Kinesiology Theses and Dissertations
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Item Aging Related Differences in Hand Intrinsic and Extrinsic Muscles for Hand Dexterity: An MRI Investigation(2009) Hsu, Jeffrey; Shim, Jae Kun; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Hand dexterity is crucial for humans to interactions with the external environment. Many activities of daily living (ADLs) such as pressing, grasping, writing and typing would be unattainable without a skillfully and proficiently functioning hand. Sexagenarians and older often experience difficulties in hand dexterity, which seriously impair their ability to perform ADLs. This study described the aging-related changes in hand muscle size and dexterity; and addressed the conflicting literature regarding the extent of atrophy to either the intrinsic or extrinsic hand muscles in the elderly. The overall hypotheses for this study were 1) that elderly adults show an aging-related decrease in hand muscle size and strength, especially a greater decrease in the intrinsic hand muscles, 2) elderly adults show an aging-related decrease in hand dexterity and 3) hand muscle size and strength are positively related to hand dexterity. This study examined hand muscle sizes with magnetic resonance imaging (MRI) and examined hand strength and other functional measures. This study found aging-related decreases in muscle size, muscle strength, hand dexterity. Furthermore, intrinsic muscles showed a greater aging-related decrease in volume and strength as compared to the extrinsic muscles. When examining relationships, muscle strength was positively correlated to multi-finger synergy and finger dependence. Also, muscle size was positively related to performance on clinical hand dexterity tests. This supports the strength-dexterity equivalence hypothesis.Item Exercise and Depression: Causal Sequence Using Cross-Lagged Panel Correlation Analysis(2009) Scott, Virginia Anne; Andrews, David L; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study sought to determine what kind of causal relationship, if any, exists between exercise and depression. A university student population (N = 178) was given the Godin Leisure Time Exercise Questionnaire and the Beck Depression Inventory-II at two time points separated by approximately one month. Cross-lagged panel correlation was used to make causal inferences based on the strength of the temporal relationships. After meeting the assumptions of synchronicity and stationarity, there was no significant difference between the cross-lagged correlations (ZPF = -0.4599, p = 0.65). Thus, no single causal pathway was dominant. While equal cross-lagged correlations can indicate spuriousness, it can also signify reciprocal causation. Exercise was not clearly the cause of reductions in depression, but neither was depression clearly the cause of physical inactivity. More complex causal pathways, such as reciprocal causation, warrant further investigation.Item MULTI-DIGIT HUMAN PREHENSION(2009) Park, Jaebum; Shim, Jae Kun; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The current dissertation addresses the central nervous system (CNS) strategies to solve kinetic redundancy in multi-digit static prehension under different geometries of hand-held objects and systematically varied mechanical constraints such as translation and rotation of the hand-held object. A series of experiments conducted for this dissertation tested the following hypotheses suggested in the current literatures for multi-digit human static prehension: Hierarchical organization hypothesis, principle of superposition hypothesis, proximity hypothesis, and mechanical advantage hypothesis. (1) Forces and moments produced by fingers during circular object prehension were grouped into two independent subsets: one subset related to grasping stability control and the other associated with rotational equilibrium control. This result supports the principle of superposition hypothesis. Individual fingers acted synergistically to compensate each other's errors. This result confirms the hierarchical organization hypothesis in circular object prehension. (2) During fixed object prehension of a rectangular object, the closer the non-task fingers positioned to the task finger, the greater the forces produced by the non-task fingers. However, during free object prehension, the non-task fingers with longer moment arms produced greater forces. The former and latter results support the proximity hypothesis and the mechanical advantage hypothesis, respectively. (3) The grasping stability control and rotational equilibrium control were decoupled during fixed object prehension as well as free object prehension. This result supports the principle of superposition hypothesis regardless of the mechanical constraints provided for these two prehension types. (4) During torque production, the fingers with longer moment arms produced greater forces when the fingers acted as agonists for the torque production. Therefore, the mechanical advantage hypothesis was supported for agonist fingers. (5) Coupling of thumb normal force