Physical Therapy Commons^™

Supraspinal Fatigue Impedes Recovery From A Low-Intensity Sustained Contraction In Old Adults, Tejin Yoon, Bonnie Schlinder-Delap, Manda L. Keller, Sandra K. Hunter

Exercise Science Faculty Research and Publications

This study determined the contribution of supraspinal fatigue and contractile properties to the age difference in neuromuscular fatigue during and recovery from a low-intensity sustained contraction. Cortical stimulation was used to evoke measures of voluntary activation and muscle relaxation during and after a contraction sustained at 20% of maximal voluntary contraction (MVC) until task failure with elbow flexor muscles in 14 young adults (20.9 ± 3.6 yr, 7 men) and 14 old adults (71.6 ± 5.4 yr, 7 men). Old adults exhibited a longer time to task failure than the young adults (23.8 ± 9.0 vs. 11.5 ± 3.9 min, …

Near Infrared Spectroscopy Describes Physiologic Payback Associated With Excess Postexercise Oxygen Consumption In Healthy Controls And Children With Complex Congenital Heart Disease, Michael J. Danduran, J. E. Dixon, Rohit P. Rao

Exercise Science Faculty Research and Publications

Exercise creates a physiologic burden with recovery from such effort crucial to adaptation. Excess postexercise oxygen consumption (EPOC) refers to the body’s increased metabolic need after work. This investigation was designed to determine the role of near infrared spectroscopy (NIRS) in the description of exercise recovery in healthy controls (NL) and children with congenital heart disease (CHD). Subjects were recruited with exercise testing performed to exhaustion. Exercise time (EXT), heart rate (HR), and oxygen consumption (VO₂) were measured. Four-site NIRS (brain, kidney, deltoid, and vastus lateralis) were measured during exercise and into recovery to establish trends. Fifty individuals …

Pain Relief In Older Adults Following Static Contractions Is Not Task-Dependent, Kathy J. Lemley, Breanna Drewek, Lauren Miller, Sandra K. Hunter, Marie K. Hoeger Bement

Physical Therapy Faculty Research and Publications

Pain complaints increase with age. Exercise is frequently utilized for pain relief but the optimal exercise prescription to relieve pain is not clear. Following static contractions, young adults experience the greatest pain relief with low intensity, long duration contractions. The pain response to static contractions in older adults however is unknown.

PURPOSE : To compare pain reports in healthy older adults before and after static contractions of varying intensity and duration.

METHODS: Pain perception was assessed in 23 healthy older adults (11 men, 12 women; 72.0 ± 6.3 yrs) using a pressure pain device consisting of a 10 N force …

Stroke-Related Changes In Neuromuscular Fatigue Of The Hip Flexors And Functional Implications, Allison S. Hyngstrom, Tanya Onushko, Robert Heitz, Anthony Rutkowski, Sandra K. Hunter, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Objective: The aim of this study was to compare stroke-related changes in hip flexor neuromuscular fatigue of the paretic leg during a sustained isometric submaximal contraction with those of the nonparetic leg and controls and to correlate fatigue with clinical measures of function.

Design: Hip torques were measured during a fatiguing hip flexion contraction at 20% of the hip flexion maximal voluntary contraction in the paretic and nonparetic legs of 13 people with chronic stroke and 10 age-matched controls. In addition, the participants with stroke performed a fatiguing contraction of the paretic leg at the absolute torque equivalent to 20% …

Muscle Fatigue And Motor Output Variability With Acute Stress In Healthy Young Adults And Veterans With Posttraumatic Stress Disorder, Manda Linea Keller

Dissertations (1934 -)

Acute stress can alter motor performance differently for men and women. The first aim of this dissertation addresses possible causes for the sex difference in the motor response of a low-intensity fatiguing contraction of the elbow flexor muscles to an acute stressor (difficult mental math) in young, healthy adults. Muscle fatigue increased for men and women when exposed to the stressor, but impairment was more prominent for the women. This work showed that fatigue in the central nervous system, specifically in cortical motor and premotor areas, as well as relaxation rates of the muscle (quantified with cortical stimulation) were not …

