Exercise Science Commons^™

Acute Effects Of Whole-Body Vibration On Lower Extremity Muscle Performance In Persons With Multiple Sclerosis, Kurt Jackson, Harold Merriman, Paul Vanderburgh, C. Brahler

C. Jayne Brahler

Background and Purpose: Whole-body vibration (WBV) is a relatively new form of exercise training that may influence muscle performance. This study investigated the acute effects of high (26 Hz) and low (2 Hz) frequency WBV on isometric muscle torque of the quadriceps and hamstrings in persons with multiple sclerosis (MS).

Participants and Method: Fifteen individuals (mean age = 54.6 years, SD = 9.6) with MS and Expanded Disability Status Scale (EDSS) scores ranging from 0-6.5 (mean = 4.2, SD = 2.3) participated in this randomized cross-over study. Following baseline measures of isometric quadricep and hamstring torque, subjects were exposed to …

Practical Applications Of Biomechanical Principles In Resistance Training: The Use Of Bands And Chains, Paul A. Swinton, Justin Keogh, Jason Lake

Justin Keogh

In recent years, it has become popular for athletes and recreational trainers to perform resistance training with the addition of bands and chains. In this paper, we consider the advantages of manipulating an exercise to match the resistance provided with the force capabilities of the lifter, which generally change throughout the movement. We explain that bands and chains can be used to manipulate a variety of exercises that have the potential to enhance performance in sport and in many daily tasks. Whilst there are many similaritiesbetween the use of bands and chains for resistance training, we note that there are …

Load Carriage Distance Run And Pushups Tests: No Body Mass Bias And Occupationally Relevant, Paul M. Vanderburgh, Nicholas S. Mickley, Philip A. Anloague, Kimber Lucius

Philip A. Anloague

Recent research has demonstrated body mass (M) bias in military physical fi tness tests favoring lighter, not just leaner, service members. Mathematical modeling predicts that a distance run carrying a backpack of 30 lbs would eliminate M-bias. The purpose of this study was to empirically test this prediction for the U.S. Army push-ups and 2-mile run tests. Two tests were performed for both events for each of 56 university Reserve Offi cer Training Corps male cadets: with (loaded) and without backpack (unloaded). Results indicated signifi cant M-bias in the unloaded and no M-bias in the loaded condition for both events. …

Glucose-Fructose Likely Improves Gastrointestinal Comfort And Endurance Running Performance Relative To Glucose-Only, P. B. Wilson, S. J, Ingraham

Athletic Performance Research

This study aimed to determine whether glucose-fructose (GF) ingestion, relative to glucose-only, would alter performance, metabolism, gastrointestinal (GI) symptoms, and psychological affect during prolonged running. On two occasions, 20 runners (14 men) completed a 120-min submaximal run followed by a 4-mile time trial (TT). Participants consumed glucose-only (G) or GF (1.2:1 ratio) beverages, which supplied ~1.3 g/min of carbohydrate. Substrate use, blood lactate, psychological affect [Feeling Scale (FS)], and GI distress were measured. Differences between conditions were assessed using magnitude-based inferential statistics. Participants completed the TT 1.9% (−1.9; −4.2, 0.4) faster with GF, representing a likely benefit. FS ratings were …

Misrepresentation Of Carbohydrate For Exercise: ‘It Is Time To Bust The Myth Of Physical Inactivity And Obesity: You Cannot Outrun A Bad Diet’, Patrick B. Wilson

Athletic Performance Research

The contention from Malhotra et al1 regarding the unimportance of carbohydrate for exercise is misguided. First, the reference they provide is an editorial2 that should not be viewed as high-quality evidence. Several oft-cited exercise studies showing benefits with high-fat diets simultaneously utilized carbohydrate restoration strategies,3 which involves “carbohydrate loading” after a high-fat diet. Thus, the evidence provided does not contradict the established belief that carbohydrate is an important fuel for endurance exercise. Second, the authors’ use of the term “carbohydrate loading” is misleading in this context. No public health organizations advocate a diet containing carbohydrate in amounts used in “carbohydrate …

Effectiveness Of Group Kickboxing As A Means To Improve Gait And Balance In Individuals With Ms, Kurt Jackson, Kimberly Edginton Bigelow, Christina Cooper, Harold L. Merriman

