Life Sciences Commons^™

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, …

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 …

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 …

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.

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 …

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 …

Human Performance Lab Newsletter, March 2010, St. Cloud State University

Human Performance Lab Newsletter

Contents of this issue include:

• Kelly's Corner by David Bacharach
• Evolution of an Ergometer by Eric Wright and Dennis Madden
• Physical Attributes of Youth in an Urban Tennis Program by Kate Kaufmann
• Stress and your Health by Ashlee Ford
• Fluid Intake and Athletic Performance by Ashley Davenport and Chad Johnson
• Improving Sudden Cardiac Arrest Survival Rate by April Kuschke

Endurance Exercise Training Effects On Body Fatness, Vo2max Hdl-C Subfractions, And Glucose Tolerance Are Influenced By A Plin Haplotype In Older Caucasians, Nathan T. Jenkins, Jennifer A. Mckenzie, Coleen M. Damcott, Sarah Witkowski, James M. Hagberg

Exercise and Sport Studies: Faculty Publications

Perilipins are lipid droplet-coating proteins that regulate intracellular lipolysis in adipocytes. A haplotype of two perilipin gene (PLIN) single nucleotide polymorphisms, 13041A>G and 14995A>>T, has been previously associated with obesity risk. Furthermore, the available data indicate that this association may be modified by sex. We hypothesized that this haplotype would associate with body fatness, aerobic fitness, and a number of cardiovascular (CV) risk factor phenotypes before and after a 6-mo endurance exercise training program in sedentary older Caucasians. The major haplotype group (13041A/14995A; n = 57) had significantly lower body mass index (BMI) and body fatness compared with …

Electromyographical Analysis Of Double Pole Ergometry: Standing Vs. Sitting, Phillip B. Watts, Randall L. Jensen

Conference Papers in Published Proceedings

No abstract provided.

Relationship Of Ground Reaction And Knee Joint Reaction Forces In Plyometric Exercises, Randall L. Jensen

Conference Papers in Published Proceedings

No abstract provided.

The Effects Of A Cloth Wrap In Stabilization Of The Ankle, Randall L. Jensen

Conference Papers in Published Proceedings

No abstract provided.

Ground Reaction Forces Of Variations Of Plyometric Exercises On Hard Surfaces, Padded Surfaces And Water, Randall L. Jensen

Conference Papers in Published Proceedings

No abstract provided.

Hamstring Muscle Activation Differences Between Genders While Performing Single Leg Landings, Randall L. Jensen

Conference Papers in Published Proceedings

No abstract provided.

Differences In Rsi And Peak Ground Reaction Force For Drop Rebound Jumps From A Hang And Box For Female Subjects, Randall L. Jensen

Conference Papers in Published Proceedings

No abstract provided.

Different Training Volumes Yield Equivalent Increases In Bmd, R. A. Pierce, L. C. Lee, C. P. Ahles, S. M. Shdo, S. V. Jaque, Ken D. Sumida

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The purpose of this study was to determine if an exercise threshold existed in stimulating an elevation in bone mineral density (BMD), via resistance training, during the growth period in male rats. 27 male rats were randomly divided into Control (Con, n = 9), 3 ladder climb resistance trained group (3LC, n = 9), and 6 ladder climb resistance trained group (6LC, n = 9). The 3LC and 6LC groups were conditioned to climb a vertical ladder with weights appended to their tail 3 days/wk for a total of 6 wks, but the 6LC group performed significantly more work than …

Balance Training Reduces Falls Risk In Older Individuals With Type 2 Diabetes, Steven Morrison, Sheri R. Colberg, Mita Mariano, Henri K. Parson, Arthur I. Vinik

Rehabilitation Sciences Faculty Publications

OBJECTIVE - This study assessed the effects of balance/strength training on falls risk and posture in older individuals with type 2 diabetes.

RESEARCH DESIGN AND METHODS - Sixteen individuals with type 2 diabetes and 21 age-matched control subjects (aged 50-75 years) participated. Postural stability and falls risk was assessed before and after a 6-week exercise program.

