This thesis analyses the relationships that exist between the coach, the parent and the athlete within the context of age-group swimming. The interest in this area grew from the researcher's own experiences as a swimmer, a parent of swimmers and a swimming coach together with the underlying belief that the three members or what Byrne (1993) terms the 'sporting triangle' approach swimming experiences with different needs and wants. If other members of this sporting triangle fail to recognise or understand these needs then conflict may arise which could detract from the positive sporting experiences of the young swimmer. Because of the dearth of literature concerning relationships between all three members of this triad the literature review provides an overview of literature concerning the coach's, parent's and swimmers' roles and their relationships with one or more members of the sporting triangle. The importance of the context in which swimming takes place is also recognised and the age-group swimming structure within the United Kingdom is discussed. The research was carried out within two swimming clubs which were at participation level of competition. Within each club the field work involved observations followed by in-depth interviews with three swimmers and their parents together with the Chief Coach. The selection of the families was based around Hellstedt's (1987) model of the coach-parent-athlete triangle. Data were analysed using a grounded theory approach and Goffman's (1984) dramaturgical approach, alongside role theory and the notion of 'positioning' (Giddens, 1984; David and Harre, 1990) provided the basis for the reflexive pluralist methodology employed. The findings confirmed the complexity of the relationships within the triad together with the importance of the context in which social interaction takes place. The continual tension that exists between structure and agency was highlighted and seen as something that must be both understood (theoretically) and addressed (empirically) in any attempt to understand social interaction. The resulting data also confirmed that members of the 'sporting triangle' do not come to a swimming situation value free but bring with them a variety of expectations, needs and wants. As a result the need for strong lines of communication between all three members of the triad is recognised. Finally recommendations are made for policy and practice which it is hoped will ensure that young athletes' sporting experiences are positive.

The aim of this thesis was to contribute to the development of an objective, evidence-based international classification system for para-swimmers by quantifying the effect of physical impairment on passive and active drag. The thesis comprises five studies. Study 1 identified a significant relationship between normalised passive drag and the para-swimmers’ International Paralympic Committee (IPC) Class, but an inconsistent difference in normalised passive drag between adjacent classes. High within-class variability in passive drag indicates that the current classification system does not always differentiate clearly between swimming groups. Study 2 found that anthropometric features of para-swimmers, such as height and body mass, differed significantly between IPC Classes, whereas Shoulder Width, Chest Depth, Shoulder Girth and Torso Girth did not. A weak correlation existed between para-swimmers’ anthropometry and their passive drag, which indicates that other factors, such as impairment type, may be more important predictors of passive drag than anthropometry. Study 3 revealed that certain impairments, such as double-leg amputation above knee level, may predispose a para-swimmer to a relatively high passive drag which disadvantages them in competition. Study 4 compared two methods of estimating active drag during front crawl swimming: the Naval Architecture Based Approach (NABA) and the Active Towing Method (ATM). The means were not statistically different. Using a sensitivity analysis, the NABA was identified as the more reliable method of assessing active drag. Study 5 found that active and passive drag of elite para-swimmers are highly correlated but no relationship existed between active drag and International Paralympic Committee S Class (IPC S Class), indicating that factors other than impairment level may be more important in determining active drag. The relationships discovered between drag, IPC Class, anthropometry and impairments will contribute to the development of the future IPC Classification system.

