Methodological Implications

10.2.1 Novel Methodology

This thesis utilised a number of data collection methods novel to swimming biomechanics. The first was the use of a multi-disciplinary approach to researching the swimming start. The combined biomechanical and performance analysis study design utilised in Section 1 was useful in guiding subsequent research methods within this thesis. The statistical analysis approach used in Chapter 4 and 5 was useful in highlighting critical factors of start performance that were not previously available or traditionally reported using solely competition analysis without the use of specialised equipment such as the Wetplate Analysis System. Furthermore, using performance analysis in the form of statistical analysis alone would not have provided information regarding the underlying mechanisms and process that underpin how the key parameters of the underwater phase affect overall start performance. Hence, more detailed biomechanical analysis was conducted in Sections 2 and 3 to support the findings in Section 1. By using a multi-disciplinary approach key parameters of the underwater phase were able to be identified and explored in detail. The multi-disciplinary approach used in this thesis is not limited to only the swimming start; comprehensive analysis should be done on all skills where elite data is available to provide a more targeted approach to biomechanics servicing.

The second novel technique utilised in this thesis was the separate measurement of wave drag using human swimmers, as opposed to estimating wave drag based on total drag measurements. Chapter 8 used a dynamometer to tow swimmers at various controlled speeds and depths, while acoustic sensors were mounted 0.9 m above the surface of the water to measure wave drag. Towing swimmers through the water in the streamlined position is a common method of measuring passive drag. However, there have been conflicting results reported in previous literature, due to the variances in towing techniques and depth control, making comparison

159 difficult. The towing method used in Chapter 8 utilised minimal equipment in order to ensure the flow around the swimmer was disrupted as little as possible while they travelled through the water. Furthermore, Chapter 8 was able to extend on the earlier work of Vennell et al. (2006), Pease (2010), Pease (2013), Pease and Vennell (2011) who suspended mannequins face up in a flume. This thesis was the first to directly approximate wave drag using human swimmers in the face-down position using acoustic sensors and the LWC method. Toussaint (2006) and Lyttle et al. (1998) have previously measured wave drag using human swimmers, however their methods were based on estimations of total drag. The use of 3D laser scans, acoustic sensors and the LWC method of calculating wave drag in this thesis demonstrated an effective method of wave drag estimation. This method can now be used in the future to further extend on the findings from Chapter 8.

10.2.2 Individual vs Group-Based Analysis

It is important to understand the difference between individual and group-based analysis as choosing the suitable research approach should be based on the available resources and study outcomes (Kinugasa, 2013). This thesis highlighted the importance of considering both approaches or using a combination of both. Chapter 4, 5, 7 and 8 used a group-based analysis, while Chapter 3, 6 and 9 utilised an individual approach. Traditionally swimming start biomechanics studies used a group-based approach and looked for significant statistical differences to answer research problems (Blanksby et al., 2002; Burkett et al., 2010; Cossor & Mason, 2001; Honda et al., 2010; Houel et al., 2012; Lyttle, Blanksby, et al., 1999; Thow et al., 2012). However, particularly when working with elite performers, the group-based approach may not be appropriate for all situations (Kinugasa, 2013).

160 There are a number of issues associated with choosing the correct analysis technique (Ball & Best, 2012). Firstly, group-based analysis can mask significant performance factors. For example, the group-based performance analysis study design used in Chapter 5 did not account for each individual’s strengths and weaknesses. The results were useful in characterising elite start performance, although the results may not apply to all individuals or swimmers who are below the elite standard. Secondly, individual-based analysis can provide important information to coaches in regards to the athlete’s movement pattern. The individual approach used in Chapter 9 was useful in identifying one aspect of each swimmer’s underwater trajectory for a more targeted approach to performance improvement. Finally, some researchers believe, that most clinical approaches are individual, particularly in clinical biomechanics. In an elite sport setting Ball and Best (2012) found that individual analysis was able to uncover significant individual specific results that were not identified using group-based analysis of the golf swing. Hence, group-based analysis for all circumstances may not be appropriate.

This thesis provided strong evidence supporting the use of both group and individual based analysis. In this thesis a group-based approach was used to identify key performance indicators before an individual-approach was used to conduct more specific analysis on technique changes with elite athletes. For example, in Chapter 4 and 5 a group-based approach was used to conduct performance analysis on a large number of elite start performances. By using this approach, standards established and insight into elite performance was critically analysed for the future benefit of coaches. Group-based analysis was also used in Chapter 7 to generalise results for a larger population and Chapter 8 to encompass a larger range of body types. Adopting this approach for these particular studies was valid to meet the desired outcomes of the studies. Individual-based analysis was used in Chapter 6 to highlight the use of a comparative study design and to demonstrate that elite athletes are able to readily change their

161 technique with little practice. Individual-based analysis was also used in Chapter 9 to account for the individual variances in start performance (i.e. different swimmers would be deficient in different areas), especially at the elite level. Further, due to low numbers an individual approach was used for analysis and determination of each subject’s intervention. Grouping results in this situation may have returned incorrect findings.

Overall, there have been arguments for and against using both of these analysis methods in the past. A combination of group and individual based analysis, like the approaches used in this thesis was affective in extracting all information and would assist to enhance coaches and sport scientists’ understanding of the practical issues in applied sport science.