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Kinesiology

Kinesiology Publications

2015

Articles 1 - 5 of 5

Full-Text Articles in Life Sciences

Methods And Considerations For The Analysis And Standardization Of Assessing Muscle Sympathetic Nerve Activity In Humans., Daniel W White, J Kevin Shoemaker, Peter B Raven Dec 2015

Methods And Considerations For The Analysis And Standardization Of Assessing Muscle Sympathetic Nerve Activity In Humans., Daniel W White, J Kevin Shoemaker, Peter B Raven

Kinesiology Publications

The technique of microneurography and the assessment of muscle sympathetic nerve activity (MSNA) are used in laboratories throughout the world. The variables used to describe MSNA, and the criteria by which these variables are quantified from the integrated neurogram, vary among studies and laboratories and, therefore, can become confusing to those starting to learn the technique. Therefore, the purpose of this educational review is to discuss guidelines and standards for the assessment of sympathetic nervous activity through the collection and analysis of MSNA. This review will reiterate common practices in the collection of MSNA, but will also introduce considerations for …

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Blood Flow And Muscle Oxygenation During Low, Moderate, And Maximal Sustained Isometric Contractions, Chris Mcneil, Matti D. Allen, Eric Olympico, J Kevin Shoemaker, Charles L. Rice Oct 2015

Blood Flow And Muscle Oxygenation During Low, Moderate, And Maximal Sustained Isometric Contractions, Chris Mcneil, Matti D. Allen, Eric Olympico, J Kevin Shoemaker, Charles L. Rice

Kinesiology Publications

Blood flow and muscle oxygenation during low, moderate, and maximal sustained isometric contractions. Am J Physiol Regul Integr Comp Physiol 309: R475–R481, 2015. First published June 17, 2015; doi:10.1152/ajpregu.00387.2014.—A reduction of blood flow to active muscle will precipitate fatigue, and sustained isometric contractions produce intramuscular and compartmental pressures that can limit flow. The present study explored how blood flow and muscle oxygenation respond to isometric contractions at low, moderate, and maximal intensities. Over two visits, 10 males (26 2 yr; means SD) performed 1-min dorsiflexion contractions at 30, 60, and 100% of maximal voluntary contraction (MVC) torque. Doppler ultrasound of …

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Forebrain Neurocircuitry Associated With Human Reflex Cardiovascular Control., J Kevin Shoemaker, Ruma Goswami Sep 2015

Forebrain Neurocircuitry Associated With Human Reflex Cardiovascular Control., J Kevin Shoemaker, Ruma Goswami

Kinesiology Publications

Physiological homeostasis depends upon adequate integration and responsiveness of sensory information with the autonomic nervous system to affect rapid and effective adjustments in end organ control. Dysregulation of the autonomic nervous system leads to cardiovascular disability with consequences as severe as sudden death. The neural pathways involved in reflexive autonomic control are dependent upon brainstem nuclei but these receive modulatory inputs from higher centers in the midbrain and cortex. Neuroimaging technologies have allowed closer study of the cortical circuitry related to autonomic cardiovascular adjustments to many stressors in awake humans and have exposed many forebrain sites that associate strongly with …

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Positional Differences In Reactive Hyperemia Provide Insight Into Initial Phase Of Exercise Hyperemia., Jeffrey L Jasperse, J Kevin Shoemaker, Eric J Gray, Philip S Clifford Sep 2015

Positional Differences In Reactive Hyperemia Provide Insight Into Initial Phase Of Exercise Hyperemia., Jeffrey L Jasperse, J Kevin Shoemaker, Eric J Gray, Philip S Clifford

Kinesiology Publications

Studies have reported a greater blood flow response to muscle contractions when the limb is below the heart compared with above the heart, and these results have been interpreted as evidence for a skeletal muscle pump contribution to exercise hyperemia. If limb position affects the blood flow response to other vascular challenges such as reactive hyperemia, this interpretation may not be correct. We hypothesized that the magnitude of reactive hyperemia would be greater with the limb below the heart. Brachial artery blood flow (Doppler ultrasound) and blood pressure (finger-cuff plethysmography) were measured in 10 healthy volunteers. Subjects lay supine with …

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Sympathetic Neural Recruitment Strategies: Responses To Severe Chemoreflex And Baroreflex Stress, Mark B. Badrov, Charlotte W. Usselman, J Kevin Shoemaker Jul 2015

Sympathetic Neural Recruitment Strategies: Responses To Severe Chemoreflex And Baroreflex Stress, Mark B. Badrov, Charlotte W. Usselman, J Kevin Shoemaker

Kinesiology Publications

This study tested the hypothesis that neural coding patterns exist within the autonomic nervous system. We investigated sympathetic axonal recruitment strategies in humans during chemoreflex- and baroreflex-mediated sympathoexcitation using a novel action potential (AP) analysis technique. Muscle sympathetic nerve activity (microneurography) was collected in 11 young individuals (6 females) during baseline and two subsequent protocols: 1) severe chemoreflex stimulation (maximal end-inspiratory apnea following rebreathe), and 2) severe baroreceptor unloading (−80 mmHg lower body negative pressure; LBNP). When compared with each respective baseline, apnea and LBNP increased AP frequency and mean AP content per sympathetic burst (all P < 0.01). When APs were binned according to peak-to-peak amplitude (i.e., into “clusters”), total clusters detected increased during both apnea (Δ7 ± 5; P …

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