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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.
391

Percent Body Fat and Fat Distribution are Not Associated with Carotid Artery Intima-media Thickness in Healthy Middle-aged Women

Goff, Kayleen Adams 11 July 2008 (has links) (PDF)
Background and Purpose – The relationship between abdominal body fat and cardiovascular health is not completely understood. This study investigated the association between percent body fat, fat distribution and intima-media thickness (IMT) in healthy middle-aged women. Methods – 224 middle-aged (mean age = 43.1 years ± 3.0), nonsmoking women were included in this study. The women were assessed with a B-mode, high-resolution ultrasonograph to measure the intima-media thickness of the right common carotid artery (CCA). Measurements for percent body fat and fat distribution were assessed using Bod Pod and waist circumference (WC) measured at the umbilicus, respectively.Results – Data were separated into quartiles with the middle two groups combined in order to identify potential differences in IMT based on waist circumference and body fat percent groups. Mean IMT for the entire sample was .569 mm ± .06. Multiple regression with and without control for potential confounding factors yielded insignificant results for all analyses. Conclusions – In the present study, using a sample of healthy middle-aged women, there were no differences in IMT based on overall body fat percent or waist circumference measurements. This finding is somewhat unexpected, however, regional body fat and CCA-IMT have been shown in some, but not all studies to be positively associated with IMT. More research is needed in this area in order to more clearly identify and understand early risk for cardiovascular disease in women.
392

Motor Function Responses to Induced Pain and Cryotherapy

Long, Blaine Cletus 19 May 2008 (has links) (PDF)
Objective: Establish and validate an experimental pain model that will create pain for at least 20-minutes and then use the model to determine if: 1) cryotherapy decreases experimentally induced pain, 2) experimentally induced pain contributes to arthrogenic muscle inhibition, and 3) cold application influences pain or arthrogenic muscle inhibition. To answer these questions we conducted two experiments, the results of which are presented in two manuscripts. Methods: Seventy (n = 30 for experiment I and n = 40 for experiment II), physically active healthy male subjects participated. Interventions: Independent variables used for experiment I were condition (5% hypertonic saline infusion/cryotherapy, no-saline infusion/cryotherapy, 5% hypertonic saline infusion/sham) and time (precondition, every minute during a condition, and 10 minutes following each condition). For experiment II, independent variables were treatment (saline infusion, saline infusion/cryotherapy, saline infusion/sham, and no-saline infusion) and time (pretreatment, posttreatment, and 30-minutes posttreatment). Dependent variables measured were pain perception, knee surface and ambient temperatures, and Hmax, and Mmax measures (experiment II only). Results: Saline caused more pain than no-saline at minutes 3, 4, and 5 during infusion. Pain caused by saline and sham application remained constant from 4 minutes during application through 1 minute following application. Cold application decreased pain for 16 minutes. Pain resulted in arthrogenic muscle inhibition following and 30 minutes following saline infusion. Cryotherapy removed inhibition following but not 30 minutes following application. Pain for the saline groups increased following infusion as measured with the pain rating index and visual analogue scale. According to pain rating index, cryotherapy did not decrease pain; however, cryotherapy decreased pain as measured with the visual analogue scales. No change in temperature occurred during the non-cooling conditions. Ambient temperatures fluctuated less than 1°C. Conclusion: Saline infusion caused anterior knee pain for over 20 minutes and resulted in arthrogenic muscle inhibition. Cryotherapy disinhibited the quadriceps motoneuron pool and reduced pain as measured with visual analogue scales. Cryotherapy did not decrease pain as measured with the McGill pain questionnaire.
393

A Comparison of the Effects of High-Resistance Cycle Training and Leg Press on the Wingate Anaerobic Test, Strength, and Time-Trial Performance

