Physical Therapy Commons^™

Lean Mass Mediates The Relation Between Temporal Summation Of Pain And Sex In Young Healthy Adults, Abdulaziz Awali, Ali Alsouhibani, Marie K. Hoeger Bement

Physical Therapy Faculty Research and Publications

Background

Previous studies have shown that women experience greater temporal summation (TS) of pain than men using a repetitive thermal stimulus. These studies, however, did not individualize the thermal stimulus to each subject’s thermal pain sensitivity. The aim of this study was to investigate sex differences in TS using an individualized protocol and potential mediators that have been shown to influence TS including physical activity and body composition.

Methods

Fifty young healthy men and women (21 men) participated in the study. Subjects completed TS testing on the right forearm using a repetitive thermal stimulus at a temperature that the subject …

Gait Variability And Energy Cost Of Overground Walking In Persons With Multiple Sclerosis: A Cross-Sectional Study, Emerson Sebastião, Rachel E. Bollaert, Elizabeth A. Hubbard, Robert W. Motl

Exercise Science Faculty Research and Publications

Objective: This study examined the associations between gait variability based on common spatiotemporal parameters and energetic cost of walking in persons with multiple sclerosis.

Design: Eighty-six persons with multiple sclerosis underwent the 6-min walk while wearing a portable metabolic unit. The cost of walking was generated by dividing the net steady-state VO₂ (milliliter per kilogram per minute) by walking speed during the 6-min walk. Participants further completed two trials of walking on the GAITRite mat at a self-selected pace for measuring spatiotemporal parameters. Variability of step length, step time, stride length, swing time, stance time, stride velocity, and single- …

Exercise-Induced Pain And Analgesia? Underlying Mechanisms And Clinical Translation, Kathleen A. Sluka, Laura Frey-Law, Marie K. Hoeger Bement

Physical Therapy Faculty Research and Publications

No abstract provided.

Associations Of Functional Connectivity And Walking Performance In Multiple Sclerosis, Rachel E. Bollaert, Kyle Poe, Elizabeth A. Hubbard, Robert W. Motl, Lara A. Pilutti, Curtis L. Johnson, Bradley P. Sutton

Exercise Science Faculty Research and Publications

Background

Persons with multiple sclerosis (MS) often demonstrate impaired walking performance, and neuroimaging methods such as resting state functional connectivity. (RSFC) may support a link between central nervous system damage and disruptions in walking.

Objectives

This study examined associations between RSFC in cortical networks and walking performance in persons with MS.

Methods

29 persons with MS underwent 3-T brain magnetic resonance imaging (MRI) and we computed RSFC among 68 Gy matter regions of interest in the brain. Participants completed the Timed 25-foot Walk as a measure of walking performance. We examined associations using partial Pearson product-moment correlation analyses (r …

Change In Bone Mineral Density Among High Frequency Apheresis Blood Donors, Walter Bialkowski

Dissertations (1934 -)

Exposure to citrate anticoagulant during apheresis blood donation induces significant decreases in serum ionized calcium with subsequent perturbations to parathyroid hormone, vitamin D, and markers of bone remodeling. Cross-sectional studies of bone mineral density (BMD) among apheresis donors exhibit conflicting results. Resolving the potential impact of the highest apheresis donation frequency represents a significant knowledge gap in ensuring adequate protections for volunteer apheresis blood donors. ALTRUYST (NCT02655055) was a randomized, longitudinal, controlled clinical trial designed to determine if repeated exposure to citrate through apheresis donation reduces BMD. Male donors, 18-65 years of age with no more than five previous apheresis …

Ischemic Conditioning Increases Strength And Volitional Activation Of Paretic Muscle In Chronic Stroke: A Pilot Study, Allison S. Hyngstrom, Spencer A. Murphy, Jennifer Nguyen, Brian D. Schmit, Francesco Negro, David D. Gutterman, Matthew J. Durand