Bilateral Oscillatory Hip Movements Induce Windup Of Multijoint Lower Extremity Spastic Reflexes In Chronic Spinal Cord Injury, Tanya Onushko, Allison S. Hyngstrom, Brian D. Schmit

Physical Therapy Faculty Research and Publications

After spinal cord injury (SCI), alterations in intrinsic motoneuron properties have been shown to be partly responsible for spastic reflex behaviors in human SCI. In particular, a dysregulation of voltage-dependent depolarizing persistent inward currents (PICs) may permit sustained muscle contraction after the removal of a brief excitatory stimulus. Windup, in which the motor response increases with repeated activation, is an indicator of PICs. Although windup of homonymous stretch reflexes has been shown, multijoint muscle activity is often observed following imposed limb movements and may exhibit a similar windup phenomenon. The purpose of this study was to identify and quantify windup …

Peak Triceps Surae Muscle Activity Is Not Specific To Knee Flexion Angles During Mvic, Kim Hébert-Losier, Anthony G. Schneiders, José A. García, S John Sullivan, Guy G. Simoneau

Physical Therapy Faculty Research and Publications

There is limited research on peak activity of the separate triceps surae muscles in select knee flexion (KF) positions during a maximum voluntary isometric contraction (MVIC) used to normalize EMG signals. The aim of this study was to determine how frequent peak activity occurred during an MVIC for soleus (SOL), gastrocnemius medialis (GM), and gastrocnemius lateralis (GL) in select KF positions, and if these peaks were recorded in similar KF positions. Forty-eight healthy individuals performed unilateral plantar-flexion MVIC in standing with 0°KF and 45°KF, and in sitting with 90°KF. Surface EMG of SOL, GM, and GL were collected and processed …

Biomechanical Effects Of Mobile Computer Location In A Vehicle Cab, Kyle Saginus, Richard W. Marklin, Patricia Seeley, Guy G. Simoneau, Stephen H. Freier

Physical Therapy Faculty Research and Publications

Objective: The objective of this research is to determine the best location to place a conventional mobile computer supported by a commercially available mount in a light truck cab.

Background: U.S. and Canadian electric utility companies are in the process of integrating mobile computers into their fleet vehicle cabs. There are no publications on the effect of mobile computer location in a vehicle cab on biomechanical loading, performance, and subjective assessment.

Method: The authors tested four locations of mobile computers in a light truck cab in a laboratory study to determine how location affected muscle activity of the lower back …

Pedaling Alters The Excitability And Modulation Of Vastus Medialis H-Reflexes After Stroke, Dana P. Fuchs, Namita Sanghvi, Jon A. Wieser, Sheila Schindler-Ivens

Physical Therapy Faculty Research and Publications

Objective

Individuals post-stroke display abnormal Group Ia reflex excitability. Pedaling has been shown to reduce Group Ia reflexes and to normalize the relationship between EMG and reflex amplitude in the paretic soleus (SO). The purpose of this study was to determine whether these changes extend to the paretic quadriceps.

Methods

H-reflexes were used to examine Group Ia reflex excitability of the vastus medialis (VM). H-reflexes were elicited in paretic (n = 13) and neurologically intact (n = 13) individuals at 11 positions in the pedaling cycle and during static knee extension at comparable limb positions and levels of …

Association Between The Female Athlete Triad And Endothelial Dysfunction In Dancers, Anne Z. Hoch, Paula E. Papanek, Aniko Szabo, Michael E. Widlansky, Jane E. Schimke, David D. Gutterman

Exercise Science Faculty Research and Publications

Objective: To determine the prevalence of the 3 components of the female athlete triad [disordered eating, menstrual dysfunction, low bone mineral density (BMD)] and their relationships with brachial artery flow-mediated dilation in professional dancers.

Design: Prospective study.

Setting: Academic institution in the Midwest.

Participants: Twenty-two professional ballet dancers volunteered for this study.