Harold L. Merriman

In recent years, there has been a particular emphasis on identifying and delivering appropriate therapeutic interventions that address the significant balance and gait impairments that affect individuals with multiple sclerosis (MS). Group interventions implemented in community settings have been especially of interest, including tai chi classes. Recently, the authors conducted a preliminary study to examine whether group kick-boxing, which requires more vigorous movements, might be a feasible intervention. Initial findings showed promise and led the authors to pursue a more rigorous follow-up study, with the objective of determining whether a 5-week group kickboxing class improved clinical measures of balance and …

Acute Effects Of Whole-Body Vibration On Lower Extremity Muscle Performance In Persons With Multiple Sclerosis, Kurt Jackson, Harold L. Merriman, Paul M. Vanderburgh, C. Jayne Brahler

Harold L. Merriman

Background and Purpose: Whole-body vibration (WBV) is a relatively new form of exercise training that may influence muscle performance. This study investigated the acute effects of high (26 Hz) and low (2 Hz) frequency WBV on isometric muscle torque of the quadriceps and hamstrings in persons with multiple sclerosis (MS). Participants and Method: Fifteen individuals (mean age = 54.6 years, SD = 9.6) with MS and Expanded Disability Status Scale (EDSS) scores ranging from 0-6.5 (mean = 4.2, SD = 2.3) participated in this randomized cross-over study. Following baseline measures of isometric quadricep and hamstring torque, subjects were exposed to …

Biomechanical Investigation Of Elite Place-Kicking, Chase M. Pfeifer

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Many studies aim to understand the fundamentals of kicking commonly displayed by soccer players [4,6,10,16,17,18,24,25,28,29,30,34,36,38,40]. Of those studies, most are limited to a two-dimensional (2D) analysis using high-speed cameras for position tracking or utilizing electromyography to observe the activity of select muscles [4,6,18,25,29,36]. The few studies that investigate kicking using a three-dimensional (3D) model are limited in their position tracking capabilities and focus mainly on joint flexion potentials and foot speed.

This dissertation is a comprehensive biomechanical analysis (kinematic and EMG) of the field-goal place-kicking techniques of four elite kickers in American football. Data were compared and contrasted with ball …

Pertinacity Issue 1 Volume 2, Yuri Hosokawa

Pertinacity

No abstract provided.

The Effect Of Various Body Positions On Performance Of The Isometric Mid-Thigh Pull, George K. Beckham

Electronic Theses and Dissertations

The purpose of this dissertation was to evaluate the effects of changing body position on the execution of the isometric mid-thigh pull (IMTP). Furthermore, while there is evidence to suggest that there is an effect of familiarization on performance of maximal strength tests, there has been no known research evaluating the effect of learning on the IMTP. The effect of familiarization was assessed by evaluating changes in variables obtained from the IMTP. Subjects did not statistically improve over the five IMTP testing sessions, regardless of the body position used, or if subjects had previous experience with weightlifting derivatives. This may …

Removable Shoe Spike System, Alex Adams, Nutech Ventures, Inc.,

Athletic Performance Research

The present system, method and apparatus are adapted for the quick and easy exchange of spikes on athletic shoes. More specifically, the system, apparatus and methods comprise a spike having an opening, an aglet adapted for coupling to the shoe, for example by way of a shoelace, and a coupling head affixed to the aglet which is adapted to couple with the opening on the spike so as to allow a user to quickly and easily replace, remove or install spikes in the athletic shoe. The disclosure thus allows the user to have the tool attached to their shoe at …

Development Of A Muscle Model Parameter Calibration Method Via Passive Muscle Force Minimization, Allison Kinney, Benjamin J. Fregly

Mechanical and Aerospace Engineering Faculty Publications

Computational predictions of subject-specific muscle and knee joint contact forces during walking may improve individual rehabilitation treatment design. Such predictions depend directly on specified model parameter values. However, model parameters are difficult to measure non-invasively. Methods for muscle model parameter calibration have been developed previously. However, it is currently unknown how the musculoskeletal system chooses muscle model parameter values. Previous studies have hypothesized that muscles avoid injury during walking by generating little passive force and operating in the ascending region of the force-length curve. This hypothesis suggests that muscle model parameter values may be selected by the body to minimize …

