257. Electromyographic Activity of Forearm Flexors and Extensor Muscles from Typing on Negatively Sloped Computer Keyboards

2000 ◽  
Author(s):  
R. Marklin ◽  
G. Simoneau ◽  
D. Cahaya
Keyword(s):  
Electromyographic Activity ◽  
Extensor Muscles

scholarly journals Comparison of Recovery Strategies on Maximal Force-Generating Capacity and Electromyographic Activity Level of the Knee Extensor Muscles

2011 ◽  
Vol 46 (4) ◽  
pp. 386-394 ◽  
Author(s):  
Nidhal Zarrouk ◽  
Haithem Rebai ◽  
Abdelmoneem Yahia ◽  
Nizar Souissi ◽  
François Hug ◽  
...  
Keyword(s):  
Knee Extensor ◽  
Neuromuscular Fatigue ◽  
Activity Level ◽  
Knee Extensors ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Active Recovery ◽  
Concentric Exercise ◽  
Extensor Muscles ◽  
Knee Extensor Muscles

Context: With regard to intermittent training exercise, the effects of the mode of recovery on subsequent performance are equivocal. Objective: To compare the effects of 3 types of recovery intervention on peak torque (PT) and electromyographic (EMG) activity of the knee extensor muscles after fatiguing isokinetic intermittent concentric exercise. Design: Crossover study. Setting: Research laboratory. Patients or Other Participants: Eight elite judo players (age = 18.4 ± 1.4 years, height = 180 ± 3 cm, mass = 77.0 ± 4.2 kg). Intervention(s): Participants completed 3 randomized sessions within 7 days. Each session consisted of 5 sets of 10 concentric knee extensions at 80% PT at 120°/s, with 3 minutes of recovery between sets. Recovery interventions were passive, active, and electromyostimulation. The PT and maximal EMG activity were recorded simultaneously while participants performed isokinetic dynamometer trials before and 3 minutes after the resistance exercise. Main Outcome Measure(s): The PT and maximal EMG activity from the knee extensors were quantified at isokinetic velocities of 60°/s, 120°/s, and 180°/s, with 5 repetitions at each velocity. Results: The reduction in PT observed after electromyo-stimulation was less than that seen after passive (P < .001) or active recovery (P < .001). The reduction in PT was less after passive recovery than after active recovery (P < .001). The maximal EMG activity level observed after electromyostimulation was higher than that seen after active recovery (P < .05). Conclusions: Electromyostimulation was an effective recovery tool in decreasing neuromuscular fatigue after high-intensity, intermittent isokinetic concentric exercise for the knee extensor muscles. Also, active recovery induced the greatest amount of neuromuscular fatigue.

EXTERNAL EXTENSION FORCE REDUCES ELECTROMYOGRAPHIC ACTIVITY OF THE WRIST EXTENSOR MUSCLES DURING GRIPPING

2003 ◽  
Vol 35 (Supplement 1) ◽  
pp. S318
Author(s):  
N van Elk ◽  
J G.M. Kooloos ◽  
M Massa ◽  
J A. de Lint ◽  
M T.E. Hopman
Keyword(s):  
Electromyographic Activity ◽  
Wrist Extensor ◽  
Extensor Muscles ◽  
Wrist Extensor Muscles ◽  
Extension Force

scholarly journals Comparison of the electrical activity in upper trapezius and wrist extensor muscles during two typewriting conditions

2014 ◽  
Vol 27 (2) ◽  
pp. 271-279 ◽  
Author(s):  
João Carlos Comel ◽  
João Pedro Batista Junior ◽  
Eliana Paula Chini ◽  
Hugo Maxwell Pereira ◽  
Rodrigo Luiz Carregaro ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Electromyographic Activity ◽  
Wrist Extensor ◽  
Upper Trapezius ◽  
Extensor Muscles ◽  
Significant Difference ◽  
Arm Support ◽  
Wrist Extensor Muscles

