Sports Sciences Commons^™

Effect Of Dolphin Kick Timing On Breaststroke Pullout Performance, Taylor L. Adams, Mickey B. Scharbrough, Scott P. Mclean

International Journal of Exercise Science: Conference Proceedings

Breaststroke pullouts are now permitted to include a dolphin kick. Two variations of the pullout are distinguished by the timing of the dolphin kick within the movement. One variation uses an early-initiation of the dolphin kick (performed before the initiation of the arm pull) while a second variation uses a late-initiation of the dolphin kick (performed at the completion of the arm pull). PURPOSE: To compare the performance of two variations of breaststroke pullouts that incorporate a dolphin kick. METHODS: Fourteen collegiate swimmers (18.9 ± 1.17 years, 73.7 ± 8.54 kg, 174.5 ± 9.88 cm) who compete in breaststroke or …

The Effect Of Tackling Training On Head Accelerations In Youth American Football, Eric Schussler, Richard J. Jagacinski, Susan E. White, Ajit M. Chaudhari, John A. Buford, James A. Onate

Rehabilitation Sciences Faculty Publications

Background: Many organizations have introduced frameworks to reduce the incidence of football related concussions through proper equipment fitting, coach education, and alteration of tackling technique.

Purpose: The purpose of this study was to examine the effects of training in a vertical, head up tackling style on the number of head accelerations experienced while tackling in a controlled laboratory situation. The authors hypothesized that training in a head up tackling technique would reduce the severity of head acceleration experienced by participants.

Design: Controlled Laboratory Study.

Methods: Twenty-four participants (11.5 ± 0.6 years old, 60.5 ± 2.2 in, 110 ± 18.4 lbs.) …

The Effects Of Self-Adherent Taping On Peak Inversion Angle And Eversion Moment Upon Landing During A Maximal Vertical Jump And A Depth Drop, Christopher M. Gregoire

Cal Poly Humboldt theses and projects

Ankle injuries are the most common injury in physically active adults with roughly 15% to 30% of all physical activity injuries being ankle injuries. The purpose of this study is to evaluate the effectiveness of a self-adherent ankle taping in reducing peak ankle inversion angle and peak ankle eversion moment upon landing during a max vertical jump and depth drop compared to jumping without a prophylactic ankle stabilizer.

Twelve volunteers participated in testing procedure on two separate days. Day one consisted of orientation while day two consisted of experimental data collection. The participant’s peak inversion angle and eversion moment were …

The Mechanics Of Front Leg Loading During Cricket Fast Bowling: Delivery Variations, Spell Demands, And The Effects Of Strength Training, Samuel J. Callaghan

Theses: Doctorates and Masters

The goal of fast bowling in cricket is to dismiss a batsman for as few runs as possible. To assist this goal, fast bowlers will attempt to maximise ball release velocity (BRV) to decrease the decision-making and stroke execution time of the opposing batsmen. Fast bowlers will also employ various delivery lengths (i.e. short, good and full) to assist in affecting a batsman’s stroke execution.

Several issues remain to be addressed with regards to the biomechanical assessment of fast bowling. This is particularly evident when analysing fast bowling performance (i.e. BRV), the implications of front foot loading (i.e. vertical and …

Assessment Of Joint Kinetics In Elite Sprint Cyclists, Lynne Munro

Theses: Doctorates and Masters

Sprint cycling requires the production of explosive muscle power outputs up to very high pedalling rates. The ability to assess muscular function through the course of the sprint would aid training practices for high-level performers. Inverse dynamics provides a non-invasive means of estimating the net muscle actions acting across any joint contributing to movement. However, analysis of joint kinetics requires motion-capture techniques that present some unique challenges for cycling. This thesis presents three studies investigating the application of a custom-designed force pedal system to examine the joint kinetics of elite trained track sprint cyclists. To provide the basis for selecting …

Reliability And Validity Of A Biomechanically Based Analysis Method For The Tennis Serve, Natalie L. Myers, W. Ben Kibler, Leah Lamborn, Belinda J. Smith, Tony English, Cale A. Jacobs, Timothy L. Uhl

Physical Therapy Faculty Publications

Background: An observational tennis serve analysis (OTSA) tool was developed using previously established body positions from three-dimensional kinematic motion analysis studies. These positions, defined as nodes, have been associated with efficient force production and minimal joint loading. However, the tool has yet to be examined scientifically.

Purpose: The primary purpose of this investigation was to determine the inter-observer reliability for each node between two health care professionals (HCPs) that developed the OTSA, and secondarily to investigate the validity of the OTSA.

