Open Access. Powered by Scholars. Published by Universities.®

Kinesiology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Social and Behavioral Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1351 - 1380 of 1423

Full-Text Articles in Kinesiology

The Need For Advanced Cardiac Life Support Certification For Open-Water Lifeguards At Huntington Beach, Ca, Daniel Jerome, Peter R. Chambers, Steve Reuter, John Porcari Jan 2008

The Need For Advanced Cardiac Life Support Certification For Open-Water Lifeguards At Huntington Beach, Ca, Daniel Jerome, Peter R. Chambers, Steve Reuter, John Porcari

International Journal of Aquatic Research and Education

The number of people visiting U.S. beaches increased in 2007 to more than 240 million people. This increase in activities does not come without danger. Lifeguards maintain beach safety, but little research is available to assist us in determining appropriate certification levels for lifeguards. The authors analyzed various injuries that occurred in the open-water environment of Huntington Beach, CA. Based on the nature of the injuries, they attempted to determine the level of training lifeguards needed. The vast majority of injuries (99%) were soft-tissue injuries, musculoskeletal injuries, or environmental injuries. It was felt that lifeguards with first-aid and basic-life-support (BLS) …


Men's Basketball 2007-2008 Team Members, Southwestern Oklahoma State University Jan 2008

Men's Basketball 2007-2008 Team Members, Southwestern Oklahoma State University

Men's Basketball Videos

Video of the 2007-2008 SWOSU men's basketball team members.

Also attached is a PDF of the 2007-2008 SWOSU men's basketball statistics, scanned from the 2008-2009 SWOSU Men's Basketball Media Guide.

This recording has no audio.


Women's Basketball 2007-2008 Team Members, Southwestern Oklahoma State University Jan 2008

Women's Basketball 2007-2008 Team Members, Southwestern Oklahoma State University

Women’s Basketball Videos

Video of the 2007-2008 SWOSU women's basketball team members.

Also attached is a PDF of the 2007-2008 women's basketball team statistics, scanned from the 2008-2009 SWOSU Women's Basketball Media Guide.

This recording has no audio.


Relationship Between Physical Activity Level, Telomere Length, And Telomerase Activity, Andrew T. Ludlow, Jo B. Zimmerman, Sarah Witkowski, Joe W. Hearn, Bradley D. Hatfield, Stephen M. Roth Jan 2008

Relationship Between Physical Activity Level, Telomere Length, And Telomerase Activity, Andrew T. Ludlow, Jo B. Zimmerman, Sarah Witkowski, Joe W. Hearn, Bradley D. Hatfield, Stephen M. Roth

Exercise and Sport Studies: Faculty Publications

The purpose of this study was to examine the relationship of exercise energy expenditure (EEE) with both telomere length and telomerase activity in addition to accounting for hTERT C-1327T promoter genotype.


Hper Biomechanics Laboratory 2006 Annual Report, Issue 5, Nebraska Biomechanics Core Facility May 2007

Hper Biomechanics Laboratory 2006 Annual Report, Issue 5, Nebraska Biomechanics Core Facility

Biomechanics Annual Report

This issue features Peripheral Arterial Disease and Geriatrics Research Update, Lab Expands with New Personnel, Labor on NIH Grant Is, “Gratifying Labor” States Dr. Stergiou, Federal Grant On Cerebral Palsy: Joint Venture Demonstrates Progress, Evolution of Wireless Gait Analysis, Innovations of Robotic Assisted Surgery Research, Incorporating Virtual Reality, Events in the Lab, Dr. Stergiou Awarded Outstanding Graduate Mentor , Collaborations in Orthopedics, The Media Features Efforts in HPER Biomechanics Lab , Other Continuing Collaborations, Other Exciting News, Publications for 2006 and The 2006-2007 HPER Biomechanics Laboratory.


Progenitor Cells And Age: Can We Fight Aging With Exercise?, Sarah Witkowski, James M. Hagberg Mar 2007

Progenitor Cells And Age: Can We Fight Aging With Exercise?, Sarah Witkowski, James M. Hagberg

Exercise and Sport Studies: Faculty Publications

No abstract provided.


