Life Sciences Commons^™

The Aging Neuromuscular System And Motor Performance, Sandra K. Hunter, Hugo M. Pereira, Kevin Keenan

Exercise Science Faculty Research and Publications

Age-related changes in the basic functional unit of the neuromuscular system, the motor unit, and its neural inputs have a profound effect on motor function, especially among the expanding number of old (older than ∼60 yr) and very old (older than ∼80 yr) adults. This review presents evidence that age-related changes in motor unit morphology and properties lead to impaired motor performance that includes 1) reduced maximal strength and power, slower contractile velocity, and increased fatigability; and 2) increased variability during and between motor tasks, including decreased force steadiness and increased variability of contraction velocity and torque over …

Short-Interval Cortical Inhibition And Intracortical Facilitation During Submaximal Voluntary Contractions Changes With Fatigue, Sandra K. Hunter, Chris J. Mcneil, Jane E. Butler, Simon C. Gandevia, Janet L. Taylor

Exercise Science Faculty Research and Publications

This study determined whether short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) change during a sustained submaximal isometric contraction. On 2 days, 12 participants (6 men, 6 women) performed brief (7-s) elbow flexor contractions before and after a 10-min fatiguing contraction; all contractions were performed at the level of integrated electromyographic activity (EMG) which produced 25 % maximal unfatigued torque. During the brief 7-s and 10-min submaximal contractions, single (test) and paired (conditioning–test) transcranial magnetic stimuli were applied over the motor cortex (5 s apart) to elicit motor-evoked potentials (MEPs) in biceps brachii. SICI and ICF were elicited on separate …

Fast Men Slow More Than Fast Women In A 10 Kilometer Road Race, Robert O. Deaner, Vittorio Addana, Rickey E. Carter, Michael J. Joyner, Sandra K. Hunter

Exercise Science Faculty Research and Publications

Background. Previous studies have demonstrated that men are more likely than women to slow in the marathon (footrace). This study investigated whether the sex difference in pacing occurs for a shorter race distance.

Materials & Methods.Data were acquired from the Bolder Boulder 10 km road race for the years 2008–2013, which encompassed 191,693 performances. There were two pacing measures, percentage change in pace of the first 3 miles relative to the final 3.2 miles and percentage change in pace of the first mile relative to the final 5.2 miles. Pacing was analyzed as a continuous variable and as two …

Toward Translating Near-Infrared Spectroscopy Oxygen Saturation Data For The Non-Invasive Prediction Of Spatial And Temporal Hemodynamics During Exercise, Laura M. Ellwein, Margaret M. Samyn, Michael E. Danduran, Sheila M. Schindler-Ivens, Stacy Liebham, John F. Ladisa Jr.

Exercise Science Faculty Research and Publications

Image-based computational fluid dynamics (CFD) studies conducted at rest have shown that atherosclerotic plaque in the thoracic aorta (TA) correlates with adverse wall shear stress (WSS), but there is a paucity of such data under elevated flow conditions. We developed a pedaling exercise protocol to obtain phase contrast magnetic resonance imaging (PC-MRI) blood flow measurements in the TA and brachiocephalic arteries during three-tiered supine pedaling at 130, 150, and 170 % of resting heart rate (HR), and relate these measurements to non-invasive tissue oxygen saturation (StO₂) acquired by near-infrared spectroscopy (NIRS) while conducting the same protocol. Local quantification …

Only Women Report Increase In Pain Threshold Following Fatiguing Contractions Of The Upper Extremity, Kathy J. Lemley, Jonathon Senefeld, Sandra K. Hunter, Marie K. Hoeger Bement

Physical Therapy Faculty Research and Publications

Purpose

The perception of pain in response to a noxious stimulus can be markedly reduced following an acute bout of exercise [exercise-induced hypoalgesia (EIH)]. Sex differences in EIH frequently occur after exercise but may be confounded by the sex differences in muscle fatigue. The purpose was to determine if sex differences in pain relief occur after an exercise protocol when muscle fatigue is similar for both young and older men and women.

Methods

Pain perception of 33 men (15 young) and 31 women (19 young) was measured using a pressure pain stimulus on the left index finger before and after …

Molecular Underpinnings Of Diabetic Polyneuropathy, Jonathon Senefeld, Sandra K. Hunter

Exercise Science Faculty Research and Publications

No abstract provided.