The men's steeplechase event requires participants to jump over thirty-five 0.914-meter-tall obstacles, 4 rigid barriers and 1 fixed barrier followed by a 3.66-meter-long water pit per lap, over a 3000-meter distance. This study investigated the effect of increasing running velocity, through a range of 5.33 m/s to 6.66 m/s, on takeoff and landing ground reaction forces, for males during steeplechase hurdling using a force plate embedded under a track surface. Subjects completed 1 trial within each of 6 different pace ranges in a random order, once with a hurdle following the force plate to measure the takeoff ground reaction forces and a second time with the hurdle prior to the force plate to measure the landing ground reaction forces. Within a repeated measures linear mixed model during takeoff, peak vertical force (r2 = 0.1968, p < 0.01) and horizontal propulsive impulse (r2 = 0.0287, p = 0.02) were positively correlated with increasing velocity, and ground time (r2 = 0.1904, p < 0.01) was negatively correlated with increasing velocity. Within a repeated measures linear mixed model during landing, vertical impact force loading rate (r2 = 0.0099, p < 0.01) was positively correlated with increasing velocity and ground time (r2 = 0.2889, p < 0.01), vertical impulse (r2 = 0.1704, p = 0.02), and horizontal braking impulse (r2 = 0.0004, p = 0.05) were negatively correlated with increasing velocity. As male steeplechasers prepared to hurdle at increasing speeds, they produced a greater peak vertical force on the takeoff step while decreasing the ground time during takeoff, and increasing the horizontal propulsive impulse to carry themselves beyond the hurdle. While landing from the hurdle at increasing speeds, the athlete decreased the amount of time spent on the landing stance and the vertical impulse, and increased the magnitude of horizontal braking impulse and vertical loading rate. The relationships of these variables: takeoff peak vertical force, takeoff ground time, takeoff horizontal impulse, landing ground time, and landing vertical loading rate to increasing velocity were all comparable to overground running responses. The data differed from running by not indicating any change in hurdling takeoff horizontal braking impulse; however, the horizontal braking impulse did increase on hurdling landing. It was expected to decrease on hurdling landing due to the foot landing more underneath the center of mass after hurdling compared to running. The decrease in landing vertical impulse as speed increased also differed from normal running steps. We suggest that further research include kinematic measures to better understand the relationship between these variables as hurdling velocity increases.

The purpose of this study was to investigate the relationship between movement competency and health related quality of life (HRQOL) in adults aged 55 to 75 years. Seventy-eight, male (40) and female (38), subjects completed the study. Their mean (SD) age, height, and mass were 64.9 (5.8) years and 63.6 (4.9) years, 1.8 (.08) m and 1.7 (.07) m, 82.6 (11.8) kg and 70.3 (17.9) kg, for male and female, respectively. Subjects completed several tests in 3 categories: movement competency (Functional Movement ScreenTM [FMS] [all 7 tests], sitting-rising test [SRT]); physical activity level (Physical Activity Scale for the Elderly [PASE]); and health related quality of life [HRQOL] (SF-36v2). A linear regression model was then developed to examine the relationship of a number of variables to quality of life. The strongest relationship to HRQOL was the FMS, with a positive correlation of 0.474 which is highly significant (p < 0.0001). Once the FMS score was accounted for, no other terms in the regression model were significant. The correlation between our two assessments of movement competency, the FMS and SRT was 0.644 which is highly significant (p < 0.0001). Our primary hypothesis was supported that those with better movement competency have a better health related quality of life. Our results suggest further research should be undertaken to see if properly administered individualized corrective therapeutic exercise programs could improve older adults' movement competency and thereby improve their quality of life.