Transcranial Doppler Estimation Of Cerebral Blood Flow And Cerebrovascular Conductance During Modified Rebreathing, Jurgen A.H.R. Claassen, Rong Zhang, Qi Fu, Sarah Witkowski, Benjamin D. Levine Mar 2007

Transcranial Doppler Estimation Of Cerebral Blood Flow And Cerebrovascular Conductance During Modified Rebreathing, Jurgen A.H.R. Claassen, Rong Zhang, Qi Fu, Sarah Witkowski, Benjamin D. Levine

Exercise and Sport Studies: Faculty Publications

Clinical transcranial Doppler assessment of cerebral vasomotor reactivity (CVMR) uses linear regression of cerebral blood flow velocity (CBFV) vs. end-tidal CO2 (PETCO2) under steady-state conditions. However, the cerebral blood flow (CBF)-PETCO2 relationship is nonlinear, even for moderate changes in CO2. Moreover, CBF is increased by increases in arterial blood pressure (ABP) during hypercapnia. We used a modified rebreathing protocol to estimate CVMR during transient breath-by-breath changes in CBFV and PETCO2. Ten healthy subjects (6 men) performed 15 s of hyperventilation followed by 5 min of rebreathing, with supplemental O2 to maintain arterial oxygen saturation constant. To minimize effects of changes …


Handling Immediate Medical Care At Aquatic Facilities: Do We Need Different Levels Of Lifeguard Certification?, Leland Yarger Feb 2007

Handling Immediate Medical Care At Aquatic Facilities: Do We Need Different Levels Of Lifeguard Certification?, Leland Yarger

International Journal of Aquatic Research and Education

The first-responder and professional-rescuer training materials and training programs consider lifeguards to be first responders in emergencies (Aehlert, 2005; American Red Cross, 2001). This article asks readers to consider whether our agency lifeguard-training programs reflect a philosophy that truly view and prepare lifeguards as first responders. If not, I challenge readers to consider whether we should alter our hiring, staffing, and in-service training procedures at aquatic facilities based on the scope and need for providing adequate emergency care at those facilities.


Escape And Rescue From Submerged Vehicles, Gerald M. Dworkin Feb 2007

Escape And Rescue From Submerged Vehicles, Gerald M. Dworkin

International Journal of Aquatic Research and Education

No abstract provided.


Cerebral Hemodynamics After Short- And Long-Term Reduction In Blood Pressure In Mild And Moderate Hypertension, Rong Zhanf, Sarah Witkowski, Qi Fu, Jurgen A.H.R. Claassen, Benjamin D. Levine Jan 2007

Cerebral Hemodynamics After Short- And Long-Term Reduction In Blood Pressure In Mild And Moderate Hypertension, Rong Zhanf, Sarah Witkowski, Qi Fu, Jurgen A.H.R. Claassen, Benjamin D. Levine

Exercise and Sport Studies: Faculty Publications

This study tested the hypothesis that acute reduction in blood pressure (BP) at the initial stage of antihypertensive therapy compromises brain perfusion and dynamic cerebral autoregulation in patients with hypertension. Cerebral blood flow velocity and BP were measured in patients with mild and moderate hypertension and in healthy volunteers at baseline upon reduction of BP within 1 to 2 weeks of administration of losartan/hydrochlorothiazide and after 3 to 4 months of treatment. The transfer function between beat-to-beat changes in BP and cerebral blood flow velocity was estimated to assess dynamic autoregulation. After 1 to 2 weeks of treatment, BP was …


The Locomotor Kinematics Of Asian And African Elephants: Changes With Speed And Size, John R. Hutchinson, Delf Schwerda, Daniel J. Famini, Robert H.I. Dale, Martin S. Fischer, Rodger Kram Oct 2006

The Locomotor Kinematics Of Asian And African Elephants: Changes With Speed And Size, John R. Hutchinson, Delf Schwerda, Daniel J. Famini, Robert H.I. Dale, Martin S. Fischer, Rodger Kram

Scholarship and Professional Work - LAS

For centuries, elephant locomotion has been a contentious and confusing challenge for locomotion scientists to understand, not only because of technical difficulties but also because elephant locomotion is in some ways atypical of more familiar quadrupedal gaits. We analyzed the locomotor kinematics of over 2400 strides from 14 African and 48 Asian elephant individuals (body mass 116-4632 kg) freely moving over ground at a 17-fold range of speeds, from slow walking at 0.40 m s-1 to the fastest reliably recorded speed for elephants, 6.8 m s-1. These data reveal that African and Asian elephants have some subtle …


Fitness, Friendship, And Fun: University Sponsored Community Pe Program, Wendi Wilcox Stanley, George M. De Marco, Lloyd L. Laubach, Corinne M. Daprano Sep 2006

Fitness, Friendship, And Fun: University Sponsored Community Pe Program, Wendi Wilcox Stanley, George M. De Marco, Lloyd L. Laubach, Corinne M. Daprano

Health and Sport Science Faculty Publications

This paper describes a University-sponsored community physical education program and the feedback received about it from teachers, children, and the college students who oversaw it. The program, called Fitness, Friendship, and Fun, was staffed by 65 first-year student interns from the University of Dayton; four graduate assistants; and two university professors. It began with 65 male and female elementary students, primarily from the fifth and sixth grades at a nearby elementary school.


