Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Original article 5 ABSTRACT Swim coaches conduct the technique analysis themselves, through observation and qualitative assessment. The latter is based on their own knowledge and experience. They have to identify the technique mistakes and assess them in terms of their impact on the swimmer's performance. Recognizing this, there is a clear need for an assessment tool which can help swimming instructors and coaches in their work with swimmers of different quality levels. The study aimed to first develop and then validate a tool for the front crawl technique assessment (FCTA). Twenty-one experienced swimming instructors and coaches evaluated 48 mistakes most common in the front crawl for their impact on swimming performance. Based on their perceptions, we developed the FCTA tool. By using the FCTA, we numerically evaluated the mistakes that occurred during participants’ maximal 50-meter front crawl test. We found a strong correlation between both the times achieved and amounts of numerically evaluated mistakes made by the participants in the swim test. These results indicated that the FCTA could be a valid tool to effectively assess the technical skills of intermediate and advanced level swimmers in front crawl. However, this was a pilot study, so all conclusions are preliminary and require further research. Keywords: swimming, teaching, qualitative technique assessment 1University of Ljubljana, Faculty of Sport, Ljubljana, Slovenia 2Primary School Branik, Branik, Slovenia 3Institute for market and media research Mediana, Sigmund Freud University, Ljubljana, Slovenia IZVLEČEK Plavalni učitelji in trenerji z opazovanjem in kvalitativno oceno analizirajo plavanje učenca. Prepoznati morajo tehnične napake in jih oceniti glede na vpliv na plavalčevo uspešnost. Pri tem sledijo lastnemu znanju in izkušnjam. Ker pa tega običajno ni dovolj, smo z raziskavo želeli ovrednotiti napake pri kravlu, izdelati mersko lestvico za preverjanje znanja plavanja (FCTA) in preveriti njeno uporabnost. Enaindvajset izkušenih učiteljev in trenerjev plavanja je ocenilo 48 napak, ki se najpogosteje pojavljajo pri kravlu. Ocenili so jih glede na njihov vpliv na plavalčevo uspešnost, od tistih z najmanjšim, do tistih z največjim vplivom. Tako smo izdelali FCTA. Z uporabo FCTA smo nato številčno ovrednotili napake, ki so se pojavile pri plavanju 50 metrov kravl maksimalno. Ta test je plavalo dvesto šestintrideset preiskovancev, kandidatov za vpis na študij fakultete za šport. Ugotovili smo močno povezanost med doseženimi časi in vsoto številčno ocenjenih napak, ki so jih preiskovanci naredili v plavalnem testu. Ti rezultati so pokazali, da bi FCTA lahko bilo veljavno orodje za učinkovito ocenjevanje tehničnih znanja kravla pri srednje dobrih in dobrih plavalcih. Vendar je bila to le pilotna študija, zato so vsi sklepi preliminarni in zahtevajo nadaljnje raziskave. Ključne besede: plavanje, poučevanje, kvalitativna ocean plavalne tehnike 4Primary School Šmarje – Sap, Šmarje – Sap, Slovenia Corresponding author*: Jernej Kapus, University of Ljubljana, Faculty of Sport Gortanova 22, 1000 Ljubljana, Slovenia E-mail: jernej.kapus@fsp.uni-lj.si Jernej Kapus 1,* Januša Stibilj 2 Katarina Košmrlj 3 Jure Virag 4 DEVELOPMENT AND VALIDITY OF THE FRONT CRAWL TECHNIQUE ASSESSMENT TOOL: A PILOT STUDY RAZVOJ IN VELJAVNOST MERSKE LESTVICE ZA OCENJEVANJE KRAVLA: PILOTSKA RAZISKAVA Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 6 INTRODUCTION Competitive swimming is based on times achieved in a swim distance. Therefore, quantitative analyses are the most widely used method of analysis by swim coaches. Besides measuring swim times, the relevant data are usually obtained by measuring stroke rate, stroke length, stroke index, index of coordination as well as breathing frequency. Moreover, the methods of quantitative analysis could also involve video-based techniques from which kinematics and kinetics can be derived from direct measurements of velocity and force by using various velocities and forces transducing devices (Sanders et al., 2006). However, in some cases a quantitative approach could not reflect the progress in the athlete's swimming technique. Indeed, the primary tools available to coaches are their observation and perceptions (Coleman 1998; Hynes, O'Grady, & O'Hare, 2013) which are qualitative by nature. The need for feedback on a technique is vitally important for learning future performances (Maslovat, & Franks 2008). Commonly, coaches conduct the technique analysis by themselves, through observation and qualitative assessment using the naked eye and video playback (Lees, 2002; Wilson, 2008). A key advantage of this is low cost and ease of implementation with large numbers of athletes (Mooney et al., 2016). Qualitative analysis in swimming comes associated with the detection and analysis of the technical mistakes (Campaniço and Silva, 1998). Technical mistakes are considered as deviations from the most efficient model of performance for given motor skill (Reischle, 1993). In swimming, the technical mistake: (i) decreases the subject’s propulsive capacity; (ii) increases drag forces; (iii) or a combination of these two factors (Barbosa et al., 2013). Since swimming velocity and efficiency are the result of the combination of propulsion versus drag, mistakes analysis (observation, identification, and intervention) is a critical factor for a higher quality of the teaching-learning process (Barbosa, 2005). Qualitative assessment is therefore based on the coaches’ own knowledge and experience. They have to identify the technique mistakes