Exercise Science Commons^™

Effects Of Functional Ankle Instability On Muscle Activation Latency In Ice Hockey Athletes: A Pilot Study, Nicolas Gonzalez, Tyler A. Wood, Nicholas E. Grahovec

Journal of Sports Medicine and Allied Health Sciences: Official Journal of the Ohio Athletic Trainers Association

This study examined lower extremity muscle activation latency during the push-off phase in ice hockey athletes with and without functional ankle instability (FAI). Ten athletes participated, divided into FAI and control groups based on the Identification of Functional Ankle Instability scale. Participants completed three push-off trials while wearing electromyography sensors on the tibialis anterior, fibularis longus, medial gastrocnemius, and gluteus medius. The FAI group demonstrated a significant increase in muscle activation latency across all muscles tested (p

Combining Haptic Feedback With Electromyography To Study Knee Injury In Stationary Cycling, Christopher Kirby

Honors Theses

Patellofemoral Pain Syndrome (PFPS) is the most prevalent overuse injury in cycling, often linked to altered neuromuscular activation patterns of the quadriceps and hamstrings. While sensory feedback has successfully modified cyclists posture, there is a critical lack of evidence-based interventions targeting the underlying muscle activation imbalances associated with chronic knee pain. This study aimed to develop and validate a novel, real-time biofeedback system that utilizes electromyography (EMG) to trigger vibrotactile cues, aiming to shift muscle onset timing earlier in the pedal stroke to mitigate PFPS-related imbalances. A closed-loop system was engineered by integrating a Delsys EMG system with a SageMotion …

Voluntary Contractions Underestimate Peak Muscle Activity In Drop Jumps, David Alan Phillips, Skylar Paletta, Michael R. Perlet

Department of Kinesiology Scholarship and Creative Works

Maximal voluntary isometric contractions (MVIC) are a common method to normalize electromyographic amplitude into standardized units of %MVIC. However, in 60% of drop jump research using an MVIC in 2018–2023, supramaximal activation or activation greater than 100% MVIC occurred. Therefore, MVICs may not be representative of peak muscle activation, leading to erroneous interpretation of muscle activation. The purpose of this study is to quantify EMG normalization difference in drop jump landings. Sixteen (10 M, 6F) participants were recruited for the study. MVICs were recorded from nine lower extremity muscles and this activation compared to the maximal activation recorded from 10 …

The Effects Of Anchor Scheme On Performance Fatigability, Neuromuscular Responses, And Perceived Factors That Contributed To Task Termination During Fatiguing Tasks, Dolores G. Ortega, Robert W. Smith, Jocelyn E. Arnett, Tyler J. Neltner, Trevor D. Roberts, Justin S. Pioske, Richard J. Schmidt, Terry J. Housh

Journal for Sports Neuroscience

Purpose: The purpose of this study was to examine the effects of sustained, isometric forearm flexion tasks anchored to a rating of perceived exertion (RPE) versus torque on the composite, inter-, and intra-individual patterns of responses for torque and neuromuscular parameters, as well as the perceived factors that contributed to task termination. Methods: Ten men (mean ± SD: age = 20.9 ± 2.2 yrs.; height = 180.0 ± 5.1 cm; body mass = 81.3 ± 10.0 kg) performed maximal voluntary isometric contractions (MVICs) before and after sustained, isometric forearm flexion tasks anchored to RPE = 6 (RPE6_FT) and …

Lower Limb Muscle Activation In Young Adults Walking In Water And On Land, Christopher Long, Christopher J. Dakin, Sara A. Harper, Joonsun Park, Aaron Folau, Mark Crandall, Nathan Christensen, Talin Louder

Kinesiology and Health Science Faculty Publications

Previous research has shown that exercise interventions requiring increased activation of the tibialis anterior (TA), the primary ankle dorsiflexor, can improve walking performance in individuals with foot drop. Correspondingly, heightened drag forces experienced during walking performed in water may augment TA activation during the swing phase of gait, potentially leading to improved walking gait on land. Therefore, this study aimed to compare surface electromyographic (sEMG) activation in the TA and medial gastrocnemius (GM) during gait performed in water versus on land. Thirty-eight healthy, recreationally active young adults, comprising 18 females and 20 males, participated in the study. Each participant completed …