Physical Therapy Faculty Research and Publications

Ischemic conditioning (IC) on the arm or leg has emerged as an intervention to improve strength and performance in healthy populations, but the effects on neurological populations are unknown. The purpose of this study was to quantify the effects of a single session of IC on knee extensor strength and muscle activation in chronic stroke survivors. Maximal knee extensor torque measurements and surface EMG were quantified in 10 chronic stroke survivors (>1 yr poststroke) with hemiparesis before and after a single session of IC or sham on the paretic leg. IC consisted of 5 min of compression with a …

Systemic Exercise-Induced Hypoalgesia Following Isometric Exercise Reduces Conditioned Pain Modulation, Ali Alsouhibani, Henrik Bjarke Vaegter, Marie K. Hoeger Bement

Physical Therapy Faculty Research and Publications

Objective

Physically active individuals show greater conditioned pain modulation (CPM) compared with less active individuals. Understanding the effects of acute exercise on CPM may allow for a more targeted use of exercise in the management of pain. This study investigated the effects of acute isometric exercise on CPM. In addition, the between-session and within-session reliability of CPM was investigated.

Design

Experimental, randomized crossover study.

Setting

Laboratory at Marquette University.

Subjects

Thirty healthy adults (19.3±1.5 years, 15 males).

Methods

Subjects underwent CPM testing before and after isometric exercise (knee extension, 30% maximum voluntary contraction for three minutes) and quiet rest in …

A Randomized Trial Of A Motivational Interviewing Intervention To Increase Lifestyle Physical Activity And Improve Self-Reported Function In Adults With Arthritis, Abigail L. Gilbert, Jungwha Lee, Linda S. Ehrlich-Jones, Pamela A. Semanik, Jing Song, Christine A. Pellegrini, Daniel Pinto, Dorothy D. Dunlop, Rowland W. Chang

Physical Therapy Faculty Research and Publications

Background

Arthritis is a leading cause of chronic pain and functional limitations. Exercise is beneficial for improving strength and function and decreasing pain. We evaluated the effect of a motivational interviewing-based lifestyle physical activity intervention on self-reported physical function in adults with knee osteoarthritis (KOA) or rheumatoid arthritis (RA).

Methods

Participants were randomized to intervention or control. Control participants received a brief physician recommendation to increase physical activity to meet national guidelines. Intervention participants received the same brief baseline physician recommendation in addition to motivational interviewing sessions at baseline, 3, 6, and 12 months. These sessions focused on facilitating individualized …

Physical Activity And Annual Medical Outlay In U.S. Colorectal, Breast And Prostate Cancer Survivors, Alice F. Yan, Yang Wang, Alexander V. Ng

Exercise Science Faculty Research and Publications

Multiple chronic conditions in cancer survivors are highly prevalent and may increase health care costs for both patients and the health care system. Studies of cancer survivors reveal positive effects of physical activity (PA) on reducing risk of cancer recurrence, other chronic conditions, and secondary cancer. Few nationally representative studies have examined how physical activity levels have affected survivors' annual economic burden in the United States.

Leisure-time physical activity data from the National Health Interview Survey was linked to health care expenditure data from the Medical Expenditure Panel Survey data (2008–2012). We calculated per-person annual total medical expenditures for identified …

Mechanisms For The Increased Fatigability Of The Lower Limb In People With Type 2 Diabetes, Jonathon Senefeld, Steven B. Magill, April L. Harkins, Alison R. Harmer, Sandra K. Hunter

Exercise Science Faculty Research and Publications

Fatiguing exercise is the basis of exercise training and a cornerstone of management of type 2 diabetes mellitus (T2D), however, little is known about the fatigability of limb muscles and the involved mechanisms in people with T2D. The purpose was to compare fatigability of knee extensor muscles between people with T2D and controls without diabetes and determine the neural and muscular mechanisms for a dynamic fatiguing task. Seventeen people with T2D (10 men, 7 women: 59.6{plus minus}9.0 years) and 21 age-, BMI- and physical activity-matched controls (11 men, 10 women: 59.5{plus minus}9.6 years) performed 120 high-velocity concentric contractions (1 contraction/3 …

