This work focuses on the propulsion of swimming micro-robots through accessible, quasi-static, fluid-filled, environments of the human body. The operating environment dictates that the system must function under low Reynolds number flow conditions. In this fluidic regime, viscous forces dominate. Inspiration is drawn from biological examples of propulsion systems that exploit the dominance of viscous forces. A system based on the prokaryotic flagella is chosen due to its simplicity; it is essentially a rigid helix that rotates about its base. To eliminate the piercing threat posed by a rigid helix, a propulsion system utilizing a flexible filament is proposed. The filament is designed such that under rotational load, and the resulting viscous drag, it contorts into a helix and provides propulsive force. Four mathematical models are created to investigate the behaviour of the proposed flexible filament. An experimental prototype of the flexible tail is built for similar purposes. An experimental rigid tail is also built to serve as a benchmark. The experimental results for propulsive force generated by the rigid tail match the Resistive-Force Theory (RFT) model. An analysis of the system concludes that experimental error is likely minor. An ADAMS model of the rigid tail, as a result of modelling error, under-predicts the propulsive force. The experimental flexible filament shows that the proposed propulsion system is feasible. When actuated, the tail contorts into a `helix-like' shape and generates propulsive force. An ADAMS model of an ideal flexible filament shows that, if a complete helix is formed, there is no loss in performance when compared to a rigid counterpart. The experimental filament is too stiff to form a complete helix and, accordingly, the ADAMS model does not simulate the filament well. To decrease this discrepancy, a second ADAMS model, attempting to directly simulate the experimental filament, rather than an ideal one, is created. Regardless, the second ADAMS model gives confidence that a multi-body dynamic model using lumped-parameter drag forces, after further modifications, can simulate the experimental flexible filament well.

The purpose of this study was to investigate the influence of oral NaHCOa administration on the alteration of acid-base balance and performance of high-intensity interval swimming. Ten male college swimmers were studied on five test days within a two-week period. Each test day consisted of five 100-yd freestyle swims with a two-minute rest interval between each bout. Subjects received two NaHCO3, two placebo and one no-drink treatments for the five test days. One hour before the onset of swimming the subjects were given 300 ml of citric acid flavored solution containing either NaCl (placebo) or NaHC03 (experimental), or received no drink. The dose of NaHCO3 solution was 0.25 9/kg-1 body weight. Before the sprint trial test a 300-yd warmup swimming was performed followed by a nine-minute rest. Performance times for each 100-yd swim were recorded. Blood samples were obtained before and one hour after treatment, two minutes after warmup and the last bout of swim. Blood, pH, lactate, standard bicarbonate (SBC) and base excess (BE) were measured. After the statistical analysis had shown there were no differences between the corresponding values of two trials for the same treatment, the data for identical treatments were combined and reanalyzed statistically as one group. All the corresponding variables between placebo and no-drink revealed no differences. Performance times of the fourth and fifth swimming bouts were faster (P < 0.05) and blood lactate after exercise was higher (P < 0.05) in NaHCO3 condition. Blood pH, SBC, BE were higher (P < 0.05) at post-treatment, post-warmup and post-last bout of swim in NaHCO3 condition. The difference between NaHCO3 and the other two conditions on the increment of lactate (2.0 mM) was proportional to that on the decrement of SBC (2.2 meq/1) after exercise. The data from the placebo and NaHCO3 treatments shown a positive correlation between hydrogen ion and lactate concentrations (r = 0.923) and a negative correlation between SBC and lactate concentrations (r = -0.941) after warmup and exercise. These data are in agreement with previous findings that during repeated bouts of exercise pre-exercise administration of NaHCO3 improves performance, possibly by facilitating the efflux of lactate and hydrogen ions from working muscles and thereby delaying the onset of fatigue.

