Medicine and Health Sciences Commons^™

Does Footfall Pattern In Forefoot Runners Change Over A Prolonged Run?, Carl W. Jewell

Masters Theses

There has been much debate on the benefits of a forefoot versus rearfoot strike pattern in distance running in terms of performance and injury prevalence. Shock attenuation occurs more prominently in soft tissues at impact in forefoot runners compared to the passive skeletal loading in rearfoot runners. Recent studies indicate that a forefoot strike pattern may not be maintainable over long distance efforts. Therefore, this study tested the hypothesis that habitual forefoot runners could not maintain their strike pattern throughout a prolonged, intensive run.

Fourteen forefoot runners ran to voluntary exhaustion on an instrumented force treadmill (average run duration: 15.4±2.2 …

Kinetic Asymmetries During Submaximal And Maximal Speed Running, Devon H. Frayne

Masters Theses

An important issue for sports scientists, coaches and athletes is an understanding of the factors within a running stride that can enhance or limit maximal running speed. Previous research has identified many sprint-related parameters as potential kinetic limiters of maximal Center of Mass velocity (Chapman and Caldwell, 1983b; Weyand et al., 2001). Bilateral asymmetry is present for many of these parameters during running; however the degree to which such asymmetries change as running speed increases is unknown. It was hypothesized that asymmetries in key sprinting parameters would be larger at maximal speed than all other tested speeds. Kinematics and kinetics …

Quantifying And Comparing The Head Impact Biomechanics Of Different Player Positions For Canadian University Football, Kody Campbell

Electronic Thesis and Dissertation Repository

Differences between Canadian and American football could affect the magnitudes of head impacts and risk of concussion to Canadian players. This study sought to quantify and compare the number, magnitude, and location of impacts that Canadian University football players of different positions experienced during games and practice in a season. A kinematic measuring device collected the linear accelerations and rotational velocities of the head from impacts experienced by players competing in practices and games. The impact magnitudes that were experienced in games were significantly larger than in practice. The offensive back position and wide receiver position had significantly larger peak …

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 …