Hper Biomechanics Laboratory 2005 Annual Report, Issue 4, Nebraska Biomechanics Core Facility Mar 2006

Hper Biomechanics Laboratory 2005 Annual Report, Issue 4, Nebraska Biomechanics Core Facility

Biomechanics Annual Report

This issue features Dr. Stergiou Receives a K25 Award from the National Institutes of Health, Training Methods to Improve Robotic Laparoscopic Surgery, Progress Update for Federal Grant: The Development of Sitting Posture in Children with Cerebral Palsy, Pioneering Gait Analysis Research, Collaboration with UNMC Department of Surgery and VA Hospital: The Effects of Peripheral Arterial Disease on Gait, Sabbatical Strengthened Collaborations in Orthopedics, Computer Modeling with Dynamic Toys Reveals Human Gait Patterns, Prestigious Awards to Dr. Stergiou, Teachers Enriched During Final Year of Banneker 2000, New Staff Joins the HPER Biomechanics Laboratory, Noteworthy Events, Internationally Recognized Bioengineer Visited HPER Biomechanics …


Disaggregating The Relative Influence Of Genetic, Environmental And Individual Factors On Ldl And Hdl Cholesterols And Bmi For A Sample Of African American (Aa) Mothers And Daughters, C. Jayne Brahler, Jewel Harden, Michelle Mchone, Matthew Soules, Eric Evans, Ann Alyanak, Fred Diakpieng, Paul M. Vanderburgh Feb 2006

Disaggregating The Relative Influence Of Genetic, Environmental And Individual Factors On Ldl And Hdl Cholesterols And Bmi For A Sample Of African American (Aa) Mothers And Daughters, C. Jayne Brahler, Jewel Harden, Michelle Mchone, Matthew Soules, Eric Evans, Ann Alyanak, Fred Diakpieng, Paul M. Vanderburgh

Health and Sport Science Faculty Publications

There are many reports about the associations between blood lipids, body mass index (BMI) and dietary cholesterol intakes both within the individual and between related individuals. The purpose of this descriptive research project was to investigate the relationships between LDL and HDL cholesterols, body mass index and dietary cholesterol intakes for a sample of African American (AA) mothers and their daughters and to attempt to separate the contribution of genetic versus environmental factors. Mother and daughter participants (n =42 and 66, respectively) were 12-14-hours fasted when blood samples were drawn, heights and weights measured, and 24 hour food recalls completed.


Hazing: What Ohio High School Teachers, Coaches And Administrators Need To Know, Corinne M. Daprano, Meghan Kenney, Peter J. Titlebaum, Michael Triola Jan 2006

Hazing: What Ohio High School Teachers, Coaches And Administrators Need To Know, Corinne M. Daprano, Meghan Kenney, Peter J. Titlebaum, Michael Triola

Health and Sport Science Faculty Publications

Once thought to be primarily an issue of concern for university fraternities and sororities, hazing has emerged as a disturbing trend with an increase in the number of incidents involving high school student athletes. High school coaches, athletic administrators, and teachers must understand that initiation rites of sport teams can sometimes spiral out of control with grave legal and financial consequences for student athletes and school officials. The purposes of this article are to:

  • Define hazing and review the history of anti-hazing legislation in the United States of America.
  • Describe hazing laws in the State of Ohio.
  • Review current research …


Student Employee Recruitment And Retention Through Campus Partnerships, Corinne M. Daprano, Megan L. Coyle, Peter J. Titlebaum Nov 2005

Student Employee Recruitment And Retention Through Campus Partnerships, Corinne M. Daprano, Megan L. Coyle, Peter J. Titlebaum

Health and Sport Science Faculty Publications

Recruitment and retention of student employees are important considerations for any recreational sports department, large or small, because student employees impact both the quantity and quality of programs and services. This article proposes a strategy for establishing partnerships with academic departments to aid in the recruitment and retention of student employees. These partnerships benefit students, the recreational sports department, academic departments, and university student retention efforts. Following a description of this strategy is an example of a partnership that has been successfully established at one Midwestern university.