and virtual finger normal force was not necessitated when horizontal translation of hand-held object was mechanically fixed. However, the coupling of two normal forces was always observed regardless of given translational constraints, and these two normal forces were independent to other mechanical variables such as tangential forces and moments. This result supports the principle of superposition hypothesis in static prehension under varied combinations of translational constraints.Item TIME TRENDS IN OVERALL DAILY PHYSICAL ACTIVITY AND CARDIOVASCULAR DISEASE RISK FACTORS BY ORGANIZED PHYSICAL ACTIVITY PARTICIPATION IN ADOLESCENT GIRLS(2009) Phillips, Jennifer; Young, Deborah Rohm; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Many youth are involved in organized physical activity (PA); however, the impact of these activities on daily PA, body fat, and cardiovascular disease (CVD) risk factors is not well understood. Purpose: To compare the overall daily PA and CVD risk factors of girls who participate in organized activities to non-participants throughout adolescence. Methods: Data from the National Heart, Lung, and Blood Institute Growth and Health Study, a 10-year observational study of Black and White girls (N=2379), were analyzed. Organized PA was defined as participation in classes/lessons and sports (0, <4, 4-19.99, ≥20 MET times/wk). Outcomes included daily PA (3-day diary), body fat (bioelectrical impedance analysis), lipids, glucose, insulin, and blood pressure. Longitudinal data were examined for each outcome using a mixed model with repeated measures. Girls were also categorized by the number of years they reported ≥4 MET times/wk of organized PA. Outcomes and risk clustering at 18-19y were evaluated with ANOVA and logistic regression, respectively, by number of participation years. Results: Organized PA and participation*time*race were related to change in daily PA and body fat (p < 0.0001). Although daily PA declined for Black girls, those with ≥20 MET times/wk had higher PA levels than all other girls (p < 0.0001). Change differed by sports participation in White girls (p=0.019); those involved ≥20 MET times/wk demonstrated better maintenance of daily PA. Black girls with ≥20 MET times/wk had significantly lower body fat than non-participants (p=0.002).White non-participants had higher body fat than those with 4-19.99 MET times/wk (p=0.006). Accumulated organized PA was related to daily PA and body fat at 18-19y. Girls who never reported participation had significantly lower daily PA at 18-19y than all other groups (p < 0.02), and significantly higher body fat at 18-19y compared to girls who reported 4y of sports participation (p=0.038). Organized PA was not related to change in other CVD risk factors or risk factor clustering at 18-19y (OR=1.05, 95% CI=0.87-1.27, p=0.59). Conclusion: Organized PA was related to daily PA and body fat for Black and White girls throughout adolescence. Appealing options should be made available and participation encouraged.Item Development and Evaluation of New Accelerometer Cut Points for Adolescent Girls(2009) Kuo, JoAnn; Young, Deborah R; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Current negative trends in adolescent disease risk factors (e.g., overweight) may be related to physical activity. To study these relationships using accelerometers, how to estimate physical activity from accelerometer counts must be better understood. PURPOSES: (1) To develop new accelerometer cut points for estimating physical activity using disease risk factors as criteria. (2) To evaluate how estimates of physical activity using these newly developed cut points agree with comparison measures (i.e., a previously suggested cut point and self-report physical activity recall questionnaires). METHODS: National Health and Nutrition Examination Survey (NHANES) and Trial of Activity for Adolescent Girls (TAAG) data were examined. New cut points were developed using iterative correlations and signal detection and receiver operating characteristic (ROC) curves. To identify new cut points, potential cut points were identified in a development sample and validated in an evaluation sample. Agreement between new cut points and comparison measures was examined using concordance correlation coefficients, Bland-Altman plots, McNemar's tests, and proportions of agreement. RESULTS: Using the correlation method, two new combinations of light, moderate, and vigorous intensity cut points were identified in NHANES (1900, 4300, and 10000 counts/min and 1900, 4000, and 5000 counts/min) and two in TAAG (1450, 1950, and 2450 counts/30 sec and 1050, 1550, and 2050 counts/30 sec). Using the signal detection/ROC curve method, eleven new cut points were identified in NHANES (ranging from 100 to 2300 counts/min) and three in TAAG (ranging from 100 to 200 counts/min). Concordance correlation coefficients for minutes of activity with a previously suggested cut point tended to be stronger (≥ 0.60) with higher cut points (≥ 2300 count/min), while those with questionnaires were less than 0.10 or the 95% confidence intervals included zero. One