Copyright 2017 National Institute of Education, Nanyang Technological University

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1 Author Title Source Institute Supervisor(s) Nur Halimah Mohamed Ramlee Seating arrangement of K2 Sprint Kayak Dean s Commendation for Undergraduate Educational Research Papers: Educational Research AY2015/2016 National Institute of Education, Nanyang Technological University Kong, Veni Pui Wah Copyright 2017 National Institute of Education, Nanyang Technological University This document may be used for private study or research purpose only. This document or any part of it may not be duplicated and/or distributed without permission of the copyright owner. The Singapore Copyright Act applies to the use of this document. Citation: Nur Halimah Mohamed Ramlee. (2017). Seating arrangement of K2 Sprint Kayak. Unpublished manuscript, National Institute of Education, Nanyang Technological University, Singapore.

2 209 Seating Arrangement of K2 Sprint Kayak Nur Halimah Binte Mohamed Ramlee National Institute of Education, Nanyang Technological University, Singapore Supervisor: Pui Wah Kong Physical Education and Sports Science Academic Group Abstract: With the aim of forming a guideline on the optimal seating arrangement in a two-seater sprint kayak, this study compared the performance of K2 kayak crews when they were seated in their regular seating arrangement and when their seating positions were switched with each other. The performance of the K2 kayak crews was compared based on the time taken to complete a 200m trial, average power, and average acceleration. Data collection was done with an action camera, two power meter paddles, and a mobile accelerometer app. This study was on four female two-seater crews from tertiary institution teams. Results showed that when the more experienced and heavier paddler takes the back seat, a faster time is taken to complete a 200m trial. Hence, this study recommends that the heavier and more experienced paddler should be seated at the back of a K2 two-seater sprint kayak. Keywords: Acceleration, power, seating arrangement, K2 1. INTRODUCTION Kayak sprint has been a discipline of Canoe Sprint since In this discipline, the two-seater K2 sprint kayak makes up the smallest crew-boat unit. Both members of this boat unit use a double-bladed paddle. Due to the proximity of the front and back seats of a kayak, a kayak crew requires stroke synchronization to avoid hitting each other's paddles as well as to propel the boat forward. Within this Canoe Sprint discipline, there is some general consensus on the seating order for a two-seater sprint kayak, such as seating according to the kayaker's overall paddling experience, their body weight and at times, personal preference. In terms of paddling experience, the more experienced paddler would take the back seat as that seating position holds the most capacity to propel and steer the overall kayak (Hotley, 2012: Renee, 2015; Nasreem, 2016). In terms of body weight, the lighter person would take the front seat (Hotley, 2012; Renee, 2015; Nasreem, 2016). This arrangement is partly due to certain kayak s structural inability to support large weight at its bow (Nasreem, 2016). Hence, the arrangement to have the smaller and lighter person seated in front is widely accepted and practiced as a general rule of thumb. Although the above consensus on the seating arrangement of a double-seater kayak is widely accepted in this sports discipline, no published literature can be found on them Literature Review This portion of the paper will borrow certain concepts from published literature written on dragon boating and rowing as kayak sprint is a relatively less researched sports discipline. Moreover, these two sports are similar to K2 sprint racing as they involve crew boat racing. There are a few studies that suggested that different seating positions in a crew-boat impose different bodily requirements on the paddlers (Zandi, Rajabi, & Tavanaei, 2010; Neville, Molloy, Brooks, Speedy, & Atkinson, 2006). According to Zandi et al. (2010), the seating position of dragon boat rowers imposes certain bodily requirements and in turn, significantly influences the rowers' tendency of sustaining an injury. It is found that regardless of gender, rowers seated in the front three rows of the dragon boat, in particular, is prone to sustain an injury as compared to middle and back rowers (Zandi et al., 2010). With reference to Powel (2009), turbulent water flow is identified as one of the environmental factors that increase paddlers tendency to