Synergy-Based Two-Level Optimization For Predicting Knee Contact Forces During Walking, Gil Serrancolí, Allison Kinney, Josep M. Font-Llagunes, Benjamin J. Fregly

Mechanical and Aerospace Engineering Faculty Publications

Musculoskeletal models and optimization methods are combined to calculate muscle forces. Some model parameters cannot be experimentally measured due to the invasiveness, such as the muscle moment arms or the muscle and tendon lengths. Moreover, other parameters used in the optimization, such as the muscle synergy components, can be also unknown. The estimation of all these parameters needs to be validated to obtain physiologically consistent results. In this study, a two-step optimization problem was formulated to predict both muscle and knee contact forces of a subject wearing an instrumented knee prosthesis. In the outer level, muscle parameters were calibrated, whereas …

Lower Extremity Biomechanics In Individuals With And Without Previous Hamstring Injury, Jessica A. Mutchler

Human Movement Studies & Special Education Theses & Dissertations

Primary risk factors for hamstrings strains such as fatigue, previous injury and strength deficits have been identified in the research, yet re-injury rates remain high among the physically active. Sub-acute analysis of the hip, knee and ankle biomechanics following a hamstrings strain have been largely overlooked and may provide additional insight into re-injury risks. It was the aim of this dissertation to explore long-term adaptations in walking and running tasks following a hamstrings strain, and to develop a hip endurance test that could be used in future studies.

Project one used a cross-sectional study with test-retest design to develop and …

The Influence Of Neuromusculoskeletal Model Calibration Method On Predicted Knee Contact Forces During Walking, Gil Serrancolí, Allison Kinney, Benjamin J. Fregly, Josep M. Font-Llagunes

Mechanical and Aerospace Engineering Faculty Publications

This study explored the influence of three model calibration methods on predicted knee contact and leg muscle forces during walking. Static optimization was used to calculate muscle activations for all three methods. Approach A used muscle-tendon model parameter values (i.e., optimal muscle fiber lengths and tendon slack lengths) taken directly from literature. Approach B used a simple algorithm to calibrate muscle-tendon model parameter values such that each muscle operated within the ascending region of its normalized force-length curve. Approach C used a novel two-level optimization procedure to calibrate muscle-tendon, moment arm, and neural control model parameter values while simultaneously predicting …

Changes In Sprint Kinetics Or Kinematics Following Static Or Dynamic Stretching, Kristyne Bartel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to determine the effects of static or dynamic stretching on hip kinematics and kinetics during intermittent sprinting. To achieve this aim, intermittent sprint athletes were asked to complete either a static or dynamic stretch, followed by a repeated-sprint protocol. Hip joint kinematics and performance measures were evaluated during the sprint, including changes that occurred in these variables over the course of the sprint protocol. In addition, hip flexion torque was measured with an isokinetic dynamometer. Ten male (age = 25±2.3 years, 175±3.2 cm, 76.2±2.7 kg) and female (age = 20±1 years, 166±1.3 cm, 60±1.1 …

Validation Of A 5k Age And Weight Run Handicap Model, Paul M. Vanderburgh, Lloyd L. Laubach

Paul M. Vanderburgh

Though increasing age and body weight (BW) have been widely known to be associated with slower distance run times, the common convention in 5K road races is to categorize competitors by age and, sometimes, BW. This has the disadvantage of assigning only small numbers of competitors to age categories and giving advantage to runners close to the minimum age or BW values allowable. Using recent advances in the modeling of distance run performance by BW combined with empirical evidence quantifying the independent effect of age on cardiovascular endurance, we previously published the derivation of the 5K Handicap (5KH), an age …

Body Weight Penalties In The Physical Fitness Tests Of The Army, Air Force, And Navy, Paul M. Vanderburgh, Todd A. Crowder

Paul M. Vanderburgh

Recent research has empirically documented a consistent penalty against heavier service members for events identical or similar to those in the physical fitness tests of the Army, Air Force, and Navy. These penalties, not related to body fatness, are based on biological scaling models and have a physiologic basis. Using hypothetical cases, we quantified the penalties for males, 60 vs. 90 kg body weight, and females, 45 vs. 75 kg, to be 15-20% for the fitness tests of these three services. Such penalties alone can adversely impact awards and promotions for heavier service members. To deal equitably with these penalties …