Modern competitive swimming is a highly structured, organized, codified and regulated sport. This has not always been the case. The aim of this thesis has been to examine the long-term development of competitive forms of swimming throughout the periods between the late sixteenth and early twentieth centuries. Despite some recent historical analyses, the emergence of swimming as a modern competitive sport is an under-researched topic. There are no sociological analyses relating to the development of competitive swimming and significant gaps within much historical research. This thesis has been conducted from a sociological perspective in order to test the relative adequacy of Norbert Elias’s concept of sportization. Figurational sociologists have often examined the concept of sportization in relation to the development of contact sports such as boxing and rugby. Some authors have sought to criticize figurational sociologists for over-emphasizing issues relating to the increasing control of violence when examining the development of such activities. In this manner, there is scope to contribute to existing empirical and theoretical knowledge by testing the relative adequacy of the concept of sportization in relation to the long-term development of the predominantly non-contact sport of competitive swimming. To this end, data have been examined from a range of documentary sources. Various swimming-based texts, treatises, periodicals and magazines were examined at the British Library and Colindale Newspaper Library in London. The original minute books of the Amateur Swimming Association and its predecessor bodies have also been analyzed. In addition, a range of digitized source material has been examined from several electronic databases. It has been argued that the development of modern competitive swimming was an unplanned and unintended outcome resulting from the complex interweaving of wider social processes in England throughout the periods between the Middle-Ages and the early twentieth century. The earliest reported swimming contests took place in the eighteenth and early nineteenth centuries in the form of a cash wager between two or more individuals. These events were less structured and regulated than modern forms of competitive swimming. Betting upon the outcome of such events was deemed to be an appropriate means to experience heightened levels of tension-excitement within the context of an emerging society in which people were increasingly expected to demonstrate greater self-control over their behaviour and emotions. More organized forms of competitive swimming gradually emerged during the nineteenth and early twentieth centuries. The emergence of an increasingly complex network of clubs, societies and associations at local, county, district and national levels facilitated such developments and contributed to the emergence of standardized rules and regulations within the emerging sport of swimming. Such developments have been explained in relation to ongoing processes of state-formation, pacification, lengthening chains of interdependence and a gradual lowering in the threshold of repugnance within England in the period between the Middle-Ages and the early twentieth century. In this manner, it has been argued that the concept of sportization is an appropriate theoretical framework for explaining the long-term development of the modern non-contact sport of competitive swimming.

Cerebral palsy is the most common motor disability in childhood. The disorders of movement and posture are characterised by abnormal patterns of movement related to defective movement coordination and regulation of muscle tone. Secondary problems that may develop include perceptions of fatigue and pain. Difficulties with body function and structure affect the levels of activity and participation of the person, such as functional independence, walking ability and participation in leisure activities. These multiple facets of functioning contribute to the known physical inactivity problem apparent in youth with cerebral palsy. In addition, these low physical activity levels contribute to further deterioration of functioning. Hence, a vicious cycle of deconditioning exists. A community-based swimming programme was proposed to combat this vicious cycle. A systematic review on the effect of an aquatic intervention on the multiple facets of functioning of youth with cerebral palsy revealed no studies that measured the effect on pain, coordination and quality of life. Moreover, none of the authors reported the perceived enjoyment of the participants during the intervention. Furthermore, there was a lack of controlled studies reporting the effect of a swimming intervention on walking ability, fatigue, functional independence, self-perception, participation in leisure activities and aquatic skills in ambulatory youth with cerebral palsy. Consequently, the aim of this thesis was to investigate the effect of swimming on these multiple facets of functioning that are associated with the low physical activity levels, in youth with cerebral palsy. A randomised controlled cross-over design was implemented to investigate the effect of a 10-week swimming intervention on pain intensity, fatigue, walking ability, bilateral and upper limb coordination, functional independence, perceived competence, global self-worth, quality of life and swimming skills. A pre-test – post-test design was used to assess the effect of taking part in a swimming programme on participation in leisure activities. Fourteen 7 to 17 year-old youth with cerebral palsy with the ability to walk with or without walking aids completed the tests on all measurement occasions. All youth had a high adherence towards the programme, participated in the intervention with high levels of enjoyment, and most youth continued to participate in swimming after completing the programme. Moreover, no adverse events due to the programme were reported and no participants withdrew from the intervention. Swimming skills improved significantly over the 10-week swimming programme, and improved significantly more than over the control period. The changes were retained throughout a 20-week follow-up period. Positive trends of improvement were evident for walking distance at maximum walking speed, upper limb coordination, functional independence in social functioning and mobility, and perceived motor competence. The intervention was not associated with increases of pain and fatigue. Participation in the swimming programme did not affect bilateral coordination, functional independence in self-care, self-perception and quality of life. The evidence of the pre-test – post-test study suggests that learning the skill of swimming encouraged participation in activities of the formal domain, active-physical and skill-based activities, and facilitated youth to engage in aquatic activities. No control data were obtained in the pre-test – post-test study; however, the results are promising in view of the known deterioration in participation with increasing age. Additionally, the present study showed that the perceptions of youth with cerebral palsy that learning a new skill is too time consuming, and that physical activity is not fun and carries a risk of injury, pain and fatigue, were eliminated in the swimming program. The consolidation of swimming skills and high levels of enjoyment during the programme, are expected to improve participation, engagement and adherence to physical activity, which was confirmed in the present study as youth participated more in aquatic activities after one year than before the start of the study. It was concluded that swimming is an enjoyable and safe community-based physical activity that may have a positive effect on the physical, social and emotional well-being in 7 to 17 year-old youth with cerebral palsy with the ability to walk. The elimination of some of the barriers confronted by youth with cerebral palsy to engaging in physical activity is important with regard to the sustainment of a physically active lifestyle. The findings suggest that participation in swimming may aid in breaking the cycle of deconditioning.

