Statement of the Problem: Understanding physical activity (PA) behaviors in children with cerebral palsy (CP) who are non-ambulatory is important to design optimal fitness interventions that reduce sedentary behaviors and promote health. There is a growing body of evidence for children with CP who are ambulatory that indicates they have decreased PA as compared to neurotypical peers. These children are at risk for poor health status and in need of adapted strategies to promote activity and reduce sedentary behaviors. However, information on PA behaviors is limited for children with CP who are non-ambulatory. Evaluating the amount and intensity of PA in children with CP who are non-ambulatory is challenging because of the heterogeneous nature of the disease and the limited repertoire of movements available to these children. Developing assessments that accurately describe PA in this population is essential to understand the nature of these limitations and to develop targeted interventions. Materials & Methods: In Study 1, PA amount and intensity in children with CP who were non-ambulatory were examined using PA (accelerometers) and HR monitors along with video observation and parent journaling over 7 days. Children were observed during a range of daily tasks to provide a detailed observation in their home and school. Parents were asked to rate their opinion of their child’s level of PA intensity during these tasks (easy, medium or hard), and these ratings were compared to the PA intensity derived from the PA and HR monitors. Levels of agreement were reported between parent report and HR and PA monitors during video recording. In Study 2, Interviews with parents of children with CP who were non-ambulatory and physical therapists (PTs) working with this population were conducted to understand how they operationalized PA and to evaluate the face validity of the Patient Reported Outcome Measurement Information System (PROMIS) ® PA parent proxy short form 8a survey as a measure of PA in this population. Each child was classified by Gross Motor Functional Classification Scale (GMFCS), the eating, drinking, classification scale (EDACS), the communication and feeding classification scale (CFCS), and the manual abilities classification scale (MACS).Results: For Study 1, 10 children and families participated in the exploratory observation with a video recording of PA in the home. A minimum of 4 consecutive days of monitor wear data was obtained for 7 of the 10 children; 3 children experienced equipment or use malfunction. There was a positive correlation between the parent level of PA intensity and intensity measured by the HR monitors, but no correlation with the PA monitors. The level of agreement of parent-reported PA intensity and HR monitors were correlated with PediCAT daily activity and mobility scores and the EDACS, CFCS, and MACS, There was no correlation between the parent responses and PA monitor-derived PA intensity levels with any functional measure. The PA monitor-derived level of intensity was correlated with the parent-reported PROMIS T-scores. No correlation was seen with the HR monitors. For Study 2, 22 PTs and 15 parents of children with CP who were non-ambulatory participated in the interviews. The PT’s and parents’ interview responses generated shared opinions about PA and how it should be operationally defined in this population. Four major themes emerged: a) PA is defined by functional activities and active movement; b) PA is challenging to measure objectively in this population; c) the environment plays a crucial role in supporting PA; and d) personal factors influence PA uptake. Both parents and PTs believed PA in this population should be increased to improve health related benefits. PA definition focused on active mobility and independent motor control by PTs, whereas the parent's definition of PA highlighted the functional and mobility achievements of their children with examples of communication and use of assistive technology and adaptive equipment. Level of assistance was used by both PTs and parents to indicate PA measurement. Parents and PTs agreed on the appropriateness of various questions on PROMIS scale, with the most appropriate questions being those that inquired about PA frequency during the week (Questions 6 and 7) Conclusions: Accelerometers, HR monitoring, and video monitoring can provide insight into daily PA in children with CP who are non-ambulatory. PA derived from HR monitors was correlated with parent-reported PA intensity during specific daily tasks, suggesting that HR monitors may better reflect PA intensity than accelerometry-based monitors in this population. In capturing PA over a longer period (e.g., 1 week), the PROMIS parent-proxy measure correlated with PA monitor-derived levels of intensity. PA monitors may best reflect general activity levels throughout the week rather than specific intensity levels during daily activities. Defining PA in children with CP who are non-ambulatory is challenging, however, parents and PTs provided insights into methods that can be used to conceptualize this challenging construct. The PROMIS short form 8a PA had some qualities that were deemed appropriate by PTs and parents alike with a preference for specific questions (Questions 6 and 7) for children with CP who are non-ambulatory. Methods to address the implementation of cardiovascular and fitness goals in this population need to be further explored.

