Life Sciences Commons^™

The Effect Of Passive Stretching And Isometric Contractions On Delayed Onset Muscle Soreness After A Typical Bout Of Exercise, John W. Gibson

Theses and Dissertations

Delayed Onset Muscle Soreness (DOMS) is a common response to activities involving lengthening contractions. Muscle inflammation is associated with DOMS and may play an integral role in protecting a muscle from damage and soreness in response to subsequent bouts of lengthening contractions. Research in animals has shown that prior exposure to passive stretching and isometric contractions of a muscle resulting in muscle inflammation attenuates the muscle inflammatory response following subsequent bouts of lengthening contractions. The purpose of this study was to determine whether passive stretching and isometric contractions in humans would reduce DOMS following a typical bout of resistance exercise. …

The Relationship Between Diet Quality And Body Composition In College Women: A Cross-Sectional Analysis, Annette Elisabeth Perkins

Theses and Dissertations

Objective. Determine the relationship between dietary quality and body weight/composition in college women. Specific emphasis was made regarding adherence to current MyPyramid guidelines, fruit, vegetable and junk food consumption.

Design/Participants. The study used a cross-sectional design. One hundred and sixty three women were recruited to participate in the study. All participants were university students (20.4 ± 1.6 y). Diet intake was measured using the Dietary History Questionnaire (DHQ) and the Healthy Eating Index (HEI) was calculated to assess diet quality. Body fat percentage was assessed using the Bod Pod and BMI was calculated using height and weight measurements. Physical activity …

The Effects Of Whole Body Vibration On Strength Gains In The Bench Press, The Back Squat, And The Power Clean In Division I Football Players, Kelly S. Poppinga

Theses and Dissertations

The purpose of this study was to determine if whole body vibration effects strength gains in the bench press, the back squat, and the power clean in division 1 football players. Thirty-one NCAA Division 1 male football players volunteered for this study and were randomly assigned to a control group (C=16) or one of two vibration groups (V1=7, V2=8). Subjects followed the training program for eight weeks. A pre-test, mid-test, and post-test one repetition max was measured at 0, 4, and 8 weeks for the bench press, the back squat, and the power clean. A 3x3 factorial ANOVA revealed varied …

The Relationship Between Fitness Level, Gender, And The Percentage Of Vo2 Max At Crossover, Christina Louise Pettigrew

UNLV Theses, Dissertations, Professional Papers, and Capstones

The “crossover” concept is a means of understanding fuel utilization over a range of exercise intensities. According to this concept, certain biochemical adaptations occur in a fit individual allowing for an increase in lipid oxidation. The present study examined whether there was a relationship between fitness level, gender, and the percentage of maximum aerobic capacity (VO2 max) at crossover. Twenty-five subjects age 18-40 participated in this study. Subjects were divided in half based on their fitness level. After completing a graded exercise test to exhaustion, the crossover point for each subject was determined relative to their VO2 max. A 2x2 …

Effects Of Short-Term, High-Force Resistance Training On High-Intensity Exercise Capacity., Patrick Abi Nader

Electronic Theses and Dissertations

The purpose of this study was to assess the effects of short-term high-intensity resistance training on time to exhaustion at maximal aerobic output. It was hypothesized that 2 weeks of training will induce improvements in performance at maximal aerobic output. Eighteen subjects participated in this study. Subjects were assigned to a control (n=8) or resistance training (n=10) groups. The resistance training group participated in 5 sessions of strength training over a period of 2 weeks on the leg press device. Both groups participated in pre and post intervention testing. After the intervention strength in the training group significantly increased (p=.00). …

Measured And Estimated Ground Reaction Forces For Multi-Segment Foot Models, Dustin A. Bruening, Kevin M. Cooney, Frank L. Buczek

Faculty Publications

Accurate measurement of ground reaction forces under discrete areas of the foot is important in the development of more advanced foot models, which can improve our understanding of foot and ankle function. To overcome current equipment limitations, a few investigators have proposed combining a pressure mat with a single force platform and using a proportionality assumption to estimate subarea shear forces and free moments. In this study, two adjacent force platforms were used to evaluate the accuracy of the proportionality assumption on a three segment foot model during normal gait. Seventeen right feet were tested using a targeted walking approach, …

Electromyographic Analysis Of The Infraspinatus And Deltoid Muscles During Shoulder External Rotation Exercises With And Without A Towel Roll, Kazuto Sakita