The Theory Of Planned Behavior: Predicting Physical Activity And Cardiorespiratory Fitness In African American Children, Jeffrey J. Martin, Pamela Hodges Kulinna, Nate Mccaughtry, Donetta Cothran, Joe Dake, Gail Frances Fahoome Oct 2005

The Theory Of Planned Behavior: Predicting Physical Activity And Cardiorespiratory Fitness In African American Children, Jeffrey J. Martin, Pamela Hodges Kulinna, Nate Mccaughtry, Donetta Cothran, Joe Dake, Gail Frances Fahoome

Kinesiology, Health and Sport Studies

The purpose of our study was to evaluate the ability of the Theory of Planned Behavior (TPB) to predict African American children’s moderate to vigorous physical activity (MVPA) and cardiorespiratory fitness. Children (N = 548, ages 9–12) completed questionnaires assessing the TPB constructs and MVPA and then had their cardiorespiratory fitness assessed with the Progressive Aerobic Cardiovascular Endurance Run (PACER) test. Commonly used Structural Equation Modeling fit indices suggested the model was an adequate representation for the relationships within the data. However, results also suggested an extended model which was examined and supported. Tests of direct paths from subjective …


Functional Electric Stimulation Cycle Ergometry Training Effect On Lower Limb Muscles In Acute Sci Individuals, Timothy J. Demchak, Jon K. Linderman, W. Jerry Mysiw, Rebecca Jackson, Jihong Sunn, Steven T. Devor Sep 2005

Functional Electric Stimulation Cycle Ergometry Training Effect On Lower Limb Muscles In Acute Sci Individuals, Timothy J. Demchak, Jon K. Linderman, W. Jerry Mysiw, Rebecca Jackson, Jihong Sunn, Steven T. Devor

Health and Sport Science Faculty Publications

The purpose of this study was to compare three different intervals for a between sets rest period during a common isokinetic knee extension strength-testing protocol of twenty older Brazilian men (66.30 ± 3.92 yrs). The volunteers underwent unilateral knee extension (Biodex System 3) testing to determine their individual isokinetic peak torque at 60, 90, and 120° ·s-1. The contraction speeds and the rest periods between sets (30, 60 and 90 s) were randomly performed in three different days with a minimum rest period of 48 hours. Significant differences between and within sets were analyzed using a One Way Analysis of …


The Effects Of An Analgesic (Biofreeze®) On The Motoneuron Pool Excitability Of The Soleus Muscle, Desiree R. Barth Aug 2005

The Effects Of An Analgesic (Biofreeze®) On The Motoneuron Pool Excitability Of The Soleus Muscle, Desiree R. Barth

All-Inclusive List of Electronic Theses and Dissertations

Objective: The purpose of this study was to determine the effects on the Hoffman reflex and motor response with an analgesic (Biofreeze®). Design: The study was a 2X6 design. The independent variables in this study were treatment and time. The dependent variables were the H-reflex (volts) and the M response (volts). Treatment was randomly assigned to control for the effects of order. Setting: This study took place in the Exercise Physiology Laboratory located in the Health and Human Performance Building at Indiana State University. Subjects: 14 volunteers who were physically active and had no known neurological problems. Measurements: Skin and …


A Social Cognitive Perspective Of Physical-Activity-Related Behavior In Physical Education, Jeffrey J. Martin, Pamela Hodges Kulinna Jul 2005

A Social Cognitive Perspective Of Physical-Activity-Related Behavior In Physical Education, Jeffrey J. Martin, Pamela Hodges Kulinna

Kinesiology, Health and Sport Studies

The purpose of the current study was to examine student and teacher physical-activity-related behavior using the theory of planned behavior and self-efficacy theory. Although teachers reported an overwhelmingly positive attitude toward teaching physical activity lessons to promote fitness development, they only devoted 4% of their class time to actually demonstrating and promoting fitness. Students were quite sedentary during class spending 61% of class time sitting, standing, or lying down. Using hierarchical regression analyses, teachers' attitudes toward teaching physically active physical education classes accounted for 50% of the variance in teachers' intention. Teachers who demonstrated/promoted fitness and who limited their general …


Effects Of Gender And Hypovolemia On Sympathetic Neural Responses To Orthostatic Stress, Qi Fu, Sarah Witkowski, Kazunobu Okazaki, Benjamin D. Levine Jul 2005

Effects Of Gender And Hypovolemia On Sympathetic Neural Responses To Orthostatic Stress, Qi Fu, Sarah Witkowski, Kazunobu Okazaki, Benjamin D. Levine