The eggbeater kick is a skill used frequently in water polo and synchronized swimming to elevate the upper body for shooting, passing, blocking or compete with the opponent for position in the water. The hips, knees, and ankles are involved in creating favourable orientations of the feet so that propulsive forces in the vertical direction can be created. Literature reporting the technique of the eggbeater kick is scarce and limited to description of kinematics or muscle activity. The relationship of the kinematics to the demands on specific muscles has not been established. The purpose of this study was to analyze the kinematics and muscle activity of the water polo eggbeater kick in fatigued and unfatigued states to provide foundational knowledge on which training programs can be based. Twelve water polo players were tested executing the eggbeater kick in the vertical position while trying to maintain as high a position as possible for the duration of the test. The test was terminated when the player could not keep the top of the sternum marker above water. Anthropometric data were collected using the ‘eZone’ method. Three dimensional coordinates for the lower limbs and two dimensional coordinates of the above water top of the sternum marker were obtained. Surface electromyography recorded the muscle activity of the Tibialis Anterior, Rectus Femoris and Biceps Femoris muscles on both legs. Differences between fatigued and unfatigued conditions and between dominant and nondominant sides were tested using a two factor ANOVA with repeated measures. Differences within subjects were also investigated on a subject by subject basis with regard to muscle activity. Results indicated differences for kinematic and muscle activity variables between fatigue levels. The amplitude of anatomic angles and speed of the feet decreased with fatigue. Significant differences were found between dominant and non-dominant sides for the ankle motion. The non-dominant ankle was more inverted and adducted than the dominant ankle during the knee flexion phase of the cycle. The Rectus Femoris muscle had consistent patterns across subjects, while Tibialis Anterior and Biceps Femoris muscles were more subject specific in their responses. The Rectus Femoris and the Biceps Femoris have an agonist/antagonist relationship during knee flexion and extension. The Tibialis Anterior was active for long periods in the cycle while dorsiflexing and inverting the foot. As a consequence activity in these muscles decreased with fatigue. These findings point towards the necessity for players and coaches to address specific motions and muscles during the training of the eggbeater technique. Future work should focus on developing eggbeater kick training programs that address specific strength and flexibility.