Interventions: The prevalence of the female athlete triad and its relationship to endothelial dysfunction.

Main Outcome Measures: Subjects completed questionnaires to assess disordered eating and menstrual status/history. They also completed a 3-day food record and wore an accelerometer for 3 days to …

Muscle Endurance, Cancer-Related Fatigue, And Radiotherapy In Prostate Cancer Survivors, Carlynn A. Alt, Elizabeth M. Gore, Marcos L. Montagnini, Alexander V. Ng

Exercise Science Faculty Research and Publications

Introduction: In this study we investigated muscle and cancer-related fatigue (CRF) in prostate cancer survivors (CS) undergoing radiotherapy (RT).

Methods: In 13 CS and 12 controls, CRF was assessed by the Piper Fatigue Scale (PFS), Epworth Sleepiness Scale—Depression subscale (CES-D), physical activity (accelerometer), and hemoglobin levels (Hb). Muscle measures included strength, activation, contractile properties, and endurance during intermittent dorsiflexion. Testing occurred before and after 6 weeks of RT in CS.

Results: After RT, the PFS score increased from initial levels in CS only without changes in sleepiness, depression, or physical activity. Hb decreased in CS only [mean …

Perspective Paper: Assessing Air Quality As Part Of A Physical Therapy Plan Of Care, Dennis Sobush, Monika Burrescia

Physical Therapy Faculty Research and Publications

Purpose: The purposes of this clinical perspective paper are (1) to expand physical therapists’ awareness to the topic of air quality as a health priority when providing professional services; and (2) to provide templates for screening the indoor clinical environments and patient profiles to avert respiratory exacerbations, especially in persons with asthma. Summary of Key Points: The location where a physical therapist practices determines the air quality indices to which a person is exposed. Poor indoor air quality can expose a person to even greater compromise of respiration (ie, Sick Building Syndrome) than outdoor air quality secondary to an array …

The Effects Of Lesions In The Dorsolateral Pons On The Coordination Of Swallowing And Breathing In Awake Goats, Joshua M. Bonis, S. E. Neumueller, B. D. Marshall, K. L. Krause, B. Qian, Lawrence Pan, M. R. Hodges, Hubert V. Forster

Physical Therapy Faculty Research and Publications

The purpose of this retrospective study was to gain insight into the contribution of the dorsolateral pons to the coordination of swallowing and breathing in awake goats. In 4 goats, cannulas were chronically implanted bilaterally through the lateral (LPBN) and medial (MPBN) parabrachial nuclei just dorsal to the Kölliker–Fuse nucleus (KFN). After >2 weeks recovery from this surgery, the goats were studied for 5½ h on a control day, and on separate days after receiving 1 and 10 μl injections of ibotenic acid (IA) separated by 1 week. The frequency of swallows did not change during the control and 1 …

Resilient Observer Design For Discrete-Time Nonlinear Systems With General Criteria, Chung Seop Jeong, Edwin E. Yaz, Yvonne I. Yaz

Exercise Science Faculty Research and Publications

A class of discrete-time nonlinear system and measurement equations having incrementally conic nonlinearities and finite energy disturbances is considered. A linear matrix inequality based resilient observer design approach is presented to guarantee the satisfaction of a variety of performance criteria ranging from simple estimation error boundedness to dissipativity in the presence of bounded perturbations on the gain. Some simulation examples are included to illustrate the proposed design methodology.

Pain Perception After Isometric Exercise In Women With Fibromyalgia, Marie K. Hoeger Bement, Andy Weyer, Sarah Hartley, Breanna Drewek, April L. Harkins, Sandra K. Hunter

Exercise Science Faculty Research and Publications

Objective: The purpose of this study was to identify exercise protocols incorporating isometric contractions that provide pain relief in women with fibromyalgia.

Design: A before-after trial.

Setting: A physical therapy department in an academic setting.

Participants: Fifteen women (mean ± SD, 52 ± 11y) with fibromyalgia.