Exercise and Sport Studies: Faculty Publications

We tested the hypothesis that women have blunted sympathetic neural responses to orthostatic stress compared with men, which may be elicited under hypovolemic conditions. Muscle sympathetic nerve activity (MSNA) and hemodynamics were measured in eight healthy young women and seven men in supine position and during 6 min of 60° head-up tilt (HUT) under normovolemic and hypovolemic conditions (randomly), with ∼4-wk interval. Acute hypovolemia was produced by diuretic (furosemide) administration ∼2 h before testing. Orthostatic tolerance was determined by progressive lower body negative pressure to presyncope. We found that furosemide produced an ∼13% reduction in plasma volume, causing a similar …


Possible Effects Field Hockey Stick Weight May Have On Player Performance During A Penalty Stroke, Lee-Ann Sharp May 2005

Possible Effects Field Hockey Stick Weight May Have On Player Performance During A Penalty Stroke, Lee-Ann Sharp

All-Inclusive List of Electronic Theses and Dissertations

Context: Wooden sticks have been used in field hockey since the inception of the game. In recent years, there has been a growing trend among players to use modern composite sticks. However, there has been no research into the possible effects the weight of these composite sticks could have on player's performances. Objective: The purpose of this study was to examine the effect stick weight would have on player perfonnance, specifically ball velocity and player accuracy, during a series of penalty strokes. Design: All subjects were required to take twenty penalty strokes on goal with each of the two differently …


Hper Biomechanics Laboratory 2004 Annual Report: A Surveillance Of The Neuromuscular System, Issue 3, Nebraska Biomechanics Core Facility Jan 2005

Hper Biomechanics Laboratory 2004 Annual Report: A Surveillance Of The Neuromuscular System, Issue 3, Nebraska Biomechanics Core Facility

Biomechanics Annual Report

This issue features 2004 - A Great Year for External Funding: Three Grants Awarded to Dr. Stergiou, Robotic Surgery Research is Funded by the Nebraska Research Initiative, Federal Grant is Awarded for the Study of the Development of Posture in Children with Cerebral Palsy, The Nebraska Research Initiative funds our Innovative Research in Gait Analysis, Collaboration with the Department of Surgery of the University of Nebraska Medical Center on the Effects of Peripheral Arterial Disease on Gait, Omaha Media Features Nicholas Stergiou, Dr. Stergiou participates in an NIH Review Panel, Prestigious Teaching Award for Dr. Stergiou, NASA Visits HPER Biomechanics …


Persistent Sympathetic Activation During Chronic Antihypertensive Therapy, Qi Fu, Rong Zhang, Sarah Witkowski, Armin Arbab-Zadeh, Anand Prasad, Kazunobu Okazaki, Benjamin D. Levine Jan 2005

Persistent Sympathetic Activation During Chronic Antihypertensive Therapy, Qi Fu, Rong Zhang, Sarah Witkowski, Armin Arbab-Zadeh, Anand Prasad, Kazunobu Okazaki, Benjamin D. Levine

Exercise and Sport Studies: Faculty Publications

Previous studies have demonstrated that antihypertensive treatment resets baroreflex control of heart rate (HR) and increases cardiac vagal baroreflex sensitivity. However, it is uncertain whether baroreflex control of muscle sympathetic nerve activity (MSNA) also resets after treatment. We tested the hypothesis that chronic antihypertensive therapy alters baroreflex regulation of MSNA in patients with untreated moderate hypertension. Seven newly diagnosed patients with systolic blood pressure (BP) of 159 5 mm Hg (mean SE) and diastolic BP of 103 4 mm Hg were studied before and after 1 to 2 weeks ´ and 3 months (chronic) of antihypertensive treatment with losartan– hydrochlorothiazide …


Qtc Is Associated With Obesity And Physical Activity Level For African American Females, C. Jayne Brahler Apr 2004

Qtc Is Associated With Obesity And Physical Activity Level For African American Females, C. Jayne Brahler

Health and Sport Science Faculty Publications

Long QT syndrome (LQTS) is an independent risk factor for cardiovascular or ischemic disease mortality. Obesity as a cause for acquired LQTS in otherwise healthy individuals is rapidly gaining the attention of the scientific community. African American people have a higher incidence of obesity compared to Caucasians, yet race-specific information is not available for their prevalence of LQTS. Chronic physical activity can help reduce the incidence of obesity, yet little is known about the effects of chronic physical activity on acquired LQTS. Subjects in this study were a volunteer sample of African American mothers (21-53 yr, n = 44) and …


