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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Identification of Falls Risk Factors in Community-Dwelling Older Adults: Validation of the Comprehensive Falls Risk Screening Instrument

Fabre, Jennifer Marie 16 April 2009 (has links)
Identifying risk factors and those at risk for falls is necessary. The first purpose of the dissertation was to validate the Comprehensive Falls Risk Screening Instrument (CFRSI) that weights falls risk factors and includes the subscale scores of history, physical, vision, medication, and environment, and a total falls risk score. The CFRSI total falls risk score was compared to subscale scores, physical activity, physical function, health-related quality of life (HRQL), and history of falls (Study 1). The second purpose of the dissertation was to determine associations between the CFRSI total falls risk score, race, education, and income (Study 2). Data were collected at falls risk screenings conducted at 10 community organizations with 286 older adults (M age=74.2 years, SD=10.0, 75.9% female, 52.9% White/Caucasian, 52.4% low-income status, and 43.1% low educational level). The total falls risk score was associated with all risk subscale scores (r=.25, p<.01 to r=.69, p<.01), total physical activity score (r=-.30, p<.01), total physical function score (r=.30, p<.01), and total HRQL scores (r=-.44, p<.01 to r=-.24, p=.03). Fallers (n=90) had higher total falls risk scores (M=41.03, SD=9.38) than non-fallers (n=188; M=34.06, SD=10.05), t(276)=5.53, p<.001). Discriminant function analysis indicated the most important predictor of falling status (i.e., fallers and non-fallers) was the history risk score (r=.96). A 2x2x2 factorial ANOVA only revealed a significant main effect for education (F[1,205]=10.19, p=.002), indicating that the total falls risk score was greater for participants with a lower educational level (M=41.1) than for those with a higher educational level (M=34.5). ANCOVA revealed that individuals with low-income reported higher falls risk scores (M=39.2) than individuals with high-income (M=34.5) when controlling for race (F[1,204]=10.4, p=.001,ç2=.05). There were no significant differences between fallers and non-fallers by education (÷2[1,N=262]=.03, p=.86) or income (÷2[1,N=212]=.38, p=.54), but there were differences by race (÷2[1,N=267]=6.44, p=.0). White/Caucasians (63.2%) were more likely to fall than African American/Black/Others (36.8%). Results provide evidence of the construct validity of the CFRSI and that sociodemographic factors such as education, income, and race are important when identifying older adults at risk for falls, determining applicability of falls risk screening instruments, and implementing falls reduction programs.
132

Development and Application of an Optimization Model for Elite Level Shot Putting

Young, Michael 24 April 2009 (has links)
Shot putting is one of the most ancient forms of athletic competition. Considerable research has been performed on the event. Despite this fact, research examining performance in the womens shot put and using the spin technique is very limited. Also, only one attempt has been made to optimize the movement of elite shot putting and no attempts have been made to use the optimization model as a standard for technical training intervention. A series of three experiments were used to explore the development of an optimization model for shot putting and its application as a basis for technical intervention for elite athletes. Experiment 1 served as an exploratory study that explored the feasibility of developing an optimization model for shot putting. The results indicated that there are 8 variables that are highly linked with performance in the shot put and supported the notion that an optimization model for the shot put could be developed. Experiment 2 expanded on and validated the findings of the first study. Results of this study yielded a five variable optimization model for the shot put. Finally, Experiment 3 sought to apply the optimization model developed in Experiment 2 to elite athletes. The results indicated that a technical intervention based on an optimization model produces meaningful changes in performance that can be attributed to changes in optimization model parameters.
133

Does Acute Passive Stretching Alter the Optimum Height for Drop Jumping?

Ritchie, Jonathan Samuel 27 May 2009 (has links)
The application of static stretching (SS) has previously been shown to limit performance in force production, reaction time, balance and vertical jump height. When looking at the effect of SS on jump performance, researchers have previously used changes in jump height, in squat jumps (SQ), countermovement jumps (CMJ) and drop jumping (DJ) from self selected heights. To date no one has looked at the effect of SS across a range of drop heights. 30 subjects (15 male and 15 female) participated in 1 familiarization trial and four performance trials. All subjects undertook two days of stretching (ST) and two days of non-stretching (NS), in randomized fashion. The stretching protocol involved five lower body stretches. Each stretch was taken to the point of discomfort (POD) and held for 15 seconds with a rest period of 15 seconds, three times. Each stretch was performed both unassisted and assisted. This was followed by 10 minutes of quiet sitting. The NS group rested for a total of 33 minutes and 30 seconds. Both groups performed a sit and reach test on arrival and after the ST protocol / NS protocol. Each subject performed a total of 12 jumps from 6 different heights with 30 seconds rest between each jump per trial. Jump heights were calculated and ground contact times (GCT) measured using the AMTI force platform system. Two-way analysis of variance revealed that SS did not alter maximal vertical jump height (p > 0.05). Therefore this study has demonstrated that a lower body SS program (5 stretches, 90 seconds per stretch) did not alter DJ height.
134