Interventions: Subjects completed 4 sessions: 1 familiarization and 3 experimental. The following randomized experimental sessions involved the performance of isometric contractions with the elbow flexor muscles that varied in intensity and duration: (1) 3 maximal voluntary contractions (MVCs), (2) 25% MVC held to task failure, and (3) 25% MVC …

Analysis Of Knee Flexion Angles During 2 Clinical Versions Of The Heel Raise Test To Assess Soleus And Gastrocnemius Function, Kim Hébert-Losier, Anthony G. Schneiders, S John Sullivan, Richard J. Newsham-West, José A. García, Guy G. Simoneau

Physical Therapy Faculty Research and Publications

STUDY DESIGN: Controlled laboratory study, using a repeated-measures, counterbalanced design. OBJECTIVES: To provide estimates on the average knee angle maintained, absolute knee angle error, and total repetitions performed during 2 versions of the heel raise test. BACKGROUND: The heel raise test is performed in knee extension (EHRT) to assess gastrocnemius and knee flexion (FHRT) for soleus. However, it has not yet been determined whether select knee angles are maintained or whether total repetitions differ between the clinical versions of the heel raise test. METHODS: Seventeen healthy males and females performed maximal heel raise repetitions in 0° (EHRT) and 30° (FHRT) …

The Underrecognized Role Of Impaired Muscle Function In Cancer-Related Fatigue, Alexander V. Ng

Exercise Science Faculty Research and Publications

No abstract provided.

Site-Specific Effects On Respiratory Rhythm And Pattern Of Ibotenic Acid Injections In The Pontine Respiratory Group Of Goats, Joshua M. Bonis, Suzanne Neumueller, Katie L. Krause, T. Kiner, A. Smith, B. D. Marshall, B. Qian, Lawrence Pan, Hubert Forster

Physical Therapy Faculty Research and Publications

To probe further the contributions of the rostral pons to eupneic respiratory rhythm and pattern, we tested the hypothesis that ibotenic acid (IA) injections in the pontine respiratory group (PRG) would disrupt eupneic respiratory rhythm and pattern in a site- and state-specific manner. In 15 goats, cannulas were bilaterally implanted into the rostral pontine tegmental nuclei (RPTN; n = 3), the lateral (LPBN; n = 4) or medial parabrachial nuclei (MPBN; n = 4), or the Kölliker-Fuse nucleus (KFN; n = 4). After recovery from surgery, 1- and 10-μl injections (1 wk apart) of IA were made bilaterally through the …

Age And Load Compliance Alter Time To Task Failure For A Submaximal Fatiguing Contraction With The Lower Leg, Erin E. Griffith, Tejin Yoon, Sandra K. Hunter

Exercise Science Faculty Research and Publications

The purpose of this study was to compare the time to failure and muscle activation of young and old adults for a sustained isometric submaximal contraction with the dorsiflexor muscles when the foot was restrained to a force transducer (force-control task) compared with supporting an equivalent inertial load unrestrained in the sagittal plane (position-control task). Seventeen young (23.6 ± 6.5 yr) and 12 old (70.0 ± 5.0 yr) adults performed the force-control and position-control tasks at 30% maximal voluntary contraction (MVC) until task failure on separate days. Despite the similar load torque for each task, time to failure was longer …

Reliability Of Surface Electromyography During Maximal Voluntary Isometric Contractions, Jump Landings, And Cutting, Mckenzie Fauth, Erich Petushek, Christina Feldmann, Brittni Hsu, Luke Garceau, Brittney Lutsch, William Ebben

Exercise Science Faculty Research and Publications

The reliability of electromyographic (EMG) data has been examined for isometric and slow dynamic tasks, but little is known about the repeatability of this data for ballistic movements. The purpose of this study was to examine the within-session, trial-to-trial reliability of a variety of quadriceps and hamstrings muscles during isometric and ballistic activities. Data were analyzed by way of intraclass correlation coefficients (ICC), intersubject coefficients of variation (CV_inter), and intrasubject coefficients of variation (CV_intra). Twenty-four subjects performed 3 repetitions each of 2 randomly ordered test exercises, including landing from a depth jump (J) and cutting after …