The objective of this study was to investigate the influence of cyclic loading on the extensibility of hamstring muscle-tendon units in vivo.Study Design: A test-retest randomised controlled trial with repeated measures was undertaken.Background: Stretching has been commonly promoted to increase the passive extensibility of the muscle-tendon units, yet the mechanism behind its proposed effects remains ambiguous. In vivo studies of stretching have mostly been limited to the viscoelastic characteristic of stress-relaxation. Few studies have investigated the characteristic of creep. Animal and cadaver in vitro creep experiments have consistently shown increases in the length of the soft tissues, with associated changes in their resistance and stiffness. These results however, might not be representative of human muscle-tendon units under in vivo conditions. Additionally, those in vivo human studies that have investigated creep phenomenon have contrasting results. To date, no known in vivo study has examined passive cyclic loading of human hamstrings to a constant load level.Method: Using a repeated measures design the extensibility of the hamstring muscles were assessed by a passive knee extension test (PKE) to maximal stretch tolerance using a KinCom® dynamometer. Those participants in the intervention group underwent 45 continuous passive cyclic loadings as the KinCom® dynamometer moved the knee joint into extension until torque reached 85% of maximal passive resistance torque measured in the passive knee extension test. The control group sat quietly relaxed during the intervention period. Measurements of hamstring passive extensibility using the PKE test were repeated at the end of the intervention.Results: Following the intervention, the PKE test showed for the cyclic loading group there was a significant (p < 0.05) increase in both maximal passive resistance torque (mean 23%) and knee joint angle (mean 6.3%). A significant (p < 0.05) decrease in passive resistance torque (mean 11.8%) when re-measured at the baseline position of maximal passive knee angle was observed. A significant increase (p < 0.05) was found for passive stiffness over the final 10% of the knee torque-angle curve. No significant difference (p > 0.05) was found for passive stiffness for the full (100%) of the torque-angle curve. Of the control group, no significant differences (p > 0.05) were observed for all variables of the PKE test. Analysis of cycle one compared to forty-five of the cyclic loading intervention procedure showed a significant (p < 0.05) increase in both passive knee joint angle (mean 5.2%) and passive stiffness (mean 28.6%) over the final 10% of the knee joint torque-angle. No significant difference (p > 0.05) was found for passive stiffness across the full (100%) knee joint torque-angle.Conclusion: The findings of the current study demonstrated that after cyclic loading the hamstring muscles lengthened and became stiffer over the final gained range of knee joint motion. Although the current study cannot determine the mechanism behind the changes in the variables of interest, these findings do provide some evidence that most likely a combination of altered stretch tolerance and local mechanical effects within the muscle-tendon unit, i.e. creep lengthening were responsible.

Caffeine is now an unrestricted ergogenic aid for competitive athletes. Previous reviews of caffeine's effects on exercise performance have been limited to qualitative analysis. The purpose of this paper was therefore to quantitatively meta-analyze the effects of caffeine on exercise performance. We identified 90 estimates of performance effects of caffeine in 32 peer-reviewed studies. All estimates were converted to mean power in an equivalent time trial then subjected to a mixed-model meta-analysis. The fixed effects were gender, training status (elite athlete, non-elite athlete, non-athlete), dietary caffeine status (habitual consumer, non-consumer), caffeine abstention period, caffeine dose (mg/kg body mass), type of caffeine (pure or in coffee), delay between ingestion and performance test, duration of test, and presence or absence of fatiguing exercise before the test. The random effects accounted for within- and between-study variance. We found that caffeine enhanced mean power by 2.8% (90% confidence limits ± 1.1%) in male non-elite athletes who are habitual caffeine consumers abstaining from caffeine for 2 d before consuming 6 mg/kg of caffeine capsules 1 h before performing a 30-min time trial without intervening fatiguing exercise. The effects for other athletes and conditions were: females, 3.1% (± 2.7%); elite athletes, 2.9% (± 1.4%); non-athletes, 1.3% (± 1.2%); habitual non-consumers, 4.0% (± 1.4%); 7 d of abstention, 3.4% (± 2.6%); 0.3 mg/kg of caffeine, 1.6% (± 5.3%); caffeinated coffee, 1.0% (± 1.6%); 2-h delay before exercise, 2.9% (± 1.2%); 6-s exercise test, 1.6% (± 1.7%); prior fatiguing exercise, 3.0% (± 1.6%). Each of these effects of caffeine varied typically between studies by ± 1.4% (the between-study random effect; 90% confidence limits ± 0.9 to ± 3.5%). We conclude that caffeine has a greater effect on performance with athletes, with habitual non-consumers of dietary caffeine, when administered as pure caffeine, and in endurance exercise, but there is considerable uncertainty about the magnitude of the effects on individuals. More research is needed to reduce this uncertainty and to determine the performance effects of caffeine with females, following longer periods of dietary abstention, in low doses, and for brief exercise. There has also been no research on effects of caffeine on the repetitive fatiguing exercise typical of team sports.