RESULTS - Diabetic individuals had significantly higher falls risk score compared with control subjects. The diabetic group also exhibited evidence of mild-to-moderate neuropathy, slower reaction times, and increased postural sway. Following exercise, the diabetic group showed significant improvements in leg strength, faster reaction times, …

The Influence Of Elliptical Chainrings On 10 Km Cycling Time Trial Performance, Jeremiah Peiffer, Chris Abbiss

Research outputs pre 2011

The use of elliptical chainrings (also called chainwheels or sprockets) has gained considerable interest in the amateur and professional cycling community. evertheless, we are unaware of any scientific studies that have examined the performancebenefits of using elliptical chainrings during an actual performance trial. Therefore, this study examined the influence of elliptical chainring use on physiological and performance parameters during a 10 km cycling time trial. Nine male cyclistscompleted, in a counterbalanced order, three 10 km cycling time trials using either a standard chainring or an elliptical chainring at two distinct settings. An attempt was made to blind the cyclists to …

Relationship Between Circulating Progenitor Cells, Vascular Function And Oxidative Stress With Long-Term Training And Short-Term Detraining In Older Men, Sarah Witkowski, Michael M. Lockard, Nathan T. Jenkins, Thomas O. Obisesan, Espen E. Spangenburg, James M. Hagberg

Exercise and Sport Studies: Faculty Publications

Exercise may contribute to the maintenance of vascular function via enhanced liberation and action of bone-marrow-derived progenitor cells. Activity related changes in oxidative stress may also influence the number and function of these cells. In the present study, we sought to determine (i) whether adaptations in reactive hyperaemic FBF (forearm blood flow) response associated with long-term endurance exercise and short-term detraining were related to resting putative progenitor cell number and function, and (ii) whether oxidative stress affected these factors. Participants included men with a history of more than 30 years of moderate-to-high-intensity exercise (HI group) and healthy low-active age- and …

Use Of Near-Infrared Light To Reduce Symptoms Associated With Restless Legs Syndrome In A Woman: A Case Report, Ulrike H. Mitchell

Faculty Publications

Introduction: We describe a potential new treatment option for patients suffering from restless legs syndrome. Contemporary treatment for restless legs syndrome consists mostly of dopaminergic drugs that leave some patients feeling nauseated and dizzy. A non-invasive, drug-free option would open new doors for patients suffering from restless legs syndrome. Case presentation: A 69-year-old Caucasian woman met International Restless Legs Syndrome Study Group criteria for the diagnosis of restless legs syndrome. She had been afflicted with restless legs syndrome for over 30 years and tried many of the available pharmaceutical remedies without success. For this study she received 30-minute treatment sessions …

Equal Bmd After Daily Or Triweekly Exercise In Growing Rats, B. D. Kayser, J. K. Godfrey, R. M. Cunningham, R. A. Pierce, S. V. Jaque, Ken D. Sumida

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The purpose of this study was to examine the efficacy of continuous resistance training (3 days/wk) compared to interrupted resistance training where 20-24 h separated an exercise bout (i.e. 6 days/wk) for enhancing bone mineral density (BMD) in growing male rats. The total volume of work performed per week between the two resistance training programs was equivalent by design. Young male rats were randomly divided into Control (Con, n = 9), 3 days/wk resistance trained group (RT3, n = 9), and 6 days/wk resistance trained group (RT6, n = 9). The RT3 and RT6 groups were conditioned to climb a …

Kinetic Quantification Of Plyometric Take Off, Flight, And Landing Characteristics, William Ebben, Tyler Vanderzanden, Brad Wurm, Luke Garceau, Christina Feldmann, Erich Petushek

Exercise Science Faculty Research and Publications

This study assessed the kinetic characteristics of a variety of plyometric exercises and assessed gender differences therein. Twenty-six men and 23 women performed a variety of plyometric exercises including line hops, 15.24 cm cone hops, squat jumps, tuck jumps, countermovement jumps, loaded countermovement jumps equal to 30% of 1 RM squat, depth jumps normalized to the subjects jump height, and single leg jumps. All plyometric exercises were performed on a force platform. Outcome variables associated with the takeoff, airborne, and landing phase of each plyometric were assessed including the peak ground reaction force during takeoff, time to takeoff, jump height, …

The Acute Time Course Of Concurrent Activation Potentiation, Luke Garceau, Erich Petushek, Mckenzie Fauth, William Ebben

Exercise Science Faculty Research and Publications

This study evaluated the acute time course of the ergogenic effect of concurrent activation potentiation (CAP). Forty-two men and women, including CAP non-responders and responders, performed a 5 second isometric knee extension on a dynamometer with the use of remote voluntary contractions (RVC). Mean torque was assessed in seven 500 millisecond (ms) time periods. A two-way repeated measures ANOVA revealed significant main effects for time period (p ≤ 0.001), but no significant interaction between time period and CAP non-responders and responders (p > 0.05). The ergogenic effects of CAP are accrued during the first 1000ms. Concurrent activation potentiation responders produce greater …

The Effect Of Concurrent Activation Potentiation During Fast Stretch Shortening Cycle Activity, Erich Petushek, Luke Garceau, William Ebben