Stites, Aaron W. 18 March 2009 (has links) (PDF)
The purpose of this study was to compare high-resistance cycle training (HRCT) with resistance training (RT), and their effects on Wingate anaerobic test watt max (Wmax) and watt average (Wave), strength (improvement in 1 repetition max [RM]), and time-trial performance. Twenty-five healthy college-age untrained male subjects were randomly assigned to the HRCT (n=10), RT (n=10), or control (n=5) group. All subjects completed pre and posttesting for the leg press (LP), 30 s Wingate anaerobic test, and 15-min time-trial. Subjects also completed familiarization tests prior to pretesting in the Wingate anaerobic test and 15-min time-trial. HRCT and RT subjects trained 2x/wk for 8 weeks with at least 48 hrs between training sessions. During each training session HRCT completed 4 x 30 sec efforts increasing resistance when >65 rotations per minute (rpm) could be maintained for the full training session. RT completed 3 x 10 repetitions of leg press with weight increasing 5 -10 lbs when all repetitions were completed during a training session. ANOVA with Tukey post-hoc was used to determine if differences existed between the groups. Within group change was analyzed using paired T-test. Effect size was computed to determine meaningfulness of differences. HRCT and RT groups both showed statistical significance (p < 0.05) pre to posttesting in LP, Wingate anaerobic test Wmax and Wave, and 15-min time-trial. Control group also showed statistical significance (p < 0.05) pre to posttesting in LP and 15-min time-trial. Significant between group differences were noted between HRCT and control in Wingate anaerobic test Wmax (p=0.03) and Wave (p = 0.007) and 15-min time-trial (p = 0.003). There was a significant difference between RT and control on the 15-min time-trial (p = 0.008). When comparing HRCT and RT no statistical difference was seen in LP, Wingate anaerobic test Wmax and Wave, and 15-min time-trial. High-resistance cycle training and RT resulted in similar strength gains. However, HRCT showed greater improvements in cycling specific activities: 30 s Wingate anaerobic test Wmax and Wave, and 15-min time-trial. Results suggested that HRCT may increase performance on bike related assessments when compared to RT.
394

The Effects of Cold Water Immersion on Fractioned Response Time

Romney, Patricia Jean 23 April 2009 (has links) (PDF)
Objectives: Quantify the effects of cold water immersion of the ankle on fractioned response time of the dominant lower limb. Design and Setting: A 2x2x5x5 crossover design with repeated measures on time and treatment directed data collection. The independent variables were gender, treatment, time (pretreatment, and post 15 seconds, 3 minutes 6 minutes and 9 minutes) and trial (5 trials for each time group). Response time (Tresp), reaction time (Treac), trial and surface temperature were measurement variables. Subjects: Thirty-six subjects, 18 females and 18 males were recruited from a physically active volunteer college student population. Measurements: Fractioned response time was tested following a 20 minute treatment. Response time and Treac were recorded by the reaction timer, and Tmov was calculated by taking the difference between Tresp and Treac. For each time/subject the high and low Tresp were discarded and the middle three trials were averaged and used for statistical analysis. A 2x2x5 ANOVA was used to determine overall differences between gender, treatment and time followed by Newman-Keuls multiple comparison tests. Results: Males were faster than females for Tresp, Treac and Tmov. Movement time and Tresp were slower with cold water immersion, but Treac was unaffected. Movement time and Tresp were fastest pretreatment, and slowest during the post 15-second time group. Though both Tmov and Tresp progressively sped up from the post 15-second through the post 9-minute time group, they did not return to pretreatment values when data collection discontinued. Conclusions: Immersing the dominant ankle in cold water for 20 minutes increases Tmov of the dominant lower limb; thereby increasing fractioned response time (Tresp).
395

Effect of Stratum Corneum Hydration on the Composition of Sweat Collected by a Local Sweat Patch Method

Taylor, Penny Renee 16 July 2009 (has links) (PDF)
The purpose of this study was to determine the effect of stratum corneum (SC) hydration by distilled water on SC ion content and sweat ion concentrations as measured by occlusive sweat patch. 10 men and 10 women completed approximately 40 minutes of moderate exercise in the heat. Select skin sites were hydrated before sweating by adhering cylinders of distilled water to forearm skin. SC samples were taken before and after exercise using the tape stripping (TS) method and sweat samples were taken with homemade filter paper sweat patches with a tegaderm backing. An increase in SC hydration was verified by a reduction in SC potassium concentration (p<0.05). SC hydration caused a significant decrease in sweat potassium (K+), calcium (Ca++), and lactate (Lac-) concentration: K+ =8.14 ± 0.46 to 6.56 ± 0.46, Ca++ = 0.86 ± 0.17 to 0.67 ± 0.18, Lac- = 11.64 ± 1.36 to 8.82 ± 1.11, euhydrated to hyperhydrated respectively(p<0.05). SC sodium (Na+) and K+ concentration increased after sweating without a sweat patch (p<0.05). Our data do not dispute the idea that electrolytes can be leached from the SC by distilled water or sweat trapped within an occlusive dressing. However, our data indicate that during normal sweating the SC "dehydrates" resulting in an increase in the electrolyte concentration. As such, we propose that the occlusive dressing does trap sweat on the skin but the important end result is that it prevents water movement out of the SC and thereby producing a more concentrated sweat.
396