This thesis uncovers the rational and Romantic assumptions about the relationship between objects and identity that are embedded in occupational therapy, and critiques current practice from that perspective. It is based on an initial assumption that there is in fact a relationship between people's identity and the objects they make, have, use and are associated with. This assumption is explored through an interpretive examination of the fields of literature that are commonly identified as informing occupational therapy, supplemented by selected popular literature. The exploration takes a philosophical approach, guided by notions from philosophical hermeneutics, including pre-understandings, the hermeneutic circle and fusion of horizons. The conclusion reached is that people informed by Western philosophies interpret the identity meanings of objects in both rational and Romantic ways. To inform the study, the nature of rationalism and Romanticism are then explained, and the implications of these philosophical traditions in relation to objects and identity are teased out. This interpretation is guided by a history of ideas methodology, which entails approaching historical texts from a new perspective, in this case the identity meanings of objects. Thus informed, occupational therapy literature, primarily that published in Britain between 1938 and 1962 is examined from the perspective of objects and identity. What is revealed is that rational and Romantic understandings of objects, and of patients' and their own identity are clearly discernible. Such understandings afforded early occupational therapists both ways to organise their growing knowledge of the therapeutic application of crafts and the transformative outcomes of occupational therapy intervention. Gradually however, factors both internal and external to the profession served to undermine therapists' Romanticism. Primary amongst these were World War II, which saw a redeployment of occupational therapists from mental health to physical rehabilitation settings; advances in rehabilitative medicine, which brought a reduction in secondary complications and the adoption of teamwork; and the development of new practice areas including domestic rehabilitation using gadgets to enhance function and pre-vocational rehabilitation. As a result, tensions between rational and Romantic understandings crystallised around two long-standing controversies. These were whether or not craft equipment such as weaving looms should be adapted to serve specific remedial purposes, and whether it was the process of making a crafted object or the quality of the finished product that was more important. In the event, these contested ideologies became largely irrelevant as craftwork was sidelined from mainstream practice. With it, occupational therapists' Romantic vision of transforming people's lives through creative activity also slipped away. Several reasons for this loss of one of the profession's founding philosophies are proposed. They include the substantial absence of the professions' philosophical foundations from its education, and the paucity of theory and research methodologies that might have informed the nature and process of transformative change that earlier occupational therapists had observed and reported. The thesis concludes by arguing for the importance of recovering a balance between rationalism and Romanticism. A call to action is issued, addressing change in educational practice, concerted research effort to identify and articulate transformative processes within occupational therapy, and political action focusing on the inclusion of Romantic perspectives within policy and strategic documents.

Reviews of clinical practice for paediatric pacemaker implantation and follow-up are necessary to provide an evidence-base for future policy and practice in this field. Epicardial pacing data available through Green Lane Hospital, New Zealand's (NZ) primary referral centre for paediatric cardiac surgery and pacemaker implantation, was reviewed with the following aims: Assessment of pacemaker lead performance over time in relation to the type of epicardial lead implanted - steroid-eluting (SE) and non steroid-eluting (NSE). Determination of the survival rate of epicardial leads. Identifying factors predicting or associated with lead failure.A database of pacing and sensing thresholds and lead impedance data at implant, 2, 6 and 18 weeks and 6 monthly intervals thereafter, was compiled and the prevalence and timing of complications in relation to lead type, location and implant route determined. In total 192 leads (155 SE, 37 NSE) were implanted in 96 patients (52 male) aged 3 days to 71 years (y) (median 1.7y), 74 patients were < 17 years of age at implant. Congenital heart defects were present in 82% of patients. Follow-up (f/u) was possible for 180 leads. Mean f/u duration for the 150 SE leads was 3.1y (2 weeks - 8.8y) and for the 30 NSE leads was 4.5y (2 weeks - 27y).SE and NSE pacing thresholds were similar at implant. NSE pacing thresholds peaked at 6 weeks post implant and remained significantly higher than SE leads throughout f/u in surviving leads, although the difference was small at 2 and 4 y. SE and NSE leads had similar ventricular sensing thresholds and lead impedances throughout the study period.Survival at 5 years for all leads was 61% (66% for SE leads and 41% for NSE leads). Primary causes of failure in the leads receiving f/u were exit block and lead fracture. The occurrence of exit block was significantly higher (p<0.0001) in NSE leads (57%) compared to SE leads (5%). Lead fracture occurred in 15% of leads with the highest fracture rate at 2-3 y post implant. Patient age and weight at implant, gender, previous cardiac surgery, lead polarity, indication for pacing and implant route were not predictors of lead failure. NSE leads were 6 times more likely to fail compared to SE leads (p <0.0001).The main study findings were: SE leads maintain lower pacing thresholds and a reduced incidence of exit block compared to NSE leads. It is therefore recommended that SE leads be developed which can penetrate fibrosed, scarred or fatty epicardial surfaces. Where SE lead use is contraindicated, alternative surgical techniques for SE lead placement should be attempted rather than implanting NSE leads. Lead fracture is a significant complication of epicardial pacing in paediatric patients. Using stronger bipolar leads implanted by the subxiphoid route may reduce the risk of fracture. Medium term survival (5 y) of SE epicardial leads is acceptable and therefore the continued use of these leads is recommended, particularly in young patients, allowing their veins to be saved for transvenous leads later in their life.