Body Mass Bias In A Competition Of Muscle Strength And Aerobic Power, Paul M. Vanderburgh, Lloyd L. Laubach

Paul M. Vanderburgh

Recently, a fitness competition called the Pump and Run (PR) has been popularized. Composed of 2 events, a 5-km road race time (RT) in seconds and a maximal-repetition bench press (BPR) with resistance based on a percentage of body mass (M), the final score (RTadj) equals RT - 30(BPR). From published findings, the authors hypothesized that the PR would impose a bias against heavier competitors. Furthermore, the potential for age bias in this event has not been evaluated. Therefore, the purpose of this study was to investigate M and age bias in the PR for men and women. For 74 …

Correction Factors For Body Mass In Military Physical Fitness Tests, Paul M. Vanderburgh

Paul M. Vanderburgh

Recent research findings combined with the theoretical laws of biological similarity make the compelling case that all physical fitness test items for the Army, Air Force, and Navy impose a 15-20% physiologic bias against heavier, not fatter, men and women. Using the published findings that actual scores of muscle and aerobic endurance scale by body mass raised to the 1/3 power, correction factor tables were developed. This correction factor can be multiplied by one’s actual score (e.g., push-ups, sit-ups, abdominal crunches, or curl-ups repetitions or distance run time) to yield adjusted scores that are free of body mass bias. These …

Derivation Of An Age And Weight Handicap For The 5k Run, Paul M. Vanderburgh, Lloyd L. Laubach

Paul M. Vanderburgh

The adverse effect of increasing age and/or body weight on distance run performance has been well documented. Accordingly, nearly all five kilometer (5K) road races employ age categories and, sometimes, a heavier body weight classification. Problems with such conventions include small numbers of runners within older age categories and the advantage given to the lightest runners within each weight category. We developed a 5K Handicap (5KH), a model that calculates an adjusted run time based on the inputs of actual 5K run time, age, and body weight for men and women. This adjusted time, then, can be compared between runners …

Occupational Relevance And Body Mass Bias In Military Physical Fitness Tests, Paul M. Vanderburgh

Paul M. Vanderburgh

Recent evidence makes a compelling case that U.S. Army, Navy, and Air Force health-related physical fitness tests penalize larger, not just fatter, service members. As a result, they tend to receive lower scores than their lighter counterparts, the magnitude of which can be explained by biological scaling laws. Larger personnel, on the other hand, tend to be better performers of work-related fitness tasks such as load carriage, heavy lifting and materiel handling. This has been explained by empirical evidence that lean body mass and lean body mass to dead mass ratio (dead mass = fat mass and external load to …

Body Mass Bias In Exercise Physiology, Paul Vanderburgh

Paul M. Vanderburgh

In certain physically demanding occupations, especially the military, body mass bias has substantive implications. Work physiologists have determined that despite body mass bias in the common military physical fitness tests, the larger service members were often better performers of the physically demanding occupational tasks (Bilzon et al., 2002; Lyons et al., 2005; Rayson et al., 2000). That is, they could carry more, more easily evacuate casualties, and better engage in heavy materiel handling. Yet, the smaller personnel were achieving better scores on the physical fitness tests, the results of which have significant promotion and advancement implications (Vanderburgh & Mahar , …

Load Carriage Distance Run And Pushups Tests: No Body Mass Bias And Occupationally Relevant, Paul M. Vanderburgh, Nicholas S. Mickley, Philip A. Anloague, Kimber Lucius

Paul M. Vanderburgh

Recent research has demonstrated body mass (M) bias in military physical fi tness tests favoring lighter, not just leaner, service members. Mathematical modeling predicts that a distance run carrying a backpack of 30 lbs would eliminate M-bias. The purpose of this study was to empirically test this prediction for the U.S. Army push-ups and 2-mile run tests. Two tests were performed for both events for each of 56 university Reserve Offi cer Training Corps male cadets: with (loaded) and without backpack (unloaded). Results indicated signifi cant M-bias in the unloaded and no M-bias in the loaded condition for both events. …