Six-Minute Walk Test Performance In Persons With Multiple Sclerosis While Using Passive Or Powered Ankle-Foot Orthoses, Morgan K. Boes, Rachel E. Bollaert, Richard M. Kesler, Yvonne C. Learmonth, Mazharul Islam, Matthew N. Petrucci, Robert W. Motl, Elizabeth T. Hsiao-Wecksler

Exercise Science Faculty Research and Publications

Objective

To determine whether a powered ankle-foot orthosis (AFO) that provides dorsiflexor and plantar flexor assistance at the ankle can improve walking endurance of persons with multiple sclerosis (MS).

Design

Short-term intervention.

Setting

University research laboratory.

Participants

Participants (N=16) with a neurologist-confirmed diagnosis of MS and daily use of a prescribed custom unilateral passive AFO.

Interventions

Three 6-minute walk tests (6MWTs), 1 per footwear condition: shoes (no AFO), prescribed passive AFO, and portable powered AFO (PPAFO). Assistive devices were worn on the impaired limb.

Main Outcome Measures

Distance walked and metabolic cost of transport were recorded during each 6MWT and …

Validation Of The Godin Leisure-Time Exercise Questionnaire Classification Coding System Using Accelerometry In Multiple Sclerosis, Robert W. Motl, Rachel E. Bollaert, Brian M. Sandroff

Exercise Science Faculty Research and Publications

Objective: There have been recent efforts toward creating a health contribution score (HCS) from the Godin Leisure-Time Exercise Questionnaire (GLTEQ) that reflects public-health guidelines for levels of moderate-to-vigorous physical activity (MVPA). The HCS yields categories of insufficiently active (less substantial or low benefits), moderately active (some benefits), and active (substantial benefits). The present study examined the validity of the GLTEQ HCS and its categories as reflecting levels of MVPA in multiple sclerosis (MS). Method: The sample included 684 persons with MS. Participants wore an accelerometer on an elastic belt around the waist above the nondominant hip during the waking hours …

A Randomized, Controlled Clinical Study To Assess The Effect Of Anodal And Cathodal Electrical Stimulation On Periwound Skin Blood Flow And Pressure Ulcer Size Reduction In Persons With Neurological Injuries, Anna Polak, Cezary Kucio, Luther C. Kloth, Malgorzata Paczula, Ewa Hordynska, Tomasz Ickowicz, Edward Blaszczak, Ewa Kucio, Krystian Oleszczyk, Krzysztof Ficek, Andrzej Franek

Physical Therapy Faculty Research and Publications

The use of electrical stimulation (ES) should be considered for treating nonhealing pressure ulcers (PUs), but optimal ES wound treatment protocols have yet to be established. A randomized, controlled, double-blind clinical study was conducted to evaluate the effects of cathodal and anodal high-voltage monophasic pulsed current (HVMPC) on periwound skin blood flow (PSBF) and size reduction of Stage 2 to Stage 4 PUs of at least 4 weeks’ duration.Persons >18 years of age, hospitalized with neurological injuries, at high risk for PU development (Norton scale <14 >points; Waterlow scale >15 points), and with at least 1 Stage 2 to Stage 4 …

Girls In The Boat: Sex Differences In Rowing Performance And Participation, Kevin G. Keenan, Jonathon Senefeld, Sandra K. Hunter

Exercise Science Faculty Research and Publications

Men outperform women in many athletic endeavors due to physiological and anatomical differences (e.g. larger and faster muscle); however, the observed sex differences in elite athletic performance are typically larger than expected, and may reflect sex-related differences in opportunity or incentives. As collegiate rowing in the United States has been largely incentivized for women over the last 20 years, but not men, the purpose of this study was to examine sex differences in elite rowing performance over that timeframe. Finishing times from grand finale races for collegiate championship on-water performances (n = 480) and junior indoor performances (n = 1,280) …