Does Joint Angle Affect Composite, Inter-Individual, And Intra-Individual Patterns Of Responses For Men During Fatiguing Isometric Forearm Flexion Tasks Anchored To A High Perceptual Intensity?, Jocelyn E. Arnett, Robert W. Smith, Tyler J. Neltner, John Paul V. Anders, Dolores G. Ortega, Terry J. Housh, Richard J. Schmidt, Glen O. Johnson

Journal for Sports Neuroscience

Purpose: The purpose of this study was to utilize the Ratings of Perceived Exertion (RPE) Clamp Model to examine the effects of joint angle on the composite, inter-, and intra-individual patterns of responses for torque and neuromuscular parameters during fatiguing isometric tasks anchored to RPE of 8 (RPE = 8) at elbow joint angles of 75° (JA75) and 125° (JA125) for men. Methods: Ten men (Mean ± SD: age: 20.7 ± 1.2 yrs; height: 181.6 ± 6.0 cm; body mass: 83.7 ± 14.9 kg) performed 2,3 s forearm flexion maximal voluntary isometric contractions (MVIC) with the dominant arm before and …

Running Biomechanics Differ During And After Pregnancy Compared To Females Who Have Never Been Pregnant, Jennifer J. Bagwell, Elizabeth Avila, Nicholas Reynolds, Jo Armour Smith, Kevin Valenzuela, Dimitrios Katsavelis

Physical Therapy Faculty Articles and Research

Background

Perinatal running participation has increased recently; however, pregnancy related symptoms can limit activity. Perinatal running biomechanics could inform interventions to help perinatal individuals maintain an active lifestyle.

Research question

Are perinatal running biomaechanics and muscle activation different compared to nulligravida females?

Methods

Sixteen pregnant participants completed self-selected velocity running during second trimester (2 T), third trimester (3 T), and postpartum (PP) and 16 matched controls completed these procedures once in this case control study. Kinematic, kinetic, and electromyography (EMG) data were collected using a motion capture system, force plates, and EMG electrodes. Peak trunk, pelvis, hip, knee, and ankle …

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 Effects Of Joint Angle And Anchoring Scheme On Performance Fatigability And Neuromuscular Responses Following Isometric Forearm Flexion Tasks To Failure, Jocelyn E. Arnett, Robert W. Smith, Tyler J. Neltner, John Paul V. Anders, Dolores G. Ortega, Terry J. Housh, Richard J. Schmidt, Glen O. Johnson

Journal for Sports Neuroscience

Purpose: The purpose of this study was to examine the effects of joint angle on MVIC and neuromuscular responses at task failure following sustained, isometric forearm flexion tasks anchored to a rating of perceived exertion (RPE) of 8 (RPE = 8) and anchored to the initial torque that corresponded to RPE = 8 (TRQ). Methods: Ten women (age: 21.0 ± 2.8 yrs; height: 168.5 ± 7.2 cm; body mass: 68.0 ± 7.2 kg) performed 2, 3 s MVICs at joint angles (JA) of 75°, 100°, and 125° (randomized order) before and after sustained, isometric forearm flexion tasks to failure at …

Effect Of Sleep Restriction On Quadriceps’ Strength And Voluntary Activation, Scott Sigrist