A Critical Examination into Motivation and Gender in Youth Physical Fitness Testing

Domangue, Elizabeth A 08 June 2009 (has links)
Fitness testing in physical education classes has emerged as an important component in efforts to assess and address health concerns related to childrens physical inactivity. To date, motivational aspects of fitness testing, especially in regard to students future intention to participate in fitness-related activities, have not been closely examined. Fitness testing practices have been identified as a dominant discourse in physical education that continue to separate girls and boys physicalities along gendered lines. This lack of understanding about the motivational implications of fitness testing programs, coupled with concerns related to the gendered nature of fitness testing, emphasize the significance of this dissertation. The purpose of this dissertation was to investigate motivational and gendered aspects of fitness testing in physical education. The first quantitative study investigated students motivational orientations towards the Presidents Challenge Physical Fitness Test [PCPFT] by comparing students who received awards with those who did not. Students who completed the PCPFT and received an award reported higher levels of task-involvement, perceived competence, effort, enjoyment, and future intention to participate in fitness testing programs than those who did not. The second quantitative study explored students motivation orientations, perceptions of the climate, and future intention to participate in fitness-related activities by comparing students who completed the PCPFT with those who completed FitnessGram. Students who participated in FitnessGram reported higher levels of task-involvement, perceived competence, and future intention to participate in fitness-related activities. The qualitative study investigated how students who participated in the two programs made sense of the gender disparities apparent across the tests, and two themes emerged. First, knowledge about gender-related conceptions of fitness was created by the students based on their schooling experiences, various modes of popular culture, familial expectations/roles, and historically-situated events that served to establish and perpetuate boys and girls as essentially different. Second, the students positioning within the two different testing programs allowed the students to produce knowledge and meaning that led to restricted bodily movements. This research extends the work of previous feminist and motivation scholars in the physical education domain and provides a basis for further study.
135

Carotid Intima-Media Thickness and Physical and Cognitive Function in Elderly Men and Women: Role of Physical Activity

Rhodes, John Brent Jr. 14 July 2009 (has links)
The incidence of cognitive impairment in the aging population remains one of the most common morbidities in the elderly, often associated with a decrease in physical function, institutionalization, and death. Several different mechanisms have been proposed, including age-related changes to the vasculature. The purpose of this study was to examine the relationship between physical activity, carotid intima-media thickness and other vascular measures, and measures of cognitive and physical function in older adults. Measures of daily physical activity, vascular structure and function, and cognitive and physical function were examined in 109 participants [age=81±11 yrs]. Daily physical activity was assessed using the Yale Activity Index (YAI) and by calculating total daily energy (TDEE) using the doubly labeled water technique. Vascular structure was assessed using carotid-intima media thickness (CIMT), while cognitive function and physical function were assessed using the Mini-Mental State Examination (MMSE) and the CSPFP-10, respectively. The average YAI score was 37.75±22.78, TDEE was 2133.02±585.68 kcal/d, CIMT was 0.91±0.06 mm, MMSE score 28.17 , and total CSPFP-10 score 42±20. A unique finding was the relationship between daily physical activity levels, vascular measures, and measures of cognitive and physical function, suggesting that those with higher levels of daily physical activity exhibit more favorable vascular, cognitive, and physical measures. In addition, more favorable measures of cognitive and physical function may be due in part to preserved vascular health. In conclusion, the findings of this study strongly suggest that maintaining a more physically active lifestyle may result in physiological changes, and yield vascular, cognitive, and physical functional benefits.
136

Motivating Middle School Students to Be Physically Active: The Role of Supportive Environments