Hper Biomechanics Laboratory 2003 Annual Report, Issue 2, Nebraska Biomechanics Core Facility Jan 2004

Hper Biomechanics Laboratory 2003 Annual Report, Issue 2, Nebraska Biomechanics Core Facility

Biomechanics Annual Report

This issue features Can chaos be used for stability in walking Robots?, Promising insights on the development of posture in infants, The effect of Parkinson’s disease in stair negotiation, How certain are the elderly in selecting a stable gait pattern?, Collaboration with UNMC to improve Robotic Surgical Techniques, Helping High School students and K-12 teachers appreciate math and science, Max Kurz receives three awards for 2003, New Textbook published, Collaborations in orthopedics and cerebral concussion, and 2003 Publications and Presentations.


Public Posting As A Strategy To Increase Walking: A Worksite Intervention, Rayleen Earney, Timothy J. Bungum Jan 2004

Public Posting As A Strategy To Increase Walking: A Worksite Intervention, Rayleen Earney, Timothy J. Bungum

Environmental & Global Health Faculty Research

Because most American adults do not meet recommended physical activity guidelines, the need for new and innovative strategies is apparent. The current study employed public posting in an attempt to increase walking behavior in a worksite setting. Pedometer generated data was publicly posted in a prominent location in the worksite. In our study that utilized a pre-experimental design, we found that walking steps were statistically higher during the intervention and in a post intervention period as compared to the baseline data. We conclude that the public posting of physical activity data has the potential to increase walking behavior.


Athleticism In Sports, Judd Allen Jan 2004

Athleticism In Sports, Judd Allen

Whittier Scholars Program

This project hypothesizes the relationship between collegiate basketball and trial law while focusing on proving that the process of preparing and participating in a collegiate basketball game directly parallels the preparation and process of competing in a legal trial. This student prepared the study through conducted interviews with lawyers and coaches and tested the following concepts: teamwork/team attributes, competitive attributes, performance attributes and commitment.


Inhibition Of Nitric Oxide Inhibition Of Nitric Oxide Synthase Does Not Alter Dynamic Cerebral Autoregulation In Humans, Rong Zhang, Thad E. Wilson, Sarah Witkowski, Jian Cui, Craig G. Crandall, Benjamin D. Levine Jan 2004

Inhibition Of Nitric Oxide Inhibition Of Nitric Oxide Synthase Does Not Alter Dynamic Cerebral Autoregulation In Humans, Rong Zhang, Thad E. Wilson, Sarah Witkowski, Jian Cui, Craig G. Crandall, Benjamin D. Levine

Exercise and Sport Studies: Faculty Publications

The aim of this study was to determine whether inhibition of nitric oxide synthase (NOS) alters dynamic cerebral autoregulation in humans. Beat-to-beat blood pressure (BP) and cerebral blood flow (CBF) velocity (transcranial Doppler) were measured in eight healthy subjects in the supine position and during 60° head-up tilt (HUT). NOS was inhibited by intravenous N G-monomethyl-L-arginine (L-NMMA) infusion. Dynamic cerebral autoregulation was quantified by transfer function analysis of beat-to-beat changes in BP and CBF velocity. Pressor effects of L-NMMA on cerebral hemodynamics were compared with those of phenylephrine infusion. In the supine position, L-NMMA increased mean BP from 83 ± …


Vasoconstrictor Reserve And Sympathetic Neural Control Of Orthostasis, Qi Fu, Sarah Witkowski, Benjamin D. Levine Jan 2004

Vasoconstrictor Reserve And Sympathetic Neural Control Of Orthostasis, Qi Fu, Sarah Witkowski, Benjamin D. Levine

Exercise and Sport Studies: Faculty Publications

Background—We tested the hypothesis that individual variability in orthostatic tolerance is dependent on the degree of neural and vasomotor reserve available for vasoconstriction.

Methods and Results—Muscle sympathetic nerve activity (MSNA) and hemodynamics were measured in 12 healthy young volunteers during 60° head-up tilt (HUT), followed by a cold pressor test (CPT) in HUT. Orthostatic tolerance was determined by progressive lower-body negative pressure (LBNP) to presyncope. The same protocols were performed randomly in normovolemic and hypovolemic conditions. We found that mean arterial pressure increased and stroke volume decreased, whereas heart rate (HR), MSNA, and total peripheral resistance (TPR) increased during HUT …