Theses and Dissertations

Standing and sidelying external rotation exercises produce high activation of the deltoid and infraspinatus. Holding a towel roll under the arm at 30° shoulder abduction during these exercises may decrease deltoid activity and increase infraspinatus activity. The objective was to determine if the addition of a towel under the arm during standing and sidelying external rotation affects EMG activity of the infraspinatus, middle and posterior deltoid, and pectoralis major, compared to the no towel condition. 20 male volunteers (age; 26 ± 3, height; 1.80 m ± .07 m, weight; 77 kg ± 10 kg) had right dominant hand, bilaterally healthy …

Kinematic Changes Of The Tennis Forehand Ground Stroke As Post Contact Ball Speed Increases, Merrill D. Funk

Theses and Dissertations

Neuromuscular and kinematic patterns during the tennis forehand have been studied extensively. However, no one has evaluated potential upper-extremity kinematic changes during the forehand as ball speed increases. The purpose of this study was to evaluate changes in shoulder and trunk kinematics as forehand ball speed increased, in an attempt to better understand how kinematics may promote forehand ball speed. Peak trunk rotation angle, shoulder horizontal abduction/adduction and internal/external rotation angle, and corresponding angular velocities were measured between initial backswing and ball contact during forehands that were performed at three different speeds (50%, 75%, and 100% of maximal post-impact ball …

Convergent Validity Of Self Reported Physical Activity With A Seven Day Recall, Benjamin J. Silber

Loma Linda University Electronic Theses, Dissertations & Projects

Accurate assessment of physical activity is important to studies interested in the relationship between physical activity and other variables. Questionnaires are the only feasible means for large-scale sampling but such self-report measures require validation due to their inherent subjectivity. The Adventist Health Study-2 (AHS-2) survey includes exercise items that were validated in the present investigation. A calibration study examined self-reports of exercise with two phone calls to 1,000 participants in which an interview-assisted 7-day physical activity recall was completed by a random sample of AHS-2 participants. Inter-index correlations both within the survey and between the survey and the 7-day physical …

The Effects Of Resistance Training On Strength And Body Composition In Postpartum Women, Katherine Bishop Pratt

Theses and Dissertations

The postpartum period represents a high-risk period for body weight retention and obesity. Several studies have investigated the role of aerobic exercise on postpartum weight retention and other body composition outcomes; however, there has been little attention given to resistance training in postpartum women. Thus, the purpose of this four-month randomized study was to determine the effectiveness of resistance training on strength, body composition, return to pre-pregnancy weight, and bone mineral density (BMD) in postpartum women. Sixty postpartum women were randomly assigned to either a resistance training group or a comparison group. The resistance training group participated in a progressive …

The Effect Of Resistance Training On Strength And Total Physical Activity In Postpartum Females, Tiffany Kaye Hinman

Theses and Dissertations

The purpose of this study was to compare strength and physical activity (PA) changes in postpartum women randomly assigned to either a four-month progressive resistance training (RT) program or a four month flexibility program. Sixty healthy women between six weeks and eight months postpartum initiated the study and 43 completed the entire study. The women tended to be overweight, were all non-smokers, and most were breastfeeding (97%) at the beginning of the study. Both groups (RT and flexibility) completed training exercises twice weekly. Both groups improved in all measures of strength (RT group: leg press, P < 0.001; bench press, P < 0.001; curl-ups, P < 0.001. Flexibility group: leg press, P = 0.009; bench press, P < 0.001; curl-ups, P = 0.005); however, the RT group had higher strength gains compared to the flexibility group over time (leg press, P < 0.005; bench press, P < 0.001; curl-ups, P < 0.007). In addition, both groups increased in low back flexibility but the group*period interaction did not reach significance (P = 0.096). Light-intensity PA increased in the RT group but not the flexibility group (P < 0.05). A group*period interaction was significant for light-intensity PA time (P = 0.031) and borderline significant for sedentary time (P = 0.054). However, controlling for the number of months postpartum and weight gain during the previous pregnancy resulted in a significant interaction for sedentary time (P < 0.05). No changes were found in moderate, vigorous, or moderate to vigorous PA within or between groups over time. In conclusion, twice-weekly RT increases strength and is associated with improvements in several PA outcomes in postpartum women; however, the mechanisms for this are unclear. The training sessions and/or increased spontaneous activity may have contributed.