Evaluation Of Vascular Control Mechanisms Utilizing Video Microscopy Of Isolated Resistance Arteries Of Rats, Kathleen M. Lukaszewicz, Matthew J. Durand, Jessica R. C. Priestley, James R. Schmidt, L. Adrienne Allen, Aron M. Geurts, Julian H. Lombard

Physical Therapy Faculty Research and Publications

This protocol describes the use of in vitro television microscopy to evaluate vascular function in isolated cerebral resistance arteries (and other vessels), and describes techniques for evaluating tissue perfusion using Laser Doppler Flowmetry (LDF) and microvessel density utilizing fluorescently labeled Griffonia simplicifolia (GS1) lectin. Current methods for studying isolated resistance arteries at transmural pressures encountered in vivo and in the absence of parenchymal cell influences provide a critical link between in vivo studies and information gained from molecular reductionist approaches that provide limited insight into integrative responses at the whole animal level. LDF and techniques to selectively identify arterioles and …

Contraction Intensity And Sex Differences In Knee-Extensor Fatigability, Paul Ansdell, Kevin Thomas, Glyn Howatson, Sandra K. Hunter, Stuart Goodall

Exercise Science Faculty Research and Publications

Females are less fatigable than males during isometric contractions across various muscles and intensities. However, sex differences in knee-extensor fatigability remain relatively unexplored. Purpose: To determine the sex difference in performance fatigability for intermittent, isometric contractions of the knee-extensor muscles. Methods: Eighteen participants (10 males, 8 females) performed intermittent, isometric, knee-extensor contractions at 30% of their maximal voluntary force (MVC) for 30 min and in a separate session at 50% MVC until task-failure. During both fatiguing protocols a MVC was performed every 60 s and electromyography (EMG) was recorded during all contractions. Results: At task completion males had a larger …

Association Between Sedentary Time And Quality Of Life From The Osteoarthritis Initiative: Who Might Benefit Most From Treatment?, Daniel Pinto, Jing Song, Jungwha Lee, Rowland W. Chang, Pamela A. Semanik, Linda S. Ehrlich-Jones, Christine A. Pellegrini, Dorothy D. Dunlop

Physical Therapy Faculty Research and Publications

Objective

To investigate the relationship between sedentary behavior and quality-adjusted life years (QALYs) among participants in the Osteoarthritis Initiative.

Design

Longitudinal, observational design.

Setting

Osteoarthritis Initiative cohort.

Participants

Individuals (N=1794) from a prospective, multicenter longitudinal cohort were classified into quantile groups based on average daily sedentary time (most sedentary, quartile 1 [Q1] ≥11.6h; 10.7h≤ Q2

Interventions

Not applicable.

Main Outcome Measures

Individual QALYs were estimated over 2 years from the area under the curve of health-related utility scores derived from the Medical Outcomes Study 12-Item Short-Form Health Survey versus time. The relationship between baseline sedentary behavior and median 2-year QALYs …

Pediatric Psychologists’ Career Satisfaction: 2015 Society Of Pediatric Psychology Workforce Survey Results., Marisa E. Hilliard, Andre A.A. Williams, Astrida S. Kaugars, Peggy Christidis, Karen E. Stamm, Cheryl Brosig, Jessica Valenzuela, Paul M. Robins, Tim Wysocki

Physical Therapy Faculty Research and Publications

Little is known about the career satisfaction of pediatric psychologists, who specialize in psychological research, teaching, and clinical service in the context of pediatric health care. As part of the larger Society of Pediatric Psychology Workforce Survey and in collaboration with the American Psychological Association Center for Workforce Studies, this study aimed to (1) describe the career domains which pediatric psychologists perceive to be important and their satisfaction in each domain, and (2) compare satisfaction of pediatric psychologists across work settings, number of positions, appointment duration, professional roles, career stage, academic rank, and gender. Responses from 336 pediatric psychologists demonstrated …

