Electromyographic Signals of the Spinal Musculature During +Gz Impact Acceleration

This study examined the effect of posttraumatic hypoxia on cerebral vascular responsivity and axonal damage, while also exploring hypothermia's potential to attenuate these responses. Rats were subjected to impact acceleration injury (IAI) and equipped with cranial windows to assess vascular reactivity to topical acetylcholine, with postmortem analyses using antibodies to amyloid precursor protein to assess axonal damage. Animals were subjected to hypoxia alone, IAI and hypoxia, IAI and hypoxia before induction of moderate hypothermia (33°C), IAI and hypoxia induced during hypothermic intervention, and IAI and hypoxia initiated after hypothermia. Hypoxia alone had no impact on vascular reactivity or axonal damage. Acceleration injury and posttraumatic hypoxia resulted in dramatic axonal damage and altered vascular reactivity. When IAI and hypoxia were followed by hypothermic intervention, no axonal or vascular protection ensued. However, when IAI was followed by hypoxia induced during hypothermia, axonal and vascular protection followed. When this same hypoxic insult followed the use of hypothermia, no benefit ensued. These studies show that early hypoxia and delayed hypoxia exert damaging axonal and vascular consequences. Although this damage is attenuated by hypothermia, this follows only when hypoxia occurs during hypothermia, with no benefit found if the hypoxic insult proceeds or follows hypothermia.

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Acute Effects on Impact Accelerations Running with Objects in the Hand

Life ◽

10.3390/life11060550 ◽

2021 ◽

Vol 11 (6) ◽

pp. 550

Author(s):

Roberto Sanchis-Sanchis ◽

Alberto Encarnación-Martínez ◽

Jose I. Priego-Quesada ◽

Inmaculada Aparicio ◽

Irene Jimenez-Perez ◽

...

Keyword(s):

Mobile Phone ◽

Step Length ◽

Stride Frequency ◽

Acute Effects ◽

Shock Attenuation ◽

Acceleration Rate ◽

Recreational Runners ◽

Impact Acceleration ◽

Spatio Temporal ◽

Extra Weight

Amateur runners usually run carrying implements in their hands (keys, a mobile phone, or a bottle of water). However, there is a lack of literature about the effects of different handloads on impact accelerations. Thus, this study aimed to analyse the effects of carrying different objects in the hand on impact accelerations during running. Nineteen male recreational runners (age 24.3 ± 6.8 years, training volume of 25 ± 7.38 km/week) performed twenty minutes of running on a treadmill at 2.78 m/s with four different conditions: no extra weight, with keys, with a mobile phone, and with a bottle of water. Impact acceleration and spatio-temporal parameters were analysed through a wireless triaxial accelerometry system composed of three accelerometers: two placed in each tibia and one placed on the forehead. A higher tibia acceleration rate in the dominant leg was observed when participants ran holding both a mobile phone (p = 0.027; ES = 0.359) and a bottle of water (p = 0.027; ES = 0.359), compared to no extra weight. No changes were observed in peak acceleration, acceleration magnitude, and shock attenuation in any other conditions. Likewise, neither stride frequency nor step length was modified. Our results suggest that recreational runners should not worry about carrying objects in their hands, like a mobile phone or a bottle of water, in short races because their effect seems minimal.

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New Measurement Techniques of Surface Electromyographic Signals in Rest Position for Application in the Ophthalmological Field

EMG Methods for Evaluating Muscle and Nerve Function ◽

10.5772/27579 ◽

2012 ◽

Author(s):

Edoardo Fiorucci ◽

Fabrizio Ciancetta ◽

Annalisa Monaco

Keyword(s):

Measurement Techniques ◽

Rest Position ◽

Electromyographic Signals

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An Electromyographic Analysis of the Deep Cervical Flexor Muscles in Performance of Craniocervical Flexion

Physical Therapy ◽

10.1093/ptj/83.10.899 ◽

2003 ◽

Vol 83 (10) ◽

pp. 899-906 ◽

Cited By ~ 121

Author(s):

Deborah Falla ◽

Gwendolen Jull ◽

Paul Dall'Alba ◽

Alberto Rainoldi ◽

Roberto Merletti

Keyword(s):

Muscle Activity ◽

Intraclass Correlation ◽

Correlation Coefficients ◽

Bipolar Electrodes ◽

Intraclass Correlation Coefficients ◽

Reliability Estimates ◽

Flexor Muscles ◽

The Mean ◽

Electromyographic Analysis ◽

Electromyographic Signals

Abstract Background and Purpose. This study evaluated an electromyographic technique for the measurement of muscle activity of the deep cervical flexor (DCF) muscles. Electromyographic signals were detected from the DCF, sternocleidomastoid (SCM), and anterior scalene (AS) muscles during performance of the craniocervical flexion (CCF) test, which involves performing 5 stages of increasing craniocervical flexion range of motion—the anatomical action of the DCF muscles. Subjects. Ten volunteers without known pathology or impairment participated in this study. Methods. Root-mean-square (RMS) values were calculated for the DCF, SCM, and AS muscles during performance of the CCF test. Myoelectric signals were recorded from the DCF muscles using bipolar electrodes placed over the posterior oropharyngeal wall. Reliability estimates of normalized RMS values were obtained by evaluating intraclass correlation coefficients and the normalized standard error of the mean (SEM). Results. A linear relationship was evident between the amplitude of DCF muscle activity and the incremental stages of the CCF test (F=239.04, df=36, P<.0001). Normalized SEMs in the range 6.7% to 10.3% were obtained for the normalized RMS values for the DCF muscles, providing evidence of reliability for these variables. Discussion and Conclusion. This approach for obtaining a direct measure of the DCF muscles, which differs from those previously used, may be useful for the examination of these muscles in future electromyographic applications.

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