Kinesiology
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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 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 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 Physiological Determinants of Candidate Physical Ability Test in Firefighters(2009) Sheaff, Andrew; Hurley, Ben; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The purpose of this study was to examine the relative importance of physiological characteristics during firefighting performance, as assessed by the Candidate Physical Ability Test (CPAT). Participants included professional and volunteer firefighters, ages 18-39 (n=33). Muscle strength, muscle endurance, muscle power, body composition, aerobic capacity, anaerobic fitness, and the cardiovascular response to stairclimbing were assessed to determine the physiological characteristics of the participants. To quantify firefighting performance, the CPAT was administered by members of the fire service. Absolute and relative mean power during Wingate anaerobic cycling test (WAnT), relative peak power during WAnT, and absolute maximal oxygen uptake (VO2max) were significantly higher in those who passed the CPAT (n=18), compared to those who failed (n=15) (P < 0.01). Absolute and relative mean power during WAnT, fatigue index during WAnT, absolute VO2max, upper body strength, and the heart rate response to stairclimbing were all significantly related to CPAT performance time (all P < 0.01). However, absolute VO2max and anaerobic fatigue resistance during WAnT combined were the best predictors of total CPAT performance (Adj. R2 = 0.817; P < 0.001). Performance on the ceiling breach and pull was the only individual CPAT task that could not be significantly predicted by the physiological characteristics assessed. Rate-pressure product during the stairclimb was not related to CPAT performance. In conclusion, measures of anaerobic and aerobic fitness best predict overall CPAT performance, as well as individual task performance. Remedial programs aimed at improving firefighting performance should target anaerobic and aerobic fitness qualities.Item Relationships Between Health Behaviors, Perceived Health Status, and Cardiovascular Disease Risk Factors in Adolescent Girls(2008) Goldsholl, Stacy Danielle; Young, Deborah R; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Poor physical fitness and diet contribute to increases in cardiovascular disease (CVD) risk factors including BMI, waist circumference (WC), systolic and diastolic blood pressure (SBP and DBP), and HDL-C levels. These behaviors are also associated with positive perceptions of health status. It was hypothesized that the associations between positive health behaviors and CVD risk factors would be mediated by perceived health status in adolescent girls. Regression models were used to test for independent effects and mediation. 185 girls were analyzed, 83% were African American and 50% were overweight. Perceived health status predicted WC, BMI, and SBP. Fat consumption predicted WC and SBP. There were no associations between health behaviors and perceived health status. Adolescent girls are able to accurately assess their overall health status regardless of fitness or dietary behaviors. Interventions should encourage girls to consider these healthy behaviors when assessing health status to increase participation in these behaviors.Item Aerobic Fitness and Prevalence of the Metabolic Syndrome in African Americans and non-African Americans in PREMIER: a randomized controlled trial(2008-08-11) Levin, Laura A; Young, Deborah R; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Background: The Metabolic Syndrome is the clustering of several cardiovascular risk factors for coronary heart disease and Type 2 Diabetes Mellitus. This syndrome is of public health importance due to its high prevalence and high correlation to all-cause, CHD, and CVD mortality. The purpose of the current study was to determine if a change in aerobic fitness in the treatment group significantly decreased the odds of Metabolic Syndrome at 6 and 18 months. Methods: There were 810 adult participants in this trial with above-optimal blood pressure and up to stage I hypertension. Participants were part of an advice-only control group or a treatment group where physical activity increases were the main component. Results: A change in aerobic fitness, independent of treatment status, was significantly associated with a decrease in prevalent Metabolic Syndrome at both 6 and 18 months (OR: 0.96, CI: 0.94 - 0.98 & OR: 0.96; CI: 0.94 - 0.98, respectively).Item The Effects of Finger Movement Conditions and Speed on Finger Interdependency(2008-09-02) Lieu, James; Shim, Jae K; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Various factors may cause non-task fingers to involuntary move during task finger movement. Finger interdependency is well documented, but only a few attempts have been made to quantify these peripheral and neurological factors, especially during different movement and frequency conditions. The purpose of the study was to quantify and differentiate the contribution of peripheral and neurological factors during different movement and speed conditions. This was examined at two different movement (active and passive) conditions and two