The Effects of Abdominal Training on Postural Control, Lower Extremity Kinematics, Kinetics, and Muscle Activation

Gage, Matthew J. 04 August 2009 (has links) (PDF)
Context: Abdominal training may decrease the risk of lower extremity injuries through improved balance and postural control. Objective: To determine the effect of an eight-week abdominal-training program on center of pressure, lower extremity joint angles, and abdominal muscle activation during a single-leg drop landing. The effects of abdominal training on abdominal muscle thickness was assessed. Design: A cohort research design. Setting: Research laboratory. Other Participants: Sixty healthy physically active college-aged students participated. They were divided into three groups: Control, Chronic ankle instability (CAI), and Healthy. Nineteen Control (age = 22.0 ± 2.72 yrs, mass = 74.1 ± 13.8 kg, height = 172.6 ± 11.3 cm, BMI = 24.8 ± 3.1 %), 21 CAI (age = 22.1 ± 2.3 yrs, mass = 77.6 ± 14.0 kg, height = 175.4 ± 12.3 cm, BMI = 25.1 ± 2.6 %), and 20 healthy (age = 22.9 ± 3.4 yrs, mass = 70.9 ± 15.6 kg, height = 172.2 ± 8.9 cm, BMI = 23.7 ± 3.3 %). Subjects in the CAI group had a history of CAI and functional ankle instability (FAI). The Ankle Instability Index and the Functional Ankle Ability Measure were used to self-report CAI and FAI respectively. Interventions: The CAI and Healthy groups participated in an eight-week abdominal-training program while the Control group maintained their normal activities of daily living and level of physical activity. Main Outcome Measures: Abdominal muscle thickness was measured biweekly throughout the study. Center of pressure excursion, muscle activation, vertical ground reaction force, and lower extremity joint angles were measured during a single-leg drop landing, pre- and postabdominal training. Results: Muscle thickness at rest increased in the rectus abdominis and external oblique muscles follow training. Eight weeks of abdominal training decreased vertical ground reaction forces and muscle activation down the lower kinetic chain. Center of pressure excursion and velocity were increased following training. Conclusions: Eight-weeks of abdominal training increased abdominal muscle thickness. Training improved neuromuscular efficiency throughout the kinetic chain and may have improved dynamic postural control. Our data also suggest CAI subjects may utilize both feedforward and feedback mechanisms to maintain postural control.
397

Comparison of Single-Use and Multiple-Use Electrodes for Sensory, Motor Threshold Amplitudes and Force Production

Maloy, Lucia 12 December 2009 (has links) (PDF)
Context: Electrodes play an important role in interfacing tissue with electrical stimulation devices. Manufacturers recommend that adhesive metallic mesh cloth electrodes be used no more than 10 times before they are discarded, however, clinically the electrodes are often used up to 30 times. Another concern is sanitation. When electrodes are used on different patients, there is a chance for cross-contamination and bacterial growth on the electrode. Objective: To compare amplitudes of perceived sensation, motor twitch and force produced at specific amplitudes using single-use electrodes that run no risk of cross-contamination, and multiple-use electrodes. Design: Mixed model ANOVA with the subject blocked. Setting: Therapeutic modalities research laboratory. Patients or Other Participants: 20 subjects comprised of 7 males (age 24.7 yrs ± 2.3 yrs, skin fold thickness 5.9 mm ± 2.4 mm) and 13 females (age 21.5 yrs ± 2.3 yrs, skin fold thickness 10.7 mm ± 4.1 mm) recruited by volunteer sample mainly from athletic and athletic training populations. They drew random numbers to determine which group they were assigned to. Interventions: Each subject had electrodes placed on their wrist extensors muscles. Measures were recorded of what intensity it took to achieve perceived sensation, motor twitch, and force produced at a specific intensity. To determine decay, multiple use electrodes were tested initially and on the 10th use. After the multiple use electrodes were tested initially, they were leached out. After eight uses, pretest procedures were repeated (10th use electrode) as the final trial on the subjects. Single use electrodes were tested one time. Main Outcome Measures: The dependent variables were sensation, motor twitch and force production. The experiment was a repeated measures study, using mixed models ANOVA with subjects blocked. Alpha was set at p<0.05. Data was analyzed using a SAS proc mixed 9.1. Results: There was no statistical difference between the measures taken during the initial trial and final trial of the multiple use electrodes for muscle twitch (FMUI MUF muscle twitch= 107.3, p= 0.09) and force production (FMUI MUF force production=28.7, p= 0.11). There was a significant difference between the single use and the multiple use electrodes for the initial and final trial. Average values in mA for perceived sensory were: single use 9.73, multiple use initial 16.70 , multiple use final 21.03; observed muscle twitch: single use 15.87, multiple use initial 29.16, multiple use final 31.78; and force produced: single use 22.8 Newtons, multiple use initial 10.0 Newtons, multiple use final 5.0 Newtons. Conclusion: Single-use electrodes produce more conductive power with fewer milliamps compared to multiple-use electrodes. Single use electrodes are just as, or more efficient as the multiple use electrodes and have the added advantage of eliminating the possibility of cross-contamination of bacteria from patient to patient.
398