Methods: Two separate studies were performed to meet these objectives. An inter-observer reliability study preceded the …

Kinematics Of The Lower Extremities During Fundamental Martial Arts Tricking Techniques, Kevin P. Grassie

Honors Scholar Theses

Martial Arts Tricking (MAT) is a relatively new sport that combines martial arts, gymnastics, acrobatics, and breakdancing for the purposes of creating aesthetic and impressive combinations of kicks, flips and twists. It has been growing exponentially through social media and the overall athletic and entertainment communities. The sport is very unique in that the movements, with their blended influences, provide novel ways for athletes to generate and utilize their momentum in a creative way. The results often include off-axis flips and twists, single-leg landings, and complicated yet fluid techniques that easily chain together.

Due to the sport only being a …

The Effect Of Dimple Error On The Horizontal Launch Angle And Side Spin Of The Golf Ball During Putting, Ashley K. Richardson, Andrew C.S. Mitchell, Gerwyn Hughes

Kinesiology (Formerly Exercise and Sport Science)

This study aimed to examine the effect of the impact point on the golf ball on the horizontal launch angle and side spin during putting with a mechanical putting arm and human participants. Putts of 3.2 m were completed with a mechanical putting arm (four putter-ball combinations, total of 160 trials). The centre of the dimple pattern (centroid) was located and the following variables were measured; distance and angle of the impact point from the centroid and surface area of the impact zone. Multiple regression analysis was conducted to identify whether impact variables had significant associations with ball roll variables; …

The Effect Of Delayed Onset Muscle Soreness On Jumping Mechanics And Performance, Ryan J. Engels

Electronic Theses and Dissertations

Background: Delayed onset muscle soreness (DOMS) is an exercise-induced muscle soreness resulting from high-intensity eccentric muscular contractions. DOMS appears to be more prevalent in athletes at the beginning of an athletic season or when new movements or exercise are first introduced. The acute effect of DOMS on jumping mechanics is currently unknown. PURPOSE: The purpose of this study is to determine the effect of delayed onset muscle soreness on vertical jump performance and jumping mechanics. METHODS: Twenty college aged, recreationally active males participated in this study (age: 21.54 ± 2.61; height: 1.82 ± 0.067; mass: 81.36 ± 9.53). Participants were …

The Effects Of Golf Stance On The Peak Knee Adduction Moment During The Golf Swing, Quenten L. Hooker

Theses and Dissertations--Kinesiology and Health Promotion

INTRODUCTION: The knee joint is one of the most frequently injured structures in the game of golf. The loads experienced by the knee during the golf swing are typically greater than those experienced during walking. In particular, a heightened lead limb peak external knee adduction moment has been linked to the progression of medial compartment knee osteoarthritis (OA). Altering movement patterns is a common strategy that can be used to reduce loading on the knee joint but has received little attention during the golf swing. Also, while such manipulations may be beneficial from an injury prevention perspective, they may have …

The Ability Of The Landing Error Scoring System To Detect Changes In Landing Mechanics: A Critically Appraised Topic, Claire E. Pointer, Tyler D. Reems, Emily M. Hartley, Johanna M. Hoch

Rehabilitation Sciences Faculty Publications

Clinical Question: Is there evidence to suggest that the Landing Error Scoring System (LESS) is able to detect functional changes in landing mechanics in healthy individuals after participation in an injury prevention program (IPP)? Clinical Bottom Line: In a healthy, physically active population, there is strong evidence to support the use of the LESS as an outcome measure for changes in landing mechanics after the implementation of IPPs. Clinicians should consider the LESS as an evaluative tool for measuring the efficacy of IPPs in clinical practice.

A Biomechanical Comparison Of Successful And Unsuccessful Power Clean Attempts, Kristof Kipp, Carolyn M. Meinerz

Exercise Science Faculty Research and Publications

Although the power clean is an almost ubiquitous exercise in the strength and conditioning setting, relatively little is known about the biomechanics of successful and unsuccessful power clean lift attempts. The purpose of this study was to determine biomechanical differences between successful and unsuccessful power clean lift attempts in male collegiate athletes. Fifteen male lacrosse players (Age: 20.1 ± 1.2; Height: 1.78 ± 0.07 m; Body mass: 80.4 ± 8.1 kg; Relative one-repetition maximum power clean: 1.25 ± 0.13 kg/kg) were videotaped during a lifting session that required the completion of maximal effort power cleans to establish a one-repetition maximum. …