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The purpose of this study was to test the hypothesis that arbutamine, a specific B₁-adrenergic agonist, will not cause different circulatory and physiologic effects than the less specific endogenous catecholamines released in response to an exercise stress test in persons with known or suspected coronary artery disease. Nine male subjects, mean age 66 years, completed symptom-limited arbutamine (ESA) and exercise (ETT) stress tests in a randomized cross-over study. The ESA delivery device controlled infusion rate to induce a graded heart rate increase of 8 bt min⁻¹. Heart rate, systolic blood pressure, diastolic blood pressure, rate pressure product, ST segment shift, and specimens for epinephrine, norepinephrine, dopamine, cortisol, insulin, glucagon, glucose, free fatty acids, glycerol, and lactate were collected at baseline, immediate post-stress, and 10, 30, and 60 minutes post-stress. The research hypothesis was rejected. Repeated measures analysis of variance for each measure demonstrated a significant (p ≤ .05) time treatment interaction in heart rate, systolic blood pressure, rate pressure product, insulin, glucagon, glycerol, free fatty acid, and lactate responses and a significant time effect for cortisol response. Circulatory differences included higher systolic blood pressure and rate pressure product responses for ETT than ESA and a more rapid recovery of circulatory variables following ETT. Metabolic differences were due to higher free fatty acid and glycerol responses for ESA than ETT and a slower recovery of these metabolites and lactate following ESA. Hormonal differences included an earlier and greater magnitude rise in insulin response for ESA than ETT. There were no differences (p ≤ .05) by treatment, time, or time treatment interaction for diastolic blood pressure, ST segment shift, catecholamines, or glucose. In conclusion, arbutamine caused different circulatory and physiologic effects consistent with differences in adrenergic receptor activity. Arbutamine caused substantial B₁₊₂ agonist effects on hormonal and metabolic responses in cardiotonic doses employed clinically for diagnostic stress testing and may impact clinical interpretation of stress test results. / Ph. D.

The American College of Sports Medicine has published formulae that are widely used to predict functional aerobic capacity for any treadmill speed and grade combination. However, it has been demonstrated that these formulae overpredict oxygen consumption (V̇O₂) for patients with coronary artery disease as well as for apparently healthy individuals. To study this, we measured V̇O₂, ventilation (V̇_E), and respiratory exchange ratio (R) responses in 21 apparently healthy subjects (AH) and 16 coronary artery diseased subjects (CAD) during a modified Balke protocol. Modification of the protocol consisted of extending the stage time from two minutes to three minutes at the higher intensities to allow a greater time for a physiological steady-state to occur. The attainment of a steady-state may lead to the reduction of or the elimination of prediction errors. No differences were observed between two and three minute VO₂ responses at maximal and submaximal exercise for either group. At peak exercise, the AH group was significantly (P≤.05) different from the CAD group when compared for heart rate (164±2.6 vs 140±4.8 bts•min⁻¹ ), V̇O₂ (33.3±1.1 vs 26.7±2.3 ml•kg⁻¹•min⁻¹), and total treadmill time (9.9±.33 vs 8.1±.54 min). At submaximal exercise, V̇O₂ responses were also significantly (p≤.05) greater for the AH group when compared to the CAD group (26.6±.95 vs 21.9±1.8 ml•kg⁻¹•min⁻¹). No significant differences were observed for RPE and blood lactate at peak exercise and V̇_E and R responses at submaximal or peak exercise between the two groups. Predicted values for peak V̇O₂ were significantly (p≤.05) higher than measured values (33.3±1.1 vs 38.8±1.1 ml•kg⁻¹•min⁻¹) and (26.7±2.3 vs 34.1±1.7 ml•kg⁻¹•min⁻¹) for the AH and CAD groups, respectively. However, no significant differences were noted between predicted and measured V̇O₂ responses at submaximal exercise for either group. Individuals classified as Type A were not significantly different from classified Type B individuals when compared for the cardio-respiratory variables measured. These data demonstrate that the ACSM prediction formulae significantly overpredict V̇O₂ for both AH and CAD subjects at maximal treadmill intensities. However, at submaximal intensities, these prediction formulae are acceptable for both groups of subjects. Furthermore, these data suggest that two minutes per stage allows sufficient time for physiological steady-state to occur at clearly submaximal intensities. Although at the higher intensities, extending the stage time beyond two minutes may be indicated. / M.S.