A "velocity-video" system was developed with the intent of measuring forward body velocity changes and technical skill during swimming. The system consists of a "swim-meter", video camera, A-D converter, Apple IIE computer, Microkey system, VCR and monitor. A correlation of 1.0 was found between the velocity computed by the "velocity-video" system and a known speed. Furthermore, comparison of the velocity pattern of breaststroke from video with digitized film revealed a correlation of 0.95. These results suggest that the "velocity-video" system is a valid method of describing swimming velocity and corresponding changes in body position. The second part of this investigation examined the relationship between physiological economy (ml 02-U_1-LBW-7L), technical skill, swim power, and performance between "superior" and "good" male and female breaststrokers. Swimmers were categorized based on best 100 yd performance time. To study physiological economy oxygen uptake was determined after a 400 yd submaximal breaststroke swim. No significant difference in economy (ml 02•m-1 -LBW-1) was noted between the superior and good swimmers for both males and females. The superior male swimmers, however, were found to have lower blood lactate values compared to the good male breaststrokers', 1.85 + 0.39 vs. 4.49 ± 0.86 mM•1-1. The superior males and females were found cover a greater distance per stroke compared to the good males and females, respectively. The ability to generate power and/or peak power was found to be an important factor in sprint performance (r = 0.91 and 0.92, respectively). During a submaximal effort the superior swimmers spent a greater amount of time during the glide and leg recovery phases of the breaststroke cycle than the good swimmers. The results of the present study suggest that the superior breaststrokers were characterized by there ability to minimize drag during the glide and leg recovery phases of the stroke cycle. This suggests greater technical skill as evidenced by the superior swimmers' ability to cover a greater distance per stroke cycle at a given speed.

Swimming performance is primarily judged on the overall time taken for a swimmer to complete a specified distance performing a stroke that complies with current regulations defined by the Fédération Internationale de Natation (FINA), the International governing body of swimming. There are three contributing factors to this overall time; the start, free swimming and turns. The contribution of each of these factors is event dependent; for example, in a 50m event there are no turns, however, the start can be a significant contributor. To improve overall performance each of these components should be optimised in terms of skill and execution. This thesis details the research undertaken towards improving performance-related feedback in swimming. The research included collaboration with British Swimming, the national governing body for swimming in the U.K., to drive the requirements and direction of research. An evaluation of current methods of swimming analysis identified a capability gap in real-time, quantitative feedback. A number of components were developed to produce an integrated system for comprehensive swim performance analysis in all phases of the swim, i.e. starts, free swimming and turns. These components were developed to satisfy two types of stakeholder requirements. Firstly, the measurement requirements, i.e. what does the end user want to measure? Secondly, the process requirements, i.e. how would these measurements be achieved? The components developed in this research worked towards new technologies to facilitate a wider range of measurement parameters using automated methods as well as the application of technologies to facilitate the automation of current techniques. The development of the system is presented in detail and the application of these technologies is presented in case studies for starts, free swimming and turns. It was found that developed components were able to provide useful data indicating levels of performance in all aspects of swimming, i.e. starts, free swimming and turns. For the starts, an integrated solution of vision, force plate technology and a wireless iii node enabled greater insight into overall performance and quantitative measurements of performance to be captured. Force profiles could easily identify differences in swimmer ability or changes in technique. The analysis of free swimming was predominantly supported by the wireless sensor technology, whereby signal analysis was capable of automatically determining factors such as lap times variations within strokes. The turning phase was also characterised in acceleration space, allowing the phases of the turn to be individually assessed and their contribution to total turn time established. Each of the component technologies were not used in isolation but were supported by other synchronous data capture. In all cases a vision component was used to increase understanding of data outputs and provide a medium that coaches and athletes were comfortable with interpreting. The integrated, component based system has been developed and tested to prove its ability to produce useful, quantitative feedback information for swimmers. The individual components were found to be capable of providing greater insight into swimming performance, that has not been previously possible using the current state of the art techniques. Future work should look towards the fine-tuning of the prototype system into a useable solution for end users. This relies on the refinement of components and the development of an appropriate user interface to enable ease of data collection, analysis, presentation and interpretation.

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree Master of Science in Medicine (Exercise Science) Johannesburg, 1997 / This investigation examined the cross- training effect of swim training on middle distance running performance. Eight, healthy, untrained subjects (mean age + SD = 24.63 + 2.77 yrs) participated in a 12 week. swim training program. Before and immediately following the training period, measurements were made of: maximal oxygen consumption (V03 max.) (treadmill); anaerobic capacity (Wingate test); knee and shoulder muscle strength (isokinetic dynamometer); 100m and 200m swim time- trials; and 400m and 800m run time-trials. VO- max. increased from a mean of 42.06 + 5.1 ml/kg/min. to 45.39 + 5.05 ml/kg/min. (8.137. ; p< 0.005). The 100m, 200m swim times and the 400m, 800m run times improved significantly in response to the swimming training (p< 0.0001). Dynamometry showed significant inc reases in power and work during knee flexion at an angular velocity of 60 °/sec; knee extension at 245 °/sec; and during shoulder f1 ex ion and extension at 195 and 245 °/sec. The Wingate test however, did not show any changes after the training period. A cross-training effect by swim training on running performance was attained among the untrained, non- competitive swimmers of this study. While mode of activity was non- specific, a training response was attained by keeping the intensity and volume of the swim training specific to middle distance run training. / IT2017