Front crawl (FC) and back crawl (BC) are similar in terms of having alternating contributions of the arms combined with a six beat kick. However, the reason for the faster swimming times of FC than BC has not yet been established. There have been several studies in which the energy expenditure (Ė) of FC and BC were investigated. However, few researchers have compared Ė between the strokes. Also, although there have been some studies for FC using 3D motion analysis, few researchers have applied 3D motion analysis for BC. There have also been some studies in which the relationship between isokinetic torque produced on an isokinetic dynamometer and FC performance has been investigated, however, the relationship between isokinetic torque and BC performance is unclear. Therefore, the aim of this study was to determine why FC is faster than BC by investigating physiological and biomechanical differences between FC and BC. Ten Portuguese male national level swimmers were recruited for this study. Three studies were conducted to achieve the aim. In the first study, Ė of FC and BC at the same testing speed below the anaerobic threshold were investigated by measuring swimmers’ oxygen uptake. Kinematic variables of FC and BC below the anaerobic threshold were also measured by 3D motion analysis in the first study. In the second study, 3D motion kinematics of FC and BC at the same selected speeds were investigated. In the third study, kinematic differences between FC and BC at the same exercise intensities, and correlations between the kinematics and isokinetic muscular torques of the swimmer in FC and BC and their differences were assessed. Below the anaerobic threshold, Ė of the swimmers in BC was significantly greater than that in FC at the same speed although there were no differences in stroke frequency (SF), stroke length (SL) and stroke index (SI). Swimmers also had significantly higher Froude efficiency (ηF) in FC than in BC. Differences in several kinematic variables (range of motion of the foot, duration of non-propulsive phases, and intra-cycle velocity variation) suggested that swimmers expended greater energy in BC than in FC. Differences in other kinematic variables (body roll angle, hand speed/acceleration, yaw angle fluctuation, centre of mass displacement, and hand/foot displacements) suggested the possibility of resistive impulse being larger in BC than in FC during the stroke cycle. Thus, FC is more economical and efficient than BC because swimmers lose less energy to the water during the non-propulsive phase, and possibly have smaller resistive impulse in FC than in BC at speeds below the anaerobic threshold. At the same selected speeds above the anaerobic threshold, ηF in BC was significantly lower than that in FC, which was due to faster mean 3D hand speed during the stroke cycle in BC than in FC. The faster mean hand speed in BC than in FC was due to the faster 3D hand speed during the pull phase, and longer relative duration of the release and above-water phases in BC than in FC. SI was also larger in FC than in BC, which was due to longer SL in FC than in BC. The longer SL in FC than in BC was due to the longer duration of propulsive phases and probably smaller resistive impulse during the stroke cycle in FC than in BC. At the same selected exercise intensities, FC was faster than BC because of higher SF. The higher SF in FC than in BC was due to the longer duration of the above-water phase in BC than in FC, longer hand path distance during non-propulsive phases in BC than in FC, earlier timing of the hand entry in relation to the underwater phase of the other hand in FC than in BC. SF in both FC and BC was significantly correlated with shoulder adduction isokinetic torque of the swimmers, however, the effect of shoulder isokinetic torque on the difference in swimming performance between FC and BC required further investigation. In conclusion, FC is faster than BC because swimmers can achieve higher SF in FC than in BC, and FC is more economical and efficient than in BC with indirect evidence that resistive force are greater in BC than in FC.

Formal long-term athlete development programmes emerged at the turn of the century and, despite some fierce criticisms, have evolved significantly since their inception. The first generation of athletes to grow up with these systems are now coming of age. The purpose of this thesis was to track a population of adolescent school-level swimmers between the ages of 12 and 18 years over an 8-year period so as to assess their performance progression as they matured under these athlete development programmes. The first study aimed to track the performances of the sub-elite athletes at an annual international school championship and to compare their progression with those of both junior elite and elite-level swimmers. In addition to narrowing the gender gap, the records of the sub-elite swimmers have continued to improve. In contrast, both of these factors remained relatively stable for junior elite and elite-level swimmers over the same period. Swimming affords athletes the possibility of within-sport specialisation. This almost unique aspect of swimming led to the two investigations of the second study. Firstly, the paired stroke combinations preferred by swimmers were determined using Cohen’s Kappa tests in a cross-sectional design. Secondly, the stability in the event selection of each swimmer during their adolescent years was explored longitudinally. Both males (33.9±5.8%) and females (36.9±6.5%) preferred to swim the 50 and 100 m freestyle events together over any other paired stroke combination. The majority of swimmers preferred to specialise in specific stroke techniques over distance specialisms with breaststroke being the only stroke in which swimmers of both sexes chose to specialise early. Most notable was that females specialised earlier than males. Studies three (males, n = 446) and four (females, n = 514) utilised mixed linear modelling to determine the quadratic functions of the performance progressions of adolescent swimmers (between the ages of 12 and 19 y) in seven individual competition events. Males progressed at more than twice the rate of females (3.5 and 1.7% per year, respectively) in all strokes over this age range. This was likely due to the fact that females reach puberty before males. Thresholds of peak performance occurred between the ages of 18.5±0.1 y (50 m freestyle and the 200 m individual medley) and 19.8±0.1 y (100 m butterfly) for males, but between the wider range of 16.8±0.2 y (200 m individual medley) and 20.6±0.1 y (100 m butterfly) for females. Using an independent sample of Dutch Junior national swimmers (n = 13), the fifth and final study aimed to evaluate the efficacy of the models developed in studies three and four as both target setting and talent identification tools. This was achieved through a mixed-methods approach where quantitative and qualitative data confirmed the applicability of the models for adolescent swimmers of any skill level. This thesis demonstrates that sub-elite swimmers have probably benefitted from first generation athlete development models. Longitudinal modelling of their data provides a valuable platform from which all adolescent swimmers can be compared and used to inform the next generation of bespoke swimming-specific youth development programmes.