Exercise Science Faculty Research and Publications

This study evaluated the effect of remote voluntary contractions (RVC) on depth jump performance. Subjects performed the depth jump in a RVC condition and a condition without RVC (NO-RVC). Ground reaction force (GRF), impulse (I), and reactive strength index (RSI) were assessed with a force platform. Data were analyzed using a two way ANOVA. Analysis of GRF showed no significant main effects for RVC condition (p = 0.46) and no interaction for RVC condition and gender (p = 0.11). Analysis of I showed no significant main effects for RVC condition (p = 0.99) and no interaction for RVC condition and …

Antagonist Conditioning Contractions Impair Agonist Functioning, Luke Garceau, Aaron Gray, Mckenzie Fauth, Phillip Hanson, Brittni Hsu, Tejin Yoon, Chris Szalkowski, Brittney Lutsch, William Ebben

Exercise Science Faculty Research and Publications

This study assessed the effect of antagonist conditioning contractions (ACC) on the subsequent force and electromyography of an agonist. Twelve subjects performed isokinetic elbow flexion on a dynamometer in 4 test conditions including a baseline condition without, and 1, 3 and 6 seconds after, isometric triceps extension. Average peak torque (T), peak torque/body weight (T:BW), average power (P), and rate of torque development (RTD) were assessed. Electromyographic data were obtained from elbow extensors and flexors. A repeated measures ANOVA with post hoc analysis demonstrated that T, T:BW, P, and RTD were higher in the baseline, compared to the post ACC …

The Effect Of Concurrent Activation Potentiation On The Knee Extensor And Flexor Performance Of Men And Women, Luke Garceau, Erich Petushek, Mckenzie Fauth, William Ebben

Exercise Science Faculty Research and Publications

This study evaluated the effect of remote voluntary contractions (RVC) during isometric and isokinetic knee flexion and extension tests and evaluated gender differences therein. Subject peak torque, rate of torque development, and power were assessed with a dynamometer in RVC and no RVC’s conditions. A two way mixed ANOVA with repeated measures for condition was used to evaluate the interaction between conditions and gender, and to assess the main effects. Main effects were evaluated with a paired samples t-test. Results revealed a significant interaction between all but one test condition and gender as well as significant main effects for all …

Dynamic Stabilization During The Landing Phase Of Plyometric Exercises, Erich Petushek, Luke Garceau, Tyler Vanderzanden, Brad Wurm, Christina Feldmann, William Ebben

Exercise Science Faculty Research and Publications

This study examined the differences in and the reliability of time to stabilization (TTS) of several plyometric exercises. Twenty six men performed a variety of plyometric exercises representing a continuum of intensities of landing instability, including line hops, cone hops, squat jumps, tuck jumps, countermovement jumps, dumbbell countermovement jumps, and single leg countermovement jumps on a force platform. A repeated measures ANOVA with Bonferroni post hoc corrections was used to evaluate the differences in TTS between plyometric exercises. Practitioners who use plyometrics to train dynamic stability and balance should create programs that progress the intensity of the exercises based on …

Aerobic Training Increases Skin Perfusion By A Nitric Oxide Mechanism In Type 2 Diabetes, Sheri R. Colberg, Laura C. Hill, Henri K. Parson, Kathleen S. Thomas, Aaron I. Vinik

Human Movement Sciences & Special Education Faculty Publications

It is well known that a number of locally released vasodilatory and vasoconstrictive compounds can affect skin perfusion. This study investigated the effects of aerobic training on the contribution of nitric oxide (NO), prostaglandins (PG), and endothelial-derived hyperpolarizing factor (EDHF) in stimulated dorsal foot skin perfusion in individuals with type 2 diabetes (T2DM). Ten previously sedentary, older individuals with T2DM (57.0 ± 3.1 years) and nine sedentary controls (53.5 ± 3.2 years) were tested before and after undertaking six months of moderate aerobic training three times weekly in a supervised setting. All subjects underwent measurement of baseline (32°C) and heat-stimulated …

The Influence Of Title Ix On Personal And Professional Biographies Of Early Career Female Club Volleyball Coaches, Dennis Dahlberg, George M. De Marco, Corinne M. Daprano, Carolyn Ridenour

Health and Sport Science Faculty Publications

Seeking to understand the relationship between Title IX and its impact on a select group of its contemporary beneficiaries, the purpose of this study was to determine the influence of Title IX on the personal and professional biographies of 8 early career female club volleyball coaches. This study utilized a modified case study design featuring constant comparison data analysis. Data were collected using a qualitative interview technique with each of the candidate’s interviews subdivided into four distinct sections. Part I of the interview established a basic personal and professional biography of each individual coach. Part II provided data on the …