movement speeds(0.25 Hz and 0.5 Hz) and compared to previous studies to confirm the proximity hypothesis. The results showed that finger interdependency was greater in voluntary than involuntary movement conditions. Finger interdependency was also greater during the slower speed(0.25 Hz) condition, and the proximity hypothesis was confirmed. Finger interdependency is larger during voluntary movement and at slower speeds, with the involvement of both peripheral and neurological factors.Item The Effects of Low-Fat Diet and Exercise on C-Reactive Protein and Metabolic Syndrome: Findings from a Randomized Controlled Trial(2008-07-09) Camhi, Sarah Michelle; Young, Deborah R; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Background: Low-fat diet (D) and exercise (E) are recommended for reducing cardiovascular disease risk. However, the independent and combined effects of D and E on C-reactive protein (CRP) and metabolic syndrome (MS) are unknown. Purpose: The purpose of this dissertation was to examine the changes in CRP and MS between control (C), D, E and diet plus exercise (D+E). Methods: Men (n=197) and postmenopausal women (n=180) with elevated low-density lipoprotein cholesterol and reduced high-density lipoprotein cholesterol, were randomized into a one-year trial with four groups: C, D, E or D+E (Stefanick et al., 1998). Weight loss was not an intervention focus. This secondary data analysis evaluated stored plasma samples for high-sensitivity CRP. MS prevalence was retrospectively found using the NCEP-ATP III definition. CRP change (ΔCRP) was examined between intervention groups using ANCOVA. Differences between groups for MS at follow-up were retrospectively investigated using logistic regression. All analyses were stratified by gender and controlled for baseline values, body fat change and other appropriate covariates. Results: In women, ΔCRP was different between D+E vs. C (-0.7 ± 0.33 mg/L, p = 0.04) and D+E vs. E (-0.9 ± 0.32 mg/L, p = 0.004). Women also had a decrease in CRP within D+E (Δ log CRP 0.2 ± 0.035 mg/L; p = 0.0002). After the intervention, ΔCRP did not differ for men between or within treatment groups. MS at follow-up was not different between C, D, E or D+E in either men or women. In women with MS, ΔCRP was different between D+E vs. C (-1.3 ± 0.43 mg/L; p = 0.006), D+E vs. E (-1.1 ± 0.44 mg/L; p = 0.02), and D vs. C (-1.2 ± 0.43 mg/L; p = 0.009). In women with MS, CRP decreased from baseline within D+E (Δ log CRP 0.2 ± 0.039 mg/L; p=0.0008). At follow-up, there were no differences between or within groups for ΔCRP in men with MS, or men without MS and women without MS. Conclusion: D and D+E may be effective treatments for reducing CRP in women with MS. Further studies are needed to replicate results and clarify the influence of gender.Item The influence of ECE-1 gene polymorphism and exercise training on plasma and urinary endothelin-1 levels in pre- and stage 1 hypertensives(2007-08-09) Attipoe, Selasi; Hagberg, James; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Endothelin-1 (ET-1) is a peptide that mediates blood pressure. ECE-1b-C-338A is a polymorphism in the ECE-1 gene that alters ET-1 synthesis. Thus, the goal of this study was to investigate the influence of the ECE-1b-C-338A polymorphism on plasma and urinary ET-1 levels, as well as on aerobic exercise training (AEX)-induced changes in these variables. Outcome variables were assessed before and after 24 weeks of AEX in hypertensive adults. Separate ANCOVAs were used to compare differences in outcome variables. Only AA homozygote men had higher plasma ET-1 levels. After AEX, there were no significant changes in the main outcome variables. Neither were these changes significantly different between genotype groups. Results suggest that this polymorphism is associated with plasma ET-1 levels in men but not with urinary ET-1 levels. Additionally, this polymorphism does not affect AEX-induced changes in plasma and urinary ET-1 levels.Item Association Between ACE Genotype and Skeletal Muscle Strength and Volume, and Their Response to Strength Training in Older Adults(2007-06-29) Charbonneau, David; Roth, Stephen; Kinesiology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Introduction: Previous studies have linked an insertion/deletion polymorphism in the angiotensin-converting enzyme (ACE) gene with variability in the response of muscle strength and mass to strength training, though conclusions have been inconsistent across investigations. The purpose of this study was to investigate the possible association between ACE genotype and skeletal muscle strength and volume, and their adaptation to strength training. Methods: A group of older, sedentary adults completed 10-weeks of strength training. Quadriceps muscle strength and volume were measured using one repetition maximum and computed tomography, respectively. Differences were compared among ACE genotype groups (II vs. ID+DD) by sex and race. Results: Baseline and post-training, skeletal muscle strength and volume were not significantly correlated with ACE genotype. ACE genotype was significantly associated with muscle hypertrophy in Caucasian males only (p=0.02). Conclusions: The ACE genotype was not associated with skeletal muscle strength, but was associated with muscle hypertrophy in Caucasian males.