The Role Of Nitric Oxide, Acetylcholine, And Vasoactive Intestinal Peptide On Skin Blood Flow During In-Vivo Electrical Field Stimulation, Robert S. Thiebaud

Theses and Dissertations

The purpose of this study was to characterize a novel technique to study neurogenic control of cutaneous vasodilation. We monitored skin blood flow (SkBF) during in-vivo electrical stimulation (e-stim) intended to activate cutaneous nerves and used intradermal microdialysis to deliver receptor antagonists to characterize their contribution to cutaneous vasodilation. We examined the role of acetylcholine receptors (RACh), nitric oxide (NO), and vasoactive intestinal peptide receptors (RVIP) on the cutaneous vasodilation induced by e-stim in the absence of the sympathetic adrenergic nervous system. Six men and three women participated in the study. Three intradermal microdialysis probes were placed in the skin …

Pre-Swing Deficits In Forward Propulsion, Swing Initiation And Power Generation By Individual Muscles In Hemiparetic Walking, Carrie L. Peterson, Allison Kinney, Steven A. Kautz, Richard R. Neptune

Mechanical and Aerospace Engineering Faculty Publications

Clinical studies of hemiparetic walking have shown pre-swing abnormalities in the paretic leg suggesting that paretic muscle contributions to important biomechanical walking subtasks are different than those of non-disabled individuals. Three-dimensional forward dynamics simulations of two representative hemiparetic subjects with different levels of walking function classified by self-selected walking speed (i.e., limited community=0.4–0.8 m/s and community walkers=>0.8 m/s) and a speed-matched control were generated to quantify individual muscle contributions to forward propulsion, swing initiation and power generation during the pre-swing phase (i.e., double support phase proceeding toe-off). Simulation analyses identified decreased paretic soleus and gastrocnemius contributions to forward propulsion …

The Role Of Movement Scaling On Quiet Eye Duration During An Aiming Task, Michelle Sachiko Okumura

Theses, Dissertations and Culminating Projects

No abstract provided.

Relationships Between Muscle Contributions To Walking Subtasks And Functional Walking Status In Persons With Post-Stroke Hemiparesis, Allison Kinney, Carrie L. Peterson, Steven A. Kautz, Richard R. Neptune

Mechanical and Aerospace Engineering Faculty Publications

Walking speed is commonly used to predict stroke severity and assess functional walking status (i.e., household, limited community and community walking status) post-stroke. The underlying mechanisms that limit walking speed (and functional walking status by extension) need to be understood to improve post-stroke rehabilitation. Previous experimental studies have shown correlations between paretic plantarflexor output during the pre-swing phase and walking speed and suggest that the paretic hip flexors can compensate in some hemiparetic subjects. Modeling and simulation studies of healthy walking have shown that the ankle plantarflexors, soleus (SOL) and gastrocnemius (GAS), and uniarticular hip flexors (IL) are essential contributors …

The Effects Of Low Frequency Ultrasound In Transdermal Drug Delivery, Aaron M. Wells

Theses and Dissertations

Objective: Determine if varying ultrasound frequency affects the delivery of 10% hydrocortisone concentrations during phonophoresis. Utilize intramuscular microdialysis probe for drug collection, thus improving the experimental model. Methods: Thirty one (10 in groups 1 and 2, 11 in group 3) healthy subjects participated in this study. Interventions: Subjects were randomly assigned to one of three treatment groups receiving 10 minute ultrasound treatments applied to a standardized area of the gastrocnemius muscle of the right leg. The ultrasound was performed over the treated area using a 10% hydrocortisone compound mixed with standard ultrasound gel. The contralateral limb served as the control …

The Effect Of Lateral Spacing On The Spring Start, Kyle Louis Grossarth

Theses and Dissertations

Sprinters are always looking for an improvement in their time, from the gun going off until the finish. An effective start can lead to reaching top velocity sooner and a decreased finish time. New developments in starting blocks, more specifically the width of the starting block pedal, has allowed for variation in foot placement in the blocks. With the ability to change how wide an athlete can place their feet in the blocks, this study looked at trying to find an optimum spacing for college level sprinters. Thirteen Male College Sprinters (mean age = 23.08 years) participated in this study. …

The Effects Of Indoor Track Curve Radius On Sprint Speed And Ground Reaction Forces, Jesse Tipasa Tukuafu

Theses and Dissertations

Sprinting on a curve is significantly slower than on a straightaway. Although the dimensions vary from track to track, indoor track curves are among the tightest curves that athletes will sprint at maximal speed. Previous studies have provided theories for how speed attenuation occurs when running on a curve. Yet, no previous research has determined how the variability of indoor track curve radii affects trained sprinters at maximal speeds. Purpose: To determine the differences in running speeds, ground time (GT), and medio-lateral (ML) impulse, with different indoor track radii. A secondary purpose was to understand the between-leg differences in GT …

