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Variabiliteit van oppervlakte electromyografie tijdens crawlzwemmen

By Jonas Martens


1. Introduction and backgroundSwimming is one of the most popular forms of physical activity for persons with a disability as it has important advantages for this population. For some, activity in water has a therapeutic or recreational goal. Others choose to move further to a competitive level. Competition for persons with loco-motor disabilities is organized under a functional classification system in which swimmers with various impairments compete against one anotherin one of 10 classes. The purpose of classification is to minimise the impact of impairment on the outcome of competition, so that athletes whosucceed in competition are those with best anthropometry, physiology and psychology and who have enhanced them to best effect. The vast majority of studies in Paralympic swimming have been related to classification. As Paralympic swimming matured, researchers concluded that the current functional classification system is fair, especially in sprint freestyle events. These conclusions however, are based on studies of end race results only (or derivates of end results). Furthermore, although the functional classification system combines dry land musculoskeletal assessment with a point system, the final decision is taken after a water based assessment depending largely on expert opinion. To address this issue, the International Paralympic Committee has begun a research project tofurther develop valid and reliable swimming specific measures of the impact of impairment on Paralympic swimming.The first study in this project aims to follow up on previous research. In the second and third study, two swimspecific measures will be examined.1. Swim speed is the resultant of propulsion and drag forces. If the purpose of classification is to estimate potential performance from a series of uncomplicated tests, the measurement of passive drag couldbe of interest. This test is a standardized method of measurement in which little skill is involved but where deliberate misrepresentation is possible and must be dealt with. 2. EMG measurements have been used for many years in competitive swimming to describe swimming technique, fatigue and causes of injuries. Differences in muscle activity could distinguish between Paralympic and Able bodied swimmers and even between classes. Muscle recruitment could also be used as a control measure during passive drag testing to counter deliberate misrepresentation.2. General hypothesis and specific aims General hypothesis : EMG can be used as a control measure during passive drag testing.As stated above, the measurement of passive drag is a potential valid and reliable measure for classification. A swimmer can alter his/her passive drag by activating certain muscles. In a classification setting, this could be considered as deliberate misrepresentation and must be countered. EMG can be used to ascertain the swimmer is passive (relaxed) during the test. Step 1No type of impairment dominates the opportunity towin a medal, or advance to the finals within the current functional classification system in freestyle events.If this hypothesis is rejected, the “fairness” of the current classification system can be questioned and the search for a new method of classification, not only based on expert opinion, but also on valid and reliable swimming specific measures, is justified.The second aim of this study is to follow up on the study of Wu & Williams, by including statistics from the last 3 Paralympic Games.The third aim of this study is to define the distribution of the most prominent impairment groups in each functional class to determine participant inclusion in study 3.Step 2There is no difference in muscle activity during front crawl swimming between single arm amputee S9 swimmers and single leg amputee S9swimmers.The aims of this study are to: 1. confirm whether the wireless EMG equipment is valid and reliable when compared to standardized (wired) EMG equipment during dry land EMG tests. 2.verify whether there is a different muscle recruitment pattern in swimming specific muscles between 2 impairment groups competing in the same functional class.Step 3EMG cannot detect differences in muscle activity during passive drag testing between a relaxed swimmerand a “cheating” swimmer in different impairment groups.The aims of this step are to:- examine the relation between physical impairment and the drag force in water during passive towing in a sample of elite competitors with loco-motor disabilities.- examine the potential of EMG being used as a control measure during passive drag testing. 3. ConclusionThe end point of the PhD is to provide the International Paralympic Committee with knowledge and tools to develop an improved classification system for swimmers with motor disabilities no longer only relying on expert opinion, but on evidence based swimming specific functional measures such as passive drag and muscle activity.nrpages: 144status: publishe

Year: 2016
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Provided by: Lirias
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