Factors That Influence Self-Reported Health Changes With Caregiving, Margaret Danilovich, Xiaoling Xiang, Daniel Pinto

Physical Therapy Faculty Research and Publications

Objective: This study examined factors associated with the self-reported change in health status as a result of caregiving. Method: Multinomial logistic regression were performed to examine the sociodemographic characteristics, care recipients’ characteristics, and caregiving experiences that affect caregivers’ perceptions of health affected by caregiving using data from 1,087 caregiver respondents in the Caregiving in the U.S. 2015 data set. Data were collected through an online or telephone survey of randomly selected adults in 50 states. Results: Worsened self-reported health with caregiving occurred for caregivers aged 50 to 64, racial/ethnic minorities, those who lived within 20 min of the care recipient’s …

Physiological Response To Firefighting Activities Of Various Work Cycles Using Extended Duration And Prototype Scba, Richard M. Kesler, Ipek Ensari, Rachel E. Bollaert, Robert W. Motl, Elizabeth T. Hsiao-Wecksler, Karl S. Rosengren, Bo Fernhall, Denise L. Smith, Gavin P. Horn

Exercise Science Faculty Research and Publications

Firefighters’ self-contained breathing apparatus (SCBA) protects the respiratory system during firefighting but increases the physiological burden. Extended duration SCBA (>30 min) have increased air supply, potentially increasing the duration of firefighting work cycles. To examine the effects of SCBA configuration and work cycle (length and rest), 30 firefighters completed seven trials using different SCBA and one or two bouts of simulated firefighting following work cycles common in the United States. Heart rate, core temperature, oxygen consumption, work output and self-reported perceptions were recorded during all activities. Varying SCBA resulted in few differences in these parameters. However, during a second …

Ventilation And Neurochemical Changes During Μ-Opioid Receptor Activation Or Blockade Of Excitatory Receptors In The Hypoglossal Motor Nucleus Of Goats, Thomas M. Langer, Suzanne E. Neumueller, Emma Crumley, Nicholas J. Burgraff, Sawan Talwar, Matthew R. Hodges, Lawrence Pan, Hubert V. Forster

Physical Therapy Faculty Research and Publications

Neuromodulator interdependence posits that changes in one or more neuromodulators are compensated by changes in other modulators to maintain stability in the respiratory control network. Herein, we studied compensatory neuromodulation in the hypoglossal motor nucleus (HMN) after chronic implantation of microtubules unilaterally (n = 5) or bilaterally (n = 5) into the HMN. After recovery, receptor agonists or antagonists in mock cerebrospinal fluid (mCSF) were dialyzed during the awake and non-rapid eye movement (NREM) sleep states. During day studies, dialysis of the µ-opioid inhibitory receptor agonist [d-Ala², N-MePhe⁴, Gly-ol]enkephalin (DAMGO; 100 µM) decreased …

Sex Differences In Spatial Accuracy Relate To The Neural Activation Of Antagonistic Muscles In Young Adults, Agostina Casamento-Moran, Sandra K. Hunter, Yen-Ting Chen, Min-Hyuk Kwon, Emily J. Fox, Basma Yacoubi, Evangelos A. Christou

Exercise Science Faculty Research and Publications

Sex is an important physiological variable of behavior, but its effect on motor control remains poorly understood. Some evidence suggests that women exhibit greater variability during constant contractions and poorer accuracy during goal-directed tasks. However, it remains unclear whether motor output variability or altered muscle activation impairs accuracy in women. Here, we examine sex differences in endpoint accuracy during ankle goal-directed movements and the activity of the antagonistic muscles. Ten women (23.1 ± 5.1 years) and 10 men (23 ± 3.7 years) aimed to match a target (9° in 180 ms) with ankle dorsiflexion. Participants performed 50 trials and we …