3 210 sustain an injury as it increases the amount of pressure exerted on paddlers. Hence as deduced by Zandi et al. (2010), front row paddlers are more susceptible to injuries as these paddlers inevitability has to withstand more pressure when paddling turbulent or stagnant water, unlike back row paddlers who would be paddling in a steady backward flow water. Thus, from the above studies, one can infer that in a K2 kayak, the seating arrangement would impose different requirement on the paddler. Hence, it also suggests that the front paddler in a K2 would have to assert more pressure and force while paddling. In addition, it was also reported that the seating position in a rowing 8 influences the paddling synchronization of a crew. A study by Wing, Allison, Cooper, and Thompson (1992) had reported that the positive correlation between the members of a crew of rowing 8 and their interstroke interval is influenced by their seating position (as cited in Wing & Woodburn, 1995, p.188). Their study had found that the paddlers seated on the same but non-adjacent side has a more positive correlation as compared to paddlers who sat on the alternate side of the rowing 8 boat (as cited in Wing & Woodburn, 1995, p.188). Hence, this study suggests that the seating arrangement in a crew boat does influence the synchronization of the crew and in turn influence their overall paddling performance Purpose The purpose of this study was to identify the implication of the seating arrangement of a two-seater K2 sprint kayak on the paddling performance of a crew. This was done by having K2 kayak sprint crews paddle 200m trials twice in different seating arrangements. Paddling performance of each crew was compared and analysed in terms of (a) time taken to complete each 200m trial, (b) average power and (c) average acceleration. Findings from this study would then be used towards forming a clear guideline on the seating arrangement of a two-seater K2 sprint kayak that can be used by teachers and coaches of school kayaking teams to ensure their student's optimal performance Hypothesis This paper hypothesized that the ideal seating arrangement was that the heavier paddler should take the back seat of the K2 sprint kayak. A quantitative study was conducted on four female twoseater sprint kayak crew. All of the participants were members of tertiary institution kayak team at the point of this study. The participants aged years and weighed kg. In terms of experience with the twoseater kayak sprint, there was one New crew (Crew 1) and three Season crews (Crew 2, 3 and 4). The New crew had not competed in any K2 sprint kayak category while the remaining crews had either competed in an international kayak competition held at Putrajaya or in Polytechnic-Institute of Technical Education (ITE) competitions. In addition, all of these crews paddle in different weighing kayaks that meet the competition weight limit of 18.0 kg (refer to Table 1 for more information on paddler details). Crew no Age (yrs) 2.2. Equipment Experience with K2 partner This study seeks to compare the performance of K2 sprint kayak crews in terms of time taken to complete the 200m trials, average power, and average acceleration Action Camera Table 1: Participants Details Seating position in K2* Height (m) Weight (kg) Paddling experience (yrs) 23 A New 25 B A Season 20 B A Season 20 B A Season 22 B *A: Front seat, B: Back seat. **Bolded: Taller, heavier, or more experienced An action camera was attached to the back of the K2 kayak sprint (refer to Fig. 1). During each trial, the camera would record the landscape that the K2 kayak crew had paddled by. By recording the landscape of the trial, the actual start and finishing timing of each trial could be determined by watching the video. This method would reduce the likelihood of human error, which would occur if a stopwatch was manually used to measure the time taken to complete the trial. 2. METHODS 2.1. Participants

