently paced maximal efforts. METHODS Eight well-trained men performed three randomly ordered time trials with different pacing strategies, in which the first 2000 m were manipu...

Fabrication of interocclusal splint at a thickness determined by the vertical dimension at which the jaw muscle EMG amplitude is minimum has been recommended. However, the effect of prior jaw motion and the effect of the recording site on the EMG amplitudes and on the vertical dimension of minimum EMG activity have not been documented. IEMG amplitudes at various static jaw positions achieved du...

Myoelectric prosthetic devices can be controlled based on surface electromyography (sEMG). However, intramuscular EMG (iEMG) has been proposed as an alternative control signal, since it may provide more stable and selective recordings with several advantages such as electrode implantation. An earlier study quantified the relationship between iEMG and grasping force, however, this was solely bas...

It is important to know the effects of the inclination of a slope on the activity of each muscle, because training by running on a sloped track is commonly used for Thoroughbred racehorses. The effects of incline (from -6 to +6%) on the forelimbs and hind limbs during walking and trotting on a treadmill were evaluated by an integrated electromyogram (iEMG). The muscle activities in the forelimb...

PURPOSE To determine the most effective electromyographic (EMG) normalization method for cycling fatigue protocols. METHODS Ten healthy subjects performed two 5-s isometric knee extension maximal voluntary contractions (MVC) at a knee joint angle of 60 degrees, two fixed cycle pedal contraction at knee joint angles of 60 degrees (60 degrees A) and 108 degrees (108 degrees A), and a dynamic si...

The purpose of this study was to examine the influence of muscular fatigue of tibialis anterior (TA) on the walk-to-run transition (WRT) and run-to-walk transition (RWT) when speed is altered at different constant accelerations (a=0.01, 0.07 and 0.05 ms(-2)). Twenty women (height: 168.9+/-3.36 cm) performed WRTs and RWTs on a motor-driven treadmill, before and after a protocol inducing muscular...

To examine whether the cerebrum is essential for producing the rapid cardiovascular adjustment at the beginning of overground locomotion, we examined heart rate (HR), mean arterial blood pressure (MAP), and integrated electromyogram (iEMG) of the forelimb triceps brachialis muscle in freely moving decerebrate cats during locomotion. Two to four days after decerebration surgery performed at the ...