Physical Activity Modulates Corticospinal Excitability Of The Lower Limb In Young And Old Adults, Hamidollah Hassanlouei, Christopher W. Sundberg, Ashleigh E. Smith, Andrew Kuplic, Sandra K. Hunter

Exercise Science Faculty Research and Publications

Aging is associated with reduced neuromuscular function, which may be due in part to altered corticospinal excitability. Regular physical activity (PA) may ameliorate these age-related declines, but the influence of PA on corticospinal excitability is unknown. The purpose of this study was to determine the influence of age, sex, and PA on corticospinal excitability by comparing the stimulus-response curves of motor evoked potentials (MEP) in 28 young (22.4 ± 2.2 yr; 14 women and 14 men) and 50 old adults (70.2 ± 6.1 yr; 22 women and 28 men) who varied in activity levels. Transcranial magnetic stimulation was used to …

The Efficacy Of Pressure Ulcer Treatment With Cathodal And Cathodal-Anodal High-Voltage Monophasic Pulsed Current: A Prospective, Randomized, Controlled Clinical Trial, Anna Polak, Luther C. Kloth, Edward Blaszczak, Jakub Taradaj, Agnieszka Nawrat-Szoltysik, Tomasz Ickowicz, Ewa Hordynska, Andrzej Franek, Cezary Kucio

Physical Therapy Faculty Research and Publications

Background. Studies show that anode and cathode electrical stimulation (ES) promotes the healing of wounds, but specific protocols for both electrodes are not available.

Objective. To compare the effectiveness of cathodal versus cathodal+anodal ES in the treatment of Category II-IV pressure ulcers (PrUs).

Design. Prospective, randomized, controlled, clinical study.

Setting. Three nursing and care centers.

Patients. Sixty-three participants with PrUs were randomly formed into a cathodal ES group (CG: N = 23; mean age of 79.35; SD 8.48), a cathodal+anodal ES group (CAG: N = 20; mean age of 79.65; SD 11.44) and a placebo ES group (PG: N = …

Neuromuscular Function In Women Postpartum, Rita Deering

Dissertations (1934 -)

Efficient abdominal muscle function is important for functional mobility in men and women, and dysfunction of these muscles has been associated with impaired function such as low back pain. This dissertation explored abdominal muscle function in healthy young men and young women who have never been pregnant (nulligravid). As pregnancy and child birth also impact the tissues of the abdominal wall, this dissertation will also explore abdominal muscle function in postpartum women. This dissertation involved three primary aims. Aim1 compared abdominal muscle function and experimental pain perception in males and nulligravid females. Maximal strength over a range of trunk angles, …

Effects On Breathing Of Agonists To Μ-Opioid Or GabaA Receptors Dialyzed Into The Ventral Respiratory Column Of Awake And Sleeping Goats, Thomas M. Langer Iii, Suzanne E. Neumueller, Emma Crumley, Nicholas J. Burgraff, Sawan Talwar, Matthew R. Hodges, Lawrence Pan, Hubert V. Forster

Physical Therapy Faculty Research and Publications

Pulmonary ventilation (V̇_I) in awake and sleeping goats does not change when antagonists to several excitatory G protein-coupled receptors are dialyzed unilaterally into the ventral respiratory column (VRC). Concomitant changes in excitatory neuromodulators in the effluent mock cerebral spinal fluid (mCSF) suggest neuromodulatory compensation. Herein, we studied neuromodulatory compensation during dialysis of agonists to inhibitory G protein-coupled or ionotropic receptors into the VRC. Microtubules were implanted into the VRC of goats for dialysis of mCSF mixed with agonists to either μ-opioid (DAMGO) or GABA_A (muscimol) receptors. We found: (1) V̇_I decreased during unilateral but increased during …

Physical Activity Minimum Threshold Predicting Improved Function In Adults With Lower‐Extremity Symptoms, Dorothy D. Dunlop, Jing Song, Jungwha Lee, Abigail L. Gilbert, Pamela A. Semanik, Linda S. Ehrlich-Jones, Christine A. Pellegrini, Daniel Pinto, Barbara Ainsworth, Rowland W. Chang

Physical Therapy Faculty Research and Publications

Objective

To identify an evidence‐based minimum physical activity threshold to predict improved or sustained high function for adults with lower‐extremity joint symptoms.