Physical activity is now a key strategy for preventing or minimising numerous chronic diseases. Worksites are an ideal location to promote regular physical activity. For workers, a large portion of waking hours is spent at work where numerous opportunities exist to accumulate physical activity. Consequently, the aims of this thesis were to: 1) systematically review worksite physical activity literature, especially in the New Zealand context; 2) identify the contribution of worksite activity to total activity levels, and the correlates contributing to physical activity levels for professional occupations; and 3) objectively measure physical activity changes with point of decision prompt visibility in professional worksites. Accordingly the thesis incorporated one systematic review and two separate studies.Effect sizes calculated in an analysis of previous worksite physical activity health promotion studies show inconclusive evidence for increased employee retention and job satisfaction, and no evidence of reduced absenteeism or productivity increases. A major criticism of worksite research is that many unvalidated and unreliable designs are used, limiting study efficacy. Research initiatives need to identify the determinants of physical activity for different occupations, ethnicities, and gender in New Zealand worksites.Study 1 (N=56) consisted of participants wearing two pedometers over a three-day block, and subsequently completing a Three-Day Physical Activity Recall (3DPAR). A moderate, positive Spearman correlation (r=0.28) existed between the METs (3DPAR) and total pedometer values. Contributions of (mean + SD)worksite (14 283 +4761), non-work (12 516 +4 172), and total (26 798 +8 933) pedometer values were analysed. The sample was divided into tertiles according to total step counts. The high activity group (HAG) achieved more physical activity outside the workday (56%) when compared to the lowest activity group (LAG) (29%). Physical activity correlates were identified using binary logistic regression and simple correlation analyses. Relationships between physical activity and active transport, manual work, sport and exercise, and individual exercise were shown.Study 2 evaluated the National Heart Foundation (NHF) point of decision prompts for increasing physical activity levels in professional worksites. Forty-six participants (27 men and 19 women) wore two pedometers for three days, over four occasions to monitor changes in physical activity. The study was a crossover design with Worksite 1 receiving the treatment for three weeks, followed by a six-week wash out period, then a three-week control. Worksite 2 was given the control prior to the treatment period. Results indicate that the NHF point of decision prompts were ineffective at increasing objectively measured work and total physical activity levels, showing trivial positive (0.04) to moderate negative Cohen effect sizes (-0.79). When point of decision prompts were visible in the worksites overall mean step counts decreased. On the basis of these findings, the NHF's point of decision prompts had no effect, or were potentially detrimental to physical activity.Nevertheless, both studies were limited by some traditional worksite design problems, including low participation and sample contamination. However, by incorporating an objective measure of physical activity (pedometers) and a robust study design, these findings are the first objective measures of worksite physical activity, and the effects of point of decision prompts in a confined sample.