Theses and Dissertations--Kinesiology and Health Promotion

Background: As little as three nights of sleep restriction reduces muscle strength. More than one-third of Americans are chronically sleep restricted (< 7.0 hours/night) and are at risk of muscle weakness (dynapenia). Presently, the mechanistic cause of sleep restriction-induced dynapenia (SRID) has not been elucidated. Rapid changes in muscle strength are typically driven by short-term changes in muscle contractility or voluntary recruitment. The purpose of this study was to investigate how sleep restriction affects muscle contractile function and voluntary recruitment. Methods: A sample of 12 subjects (age 24.8 ± 2.6y) underwent isometric and isokinetic knee extensor muscle testing following 3d of adequate sleep (SA; 8.05 ± 0.45h), 3 d of sleep restriction (SR; 5.02 ± 0.05h), and 7d of washout (WO, 8.27 ± 0.50). The morning (7-11a local time) following the last day of each sleep period, subjects performed muscle strength testing using an isokinetic dynamometer. Subjects sat upright with the dominant leg secured at 60⁰ of knee flexion to optimize maximal quadriceps torque. They then performed 3 maximal voluntary isometric contractions (MVICs) of the quadriceps. Then subjects performed 6 submaximal contractions at 15, 30, 45, 60, 75, and 90% of the greatest MVIC. Next, subjects completed an interpolated twitch experiment while on the isokinetic dynamometer to assess voluntary activation. Finally, subjects completed 5 repetitions of isometric contractions, in descending order, at speeds of 300, 240, 180, 120, and 60 degree/s. From these methods we measured the highest MVIC, calculated the voluntary activation (VA), measured twitch properties, and compared the torque-EMG relationship. One-way repeated measures ANOVA were used to compare sleep, MVIC, and VA values, two-way (time x twitch property) repeated measures ANOVA was used to compare twitch properties and the torque-EMG relationship. Results: MVIC torque decreased following SR compared to SA before and after sleep restriction (SA: 217.1 ± 69.4 Nm vs. SR: 199.4 ± 67.1 Nm, p = 0.032). MVIC after WO (219.2 ± 54.2 Nm) was significantly greater than SR (p = 0.018) but was not significantly different from SA (p = 0.991). Although peak isokinetic torque decreased with increasing velocity (p < 0.001), there was no significant effect of sleep or sleep x speed interaction. Peak twitch torque and rate of torque
development, but not relaxation rate, were significantly greater in the potentiated state, but no significant effect of sleep or sleep x time interaction was noted. Sleep 3 condition did not significantly affect voluntary activation (SA: 86.3 ± 11.1% v. SR:86.6 ± 11.9% v. WO 87.7 ± 11.1%; p = 0.695). The torque output at various levels ofelectromyography (EMG) activity was not significantly different among sleep conditions (p = 0.383). The mean power frequency (MPF) of the VL was …

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

College of Graduate Studies: Theses & 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 …

Muscular Performance And Neuromuscular Fatigue Are Not Sex-Dependent During Low-Load Fatiguing Bilateral Leg Extension Exercise, Taylor K. Dinyer, Evangeline P. Soucie, Pasquale J. Succi, Caleb C. Voskuil, M. Travis Byrd, Haley C. Bergstrom

Journal for Sports Neuroscience

Purpose. This study examined the sex-related differences in muscular performance and neuromuscular (electromyographic [EMG] and mechanomyographic [MMG] amplitude [AMP] and mean power frequency [MPF]) responses during fatiguing leg extension repetitions performed at the critical load (CL). Methods. Eleven men and nine women completed one-repetition maximum (1RM) testing, repetitions to failure at 50, 60, 70, and 80% 1RM to determine CL, and repetitions to failure at CL, on separate days. The EMG and MMG, AMP and MPF signals and number of repetitions completed were recorded. Results. There were no sex-dependent responses in the %1RM that corresponded to, the number of repetitions …

Swimmers’ Upper Trapezius Activation During Shoulder Abduction Compared To Non-Overhead Athletes, Kendra Graham

Senior Honors Projects

Overhead sports such as baseball, tennis, volleyball, softball and swimming are known to cause rotator cuff imbalances and injuries. These injuries are typically caused by the repeated use of “throwing motion,” where the humerus is externally rotated and shoulder abducted and elevated. Previous research has shown that the function of the upper trapezius muscle in overhead athletes is likely to have improper activation (timing, magnitude) during various shoulder motions and/or activities of daily living. Swimmers are especially susceptible to this improper activation due to the use of their upper limbs in a repeated throwing motion. The added resistance of the …

Evidence For The Use Of Dynamic Maximum Normalization Method Of Muscle Activation During Weight Back Squats, Eva Maddox, Hunter J. Bennett

