Life Sciences Commons^™

A Comparison Of Ground Reaction Forces And Muscle Activity Of The Tsunami Bar® Against A Rigid Barbell During Back Squat Phases, John Carver Middleton

Theses and Dissertations

An Institutional Review Board (IRB)-approved study was conducted to investigate the effects of the Tsunami Bar® (TB), a flexible barbell, on ground reaction force (GRF) production and muscle activity in the quadricep, hamstring, and gluteal muscle groups during phases of the squat exercise and compare the effects to the effects to using a rigid barbell (RB). A two-by-two repeated measures Analysis of Variance (ANOVA) test was used to compare the results. Descriptive statistics showed significantly higher GRFs for the TB during the unweighting phase, significant differences in GRFs between speeds for each phase, significantly higher forces on average with the …

The Interaction Of Treadmill Type And Incline Slope On Biomechanics And Muscle Activation During Human Locomotion, Rohit Kundu

Cal Poly Humboldt theses and projects

Treadmills are widely used in biomechanical research. However, variations in treadmill design and running surfaces may affect biomechanical variables such as muscle activation and impact acceleration. In addition, incline walking on treadmills leads to changes in the pattern of muscle activation, particularly at steeper inclines. Despite extensive research on the effects of running surfaces and inclines on biomechanical variables (gait, muscle activation, impact force), the impact of varying treadmill manufacturers on biomechanical variables at high inclines remains unclear. Purpose: To determine whether the type of treadmill deck influences surface electromyography (EMG) patterns and impact accelerations at high incline (20%) walking …

The Effect Of Tempo On Prone Hamstring Exercise - An Exploration Of Unilateral Bias, Derick A. Anglin

Electronic Theses and Dissertations

Hamstring injuries are common muscle-skeletal injuries with a high recurrence rate. While unmodifiable risk factors (e.g., previous injury) vary, recent evidence has questioned the utility of eccentric exercise in preventing hamstring strains. Furthermore, whether eccentric exercise can transfer to sprinting’s kinetic and kinematic requirements is of question. Therefore, this investigation examines exercise tempo (fast vs. slow eccentric phase), movement strategy (bilateral vs. unilateral), and external load characteristics (coupled vs. independent) bias concentric (CON) and eccentric (ECC) biceps femoris (BF) mean electromyography (mEMG). METHODS: Twenty college-aged students aged 18 – 33 (M = 23.4, SD = 3.12 years) with …

A Biomechanical Analysis Of Back Squats: Motion Capture, Electromyography, And Musculoskeletal Modeling, Eva Maria Urdiales Maddox

Human Movement Studies & Special Education Theses & Dissertations

Previous literature evaluating maximal back squats have failed to identify key components of the study decisions and procedures that would allow for duplication. Firstly, the existence of a sticking region in maximally weighted resistance exercises is frequently discussed and has been described as a force-reduced transition phase between an acceleration phase and a strength phase of a lift. However, the etiology has yet to be agreed upon. Second, Electromyography (EMG) is frequently used to assess muscle activations. However, no best practice for EMG normalization has been proposed. Two methods are commonly implemented for normalizing EMG: a maximum voluntary isometric contraction …

Examination Of Sex- And Intensity-Specific Fatigue During Bilateral Leg Extension Exercise, Taylor Kayln Dinyer

Theses and Dissertations--Kinesiology and Health Promotion

The purposes of this study were to: 1) examine sex-related differences in the performance of repetitions to failure below (CL_-10%, CL_-20%) and above (50%, 60%, 70%, and 80% 1RM) the critical load (CL) to make inferences regarding the mechanisms responsible for variability in the performance of repetitions to failure at varying loads; 2) examine the time course of neuromuscular and muscle oxygen saturation responses during the performance of repetitions to failure below and above the CL; 3) to make inferences regarding motor unit activation strategies used to maintain force during the completion of repetitions below and …

Effect Of Caffeine Supplementation On Vertical Jump Performance, Heart Rate Variability, And Electromyography, Collin T. Garner

Masters Theses

Research into caffeine’s ability to improve anaerobic performance is inconclusive. Eleven anaerobically trained individuals (mean age: 23.45 ± 1.51 years) participated in this study. Assessments of resting heart rate variability (HRV), exercise heart rate variability, surface electromyography (sEMG), static vertical jump (SJ), and countermovement vertical jump (CMJ) were conducted before and after administration of placebo and caffeinated treatments. Three trials of each vertical jump technique were performed before and after treatment administration. A 60-minute absorption period was utilized for absorption of the treatment following its ingestion. All participants performed testing on two separate occasions, once under the placebo condition and …

Effects Of Instability On Core Muscle Activation In A Side Bridge, Erin E. Kishman

Masters Theses

Training the musculature of the core continues to be perceived as an essential component of conditioning and rehabilitation settings (11). A popular way to train the core is with the use of instability devices, such as Swiss ball or suspension trainer. However, there is limited research on the effects of these devices on core muscle activity. The purpose of this study was to examine core muscle activity during side bridge variations with and without instability devices (Floor, Swiss Ball, and TRX) through electromyography (EMG) of the rectus abdominis, external oblique, erector spinae, and latissimus dorsi. 39 participants performed three variations …