Zhang, Tao 09 July 2009 (has links)
It is clearly documented that promoting regular physical activity participation at young ages increases the likelihood that school-aged students will lead active lifestyles as adults. Unfortunately, more than a third of school-aged students do not engage in sufficient amounts of physical activity necessary to produce significant health benefits (USDHHS, 2000, 2008). Public health officials and physical educators highlight the importance of promoting motivation for physical activity by creating a supportive physical activity environment that should positively influence students choices to be physically active. The major objective of this dissertation was to explore the roles of supportive social environments and physical environments on middle school students motivation and participation in physical activity within and beyond physical education classes. Three related quantitative studies were designed to achieve this goal. In study one, using self-determination theory as a framework, a structural model of hypothesized relationships among perceived social support from physical education teachers, psychological need satisfaction, intrinsic motivation, and physical activity was tested. The findings supported the mediating role of psychological need satisfaction and intrinsic motivation on middle school students physical activity. Guided by the social ecological model, the predictive strength of predisposing personal factors (self-efficacy), reinforcing social factors (parents support, friends support, and teachers support), and enabling physical environmental factors (equipment accessibility and neighborhood safety) toward middle school students physical activity was investigated in study two. The results of this study highlight the importance of multilevel factors on students physical activity behavior. The intent of study three was to integrate the constructs of self-determination theory with the social ecological model to predict middle school students engagement in physical activity within and beyond physical education classes by testing hypothesized models. The findings indicated that it is possible to integrate self-determination theory with social ecological model, but the integration of these theories did not produce a superior model as compared to the individual theories. The overall results highlight the importance of supportive social and physical contexts in understanding middle school students physical activity motivation and engagement, and provide an empirical evidence to guide implications for physical educators, administrators, health promoters, and researchers.
137

Effects of Exercising with a Weighted Vest on the Output of Lower Limb Joints in Countermovement Jumping

Tahayori, Behdad 09 July 2009 (has links)
The effect of exercising with a weighted vest equal to 15% of body mass on vertical jump height was assessed. It was hypothesized that the defined treatment protocol could enhance jumping performance by increasing hip, knee and ankle joint power. The findings of this study showed that the defined active stretching protocol significantly increases jump height in male participants (0.3364 m compared to0. 3456 m from pre to post exercise respectively) but did not yield a significant increase in females. No significant changes in joint angle, torque, power or velocity were observed between the pre and post exercise jumping. However, the pre-take off phase of jumping was significantly decreased after the exercise. Also a significant increase in the initial velocity was observed in the post loaded jumping in men (2.507 m/s Vs. 2.588 from pre to post exercise respectively). Analysis of jumping with the weighted vest revealed numerous significant changes in temporal aspects of jumping as well as joint output. It was observed that performing the weighted jumping for five sets of three repetitions, could increase the jump height which was originally decreased by applying the vest. Findings of the analysis of jumping with the weighted vest and those of jumping after the removal of the vest did not support the increase of a specific parameter for a specific joint. Rather, it suggests that the application of this treatment increases the performance by optimizing the timing of various movement sequences.
138

Does Practice of Multi-directional Stepping with Auditory Stimulation Improve Movement Performance in Patients with Parkinsons Disease?

Kadivar, Zahra 13 October 2009 (has links)
Parkinsons disease (PD) is a debilitating neurodegenerative disorder causing many physical limitations. Rhythmic auditory stimulation (RAS) influences motor complications not alleviated by medicine and has been used to modify straight line walking in this population. However, motor complications are exacerbated during more complex movements including those involving direction changes. Thus immediate RAS effects on direction switch duration (DSD) and other kinematic measures during a multi-directional step task were investigated in PD patients. Long term RAS application was also explored by evaluating functional gait and balance and kinematic step measures before and after 6 weeks of multi-directional stepping either with (Cue, C group) or without (No cue, NC group) RAS use. Evaluations were also administered 1, 4 and 8 weeks after training termination. Kinematic measures were collected during stepping without, then with RAS for the C group and without RAS for the NC group. Step testing/training was performed at slow, normal and fast speeds in forward, back and side directions. Participants with PD switched step direction during the stepping task faster with RAS use before training. Like straight line walking RAS application influenced the more complex task of direction switching and counteracted the well-known bradykinesia in PD. After training both groups improved their functional gait and balance measures and maintained balance improvements for at least 8 weeks. Only the C group retained gait improvements for at least 8 weeks after training termination. Adding RAS resulted in functional benefits not observed in training without it. Kinematic measures compared before and after step training clarified the underlying contributors to functional performances. Both groups reduced the variability of DSD. The C group participants maintained this alteration longer. DSD reduction also occurred after training and was retained for at least 8 weeks for this group. These outcomes further support the advantages of adding RAS to training regiments for those with PD. The current results indicate that RAS effects are not limited to simple activities like straight line walking. Moreover, RAS can be used for improving and maintaining improvements longer in activities involving various forms of transition which present most difficulties for those with PD.
139