Nine male CHD patients volunteered for testing to determine variations in heart rate response (HR), walk-jog velocity (W) and compliance to the target heart rate zone under three monitoring conditions. Determination of variations in W, peripheral perceived exertion (RPE_L) chest perceived exertion (RPE_C) and post-exercise lactate accumulation (La) during exercise which was held constant between 60-80% maximum HR reserve were also made. Procedures consisted of three 20 min walk-jog exercise conditions. First, two baseline condition (BC) trials were performed on separate days with exercise intensity regulated through intermittent defibrillator-ECG HR checks and radial/carotid artery palpation. Next, continuous telemetry monitoring of HR by staff was added during a single exercise trial (TC). Finally, two Exersentry_Rcondition (EC) trials were performed on separate days with continuous feedback concerning HR response provided to the patient via Exersentry_R devices. Evaluation of HR and W revealed no significant variation between conditions. However, % target HR reserve attained was significantly (p>0.05) lower during early and late BC, as compared to TC. Furthermore, "frequency in" vs "frequency out" of target HR zone was significantly (p>0.05) greater during EC, as compared to TC. During EC, no significant variations in HR, W, La, RPE_L and RPE_C were noted. Correlation coefficient values between 0.76-0.95 and 0.58-0.80 were reported for RPE_L and RPE_C, respectively. This data suggested that continuous feedback concerning HR response resulted in the greatest compliance to the target HR zone. With the exception of the first five min of EC, only RPE_L reliably mirrored HR and W. Index terms: Intermittent heart rate monitoring, continuous heart rate monitoring, heart rate response, walk-jog velocity, target heart rate compliance, peripheral perceived exertion, chest perceived exertion, post-exercise lactate accumulation. / M.S.

The subjects were DUI probationers placed by the court system in the Virginia Alcohol Safety Action Program (VASAP). Due to their high risk level, the subjects were placed in treatment programs. An exercise program was incorporated in a VASAP treatment program to investigate the reduction in alcohol drinking frequency and quantity by implementing a weekly questionnaire as a repeated measure in an experimental vs. a control group design. Within these same groups, depression was measured through a pre-post design using the Beck Depression Inventory as a psychometric measure. The two arms of the study were evaluated by weekly ordinal data analyzed using a repeated measure ANOVA and a pre-post design using a 2x2 table with the appropriate ANOVA at a .05 level of significance. The results indicated no significant difference between the groups. There experimental group established a reduction in alcohol consumption and depression at a faster rate than the control group. / Master of Science

Nine patients with intermittent claudication diagnosed at least 6 months before this investigation were evaluated to determine the effects of walking exercise on serum lactate accumulation (HLa, mmol⁻¹), ankle pressure index (API), total treadmill time (sec), and onset of leg pain (sec) in the most severely diseased limb. Subjects were evaluated via a functional walking tolerance test before participation in a thrice-weekly exercise program lasting 6 weeks. Post- treatment, the participants were re-evaluated on an identical walking test. Measurements of HLa accumulation and API were taken at rest and immediately following termination of the treadmill test. In the training sessions, body weight (kg), exercise heart rate (HR), systolic blood pressure (SBP), and distance traveled (m) were recorded daily. There were no significant changes (p<.05) after training in total time (mean increase = 23.7%) or time for onset of pain in the treadmill test (mean increase = 30.1%). Neither were there significant changes (p<.05) in API or HLa levels taken immediately after exercise, when pre- and post-training treadmill test data were compared. The weekly responses for exercise HR, and SBP, as well as body weight remained stable throughout. Mean distance walked by the subjects increased 203% (± 45%) across the 6 weeks. These data suggest that increases in total distance walked in an exercise program were apparently not related to HLa accumulation or API measurements in the working muscles, and that other mechanisms must be investigated in future studies to explain enhanced performance of such subjects. / Master of Science

Forty normal subjects, 19 males and 21 females, between the ages of 16 and 43 years were studied to examine the reliability of Cybex knee extension curves utilizing Segmental Curve Analysis (SCA). Each subject performed a standardized isokinetic knee extension/flexion test on the Cybex II isokinetic dynamometer. Test protocol consisted of 5 maximum repetitions at a speed of 60 deg/sec. Within one week of the initial test, each subject performed a retest. During testing, all torque and angle measurement information from the Cybex was transmitted to the SCA system. The SCA system plotted, analyzed, and quantified each torque curve for seven specific parameters. The following parameters were quantified by the SCA system: (1) torque at 20 degrees, 70 degrees, and peak torque of knee extension; (2) area of the curve to 20 degrees, 70 degrees and peak torque of knee extension; and (3) area of the torque curve between 20 and 70 degree angles of knee extension. The parameters of peak torque (r=.83 to .97; R=.98 to .99), area to 70 degree angle of knee extension (r=.76 to .87; R=.96 to .98), and area between 20 and 70 degree angles of knee extension (r=.75 to .92; R=.97 to .99) appeared to be the most reliable across trials and days, and were also found to elicit the least amount of variation for both male and female subjects. Coefficients of variation on the parameters of peak torque, area to 70, area between 20 and 70 for females ranged from 15% to 18%. For males, the coefficients of variation for peak torque, area to 70, and area between 20 and 70 ranged from 23% to 27%. Variables quantifying torque and power indices in the middle segment of torque curves appeared to be most reliable as analyzed by the SCA system. / Master of Science