High-Frequency Electrically Stimulated Skeletal Muscle Contractions Increase P70S6k Phosphorylation Independent Of Known Igf-I Sensitive Signaling Pathways, Sarah Witkowski, Richard M. Lovering, Espen E. Spangenburg

Exercise and Sport Studies: Faculty Publications

Insulin-like growth factor (IGF-I) is hypothesized to be a critical upstream regulator of mammalian target of rapamycin (mTOR)-regulated protein synthesis with muscle contraction. We utilized a mouse model that expresses a skeletal muscle specific dominant-negative IGF-I receptor to investigate the role of IGF-I signaling of protein synthesis in response to unilateral lengthening contractions (10 sets, 6 repetitions, 100. Hz) at 0 and 3. h following the stimulus. Our results indicate that one session of high frequency muscle contractions can activate mTOR signaling independent of signaling components directly downstream of the receptor.

Comparison Of Body Composition Between Physically Active And Inactive Wheelchair Users, Masaru Teramoto

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to examine the association between regular physical activity and body composition in individuals with physical disabilities. The study was designed to compare body composition parameters between wheelchair users participating in adapted sports programs and those being physically inactive. Male wheelchair users were recruited and classified based on physical activity level (active or inactive) and disability type (paraplegic or quadriplegic). Regional and whole-body percent body fat (%BF), lean body mass (LBM), and bone mineral density (BMD) were assessed by dual-energy X-ray absorptiometry. These variables were then compared among the groups using a two-way between-groups multivariate …

Thrombin And Exercise Similarly Influence Expression Of Cell Cycle Genes In Cultured Putative Endothelial Progenitor Cells, Michael M. Lockard, Sarah Witkowski, Nathan T. Jenkins, Espen E. Spangenburg, Thomas O. Obisesan, James M. Hagberg

Exercise and Sport Studies: Faculty Publications

Acute exercise and exercise training may influence putative endothelial progenitor cell (EPC) number and colony forming units (CFU-ECs), although the mechanisms remain unclear. This study examined the effects of in vitro thrombin supplementation and acute exercise on CFU-EC gene expression, associated with cellular proliferation and differentiation. The effect of habitual physical activity was evaluated through analysis of EPCs from chronically high- and low-active men. Participants were healthy high- and low-active men (n = 23), aged 55-80 yr. Circulating CD34+/VEGFR2+ number, CFU-ECs, plasma prothrombin fragment (F1+2), and thrombin-antithrombin III were measured at rest and after 30 min of exercise. Gene expression …

Comparison Of A Reduced Carbohydrate And Reduced Fat Diet For Ldl, Hdl, And Vldl Subclasses During 9-Months Of Weight Maintenance Subsequent To Weight Loss, James D. Lecheminant, Bryan K. Smith, Eric C. Westman, Mary C. Vernon, Joseph E. Donnelly

Faculty Publications

Objectives: This study compared LDL, HDL, and VLDL subclasses in overweight or obese adults consuming either a reduced carbohydrate (RC) or reduced fat (RF) weight maintenance diet for 9 months following significant weight loss. Methods: Thirty-five (21 RC; 14 RF) overweight or obese middle-aged adults completed a 1-year weight management clinic. Participants met weekly for the first six months and bi-weekly thereafter. Meetings included instruction for diet, physical activity, and behavior change related to weight management. Additionally, participants followed a liquid very low-energy diet of ~2092 kJ per day for the first three months of the study. Subsequently, participants followed …

Women’S Cycle Racing: Past Strategies, Future Challenges, Shelley Lucas

Shelley Lucas

In this presentation, I explore the challenges associated with long distance women’s road cycle racing from a variety of perspectives, including athletes, managers, promoters, and governing bodies. This exploration covers several decades, c. 1950s - 1980s, from some of the earliest sanctioned international competitions to the inclusion of women’s cycling into the Olympic Games. Women in many endurance sports, including cross-country skiing and running, have faced barriers related to sex discrimination in the larger society and in maledominated sport organizations, and cycling falls into this same tradition. An analysis of both primary and secondary sources indicates that historical, biological, and …

Resistance Training Increases The Expression Of Ampk, Mtor, And Glut4 In Previously Sedentary Subjects And Subjects With The Metabolic Syndrome., Andrew Steven Layne