4 211 such that the X, Y and Z axis corresponds as left-right, front-back and up-down respectively. In addition, the tri-axial acceleration data measured by this app can be saved in CSV format and transferred to a computer through . Fig. 1: K2 kayak set-up Kayak Power Meter Both members of the K2 kayak crew used the Kayak Power Meter paddle instead of their personal ones. It was used to measure and record each paddler s power. Created by One Giant Leap, it is an adjustable and instrumented carbon-fiber kayak shaft. Its length and blade angle is adjustable. Hence, making it possible to adjust the Kayak Power Meter paddle to mimic the dimensions of a paddler s personal paddle. Thus, contributing to a more accurate measurement of the paddler s performance during data collection. Fig. 2: One Giant Leap s Kayak Power Meter In addition, the Kayak Power Meter paddle has multiple built-in force and motion sensors, which are capable of measuring and recording the paddler s direct power output. The recorded power output can be transferred onto a laptop using a USB cable as well as One Giant Leap Windows Desktop App. The later app is a necessary software counterpart to set-up the Kayak Power Meter prior to a trial as well as to transfer the recorded power data after the trial (refer to 2.3 for more details.) 2.3. Procedure Fig. 3: Accelerometer software display Trials were arranged with each K2 kayak crew separately. Prior to the trials, each participant had their (i) height, (ii) weight, (iii) blade tip to top hand distance, and (iv) blade tip to bottom hand distance measured. The initial two is required to determine the criteria used to arrange the seating arrangement in a K2 kayak crew. The latter two measurements are required by the One Giant Leap Window's Desktop App before the Kayak Power Meter can be used (refer to Fig. 4) Accelerometer Sensor Kinetics Pro, a kinetic sensor app, was downloaded onto a mobile phone and attached on the back of the K2 sprint kayak (refer to Fig.1). This app was chosen as a tri-axial accelerometer is one of the many kinetic sensors that the app supports. It is able to measure and record the acceleration of the K2 sprint kayak crew in three dimensions: X, Y, and Z (refer to Fig. 3). During the trial, the accelerometer is placed Fig. 4: Part of One Giant Leap Window s Desktop software The latter two measurements, blade tip to top hand distance, and blade tip to bottom hand distance, were also used to adjust the actual Kayak Power Meter paddle according to each paddler s preferred paddle dimensions.

5 212 Two 200m trials were conducted with each crew. Both members of the K2 crew kayak crew used the Kayak Power Meter paddle. Both of these paddles were calibrated to synchronise with each other prior to the trial. During the first trial, the K2 kayak crew would paddle in their usual seating position. In this paper, the paddler seated in the front seat is referred as A, while the paddler seated at the back seat is referred as B. Hence, the acronym AB will be used to refer to the crew s usual seating arrangement (refer to Fig. 5). corresponding average power and acceleration to determine the factors that contributed to a faster finishing time. Comparisons were also be made within each crew well as across different crew. This was to determine if there were any other trends that could be perceived Power Analysis of power measurements was done to obtain the average power. Firstly, the measurements recorded by the Kayak Power Meter paddle was uploaded onto One Giant Leap: Analysis App. The Analysis App would then generate graphs with the uploaded data (refer to Fig. 6). Fig. 5: AB seating position During the second trial, the front and back paddlers would switch their seating positions with each other. Hence, the acronym BA will be used to refer to the trial where the paddlers switched their seating arrangement with each other. Before the start of each trial, a mobile app accelerometer and a camera were attached to the back of the boat. Both of these devices were placed on Recording' mode at the start of each trial. At the end of each trial, the various recorded data were transferred onto a computer for analysis Analysis The various gathered data were first analysed according to crew, in the following sequence; (i) data gathered in their regular K2 crew seating position (AB), followed by (ii) data gathered in the switched seating position (BA). After which, the analysed AB and BA data were compared with each other Time taken to complete the 200m trials The time taken by each crew to complete the trials acted as the basis to determine which seating position in a K2 sprint kayak would result in the most optimal paddling performance. As mentioned above, each crew had two trials, one in the regular (AB) and another in the switched (BA) seating position. For each crew, the trial with the fastest finishing time was identified first. From there, comparisons and inferences were made on its Fig. 6: Software Display of One Giant Leap s Analysis of paddle power was done by first identifying the period with the highest peak. For example, in Fig. 6, the period with the highest peak would be within s. Within this period, ten consecutive strokes were then selected. For each stroke, the highest and lowest peak value for power were identified to calculate its absolute difference. The absolute difference for ten strokes was then averaged out to obtain the average peak power. These sequences were repeated for all crews in both AB and BA seating arrangement Acceleration Similarly, for acceleration, the analysis was done to obtain average acceleration. Acceleration data was transferred onto Excel scatter graph and analysis was done in the same period that was selected for power analysis. For example, for Crew 1, AB seating position, the power analysis was done on s. Thus, the same period was selected for acceleration analysis. This was to obtain a corresponding power-acceleration analysis. After the same power analysis period was identified on the acceleration data, ten highest peaks for X, Y and Z axis was selected. For each highest peak point, its corresponding lowest point was identified. Once ten highest peak points were identified, these were