Mechanical Demands Of The Hang Power Clean And Jump Shrug: A Joint-Level Perspective, Kristof Kipp, Philip Malloy, Jordan Smith, Matthew D. Giordanelli, Michael T. Kiely, Christopher Geiser, Timothy J. Suchomel

Exercise Science Faculty Research and Publications

The purpose of this study was to investigate the joint- and load-dependent changes in the mechanical demands of the lower extremity joints during the hang power clean (HPC) and the jump shrug (JS). Fifteen male lacrosse players were recruited from an NCAA DI team, and completed three sets of the HPC and JS at 30%, 50%, and 70% of their HPC 1-Repetition Maximum (1-RM HPC) in a counterbalanced and randomized order. Motion analysis and force plate technology were used to calculate the positive work, propulsive phase duration, and peak concentric power at the hip, knee, and ankle joints. Separate three-way …

Muscle-Specific Effective Mechanical Advantage And Joint Impulse In Weightlifting, Kristof Kipp, Chad Harris

Exercise Science Faculty Research and Publications

Lifting greater loads during weightlifting exercises may theoretically be achieved through increasing the magnitudes of net joint impulses or manipulating the joints’ effective mechanical advantage (EMA). The purpose of this study was to investigate muscle-specific EMA and joint impulse as well as impulse-momentum characteristics of the lifter-barbell system across a range of external loads during the execution of the clean. Collegiate-level weightlifters performed submaximal cleans at 65, 75, and 85% of their 1-repetition maximum (1-RM) while data from a motion analysis system and a force plate were used to calculate lifter-barbell system impulse and velocity, as well as net extensor …

Ball Pressure Correlations With Peak Impact Force And The Potential For Cumulative Mtbi When Heading A Soccer Ball, Nicolas Leiva, Daniel Y. Shyu, Josh Auger, Eric Nauman

The Summer Undergraduate Research Fellowship (SURF) Symposium

Soccer is a unique sport in which athletes use their heads as tools for gameplay, which may ultimately cause cumulative traumatic brain injuries. Due to rising popularity of soccer in the United States alongside the increased occurrence of CTE and mTBI in other contact sports, there is a growing concern over how to keep the repetitive forces caused by heading, as low as possible. Different variables that can affect the peak force felt when heading a soccer ball can be simulated and compared with in-game data, however, this has never been properly tested before. In the present study two size …

Development Of Standard Criteria To Evaluate The Effectiveness Of Helmets At Decreasing The Risk Of Concussions, Daniel Y. Shyu, Goutham N. Sankaran, Kevin G. Mciver, Nicolas Leiva, Eric A. Nauman

The Summer Undergraduate Research Fellowship (SURF) Symposium

In many sports, such as American football, accumulations of mild traumatic brain injuries have been suggested as a possible link to neurodegeneration and future mental disorders. With head impacts occurring at all levels of competition and in different sports, it is critical to develop an accurate method for quantifying the effects of head impacts and determining the efficacy of helmets. This study examines the derivation of different dimensionless numbers and ascertains the critical factors needed to predict the effects of head impacts, specifically the resulting accelerations from an impact. Given a known force of impact, parameters such as peak translation …

The Effects Of A Hip Flexor Stretching Program On Running Kinematics In Individuals With Limited Passive Hip Extension, Jeff H. Mettler

Theses and Dissertations--Kinesiology and Health Promotion

INTRODUCTION: Tightness of the hip flexor muscle group may contribute to altered sagittal plane kinematics of the lumbo-pelvic-hip (LPH) complex during dynamic movements. Therefore, the purpose of this study is to analyze the effects of a three-week home-based stretching program on passive hip extension (PHE), as well as on active hip extension (AHE), anterior pelvic tilt (APT), and lumbar spine extension (LSE) when running. METHODS: Twenty healthy subjects with limited PHE underwent a 3D gait analysis both prior (PRE) and following (POST) a three-week static hip flexor stretching program. RESULTS: Following the stretching program, peak PHE increased significantly (P < 0.001), while no significant improvements were reported in AHE, APT, or LSE. In addition, no relationship was found between the change in PHE with either the change in AHE, APT, or LSE. Finally, a high relationship was observed between AHE and APT during running (r = 0.83, p < 0.001), and low relationships were observed between APT and LSE (r = -0.41, p = 0.08) and AHE and LSE (r = -0.34, p = 0.15). CONCLUSION: A three-week static stretching program of the hip flexor musculature resulted in an increase in PHE, but the sagittal plane kinematics of the LPH complex during running remained unchanged. The correlations observed between AHE, APT, and LSE suggest there is a kinematic relationship between the hip, pelvis, and spine.