In swimming, technical performance is a vital indicator of successful performance; however, during phases of high-intensity training, technique can be negatively influenced by fatigue. Advances in video technology have made it possible to increase coaches’ capacity to monitor athletes’ technical performances during training. Yet research examining the biomechanical responses that occur with fatigue using video methods, which are applicable and relevant to coaches during training, is scarce. The limited research to date that has examined the biomechanical responses that occur with fatigue has been restricted to examining fatigue during race-like situations and have used technology which is not available for use by coaches during training. Whilst this research indicates that changes occur during races, it does not apply to coaches for use during training. As fatigue, and its management, is a vital component of the training process, identifying a method of monitoring fatigue during training, which is applicable to coaches, is essential for athlete development. This research is therefore intended to address this by exploring the implications of 2-dimensional (2-D) video analysis in the management of fatigue, during training, by competitive swimming coaches. To explore this, this thesis comprises of four studies. The aim of the first study was to investigate whether 2-D video analysis methods currently used by coaches can measure data validly and reliably. To achieve this, the accuracy, precision, reliability and validity of thirty-five variables (thirty-four technical measures and swim time) were calculated using Dartfish Pro Suite motion analysis software, version 6.0 (Dartfish Ltd, Fribourg, Switzerland) and compared to the smallest worthwhile change. By calculating and comparing these measures, only those technical variables which can be measured with accuracy and precision could be determined objectively. A series of fifteen variables (fourteen technical measures and swim time) were found to be precise, valid and reliable when measured using Dartfish Pro Suite motion analysis software, version 6.0. Using the previously established technical measures, the aim of the second study was to assess if these measures can determine whether technical changes can occur during a high-intensity training session. To achieve this, a group of seventeen elite breaststroke swimmers completed a standard swim set. This involved repeating maximal effort 100m swims on a limited swim-rest time, designed to induce a fatigued state representative of high-intensity training conditions. To determine whether technical changes as a result of fatigue could be detected, the fourteen kinematic technique variables and swim time (fifteen dependent variables in total) were recorded and analysed using 2-D Dartfish Pro Suite motion analysis software, version 6.0 from video recordings of the first and last 100m swim of each swimmer. In addition, 95% confidence intervals were determined to investigate any commonalities or individual differences among swimmers in changes in technical parameters. It was found that during one high-intensity session, technical changes can occur in a group of elite swimmers. The largest changes were shown in leg glide duration (64.6%), swim time (33.2%), stroke rate (35.3%), stroke length (-29.2%), and average velocity (-10.2%) and were shown to have statistically significant (p < 0.05) differences between the first and last 25m of the swim set. These changes were also shown to be common amongst all swimmers and occurred early in the swim set. To evaluate coaches understanding of fatigue and its management during training, the aim of the third study was to assess coaches’ current practices and knowledge regarding fatigue during training. To achieve this, a questionnaire was distributed to over 370 coaches throughout the UK. The questionnaire was separated into multiple sections which assessed: coaches’ current understanding of the topic of fatigue; the methods coaches’ employ to monitor fatigue during a training session; and the processes used to manage fatigue during the training process. It was found that up to 98% of the coaches consider fatigue, its effect and management important in the development of their swimmers. Despite this, there is a lack of consistency in knowledge and methods used by coaches to monitor this. As a result, coaches are continuing to use traditional methods to monitor their athletes which are quick and reliable, specifically stopwatches (100%) and visual observation (98%). Due to the predominant use of visual observation to monitor fatigue, and the identification of technical changes with fatigue, the aim of the fourth study was to assess whether coaches could visually identify changes in the previously established technical markers and whether this could be improved through education of fatigue and video analysis methods. To achieve this, two groups of ten competitive swimming coaches observed a series of videos of three swimmers taken pre- and post- training, and were asked to identify any technical factors which they perceived to change. One group underwent an intervention using Dartfish Pro Suite motion analysis software, version 6.0 and underwater analysis to assess whether this improved their ability to visually observe fatigue in elite swimmers. The remaining group of coaches acted as a control group and received no feedback. Following the one hour intervention, the coaches’ observations slightly improved, however this improvement was not statistically significant (p > 0.05) nor retained after 4 weeks. Although the coaches’ perceptions of fatigue during training varied, they did show a keen interest in further training and education on fatigue and 2-D video analysis. The results from this research indicate that 2-D video analysis is an effective and useful tool, which has practical applications: in monitoring fatigue during a training session; guiding training programmes to maximise training potential; and developing coaches’ identification and management of fatigue during training through education programmes.