Predictors Of Retention In Physical Therapy: Client-, Disease-, And Treatment-Related Factors, Marc A. Silva

Counselor Education and Counseling Psychology Research Exchange Conference

OBJECTIVES: The objectives of the study are to (1) document the incidence of veterans who prematurely terminate physical therapy before medically indicated, and (2) identify reliable predictors of treatment retention and attrition. The potential benefit of this study is the identification of reliable variables that predict who is at risk for terminating physical therapy prematurely, which may lead to targeted interventions designed to increase treatment retention. RESEARCH DESIGN: This study will be a retrospective design involving a review of medical records of veterans receiving referral to physical therapy. METHODOLOGY: Multinomial logistic regression (MLR) will be used to examine the effects …

Gender-Based Analysis Of Hamstring And Quadriceps Muscle Activation During Jump Landings And Cutting, William Ebben, Mckenzie Fauth, Erich Petushek, Luke Garceau, Brittni Hsu, Brittney Lutsch, Christina Feldmann

Exercise Science Faculty Research and Publications

This study evaluated gender differences in the magnitude and timing of hamstring and quadriceps activation during activities that are believed to cause anterior cruciate ligament (ACL) injuries. Twelve men (age = 21.0 ± 1.2 years; body mass = 81.61 ± 13.3 kg; and jump height = 57.61 ± 10.15 cm) and 12 women (age = 19.91 ± 0.9 years; body mass = 64.36 ± 6.14 kg; and jump height = 43.28 ± 7.5) performed 3 repetitions each of the drop jump (jump) normalized to the subject's vertical jump height, and a sprint and cut at a 45-degree angle (cut). Electromyography …

Response To Task-Specific Sex Differences In Muscle Fatigue: Is There A Common Underlying Cause?, Sandra K. Hunter

Exercise Science Faculty Research and Publications

No abstract provided.

Sex Differences In Response To Cognitive Stress During A Fatiguing Contraction, Tejin Yoon, Manda Linea Keller, Bonnie Schlinder-Delap, April L. Harkins, Romuald Lepers, Sandra K. Hunter

Exercise Science Faculty Research and Publications

This study compared the time to task failure for a submaximal fatiguing contraction in the presence and absence of a cognitive stressor in men and women. In study 1, 10 men and 10 women (22 ± 3 yr of age) performed an isometric fatiguing contraction at 20% maximal voluntary contraction force until task failure with the elbow flexor muscles during two separate sessions. Subjects performed a mental-math task during one of the fatiguing contractions that aimed to increase anxiety and stress (stressor session). Salivary cortisol and reported levels of arousal (visual analog scale for anxiety, and State-Trait Anxiety Inventory …

Μ-Opioid Receptor Agonist Injections Into The Presumed Pre-Bötzinger Complex And The Surrounding Region Of Awake Goats Do Not Alter Eupneic Breathing, K. L. Krause, Suzanne E. Neumueller, B. D. Marshall, T. Kiner, Joshua M. Bonis, Lawrence Pan, B. Qian, Hubert V. Forster

Physical Therapy Faculty Research and Publications

Opioids are clinically important in the alleviation of pain. An undesirable side effect of opioids is depression of breathing. Data from isolated preparations suggest this effect is due to attenuation of discharge activity of neurons in the pre-Bötzinger complex (preBötzC), a medullary area with respiratory rhythmogenic properties. The purpose of this study was to examine how [d-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (DAMGO), a μ-opioid receptor agonist, affected breathing after injection into the presumed preBötzC of the adult awake goat. We hypothesized that DAMGO would cause breathing to decrease and become irregular when injected into the presumed preBötzC and the surrounding region of the conscious …

Observation Of Amounts Of Movement Practice Provided During Stroke Rehabilitation, Catherine E. Lang, Jillian R. Macdonald, Darcy S. Reisman, Lara Boyd, Teresa Jacobson Kimberley, Sheila M. Schindler-Ivens, T. George Hornby, Sandy A. Ross, Patricia L. Scheets

Physical Therapy Faculty Research and Publications

Objective

To investigate how much movement practice occurred during stroke rehabilitation, and what factors might influence doses of practice provided.