new cut point (1800 counts/min) was similar (p = 0.6) to a comparison measure for classifying meeting recommendations. CONCLUSIONS: Some cut points may be more strongly associated with disease risk factors than previously suggested cut points developed using oxygen consumption, but associations are not strong. The new cut points and comparison measures may be measuring different aspects of physical activity, as they were in poor agreement.Item Closed Loop System Identification of Postural Control with Bilateral Vestibular Loss(2009) Amenabar, Katharine Elizabeth; Jeka, John J; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Human upright stance can be characterized as a combination of feedback and plant. Feedback consists of integrated sensory signals, producing estimates of position and velocity of the body segments while plant includes both musculotendon dynamics and body dynamics. Separating plant and feedback is possible mathematically through closed loop system identification. By studying bilateral vestibular loss (BVL) patients it is hoped knowledge regarding human posture and the role of the vestibular system will be gained. Two BVL patients and two age, height and gender matched controls had visual and mechanical perturbations applied simultaneously to determine these properties. Both leg and trunk kinematics and EMG data were collected. Using frequency response functions plant and feedback properties were calculated. Plant and feedback dynamics differ. BVL patients show more variable weighted hip EMG data, supporting the idea that this population can not properly use hip movement with their lack of vestibular system.Item Probing Postural Stability Mechanisms in Locomotion(2009) Logan, David Michael; Jeka, John J; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)It is not currently known if those upright stability mechanisms utilized in standing posture are present in locomotion. In this investigation, subjects walked or stood on a treadmill in three speed conditions (posture, 1 km/h, 5 km/h) in front of a visual scene consisting of randomly oriented triangles. The triangles translated in the Anterior-Posterior (A/P) direction in either a low or high amplitude condition. Frequency response functions (FRFs) of both the A/P displacement of bilateral kinematic markers and their corresponding segment angles in response to the visual scene translations were computed. Gain and phase of these FRFs had consistent responses in high amplitude visual conditions in the trunk (hip and shoulder displacements, trunk angle), which motivated further comparisons within the trunk during posture and locomotion. In doing so, the postural processes of orientation and equilibrium control were teased apart during locomotion.Item EXAMINING THE RELATION BETWEEN STUDENT EXPECTANCY-VALUE MOTIVATION, ACHIEVEMENT IN MIDDLE-SCHOOL PHYSICAL EDUCATION, AND AFTER-SCHOOL PHYSICAL ACTIVITY PARTICIPATION(2009) Zhu, Xihe; Chen, Ang; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The expectancy-value theory (Eccles et al., 1983) explains that student motivation is primarily determined by one's expectancy-beliefs, task values, and perception of the task, and that these factors directly influence student achievements and behavior choices. Based on the expectancy-value theory, the purpose of this study sought to unravel the relation among middle-school students' expectancy-value motivation, achievement in physical education, and after-school physical activity participation. Participants consisted of 854 sixth, seventh, and eighth grade students in 13 schools from a large metropolitan school district. Students' expectancy-value motivation was measured using the expectancy-value questionnaire; achievements in physical education was measuring using pre-posttest on psychomotor skill (including badminton striking and basketball dribbling skills) and fitness knowledge; after-school physical activity participation data were collected using three-day Physical Activity Recall. Data were analyzed both quantitatively using inferential statistics and structural equation modeling, and qualitatively using open coding approach. The results of the study suggested that middle-school students' expectancy beliefs and task values were relatively high (~4 on a 5-point scale) and their psychomotor skill (i.e., badminton striking skill) and fitness knowledge significantly improved in physical education over the academic year. Further analyses using structural equation modeling revealed that students' expectancy beliefs significantly predicted their psychomotor achievement, which in turn predicted their after-school physical activity participation. The model explained about 14.6% of variance in psychomotor achievement and 3.3% in students' after-school physical activity participation. Cost is a critical component in the expectancy-value theory. All three dimensions of cost conceptualized by Eccles et al. (1983) were identified in the data. Students' cost conceptions were found associated with task values, not with expectancy beliefs and achievements. Despite the cost, most of the students expressed