Electronic Theses and Dissertations

Exercise has been considered a cornerstone of diabetes prevention and treatment for decades, but the benefits of resistance training are less clear. Nineteen non-diabetic subjects (10 metabolic syndrome, 9 sedentary controls) underwent 8 weeks of supervised resistance training. After training, strength and V̇ O_2max increased by 10% in both groups. Percent body fat decreased in subjects with the metabolic syndrome. Additionally, lean body mass increased in both groups (p<0.05). Expression of glucose transporter protein-4 (GLUT4), the principle insulin-responsive glucose transporter, increased significantly in both groups. 5-adenosine monophosphateactivated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) expression increased in both groups, indicating increased protein synthesis and mitochondrial biogenesis. Markers of insulin resistance measured by a euglycemic hyperinsulinemic clamp did not improve in subjects with the metabolic syndrome but increased significantly in control subjects (13%). Resistance training upregulates intracellular signaling pathways that may be beneficial for ameliorating the metabolic syndrome.

Research Associations Between Sport And Screen-Entertainment With Mental Health Problems In 5-Year-Old Children, Lucy J. Griffiths, Marsha Dowda, Carol Dezateux, Russell R. Pate

Faculty Publications

Background: Few studies have examined the benefits of regular physical activity, and risks of sedentary behaviour, in young children. This study investigated associations between participation in sports and screen-entertainment (as components of physical activity and sedentary behaviour), and emotional and behavioural problems in this population.

Methods: Cross-sectional analysis of data from 13470 children (50.9% boys) participating in the nationally representative UK Millennium Cohort Study. Time spent participating in sports clubs outside of school, and using screen-entertainment, was reported by the child's mother at child age 5 years, when mental health was also measured using the Strengths and Difficulties Questionnaire.

Results: …

Home Program Of Hip Abductor Exercises: Effect On Knee Joint Loading, Strength, Function And Pain In Persons With Knee Osteoarthritis, Elizabeth A. Sled, Latif Khoja, Kevin J. Deluzio, Sandra J. Olney, Elsie G. Culham

Allied Health Faculty Publications

Background Hip abductor muscle weakness may result in impaired frontal-plane pelvic control during gait, leading to greater medial compartment loading in people with knee osteoarthritis (OA).

Objective This study investigated the effect of an 8-week home strengthening program for the hip abductor muscles on knee joint loading (measured by the external knee adduction moment during gait), strength (force-generating capacity), and function and pain in individuals with medial knee OA.

Design The study design was a nonequivalent, pretest-posttest, control group design.

Setting Testing was conducted in a motor performance laboratory.

Patients An a priori sample size calculation was performed. Forty participants …

Neuromechanical Analysis Of Anterior Cruciate Ligament Risk Factors In Female Collegiate Soccer Athletes, Nelson Cortes

Human Movement Sciences & Special Education Theses & Dissertations

The anterior cruciate ligament (ACL) acts in an essential role to prevent anterior tibial displacement when experiencing jump-landing forces that are applied to the lower extremity; more than 100,000 injuries per year in the United States in sport activities that often require landing, deceleration-acceleration, cutting and pivoting actions have been reported. The aim of this study was to examine the nature of any lower limb coupling differences between a drop-jump and a side-step cutting actions, assess kinematic and kinetic differences between three tasks, and evaluate the effects of two landing techniques in biomechanical risk factors while performing two unanticipated tasks. …

A Comparison Of Three Computer-Based Methods Used To Determine Emg Signal Amplitude, Doug Renshaw

Doug Renshaw

No abstract provided.

Fat-Free Mass And Gender Influences The Rapid-Phase Excess Postexercise Oxygen Consumption, Linda S. Lamont Ph.D.

Linda S. Lamont Ph.D.

The purpose of this study was to determine the influence of gender dimorphism and body composition on post-exercise oxygen consumption during the rapid recovery phase.

Ground Reaction Forces Generated By Twenty-Eight Common Hatha Yoga Postures, Sylvia Joan Wilcox

Theses and Dissertations

Yoga adherents claim many benefits of the practice, including promotion of bone health and prevention of osteoporosis. However, few, if any, studies have investigated whether yoga enhances bone mineral density. Furthermore, none have identified force generation in yoga. The purpose of this study is to collect ground reaction force (GRF) data on a variety of common hatha yoga postures that would be practiced in fitness centers or private studios. Twelve female and eight male volunteers performed a sequence of 28 common hatha yoga postures while ground reaction force data were collected with an AMTI strain-gauge force plate. The sequence was …