Introduction The proper use of the position of the arm and wrist while typing may reduce muscle overload and prevent musculoskeletal disorders.Objective To evaluate the electromyographic activity of upper trapezius and wrist extensor muscles during two typewriting conditions.Materials and methods : Six healthy females (Xage = 42 years,SD= 10), (Xheight = 1.65m, SD = 0.05) and (Xweight = 71kg, SD = 16) participated in this study. The task was performed with a newly developed arm support and without the support. A perceived exertion scale was used with all subjects. An ANOVA with repeated measures was used to verify differences in perceived exertion and root mean square (RMS).Results There were no statistically significant differences for the RMS between the typewriting tasks. The condition without arm support presented a significantly greater mean velocity and amount of words typed (P= 0.02; P= 0.03) and there was a significant difference in perceived exertion during the condition without arm support (P= 0.03). Electromyographic activity did not present differences.Conclusion The muscle electrical activity was not altered regardless the arm support and occurred the improvement of the perceived exertion after 10 minutes of typing without support. Long-term studies are needed.

Activity of Spinal Interneurons and Their Effects on Forearm Muscles During Voluntary Wrist Movements in the Monkey

1998 ◽  
Vol 80 (5) ◽  
pp. 2475-2494 ◽  
Author(s):  
Steve I. Perlmutter ◽  
Marc A. Maier ◽  
Eberhard E. Fetz
Keyword(s):  
Dorsal Root ◽  
Red Nucleus ◽  
Electromyographic Activity ◽  
Response Patterns ◽  
Spinal Interneurons ◽  
Forearm Muscles ◽  
Extensor Muscles ◽  
Flexion Extension ◽  
Flexor Muscles ◽  
The Mean

Perlmutter, Steve I., Marc A. Maier, and Eberhard E. Fetz. Activity of spinal interneurons and their effects on forearm muscles during voluntary wrist movements in the monkey. J. Neurophysiol. 80: 2475–2494, 1998. We studied the activity of 577 neurons in the C6–T1 spinal cord of three awake macaque monkeys while they generated visually guided, isometric flexion/extension torques about the wrist. Spike-triggered averaging of electromyographic activity (EMG) identified the units' correlational linkages with ≤12 forearm muscles. One hundred interneurons produced changes in the level of average postspike EMG with onset latencies consistent with mono- or oligosynaptic connections to motoneurons; these were classified as premotor interneurons (PreM-INs). Most PreM-INs (82%) produced postspike facilitations in forearm muscles. Earlier spike-related features, often beginning before the trigger spike, were seen in spike-triggered averages from 72 neurons. Postspike effects were present in one muscle for 64% of the PreM-INs. Neurons with divergent linkages to larger “muscle fields” usually generated postspike effects in synergistic muscles. Fifty-eight percent of the PreM-INs had postspike effects in flexor muscles only and 29% in extensor muscles only. Postspike effects were distributed relatively evenly among the primary flexor and extensor muscles studied. The mean percent change in EMG level from baseline and the mean onset latencies for postspike facilitations and postspike suppressions were similar. PreM-INs exhibited a variety of response patterns during the generation of isometric wrist torque. The response patterns and output effects of 24% of the PreM-INs were consistent with a strict reciprocal organization of flexor and extensor muscle control. For another 60% of the PreM-INs, there was a congruent relation between activity and output effects for only one direction of torque production. These neurons were active for both flexion and extension torques, including 37 neurons that exhibited bidirectional increases in discharge rate. The relatively small number of postspike suppressions observed suggests that inhibitory interneurons were silent when their target muscles were recruited. Compared with premotor neurons in the motor cortex, the red nucleus and the C8–T1 dorsal root ganglia, spinal PreM-INs affected flexor muscles in greater proportions and had smaller muscle fields. The magnitudes of postspike facilitations were similar in all premotor populations. Bidirectional activity, common for PreM-INs, was rare for corticomotoneuronal and premotor dorsal root ganglion cells, which discharge only for torques in their preferred direction.

Electromyographic activity of voluntarily activated trunk flexor and extensor muscles in post-stroke hemiparetic subjects

2004 ◽  
Vol 115 (4) ◽  
pp. 790-796 ◽  
Author(s):  
Ruth Dickstein ◽  
Sara Shefi ◽  
Emanuel Marcovitz ◽  
Yael Villa
Keyword(s):  
Electromyographic Activity ◽  
Post Stroke ◽  
Extensor Muscles
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