A Comparison of the Traditional, Swing, and Chicken Wing Arm Movements on Volleyball Blocking in NCAA Division 1 Female Athletes

Neves, Taubi J. 08 March 2010 (has links) (PDF)
Blocking is highly correlated with team success. The identification of specific techniques that produce a more successful block would be helpful knowledge for coaches and players. This study compared the traditional, swing, and chicken wing arm swings in combination with the running step footwork pattern in order to determine which arm swing enabled athletes to perform a more effective block. The time it took the athletes to get off the ground and get their hands above (vertically) the net was calculated. The distance the hand reached over the net or hand penetration (displacement between the net and finger in the anterior and vertical planes) was also measured. Lastly, jump height was calculated. High-speed videography was used to capture the blocking movements of thirteen female NCAA Division I athletes. Data were analyzed using a repeated measures ANOVA test, pairwise comparison, and co-variate analysis. The chicken wing block arm swing was quickest in getting the athlete off the ground and getting their hands above the net. The swing block was greatest for hand penetration and jump height. These results can help coaches and players decide which arm swing will benefit them most as a blocking team and as individual blockers.
399

The Effects of Resistance Training on Strength and Body Composition in Postpartum Women

Pratt, Katherine Bishop 11 August 2010 (has links) (PDF)
The postpartum period represents a high-risk period for body weight retention and obesity. Several studies have investigated the role of aerobic exercise on postpartum weight retention and other body composition outcomes; however, there has been little attention given to resistance training in postpartum women. Thus, the purpose of this four-month randomized study was to determine the effectiveness of resistance training on strength, body composition, return to pre-pregnancy weight, and bone mineral density (BMD) in postpartum women. Sixty postpartum women were randomly assigned to either a resistance training group or a comparison group. The resistance training group participated in a progressive resistance training program twice weekly for four months. The comparison group participated in a flexibility program twice weekly for four months. Strength changes were assessed for the upper body (bench press), lower body (leg press), and the core (abdominal curl-ups). Body composition, including BMD, was measured by dual energy x-ray absorptiometry. Over the four-month study, the resistance training group demonstrated a 36.7% increase in bench press, a 31.1% increase in leg press, and a 222.6% increase in abdominal curl-ups (p < 0.05). The flexibility group improved by 7.7% for bench press, 6.6% for leg press, and by 43.0% for abdominal curl-ups (p < 0.05). Group*period interactions were significant for the leg press, bench press, and abdominal curl-ups (p < 0.05). Both groups decreased in body weight, body fat percentage, and fat tissue (p < 0.05). Neither group significantly changed in lean tissue, whole body BMD, and hip BMD (p > 0.05). Group*period interactions were not significant for any body composition outcome (p > 0.05). These results suggest that a twice weekly resistance training program is superior to flexibility training to increase strength; however, resistance training may not be enough to influence body composition to a greater extent than flexibility training in postpartum women. More research is warranted.
400

Children's Perceptions of a District-Wide Physical Education Program

Watts, Tirza Ramona 15 July 2009 (has links) (PDF)
It is important that physical educators, teacher educators, and researchers do all they can to understand and help promote positive attitudes among students, as attitudes toward physical education (PE) may influence students' physical activity intentions and behaviors. The purpose of this study was to identify children's perceptions of PE as it is delivered via a district-wide PE program. Specifically, the study examined the following: (a) student perceptions of enjoyment and usefulness of the PE program as it is systematically delivered in their district, (b) student likes and dislikes with respect to PE, and (c) student voice as expressed directly by the students. The study used a previously validated attitude questionnaire (N = 277) with fifth and sixth grade students (ages 10-13) and follow-up focus-group and individual interviews (n = 24) to identify student perceptions of PE. Results identified three main categories: (a) teacher engagement, (b) student engagement, and (c) the impact of PE on students. Findings show students in this study had positive attitudes toward PE. This was due to curriculum and teachers, both perceived as enjoyable and useful. The quality of the PE these students received was possible through the components of the district-wide PE program.

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