College of Education & Professional Studies (Darden) Posters

The purpose of this study was to evaluate intra and inter-participant variability and reliability of muscle activations when analyzed using maximum voluntary isometric contractions (MVIC) and dynamic maximum (DMVC) normalization methods. Muscle activations were collected on twenty-seven participants (13 females, 14 males) performing one-repetition maximum (1RM) and submaximum (80%) back squats. Data from submaximum squats were normalized to MVICs and DMVCs. Data were compared using intra-class correlations over two testing days, variance ratio, and coefficients of variation. Mixed-model ANOVAs were used to elucidate the influence on intra- (method) and inter- (sex) subject variability. Reliability levels were good for rectus femoris …

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 …

Single-Subject Analyses Reveal Altered Performance And Muscle Activation During Vertical Jumping, John R. Harry, Jeffrey D. Eggleston, Janet S. Dufek, C. Roger James

Kinesiology and Nutrition Sciences Faculty Research

Effects of barefoot and minimal footwear conditions on performance during jumping (i.e., jump displacement) are unclear with traditional group-level studies because of intra- and interindividual variability. We compared barefoot, minimal, and conventional athletic footwear conditions relative to countermovement vertical jump (CMVJ) performance and muscle activation using a single-subject approach. Fifteen men (1.8 ± 0.6 m; 84.5 ± 8.5 kg; 23.8 ± 2.3 y) performed three CMVJ trials in barefoot, minimal, and conventional footwear conditions while ground reaction forces (GRF) and electromyograms of eight lower extremity muscles were recorded. The Model Statistic procedure (α = 0.05) compared conditions for CMVJ displacement, …

Biomechanical Properties Of Land Based And Shallow Water Wait: A Comparative Review Of Literature, Mostafa Yaghoubi, Philip Fink, Wyatt H. Page, Sarah P. Shultz

International Journal of Aquatic Research and Education

Aquatic locomotion exercises are frequently used in rehabilitation and cross-training for land-based athletes. Hydrostatic pressure, thermal conductivity and drag force affect a person's ability to move; therefore, it is important to understand differences of biomechanical gait in water vs land. This review investigated biomechanical differences between shallow water and land-based exercises. PubMed, Google Scholar, SPORTDiscus and Scopus were searched; 33 studies included walking forward (27), backward (6) and running (6). Electromyographic amplitude was similar or less in submaximal intensity during aquatic gait, in comparison to on land. At maximal intensities, however, the amplitude was similar (n=5) or higher (n=4) in …

Early And Late Rapid Torque Characteristics And Select Physiological Correlates In Middle-Aged And Older Males, Alex A. Olmos, Matthew T. Stratton, Phuong L. Ha, Benjamin E. Dalton, Trisha Vandusseldorp, Gerald Mangine, Yuri Feito, Micah J. Poisal, Joshua A. Jones, Tyler M. Smith, Garrett Hester

Faculty Articles

Purpose

The purpose of this study was to compare early and late rapid torque parameters of the plantar flexors (PFs) in middle-aged (MM) and older (OM) males, and determine the effect of normalization to peak torque (PT) and muscle cross-sectional area (CSA).

Methods

Twenty-nine healthy, MM (n = 14; 45 ± 2 yrs) and OM (n = 15; 65 ± 3 yrs) performed rapid, maximal isometric contractions of the PFs. PT, as well as rate of torque development and impulse during the early (0–50 ms; RTD_0-50, IMP_0-50) and late (100–200 ms; RTD_100-200, IMP_{100-200 …}

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.

Time Course Of Changes In Neuromuscular Parameters During Fatiguing High-Load And Low-Load Concentric Dynamic Constant External Resistance Leg Extension Muscle Actions, Cory M. Smith

Department of Nutrition and Health Sciences: Dissertations, Theses, and Student Research

The purpose of this study was to simultaneously assess electromyographic (EMG) and mechanomyographic (MMG) signals to examine the time course of changes in EMG amplitude, EMG frequency, MMG amplitude, and MMG frequency from the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) muscles during high-load (70%1 repetitions maximum; 1-RM) and low-load (30% 1-RM) concentric, dynamic constant external resistance (DCER) leg extension muscle actions to failure. Twelve men performed two randomized visits consisting of either 30 or 70% 1-RM DCER leg extension muscle actions to failure. Maximal voluntary isometric contractions (MVIC) and 1-RM measurements were performed before and after …

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 …

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 …

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 …