Design

Observational survey of stroke therapy sessions.

Setting

Seven inpatient and outpatient rehabilitation sites.

Participants

We observed a convenience sample of 312 physical and occupational therapy sessions for people with stroke.

Interventions

Not applicable.

Main Outcome Measures

We recorded numbers of repetitions in specific movement categories and data on potential modifying factors (patient age, side affected, time since stroke, FIM item scores, years of therapist experience). Descriptive statistics were used to characterize amounts of practice. Correlation and regression analyses were …

Sex Differences And Mechanisms Of Task-Specific Muscle Fatigue, Sandra K. Hunter

Exercise Science Faculty Research and Publications

Women can be less fatigable than men due to sex-related differences within the neuromuscular system that impact physiological adjustments during a fatiguing task. The involved mechanism(s) for the sex difference, however, is task specific. This review explores the novel hypothesis that variation of the task will alter the magnitude of the sex-difference in muscle fatigue and the contribution of involved mechanisms.

Elastic, Viscous, And Mass Load Effects On Poststroke Muscle Recruitment And Co-Contraction During Reaching: A Pilot Study, Tina M. Stoeckmann, Katherine J. Sullivan, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

Background: Resistive exercise after stroke can improve strength (force-generating capacity) without increasing spasticity (velocity-dependent hypertonicity). However, the effect of resistive load type on muscle activation and co-contraction after stroke is not clear.

Objective: The purpose of this study was to determine the effect of load type (elastic, viscous, or mass) on muscle activation and co-contraction during resisted forward reaching in the paretic and nonparetic arms after stroke.

Design: This investigation was a single-session, mixed repeated-measures pilot study.

Methods: Twenty participants (10 with hemiplegia and 10 without neurologic involvement) reached forward with each arm against equivalent elastic, viscous, and mass loads. …

Normal Breathing Pattern And Arterial Blood Gases In Awake And Sleeping Goats After Near Total Destruction Of The Presumed Pre-Bötzinger Complex And The Surrounding Region, Katie L. Krause, Hubert Forster, T. Kiner, S. E. Davis, Joshua M. Bonis, B. Qian, Lawrence Pan

Physical Therapy Faculty Research and Publications

Abrupt neurotoxic destruction of >70% of the pre-Bötzinger complex (preBötzC) in awake goats results in respiratory and cardiac failure (Wenninger JM, Pan LG, Klum L, Leekley T, Bastastic J, Hodges MR, Feroah TR, Davis S, Forster HV. J Appl Physiol 97: 1629–1636, 2004). However, in reduced preparations, rhythmic respiratory activity has been found in other areas of the brain stem (Huang Q, St. John WM. J Appl Physiol 64: 1405–1411, 1988; Janczewski WA, Feldman JL. J Physiol 570: 407–420, 2006; Lieske SP, Thoby-Brisson M, Telgkamo P, Ramierz JM. Nature Neurosci 3: 600–607, 2000; St. John WM, Bledsoe TA. J Appl …

Does Plasma Ss-Endorphin Influence Exercise-Induced Hypoalgesia In Healthy Adults?, Kathy Lemley

Maria Dittman Library Research Competition: Student Award Winners

Anecdotal reports can be found in the literature of athletes who suffer from an injury, yet continue to participate in their sport with little or no pain. These reports have resulted in an interest in the possible role of stress, including exercise, in analgesia. Exercise-induced hypoalgesia (EIH), a decrease in pain perception following exercise, has been found to occur in healthy adults. In the 1970’s opioid peptides with analgesic properties were discovered (Dalayeun, Nores & Bergal, 1993). One of these peptides, β-endorphin, is believed to be released from the anterior pituitary into the circulation under a variety of stressors, including …