Thesis (M.A.)--Boston University

The purpose of the present study was to determine the effect of including a dryland activation during a 30-minute transition phase time between pool warm-up and competition on elite swimming performance. Previous research has shown the benefits of shorter transition times, or transition times that include dryland activation, improve swimming performance. Nine elite swimmers from the High-Performance Centre Victoria, 2 males and 7 females (18.7 ± 4.3 yrs), completed two testing sessions separated by one week, consisting of a 30-minute traditional (TRAD) or dryland (DL) transition phase followed by a 200-metre time-trial (TT). The swimmers swam the TT in their primary 200m event. Both transition phases were identical through the first 20-minutes but for the next 10 minutes, swimmers either sat quietly for 10 minutes (TRAD) or completed a 5-minute dryland activation 5 minutes pre-TT (DL). The dryland activation consisted of 2 sets of 40 seconds of jumping jacks and 6 explosive burpees completed self-paced but within a 5 minute time limit. Core temperature (Tcore) and Heart Rate (HR) were measured throughout the entire testing sessions. TT performance was significantly faster (p < .010) following DL (130.61 ± 10.46 secs) compared to TRAD (131.71 ± 11.08secs), an improvement of 0.84%. The third 50m split was also significantly faster (p < 0.18) following DL (34.83 ± 4.28secs) compared to TRAD (35.47 ± 4.47secs). Heart rate was significantly elevated following the dryland activation compared to the same time in TRAD (134 ± 22 vs. 84 ± 13bpm, p < 0.001). There were no significant differences in Tcore between the two transition phase conditions. The results from this research support the inclusion of a dryland activation during the transition phase of elite swimming competitions. As the smallest of differences can influence final placing at international level swimming competitions, the small gains found in the present study may have considerable implications for optimal swimming performance. / Graduate

In competitive swimming a spread in time of only 0.10, and 0.16 seconds constituted the difference between finishing second and seventh, and first and eighth, respectively, in the women's 50 yard freestyle at the 1993 NCAA Division III National Swimming & Diving Championships. Based on data collected over a period of years Maglischo (1993) noted that "improving the start can reduce race times by at least 0.10 second" (p. 544). Therefore it is beneficial to the outcome of a race to direct attention to maximizing the effectiveness of the racing start. The primary purpose of this study therefore was to compare kinetic and kinematic components of the grab and track style starts. During the past two decades extensive kinematic research has been done using cinematography. These studies used time, velocity, displacement, and the measure of angles (i.e. at takeoff and entry) to measure the relative effectiveness of various racing starts. Conversely, there has been limited analysis of racing starts using kinetic measurements. Four kinetic and five kinematic variables were evaluated in this study to compare the relative effectiveness of the starting techniques. Ten female varsity swimmers, who had used both starts interchangeably in competition, were selected for this study. Force components were obtained directly from a Kistler force platform. Block time, horizontal and vertical impulse, and average horizontal and vertical force values were obtained in subsequent analysis of the Force-time data. Each subject was videotaped as she executed three trials of each start. The video data were digitized and then analyzed using two dimensional video analysis techniques. The type of start technique used on each trial was randomly ordered. Kinematic variables of horizontal and vertical displacement of the center of mass, average horizontal velocity and vertical velocity were also obtained from the video data in order to determine which of the two starting techniques (i.e. grab vs. track) was the most effective. 2x10 (starting technique x subject) repeated measures Analyses of Variance indicated significant differences (p<0.01) between the starting styles for five of the nine dependent variables measured which provided support for the original contention that the track style start was the more effective of the two racing start techniques investigated. The results of this study provide support to the empirical and observational findings of earlier researchers. / Graduation date: 1995

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