Muscle Activation Analysis With Kinematic Comparison Between Wind-Up And Stretch Pitching With Respect To The Upper And Lower Extremities, Megan M. Smidebush

Theses and Dissertations--Kinesiology and Health Promotion

Introduction: Baseball pitching is considered one of the most intense aspects within the game of baseball, as well as the most complicated dynamic throwing task in all of sports. The biomechanics of pitching have been heavily investigated in an attempt to identify optimal pitching mechanics in terms of pitching performance. Previous quantified upper body kinetics research has concluded that improved muscle strength is needed in attempting to achieve adequate upper body kinetics and efficient pitching performances. Therefore, it is the purpose of this research study to compare the lower extremity muscle and upper extremity muscle activation patterns and kinematic variables …

Muscle Synergy During A Single Leg Standing Test In Ambulatory Children With Cerebral Palsy, Brennan L. Smith

Theses and Dissertations--Kinesiology and Health Promotion

INTRODUCTION: Cerebral Palsy (CP) is a sensorimotor disorder characterized by dysfunctional motor coordination, balance problems, and loss of selective motor control. Motor coordination exhibited as co-contraction, has been subjectively quantified using gait analysis, but recent studies have begun to objectively analyze the amount of co-contraction by collecting electromyography (EMG) data. Center of pressure excursion (COPE) measurements collected during a single leg standing test (SLST) have shown to be more valid measurements of balance in populations with motor disabilities than a SLST alone. A recent study has correlated increased COPE velocity with a lower fall risk as determined by reported fall …

The Effects Of A Short-Term Endurance Training Program With Blood Flow Restriction Cuffs Versus Acsm Recommended Endurance Training On Arterial Compliance And Muscular Adaptations In Recreationally Active Males, Brittany N. Esparza

Theses and Dissertations

RESULTS: Significant time and group interaction found in cardiac ejection time (p<.05). Significant condition difference between blood flow restriction (BFR) and control for heart rate (HR) max (p=.05) and maximum oxygen consumption (VO2) (p<.05). Significant time difference found in pulse wave velocity femoral to distal (p<.05). Significant repetition main effect (p<.01) for root mean square (RMS) and median frequency (MDF) of Thorstensson. Significant time and group interaction in vastus lateralis of MDF (p<.01). Significant repetition main effect for RMS and MDF ratio (p<.01) Significant time and repetition interaction in vastus lateralis of RMS ratio (p<.03)

CONCLUSION: The BFR session showed improvement in both post HR max and post VO2 in comparison to the control group. This may have been caused by increased tolerance to pain/metabolic by-products for HR and increased efficiency at extracting oxygen for VO2

Neuromuscular And Arterial Compliance Responses To Different Resistance Training Frequencies And Protocols, Patrick Murphy

Theses and Dissertations

PURPOSE: The purpose of this study was to determine the impact of blood flow restriction and resistance training on arterial elasticity, EMG activity, and strength indices among sedentary to recreationally active females who completed 6 weeks of resistance training.

RESULTS: Significant time*condition interactions occurred in LE-1RM (p

CONCLUSION: The research group(s), 1–2 days/week with and without blood flow restriction, may increase training adaptations and responses parallel to the control group (3 days/week). There appears to be no differences in arterial compliance between groups.

Static Stretching And Preconditioning Exercise Augments Power Output In Recreational Athletes, Mark R. Mason

Theses and Dissertations--Kinesiology and Health Promotion

The purpose of this study was to determine the independent and combined effects of performing a preconditioning exercise and antagonist stretching on vertical jump (VJ) performance. Twenty club rugby players performed a VJ in four conditions: control condition, following static stretching, following a preconditioning exercise, and following the combined treatment of static stretching and a preconditioning exercise. Electromyographic (EMG) activity was measured in the gluteus maximus, vastus lateralis, gastrocnemius medialis, and tibialis anterior during the VJ trials. Repeated measures ANOVA were used to compare VJ and EMG outcomes across conditions. A Bonferroni correction was used to account for multiple post-hoc …

Central And Peripheral Weight Gain Affect Trunk Kinematics And Lower-Extremity Muscle Activation Differently During Sit-To-Stand, Michelle Christine Walaszek

Theses and Dissertations--Kinesiology and Health Promotion

Background: Obesity-induced alterations in biomechanics and muscle recruitment during activities of daily living, such as sit-to-stand (STS) are often attributed to increases in adipose tissue (AT) mass. Central or peripheral distribution of AT may differently affect biomechanics and muscle recruitment.