high willingness to attend physical education for motivational purposes and health benefits from physical activities. The findings of this study imply that students tend to have high expectancy-value motivation in physical education. The motivation is likely to have small but significant predication of psychomotor skill improvement; which, in turn, related with after-school physical activity participation.Item Influence of audience characteristics on their behaviors across different sport media platforms(2009) Kwak, Dae Hee; McDaniel, Stephen R; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation explores sport media consumption behavior through a series of three investigations. Using the broad U & G approach (Katz et al., 1974) as an overarching paradigm of this dissertation, the three investigations take a distinct theoretical and methodological approach in the examination of various sport media consumption behaviors across different media platforms (i.e., Internet, videogame, and print media). Study One explores factors that influence the adoption of popular online-sport phenomenon--fantasy sport leagues. Study One uses the Technology Acceptance Model (TAM; Davis, 1989) as a theoretical framework and examines how attitude toward watching football on TV, perceived ease of using the fantasy sport website, perceived knowledge of sport, and subjective norms play a role in explaining subjects' attitudes and behavioral intentions toward playing fantasy football. Study Two revisits the satisfaction-loyalty relationship model in the context of sport video gaming (SVG). Specifically, the second study extends the well-documented satisfaction-loyalty relationship (Oliver, 1999; Suh & Yi, 2006; Yi, 1990) by incorporating brand attitudes and perceived skill in the relationship between satisfaction and loyalty. The findings of Study Two highlight the importance of customer expertise and brand attitudes in a hedonic consumption context that involves a learning component. Study Three replicates and extends existing literature in perceived message sensation value (PMSV) and message processing (Everett & Palmgreen, 1995; Niederdeppe, 2005; Niederdeppe, Davis, Farrelly, & Yarsevich, 2007; Palmgreen, Stephenson, Everett, Baseheart & Francies, 2002), by utilizing a specific message feature (i.e., violence) in the ad stimuli. Study Three is the first known attempt to investigate the arousal-enhancing effect of violent images in the PMSV context. After successfully validating the ad stimuli manipulated by level of violence, this study explores the effect of PMSV on arousal and ad evaluations. The results of Study Three generally support the PMSV main effect on ad responses, suggesting that a high-PMSV ad elicits higher arousal and favorable AAd, and AB than a low-PMSV ad (Donohew et al., 1991; Donohew et al., 1995; Everett & Palmgreen, 1995; Niederdeppe, 2005; Palmgreen et al., 2001; Stephenson, 2002, 2003). Meanwhile, the moderating effect of SS received limited support. Overall, Study Three provides initial evidence that violence, as a specific PMSV-enhancing feature, can elicit arousal and favorable ad evaluations among a college student cohort.Item Retention of a novel visuomotor gain in patients with Parkinson's disease is context-specific(2009) Venkatakrishnan, Anusha; Contreras-Vidal, José L; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Hypometria or reduced movement amplitude is a major concern in Parkinson's disease (PD) since it impairs multiple functional activities of daily living, including fine motor control tasks, such as handwriting. Recent research using virtual or computer-based environments, wherein visual information about hand movement is altered and dissociated from perception (e.g., position sense or kinesthesia) of hand movement itself, has shown increases in handwriting size in patients with PD. In fact, preliminary findings in our laboratory have shown that gradual alterations in visual feedback of movement facilitate adaptation of handwriting size in patients with PD, plausibly by recruiting neural networks other than the basal ganglia, such as those in cerebellum. The purpose of this study was to determine whether these adaptive effects persist after a week following visuomotor training in patients with PD and can favorably transfer to other functional writing and drawing tasks. Thirteen patients with Parkinson's disease and twelve healthy, age-matched subjects practiced handwriting either under gradually manipulated (intervention) or intact (placebo) visual display of handwriting size. The results from this study show for the first time, that these adaptive effects may persist for at least up to a week in PD; however, a single training session seemed inadequate to transfer these acquired changes to paper-pen writing and drawing. Additionally, experimental manipulation of task demands during training also helped maintain movement quality in patients with PD as against the placebo group. These findings have important implications in designing rehabilitative interventions to enhance functional sensorimotor performance in patients with PD.