Validity Of Boston Marathon Qualifying Times, Paul M. Vanderburgh

Paul M. Vanderburgh

Purpose: To assess the validity of Boston Marathon qualifying (BMQ) standards for men and women. Methods: Percent differences between BMQ and current world records (WR) by sex and age group were computed. WR was chosen as the criterion comparison because it is not confounded by intensity, body composition, lifestyle, or environmental factors. A consistent difference across age groups would indicate an appropriate slope of the age-vs-BMQ curve. Inconsistent differences were corrected by adjusting BMQ standards to achieve a uniform percentage difference from WR. Results: BMQ standards for men were consistently ~50% slower than WR (mean 51.5% ± 1.4%, range 49.6–54.4%), …

Contributions Of Body Fat And Effort In The 5k Run: Age And Body Weight Handicap, Anne R. Crecelius, Paul M. Vanderburgh, Lloyd L. Laubach

Paul M. Vanderburgh

The 5K handicap (5KH), designed to eliminate the body weight (BW) and age biases inherent in the 5K run time (RT), yields an adjusted RT (RTadj) that can be compared between runners of different BW and age. As hypothesized in a validation study, however, not all BW bias may be removed, because of the influences of body fatness (BF) and effort (run speed; essentially the inverse as measured by rating of perceived exertion (RPE)). This study's purpose was to determine the effects of BF and RPE on BW bias in the 5KH. For 99 male runners in a regional 5K …

Contributions Of Body Fat And Effort In The 5k Run: Age And Body Weight Handicap, Anne R. Crecelius, Paul M. Vanderburgh, Lloyd L. Laubach

Anne R. Crecelius

The 5K handicap (5KH), designed to eliminate the body weight (BW) and age biases inherent in the 5K run time (RT), yields an adjusted RT (RTadj) that can be compared between runners of different BW and age. As hypothesized in a validation study, however, not all BW bias may be removed, because of the influences of body fatness (BF) and effort (run speed; essentially the inverse as measured by rating of perceived exertion (RPE)). This study's purpose was to determine the effects of BF and RPE on BW bias in the 5KH. For 99 male runners in a regional 5K …

Reactive Hyperemia Occurs Via Activation Of Inwardly-Rectifying Potassium Channels And Na+/K+-Atpase In Humans, Anne R. Crecelius, Jennifer C. Richards, Gary J. Luckasen, Dennis G. Larson, Frank A. Dinenno

Anne R. Crecelius

Rationale: Reactive hyperemia (RH) in the forearm circulation is an important marker of cardiovascular health, yet the underlying vasodilator signaling pathways are controversial and thus remain unclear. Objective: We hypothesized that RH occurs via activation of inwardly rectifying potassium (KIR) channels and Na+/K+-ATPase and is largely independent of the combined production of the endothelial autocoids nitric oxide (NO) and prostaglandins in young healthy humans. Methods and Results: In 24 (23±1 years) subjects, we performed RH trials by measuring forearm blood flow (FBF; venous occlusion plethysmography) after 5 minutes of arterial occlusion. In protocol 1, we studied 2 groups of 8 …

Gait Intervention For Improvements In Human Top Speed Running, Michelle Buechner

Graduate Student Theses, Dissertations, & Professional Papers

Between individuals faster sprinting speeds are achieved by applying greater stance average forces against the running surface. Recent evidence further indicates that elite level performers also strike the ground with leg kinematics that differ from those of non-elites and that these leg movements act to enhance the force transients occurring in the milliseconds following foot-ground impact. I investigated whether sprint performance could be enhanced through a short term gait intervention, consisting of 3 laboratory training sessions wherein subjects (n = 6) completed 5 high-speed runs on an instrumented force treadmill at 90% of their measured top sprint. The subjects received …

A Pilot Study Investigating The Reasons For Playing Through Pain And Injury: Emerging Themes In Men’S And Women’S Collegiate Rugby, Leilani Madrigal, Jamie Robbins, Diane L. Gill, Katherine Wurst

Athletic Performance Research

Collegiate rugby is a competitive, collision sport, yet insufficient empirical evidence exists regarding participants’ perspectives on pain and injury. This study addressed male and female rugby players’ experiences with injury, and their views about playing through pain and injury. Eleven rugby players (five male; six female) competing in USA Rugby’s National College 7’s tournament participated in semi structured interviews, which were recorded, transcribed, and content-analyzed. Two major themes emerged: passion for sport and sport ethic. Passion for sport was composed of (a) love of the sport, (b) meaning of the sport, and (c) desire to be on the field. Sport …