Methods: Fifteen healthy, normal weight (BMI 22.4 ± 1.9 kg/m², 24.1 ± 4.2 years) subjects volunteered. External loads equivalent to a 5 kg/m² BMI increase were applied in three conditions: unloaded (UN), centrally loaded (CL), and peripherally loaded (PL). Subjects completed three successful STS movements in a backless chair under each load condition in random order. Motion …

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 …

Lower Extremity Neuromechanics During A Forward-Side Jump Following Functional Fatigue In Patients With Ankle Instability, Hyun Kim

Theses and Dissertations

Ankle instability (AI) and fatigue impair neuromuscular control as well as dynamic joint stability of the lower extremity. No one has comprehensively examined the effects of AI and fatigue on neuromechanics of the lower extremity during a functional activity. Deficits associated with AI and fatigue could be additive in increasing the risk for injury in patients with AI. PURPOSE: To examine the interaction of AI and fatigue on lower extremity muscle activity, kinematic, and kinetic patterns during a forward-side jump. METHODS: 25 AI (23.3 ± 1.9 yrs, 176.5 ± 10.5 cm, 70.9 ± 11.4 kg), and 25 matched control subjects …

Acute Effects Of Dynamic Stretching On Flexibility And Agonist-Antagonist Muscle Activity, Lance T. Beisley

EWU Masters Thesis Collection

"Flexibility is an important determinant of health and important in sport performance. ADS and SPST are the methods most often used in training flexibility for sport. Although ADS appears to dominate SPST in measures of power and agility, the mechanisms are unclear. The purpose of this study was to delineate the effects of ADS on AROM and agonist-antagonist mean and peak EMG. The ADS protocol involved three sets of ten repetitions of leg kicks while in the supine position with the pelvis and contralateral limb fixed in extension. Participants moved the leg at the hip in a kicking motion to …

Evaluation Of Shake Weight Protocol In Senior Populations, Isaac F. Cook

Graduate Theses and Dissertations

The Shake Weight® (SW®) is designed to improve muscular fitness in a quick and inexpensive way. This study aimed to determine if the SW® was an effective tool at improving muscular fitness, body composition, and bone mineral density (BMD) in post-menopausal women. Participants were 17 healthy, post-menopausal women from aMidwestern University and divided into two training (SW® and HIT) interventions that lasted 10 weeks. HIT participants performed three sets of 8 repetitions at 80% of their estimated 1RM for the chest press, leg press, lat pulldown, and seated row. SW® participants performed the exercises prescribed by the SW® manufacturer. Changes …

The Effect Of Anterior Knee Pain On Serum Cartilage Oligomeric Matrix Protein And Muscular Cocontraction During Running, Scott T. Woodland

Theses and Dissertations

Knee pain can alter lower-extremity neuromechanics and often results in functional disability. The relationship between lower-extremity neuromechanical alterations, due to anterior knee pain, and articular cartilage condition is unclear. The purpose of this study was to determine the independent effect of anterior knee pain during running on articular cartilage condition, as reflected by serum cartilage oligomeric matrix protein concentrations and muscle cocontraction duration. Seven men and five women completed a 30-min run in three different sessions: control (no infusion), sham (isotonic saline infusion), and pain (hypertonic saline infusion). Saline was infused into the right infrapatellar fat pad for the duration …

Contributions Of Muscle Fatigue To A Neuromuscular Neck Injury In Female Standard Ballroom Dancers, Teri Riding

Theses and Dissertations

Objective: To investigate the potential etiology of a loss of neck control injury in female standard ballroom dancers. The median frequency (MF) as measured by electromyography (EMG) of the left upper trapezius (UT), left splenius capitius (SPL), and right sternocleidomastoid (SCM) of injured dancers was compared to non-injured dancers. This comparison was performed to identify whether dancers with a history of loss of neck control have a greater amount of fatigue than those with no history of this particular injury. Design and Setting: A 2 x 6 factorial design was used for this investigation. The independent variables were group (injured …

Emg Analysis Of Core And Thigh Musculature Contribution During Double And Single Leg Squats On Both Stable And Unstable Surfaces, Julie M. Whitehead

Human Movement Studies & Special Education Theses & Dissertations

The purpose of this study was to determine EMG activity of the hip stabilizers, thigh, and core muscles during various squatting exercises in order to better appreciate the contribution of the core and thigh during weight bearing functional activity. Surface EMG electrodes were placed over the rectus abdominis (RA), internal oblique (IO), external oblique (EO), erector spinae (ES), vastus medialis (VM), biceps femoris (BF), and gluteus medius (GM). The right leg was used for any single leg exercises perforn1ed. Each subject performed three double leg and three single leg un-weighted squats to 60 degrees of knee flexion on a stable …

Comparison Of The Emg Activity Of The Supraspinatus And Infraspinatus Muscles During Various Closed Chain Exercises, I-Chen Lin

Rehabilitation Sciences Theses & Dissertations

Advantages of closed chain exercises used in the lower extremity have been well documented. However, the effects of closed chain exercises on the upper extremities have not been studied very much. Thus, the purpose of this research is to analyze the EMG activity of the supraspinatus and infraspinatus muscles and compare the relative amounts of activities by performing different isotonic closed chain exercises and an open chain exercise in normal subjects. The supraspinatus and infraspinatus muscles in 1 o healthy subjects were studied with fine wire, intramuscular, electromyographic electrodes while performing 5 closed chain exercises and a D2. open chain …