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.

L’objectif de ce travail est de caractériser la dynamique des coordinations de nageurs experts en fonction de la manipulation de contraintes de tâche (vitesse de nage) et d’environnement (écoulement). Les coordinations intra- et inter-membre (bras vs. bras et bras vs. jambes) sont déterminées à l’aide de centrales inertielles positionnées sur des nageurs experts, réalisant deux tâches de scanning dans une piscine et un bassin à contre-courant. Nous caractérisons l’effet de l’environnement en comparant la coordination intra-bras à la même vitesse de nage dans les deux bassins, puis la dynamique de cette même coordination et de la coordination bras vs. bras lors d’une tâche impliquant huit vitesses. Finalement, la dynamique des coordinations bras vs. jambes est analysée, tout comme l’asymétrie droite/gauche.Nos résultats montrent que le flume canalise l’émergence de comportements fonctionnels, en particulier en faisant décroître la durée de la phase de glisse du fait de l’écoulement dynamique de la masse d’eau. L’augmentation de la vitesse de nage montre de plus larges implications des jambes dans la propulsion. La nage dans le flume conduit à une force de couplage plus faible entre les bras et les jambes et de plus larges asymétries droite/gauche. Les nageurs experts sont donc capables d’adapter leurs coordinations intra- et inter-segmentaires et peuvent transiter entre différents patrons en fonction des contraintes auxquelles ils font face. Ainsi, des périodes de stabilité sont couplées avec des périodes de flexibilité comportementales, exemplifiant leur habileté pour réaliser le but de la tâche en interagissant fonctionnellement avec l’environnement aquatique. / The aim of this thesis is to investigate the coordination dynamics of expert swimmers as a function of both task (swimming speed) and environmental (fluid flow) constraints manipulation. The intra - and inter-segmental coordination (arms vs. arms and arms vs. legs) are assessed by inertial measurement units positioned on expert swimmers swimming two separated scanning tasks in a flume and in a pool. We investigate the effect of aquatic flow by comparing the upper limb coordination when the swimmers swim at a similar speed in pool and flume, then, the upper limb coordination dynamics during a scanning procedure where speed is increased through eight steps. Finally, the arms vs. legs coordination dynamics and the right/left asymmetry were analyzed.Our findings demonstrate that flume is channeling the emergence of functional expert swimmers’ movement patterns, in particular the decrease of glide phase duration related to the moving body of water. The increase of speed reveals larger implications of the lower limbs in the propulsion. Flume swimming leads to lower coupling strength between oscillators and higher asymmetries in the flume. Our findings thus demonstrated that experts are able to adapt their coordination patterns at different levels (intra-segmental of the upper limbs / inter-limb i.e., arms vs. legs) and by transiting between different patterns according to the constraints encountered. Thus swimmers exhibit both periods of behavioral stability and periods of adaptive flexibility, showing their ability to achieve the task-goal by functional interaction with the aquatic environment.