The Influence Of Hip Mobility And Fatigue On Spinal Flexion And Muscle Activation In Rugby Scrum Performance, Joshua D. Clayton

Theses and Dissertations (Comprehensive)

Introduction: Rugby scrumming is a means of restarting play following a minor rule infringement that can occur up to 28 times per game. The scrum poses a significant injury risk, with more days missed due to injury per event than any other rugby activity. Rugby players also have a significantly higher rate of spine injury than the general population, perhaps due to flexion in combination with high compression forces, which has been cited as the main mechanism of injury. Flexion of the spine has also been associated with poor hip mobility and quadriceps fatigue in other athletic tasks and may …

Accuracy In The Badminton Short Serve: A Methodological And Kinematic Study, Shayne Marc Vial

Theses: Doctorates and Masters

In sports, accuracy is an essential component of actions such passing, shooting, and aiming. Executing a movement or action that requires a high degree of accuracy is a critical determinant of success in many individual and team sports. Each sport has different methods for evaluating accuracy, however an overarching goal is to determine whether an object hits its target, or assess the distance by which it misses. However, in some sports accuracy is not readily measureable because an object might not reach a target, i.e. the object is intercepted, or it collides with another object or a person, or an …

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 …

Influence Of Traditional And Nontraditional Entries On Figure Skating Jumps, Bryanna L. Nevius

Undergraduate Review

The purpose of this study was to determine whether or not adding a non-traditional jump entry into a routine is more beneficial to the skater or if there is more value in performing the same jump with a traditional entry. Specifically, the study examined the kinematics of a non-traditional verses a traditional jump entry by looking at the angles of the hip, knee, and ankle joints at take-off and landing. Maximum jump height, airtime, and horizontal displacement were also examined. It was hypothesized that non-traditional entries would change jump kinematics when compared to the same jumps performed from traditional entries. …

Biomechanical Analysis Of Race Walking Compared To Normal Walking And Running Gait, Jaclyn D. Norberg

Theses and Dissertations--Kinesiology and Health Promotion

Human locomotion is phenomenon that is extraordinarily complex. It is evident that a complete description of locomotion involves consideration of kinematics, kinetics, and muscle activity of the extremities in all of their various movements. Race walking (RW) is a form of upright locomotion that differs from normal walking and running by its form dictated by the International Amateur Athletics Federation (IAAF). Despite the similarities to both normal walking (NW) and running (RU), RW has not been the subject of equally intensive investigations.

This study explores the comprehensive biomechanics of race walking and how it compares to NW and RU. A …

Use Of Audio Biofeedback To Reduce Tibial Impact Accelerations During Running, Claire M. Wood, Kristof Kipp

Exercise Science Faculty Research and Publications

Visual biofeedback of tibial peak positive acceleration (PPA) during running has been used successfully as a method of gait retraining to reduce PPAs. Audio biofeedback generated from PPA may present a novel, portable alternative. The purpose of this study was to investigate the feasibility of using PPA-generated audio biofeedback to reduce PPAs while running. Nine runners were fitted with a wireless accelerometer on their left tibia. PPAs were recorded and a custom LabVIEW program was used to emit a single beep once the PPA reached a preset threshold. The numerical difference between this threshold and peak PPA during running was …

Delivery And Pitch Type Alter Ground Reaction Forces In Baseball Pitching, Garrett Kass

Featured Research

Ground reaction forces (GRFs) exerted on a pitcher in reaction to the push of their legs against the ground create torques about the center-of-mass (CM) and generate the angular momentum necessary to rotate the body, including the segments of the throwing arm. Thus examination of GRFs provides insight into the causal mechanisms responsible for segmental rotation in baseball pitching. PURPOSE: To determine the effects of delivery [wind-up (WU) vs. stretch (ST)] and pitch type [fastball (FB) vs. change-up (CU)] on GRFs in pitching. METHODS: Eight collegiate baseball pitchers (4 right-handed and 4 left-handed) provided voluntary informed consent and threw maximal …

Is There A Relationship Between Hip Structure, Hip Muscle Strength, And Lower Extremity Frontal Plane Kinematics During Treadmill Running?, Michael William Robinson Baggaley

