Life Sciences Commons^™

Examination Of Lower Extremity Muscle Activity During An Overhand Lacrosse Shot In Females, Brianna Millard

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study intends to provide a basic biomechanical understanding of a specific movement within the sport of lacrosse, an overhand goal shot. Its purpose is to identify the different muscles of the lower extremity and the roles they perform during each phase of the lacrosse shot. Specifically, the study will compare how active muscles are between phases as well as between two different shot speeds. This research provides insight into the importance of timing muscle contractions that lead to a more accurate and faster shot.

Subjects (n=5 females, age: 21.8 ± 2 years, height: 162.56 ± 15.24cm, mass: 63.68 ± …

Shock Attenuation In Landing, Bryon Christopher Applequist

UNLV Theses, Dissertations, Professional Papers, and Capstones

Shock attenuation (SA) has been well studied in activities such as walking and running (Chu, et al. 2004; Derrick, et al. 2004; Mercer, et al. 2003); however, there is a lack of research regarding SA during landing. Furthermore, there is lack of information regarding which structures attenuate shock. The purpose of this study was to examine SA among the leg-hip, hip-head, and leg-head segments during landing. Each subject (n=10, Age 26.3 ± 2.71 years, Height 1.68 ± 0.08 m, Mass 70.49 ± 16.03 kg) was instrumented with accelerometers at the leg, hip and forehead. Subjects then performed landings from three …

The Effect Of Footwear On The Mechanics Of The Lower Back During Treadmill Running, Jeffrey Ray Mcclellan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Little is known regarding the effect that footwear cushioning can have on the mechanics of the low back. The purpose of this study was to 1) determine the material characteristics of a minimalist running shoe tested with and without a commercially available shoe insole, 2) determine if there are differences in lower back or knee kinematics when minimalist shoes are worn with and without a shoe insole during treadmill running, and 3) determine if there are differences in levels of muscle activation when minimalist shoes are worn with and without a shoe insole during treadmill running. Following the receipt of …

Effects Of Positive Feedback On Oxygen Consumption And Heart Rate During A 3-Minute Step Test, Leighann Dewitt

UNLV Theses, Dissertations, Professional Papers, and Capstones

The positive effects of enhanced expectancies on motor performance and learning have been demonstrated by numerous studies. A more recent study by Stoate, Wulf, and Lewthwaite (2012) showed than enhancing one's expectancy by giving positive feedback increased movement efficiency and decreased oxygen consumption in experienced runners during a 20 minute running test at 75% of max oxygen consumption, compared to those who received no feedback. The purpose of the present study was to test if enhancing expectancies can improve movement efficiency (i.e., reduce oxygen consumption) during a sub-maximal exercise test. Participants were randomly assigned to one of two groups, enhanced …

Lower Limb Acceleration During The Block-Start Vs. Selected Power And Strength Exercises, Thomas A. Ordelt

Electronic Theses and Dissertations

The purpose of this study was to determine the effect of load changes on angular accelerations of the ankle, knee and hip joints. Accelerations were measured in the squat (S), power clean (PC) and power hang clean (PHC), and compared to the accelerations in the push-off phase of the sprint start (SS). Methods: Nine female Division I college track athletes performed block sprint-starts, single-leg squat jumps (1S0) with 0% of 1RM, squats (jump) with 0, 25, 40% of 1RM, and PC and PHC with 30, 50, 75, 100% of 1RM. The fastest trial of each exercise was analyzed for minimum …

Head Stabilisation During Running In Place Of Children With Varying Motor Proficiency Levels, Craig Atkins

Theses : Honours

Understanding head motion in children may contribute to development of effective strategies to improve coordination of children. The purpose of this study was to investigate head motion in children during stationary running. Twelve healthy 8-year-old children participated in this study and underwent a running proficiency test based on the Test for Gross Motor Proficiency (TGMO). Subjects were then videotaped while running for one minute "on the spot". Reflective markers were digitised for analysis of head motion relative to the external environment, and relative to the trunk. Resultant and component head angular velocities were calculated for each subject over five consecutive …

Head Motion In Overarm Throwing For Children With Varying Levels Of Motor Proficiency, Kevin J. Netto

Theses : Honours

The overarm throw has been classified as a fundamental motor skill that is the basis for a number of more complex sporting skills. There are a number of developmental stages over which a child progresses to the mature form of the skill. Control of the overarm throw, especially towards a target is very dependent on visual and vestibular information for successful execution. The quality of the information is, in tum, dependant on the head movement of the performer during the execution of the skill. It has been reported that head angular velocities above 350 degrees/second result in a degradation of …