Comparison of Brachial Artery Vasoreactivity in Elite Athletes and Age-Matched Controls

Blalock, Paul Joseph 28 October 2009 (has links)
The ability to distribute blood from areas with low demand to areas with high demand, such as occurs during exercise, is a critical function of the circulatory system. PURPOSE: To compare the resting diameter and vasoreactivity of the brachial artery in elite strength athletes to those of age-matched controls. We hypothesized that the brachial arteries of strength athletes would have larger diameters at rest, and show greater vasoreactivity in response to cuff occlusion and a cold pressor test than in untrained individuals. METHODS: Eight elite strength athletes (age, 23 ± 2 years) and ten age-matched controls (age, 22 ± 1 years) were studied. Using high-resolution ultrasonography, brachial diameter was assessed at rest and following 5 minutes of forearm occlusion (BAFMD) and a cold pressor test. RESULTS: The average resting brachial diameters of strength athletes (5.39 mm ± 1.51) was significantly larger than the diameters of the control group (3.73 mm ± 0.71). On average, strength athletes showed significantly greater vasodilation (BAFMD % Δ athletes, 8.21% ± 1.78; controls 5.69% ± 1.56) in response to cuff release and significantly greater vasoconstriction (CPT % Δ athletes, -2.95 ± 1.07; controls -1.20 ± 0.48) in response to the cold pressor test. The combined effect of vasodilation and vasoconstriction indicates a greater physiologic vascular operating range in the athletes (0.55 mm) compared to the controls (0.25 mm). CONCLUSIONS: This study reports significant differences in vascular responses to vasodilatory and constrictor stimuli of elite strength athletes and age-matched controls. These differential responses in the elite athletes suggest a well-adapted vasculature defined by a wide vascular operating range.
140

A Comparison of Isotonic and Elastic Resistance Exercise on Trapezius Muscle Balance in Overhead Athletes

Page, Phillip 11 November 2009 (has links)
The scaption exercise (elevation of the arm in the scapular plane) is often performed in shoulder rehabilitation and preventive exercise programs. Three studies were performed to better understand the activation characteristics of the upper trapezius (UT) and lower trapezius (LT) muscles during scaption. The purpose of these studies was to 1) quantify and compare trapezius muscle activation ratios and onset of activation in normal subjects, 2) compare the findings from normal subjects with overhead athletes, and 3) compare the activation ratios and onset of the trapezius with 2 modes of resistance (elastic and isotonic) in overhead athletes. Methods. Healthy college-aged subjects performed scaption to 90⁰ with (W) and without (UW) standardized resistance. The average activation of the UT and LT was determined with surface electromyography (EMG) over 30⁰ increments in concentric and eccentric directions. The UT:LT ratio was then determined for each interval and condition, as well as the average onset of activation. Statistical analysis using repeated measures and t-tests were used to determine significant differences. Results. The UT:LT ratios of both W and UW conditions demonstrated a u-shaped curve over 90⁰. The UW condition consistently demonstrated significantly higher UT:LT ratios ranging from 1.5 to 4.5, while the W ranged from 0.9 to 2.4. There was no significant difference in activation ratios between athletes and non-athletes, or between elastic and isotonic resistance. The UT demonstrated earlier activation than the LT in the UW condition. The LT reduced its latency with the addition of resistance, reversing the firing order in overhead athletes. Isotonic resistance provided slightly faster activation of the LT compared to elastic resistance. Conclusion. These 3 studies suggest that overhead athletes demonstrate the same UT:LT ratios as non-athletes over 90⁰ during scaption with and without resistance. Adding resistance to the scaption exercise significantly reduces the UT:LT ratio and reverses the firing order, activating the LT significantly earlier than the UT. Both elastic and isotonic resistances demonstrate similar activation ratios in overhead athletes, although isotonic resistance activates the LT faster than elastic resistance. Using these results, clinicians may improve their clinical decision-making in prescribing scaption exercises.

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