Methods

Prospective multisite data from 1,629 adults, age ≥49 years with symptomatic lower‐extremity joint pain/aching/stiffness, participating in the Osteoarthritis Initiative accelerometer monitoring substudy were clinically assessed 2 years apart. Improved/high function in 2‐year gait speed and patient‐reported outcomes (PROs) were based on improving or remaining in the best (i.e., maintaining high) function quintile compared to baseline status. Optimal thresholds predicting improved/high function were investigated using classification trees for the legacy federal guideline metric requiring 150 minutes/week of moderate‐vigorous …

Cardio-Protection Afforded By Β-Blockade Is Maintained During Resistance Exercise, Alexander V. Ng, Jason M. Conviser, Shawn S. Rockey, D. Paul Thomas

Exercise Science Faculty Research and Publications

Objectives

Whether or not the cardio-protective effect of β-adrenergic blockade is retained during resistance exercise has not been systematically evaluated. Therefore the purpose of this study was to measure selected cardiorespiratory responses to isometric exercise involving hand-gripping, single-leg extension, or double-leg dead-lift, under placebo (control), β₁-selective (atenolol), and non-selective (propranolol) adrenergic blockade conditions.

Design

Eleven young male adults were evaluated in a randomized, double-blinded, repeated measures study design and performed all three exercise modalities at 30% of maximal voluntary contraction under placebo, atenolol and propranolol conditions.

Methods

Heart rate, systolic and diastolic blood pressure, rate-pressure product, oxygen uptake, …

State-Dependent And -Independent Effects Of Dialyzing Excitatory Neuromodulator Receptor Antagonists Into The Ventral Respiratory Column, Thomas M. Langer Iii, Suzanne E. Neumueller, Emma Crumley, Nicholas J. Burgraff, Sawan Talwar, Matthew R. Hodges, Lawrence Pan, Hubert V. Forster

Physical Therapy Faculty Research and Publications

Unilateral dialysis of the broad-spectrum muscarinic receptor antagonist atropine (50 mM) into the ventral respiratory column [(VRC) including the pre-Bötzinger complex region] of awake goats increased pulmonary ventilation (V̇i) and breathing frequency (f), conceivably due to local compensatory increases in serotonin (5-HT) and substance P (SP) measured in effluent mock cerebral spinal fluid (mCSF). In contrast, unilateral dialysis of a triple cocktail of antagonists to muscarinic (atropine; 5 mM), neurokinin-1, and 5-HT receptors does not alter V̇i or f, but increases local SP. Herein, we tested hypotheses that 1) local compensatory 5-HT and SP responses to 50 mM atropine …

Sex Differences In Neuromuscular Fatigability Of The Knee Extensors Post-Stroke, Meghan Kirking, Reivian B. Barillas, Philip A. Nelson, Sandra K. Hunter, Allison S. Hyngstrom

Exercise Science Faculty Research and Publications

Background and Purpose: Despite the implications of optimizing strength training post-stroke, little is known about the differences in fatigability between men and women with chronic stroke. The purpose of this study was to determine the sex differences in knee extensor muscle fatigability and potential mechanisms in individuals with stroke. Methods: Eighteen participants (10 men, eight women) with chronic stroke (≥6 months) and 23 (12 men, 11 women) nonstroke controls participated in the study. Participants performed an intermittent isometric contraction task (6 s contraction, 3 s rest) at 30% of maximal voluntary contraction (MVC) torque until failure to maintain the target …