6 213 averaged out and labelled as average maxima. Similarly, its corresponding lowest points were averaged out and labelled as average minima. With these average maxima and minima calculated, the average absolute peak difference for acceleration was obtained. 3. RESULTS Before identifying which seating arrangement (regular: AB or switched: BA) had a faster finishing time, the participants details was studied first. This was to determine how each K2 crew arrange themselves in the usual training setting. These would also be used to infer the implications a K2 crew s seating arrangement has on their paddling performance. From Table 1 (refer to 2.1), one can identify that the seating arrangement in a K2 sprint kayak was determined in the following sequence of importance: paddling experience, weight and lastly, height. In Crew 2 and 4, paddlers at the back seat (B) have more experience, mass, and taller height. For Crew 3, both paddlers have the same years of experience and the heavier paddler takes the back seat. Interestingly for Crew 1, although the back paddler (B) is (slightly) lighter and shorter than the front paddler (A), B takes the back seat as she is the more experienced paddler. Thus, from the above, the common characteristics of the paddler seated at the back (B) are: they are more experienced and have more mass. From Table 2, one can identify that with the exception of Crew 1, the remaining crews had a faster finishing time when they paddled in the regular (AB) seating positions. In terms of power, Crew 1 and 2, had the highest average power when they were seated in the switched up (BA) seating position. Crew 3 and 4 had the highest average power when they were seated in the regular (AB) seating position. In terms of acceleration, the trial where Crew 1 and 2 had the least average peak difference resulted in a faster finishing time. For Crew 1, this occurred while they were in the switched up (BA) seating position. For Crew 2, this occurred while they were in their regular (AB) seating position. The acceleration trend differed for the remaining crews. For Crew 3 and 4, the trial that had the most average peak difference resulted in a faster finishing time. For both crews, this occurred while they were in their regular seating (AB) seating position. Table 2: Summary of all data Time taken to complete trial, average power, and average acceleration Crew 1 AB BA Crew 3 AB BA Time taken (s) Time taken (s) power power *Acceleration (m/s 2 ) minima peak difference X Y Z X Y Z maxima minima peak difference Crew 2 AB BA Crew 4 AB BA Time taken (s) Time taken (s) power power X Y Z X Y Z *Acceleration maxima (m/s 2 ) *Acceleration (m/s 2 ) X Y Z X Y Z *Acceleration maxima (m/s 2 ) minima peak difference X Y Z X Y Z maxima minima peak difference *A tri-axial accelerometer was used. X: left right, Y: font back, Z: up down. **Bolded: Heavier or higher power acceleration