Obesity and its subsequent disease states are major health problems in the United States. In many ways, obesity can be considered a “disease state” itself due to the changes it causes on the body. High-intensity exercise also places acute stress the body, putting humans in recovery from exercise in a state that may be analogous to a temporary disease state. The purpose of this study was to examine biomarkers associated with obesity (CRP and Leptin) before and after continuous and intermittent bouts of exercise in an obese but otherwise healthy sample vs. a healthy, non-obese sample. This investigation focused on examining the obese sample’s biomarkers at rest compared to those of the healthy group immediately and 1 hour-post exercise. Eighteen male subjects participated, with nine in each group. Each subject performed a VO2 max test and a series of three anaerobic Wingate tests at least one week apart in a cross-over study design. Blood was taken at baseline, immediately-post, and 1-hour post for each exercise mode. A significant difference was noted between groups for CRP at baseline on the VO2 testing day. A significant difference between groups existed in leptin levels at baseline on both testing days. The only significant change was the decrease in leptin from post to 1- hour post for during the VO2 in the obese group. However, both exercise protocols demonstrated various effects on the subjects and groups. Healthy participants were examined individually, and two of them showed possible signs of being at risk for obesity and its subsequent disease states based on post exercise “spikes” in CRP and leptin that caused the levels of the biomarkers to be closer to those in the obese group at rest. Another three subjects saw at least two spikes. Thus, a total of five subjects could potentially be “at-risk” based on the assumptions of the present study. These results suggest CRP and Leptin could potentially hold the ability to classify someone in a “preobesity state.” Further investigations are warranted based on these initial results and should focus on biomarkers more specific to obesity.

To regular exercise and a healthy diet, the American Heart Association (AHA) strongly recommends rope jumping, and according to previous studies, rope jumping is considered a very strenuous exercise. Therefore the purpose of this study was to determine the steady state metabolic cost of repetitive jumping on the Digi-Jump machine, and to determine if exercise on this device is more or less strenuous than similar exercise with a jump rope. We also evaluated relative intensity of this type of exercise, based on each person’s VO2max as measured on a treadmill. Twenty – seven subjects completed two trials, one jumping trial at a rate of 120 jumps per minute (JPM) with the jumping height set at .5 inch for 5 min, and one graded exercise test (GXT) using the Bruce protocol. Oxygen uptake (VO2), heart rate (HR), respiratory exchange ratio (RER), and rating perceived exertion (RPE) were measured each minute during each trial. Results of this study indicated that steady state VO2 during the 5 min jump test was reached at the 3rd min (p < .05), therefore we equated all other variables (HR, RE, RPE) steady state to be from 3rd min. Average jumping steady state VO2 was 31.1 ± 5.5 ml/kg/min, while average VO2max was 56.4 ± 12 ml/kg/min, thus steady state VO2 during jumping trial was 57.1% of VO2max. Average jumping steady state HR was 149. 2 ± 20.1 bpm, while mean GXT HR was 184.7 ± 9.9 bpm, thus steady state HR during jumping trial was 80.9% of their maximal HR obtained during GXT. Average jumping steady state RER was .99 ± .6,while average GXT RER was 1.15 ± .07, thus steady state RER during jumping trial was 86%, and average jumping steady state RPE was 13.5 ± 1.5, while average GXT RPE was 17.9 ± 1, thus steady state RPE during jumping trial was 75.2%. These data indicate that jumping is a strenuous activity, even if the trial is done on Digi – Jump machine without rope.

Special Weapons and Tactics (SWAT) operators are specially trained personnel that are required to carry equipment to perform high risk tasks. Given the need to carry this equipment, it is important to understand the potentially deleterious effect that the additional load may have on tactical performance. Furthermore, it is important to identify physical fitness characteristics that are associated with the potential decrement in performance. Therefore, the purpose of this study was to evaluate the effect of load carriage on tactical performance and identify fitness characteristics associated with any decrement in performance. Twelve male operators performed a simulated tactical test (STT) on a live firing range with (loaded condition) and without external equipment (unloaded condition) and completed a battery of physical fitness assessments. Time to complete the STT in the loaded condition increased by 7.8% compared to the unloaded condition. Nine of the 13 STT tasks were performed significantly slower in the loaded condition. VO2peak was negatively associated and fatigue index was positively associated with the overall STT delta time. These findings indicate that a higher aerobic capacity and lower anaerobic fatigability are related to a greater resilience to carrying a load while performing tactical tasks.