Theses and Dissertations--Kinesiology and Health Promotion

INTRODUCTION: Excessive hip adduction (HADD) has been associated with a number of lower extremity overuse injuries, and it has been suggested that it may be the result of reduced strength of the hip abduction musculature. Hip structure has been postulated to influence both hip abduction (HABD) strength and HADD. The purpose of this study was to investigate the relationship between hip structure, HABD strength, and frontal plane kinematics during running. METHODS: Peak isometric HABD strength, lower extremity kinematics, femoral neck-shaft angle (NSA), and pelvis width-femur length (pw-fl) ratio were recorded for 25 female subjects. Pearson correlations (P < .05) were performed between variables. RESULTS: A fair relationship was observed between femoral NSA and HABD strength (r = …

Neuromuscular Factors Affecting Stretch-Induced Torque Loss, Gabriel Siqueira Trajano

Theses: Doctorates and Masters

The mechanisms underpinning the immediate torque loss induced by acute, static muscle stretching are still not clear. The current research was designed to examine the neuromuscular factors influencing this torque loss. In Study 1, the contributions of central versus peripheral factors to the stretch-induced torque loss were investigated. Measures of central drive, including the EMG amplitude normalised to the muscle compound action potential amplitude (EMG:M), percent voluntary activation (%VA) and first volitional wave amplitude (V:M), and measures of peripheral function, including the twitch peak torque and 20:80 Hz tetanic torque ratio were made before, and immediately and 15 min after …

Correlations Between Internal And External Power Outputs During Weightlifting Exercise, Kristof Kipp, Chad Harris, Michelle B. Sabick

Exercise Science Faculty Research and Publications

Identifying loads that maximize mechanical power is important because training at such loads may optimize gains in dynamic athletic performance. The purpose of this study was to examine correlations between measures of external mechanical power output and internal mechanical joint power output across different loads during a weightlifting exercise. Ten subjects performed 3 sets of the clean exercise at 65, 75, and 85% of 1 repetition maximum (1RM). Peak external mechanical power output was calculated with 4 commonly used methods, whereas an inverse dynamics approach was used to calculate peak internal mechanical power output for the hip, knee, and ankle …

A Feedback Inclusive Neuromuscular Training Program Alters Frontal Plane Kinematics, Eric K. Greska, Nelson Cortes, Bonnie L. Van Lunen, James A. Oñate

Rehabilitation Sciences Faculty Publications

-Anterior cruciate ligament (ACL) neuromuscular training programs have demonstrated beneficial effects in reducing ACL injuries, yet further evaluation of their effects on biomechanical measures across a sports team season is required to elucidate the specific factors that are modifiable. The purpose of this study was to evaluate the effects of a 10-week off-season neuromuscular training program on lower extremity kinematics. Twelve Division I female soccer players (age: 19.2 ± 0.8 years, height: 1.67 ± 0.1 m, weight: 60.2 ± 6.5 kg) performed unanticipated dynamic trials of a running stop-jump task pretraining and posttraining. Data collection was performed using an 8-camera …

Weightlifting Performance Is Related To Kinematic And Kinetic Patterns Of The Hip And Knee Joints, Kristof Kipp, Josh Redden, Michelle B. Sabick, Chad Harris

Exercise Science Faculty Research and Publications

The purpose of this study was to investigate the correlations between biomechanical outcome measures and weightlifting performance. Joint kinematics and kinetics of the hip, knee, and ankle were calculated while 10 subjects performed a clean at 85% of 1 repetition maximum (1RM). Kinematic and kinetic time-series patterns were extracted with principal components analysis. Discrete scores for each time-series pattern were calculated and used to determine how each pattern was related to body mass–normalized 1RM. Two hip kinematic and 2 knee kinetic patterns were significantly correlated with relative 1RM. The kinematic patterns captured hip and trunk motions during the first pull …

Center Of Pressure Excursion During The Golf Putting Stroke In Low, Mid And High Handicap Golfers, Ashley K. Richardson, Gerwyn Hughes, Andrew C.S. Mitchell

Kinesiology (Formerly Exercise and Sport Science)

Golf handicap is significantly correlated to putting performance with low handicap golfers (LH) demonstrating increased putting accuracy compared with high handicap golfers (HH). Smaller center of pressure excursion (CPE) during putting has been demonstrated by LH golfers, suggesting balance is important during successful putts. The aim of this study was to examine CPE in low, mid and high handicap golfers about the mediolateral axis (ML) and anteriorposterior axis (AP). Nineteen subjects participated in the study; subjects were split into LH, mid handicap and HH groups. Subjects completed five successful 2.5m putts, standing on an RS FootScan. The LH group demonstrated …