7 DISCUSSION The purpose of this paper was to form a guideline for the seating arrangement in a K2 sprint kayak crew. This was done by looking at the crews seating arrangement in each trial and infer the implications of the seating arrangement on the crew s performance. Each kayak crews performance was compared in terms of time taken to finish the trial, average power, and average acceleration. The results indicated that when the heavier paddler was seated at the back of the K2 sprint kayak, that trial would result in a faster time taken to finish the trial. In addition, with the exception of one crew (Crew 2), this seating arrangement (the heavier paddler seated at the back) would also result in a higher average power. Another study had proposed that a paddler with heavy mass would cause the kayak to sit further in the water and expand the kayak s wetted area (Michael, Rooney, & Smith, 2008). This expanded wetted area would increase the wave and frictional drag that the paddler has to overcome in order to propel the boat forward (Michael et al., 2008). Thus, this study supported that increasing the wetted area at the back of the K2 sprint kayak rather than the front, would result in higher power production and faster finishing time. Interestingly, when the back paddler is heavier and less experienced, it also resulted in a faster finishing time. With reference to Crew 1, their regular (AB) seating position is that the less experienced and heavier paddler would take the front seat and the more experienced and lighter paddler would take the back seat. When this crew switched their seating position (BA) during the second trial, the paddler who is heavier and less experienced sat at the back. This trial, however, resulted in a faster finishing time, with a difference of -2.1s. The above occurrence can be explained by a claim made by Paddler A in Crew 1, the lighter and more experienced paddler. She had mentioned that when her seating position was switched from back to front, she was able to exert more force. Her claim was also supported by her individual average power measurements during the two trials. Her average power measurements while she was seated at the back, was indeed greater as compared to when she was seated in front (refer to Appendix A). However, at this point in time, it is unclear whether placing a heavier paddler at the back seat of a K2 regardless of experience will result in a better paddling performance. This finding was only reflected for one crew (Crew 1) in this study. For the remaining crews, the paddlers who took up the back seat were both heavier and have more years of paddling experience. Moreover, one also has to be aware that the 200m trials were also carried out in a calm, man-made water catchment area where less predictable environmental conditions such as tidal waves were eliminated. Hence, a further study is needed to find out whether the back paddler of a K2 sprint kayak should be selected based entirely on body weight, regardless of the paddler s experience level. For acceleration, the results gathered through the methodology used in this study showed no clear trends. No clear discernable patterns can be inferred from the results by comparing the crews finishing time, average power and average acceleration. 5. CONCLUSION 5.1. Recommendation for K2 seating arrangement for coach and P.E teacher In conclusion, this study recommends that the heavier and more experienced paddler should occupy the back seat of the K2 sprint kayak. This seating arrangement would result in a better performance in the K2 sprint kayak. The results of this study also suggests that in the instance where a K2 crew has a heavier and less experienced paddler, there is a possibility that placing such paddler in the back seat would result in a faster finishing time. This suggestion, however, requires more study to confirm its validity Limitation of study/ Follow- up of study This study has a small sample size of four female kayak crew. A small sample size will inevitably result in limited inferences as it is unclear whether a particular finding was legitimate or coincidental. Hence, a similar study can be conducted with a bigger sample size in order to find clear and legitimate trends. Future studies may also include male K2 crews. In addition, for this study, each crew is subjected to two trials with a short 5-10 minutes break in between. This may lead to less accurate measurements for the second trial as there is a possibility that the paddlers may be physically drained from the first trial. Hence, for further studies, the different trial can be conducted on different days. 6. ACKNOWLEDGEMENT

8 215 I would like to thank Associate Professor Kong Pui Wah and Cheryl Sihui Tay for their kind and insightful guidance. I would also like to thank the Canoe/Kayak Sprint team from the National University of Singapore, Singapore Institute of Technology, Singapore Polytechnic and Temasek Polytechnic for participating in this study. 7. REFERENCES Allison (2016). Where is the best place to sit in a tandem kayak? Retrieved from Neville, V. J., Molloy, J., Brooks, J. H., Speedy, D. B. & Atkinson, G. (2006). Epidemiology of injuries and illnesses in America s Cup yacht racing. British Journal of Sports Medicine, 40, doi: /bjsm Hotley, T. (2012). Kayak instructional article. Retrieved from Michael, S., Rooney, K., Smith, R. (2008). The metabolic demands of kayaking: A Review. Journal of Sports Sciences and Medicine, 7, 1-7. Retrieved from Nasreen, S. (2016). How to tandem paddle a kayak. Retrieved from how_3140_tandem-paddle-kayak.html Powel, C. (2009). Injuries and medical conditions among kayakers paddling in the sea environment. Wilderness and Environmental Medicine, 20, Renee, J. (2015). How to row a tandem kayak. Retrieved from article/ comparison-of-rowing-kayaking-forexercise/ Wing, A. M. & Woodburn, C. (1995). The coordination and consistency of rowers in a racing eight. Journal of Sports Sciences, 13, doi: / Zandi, S. H., Rajabi, R., & Tavanaei, A. (2010). Are gender, position in boat and training load associated with the injuries in elite dragon boat paddlers? World Journal of Sports Sciences, 3, Retrieved from

9 216 Appendix A: power (Values of each consecutive stroke) This appendix is a breakdown on how average power was calculated. As mentioned in the write-up, ten consecutive strokes were from the highest peak period. Below lists down the measurement of each stroke (left and right stroke) that was used to obtain average power. Crew 1 *A *B B A 10: : : : : : : : : : Crew 2 *A *B B A 5: : : : : : : : : : Crew 3 *A *B B A 5: : : : : : : : : : Crew 4 *A *B B A 5: : : : : : : : : : * A: Font paddler in regular seating arrangement, B: Back paddler in regular seating arrangement