and remediate them. However, the first step requires an appropriate preparation and a background knowledge, such as understanding: 1.) the ideal form of a movement in each phase, and 2.) the impact of the particular mistake on the technique performance. The presentations of correct form of swimming techniques are well known in written, diagrammatic as well as in pictorial form. Coaching manuals tend to rely on the sequential breaking down of a selected movement into its various phases and templates based on expert performance (Lees, 2002). In this context, it is surprising that the studies by Pion and coworkers (1988) and Stibilj and Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 7 coworkers (2020) were, to our knowledge, the only attempt to date to evaluate a swimming technique, i.e., breaststroke and breaststroke, respectively, based on mistakes. Therefore, the aim of the current pilot study was to develop and to validate a tool for the front crawl technique assessment (FCTA). With this in mind, we conducted two studies. In Study 1, we developed the FCTA tool based on perceptions of experienced swimming instructors and coaches regarding common mistakes in front crawl (FC) swimming. In Study 2, we examined the validity of the FCTA tool by using the times of the maximal 50-meter swim test. The institutional review board (Ethics Committee of University of Ljubljana, Faculty of Sport) approved the study protocol. The study was conducted according to the principles expressed in the Declaration of Helsinki. STUDY 1 – Development of the FCTA Tool METHODS Participants Twenty-one swim coaches (11 males and 10 females; ages 34 ± 11 years) with the certificate of the Slovenian Swimming association participated in the study. They have at least 10 years of experience in teaching and training non-swimmers and swimmers of different ages and genders and at different quality levels. They received written and verbal instructions before the beginning of the study. They provided an informed written consent. Procedures A self-administered questionnaire was distributed to all participants. Categories of questions included 1) teaching experiences and 2) the impact of various mistakes on FC performance. The latter category was related to the assessment of a particular mistake in terms of its importance in the learning programme of an advanced swimmer, i.e. a potential competitive swimmer at any level, ranging from the youngest age group to masters swimmers, and in different sports such as triathlon, open water swimming and pool swimming. Participants were asked to mark 48 mistakes that are most common when swimming FC (Maglischo, 2003). Mistakes were grouped according to body position, kicking, stroking, and coordination. Before the data collection, each mistake was presented to participants by using video clips or pictures. Thereafter they evaluated the mistakes on a seven-point scale in regard of their impact on FC swimming performance (Table 1). Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 8 Table 1. Table depicting 7-point scale for mistakes evaluation in regard of their impact on FC swimming performance. SCORE LEVEL OF IMPACT 1 No impact 2 Minimal impact 3 Lower than moderate impact 4 Moderate impact 5 Higher than moderate impact 6 High impact 7 Severe impact Statistical analyses The data presented in the results are descriptive in nature. Statistical analyses were performed using the SPSS package (version 15.0, SPSS Inc., Chicago, USA). Based on participants' evaluation, the median and the interquartile range (IQR) were calculated for each mistake. Thereafter, we arranged the mistakes ranging from no impact to severe impact in order to establish the FCTA tool. RESULTS The results of coaches’ evaluation of observing FC mistakes are presented in Table 2 and Table 3. Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 9 Table 2. Medians (IQR) of FC mistakes scores due to body position and kicking. The mistakes are ranked from those with lower impact to those with severe impact on FC swimming performance. MISTAKES MEDIAN (IQR) BODY POSITION The head is too deep 4.5 (3 - 6) No long-axis rotation 5 (4 - 6) Too much hip rotation 5 (5 - 6) Hips are too deep 5 (5 - 6) Disruption of the lateral alignment 5.5 (5 - 6.75) Not keeping the whole body in a straight line 6 (5 - 6) KICKING Kicking too high 3.5 (3 -5) Kick amplitude too small 4 (2 - 5) Feet not turned in 4 (3 - 5.75) Kicking is not rhythmical 4 (3.25 - 5.75) Extending the ankles too little at the end of kick 4.5 (3 - 6) Feet not extended 5 (4 - 5) Kick amplitude too large 5 (3 - 5.75) Kicking not continuous 5 (3 - 5.75) Kicking from the hip only 5 (3 - 6) Kicking too deep 5 (3 - 6) Crossover kicking 5 (3 - 6) Kicking from the knee 5.5 (4.25 - 7) Bicycle kicking 6.5 (5.25 - 7) Asymmetrical kicking with one leg to the side 7 (6 - 7) Dorsiflexing the feet 7 (6 - 7) Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 10 Table 3. Medians (IQR) of FC mistakes scores due to stroking, breathing and coordination. The mistakes are ranked from those with lower impact to those with severe impact on FC swimming performance. MISTAKES MEDIAN (IQR) STROKING Keeping fingers too wide apart 3 (2 - 5) Wrist drop during stroke 5 (3.25 - 5.75) Finger-tips do not enter the water first 5 (4 - 6) No hand acceleration during the pull 5 (4 - 6) Swing arm over the water low and wide 5 (4 - 5.75) Entering the hand far outside the shoulder line 5 (4 - 6) Entering the hand across the centre line 5 (4 - 6) Insweep too short 5 (4.25 - 6) Insweep too long 5.5 (3.25 - 6) Wrist drop during entry 6 (5 - 6) Underreaching during entry 6 (5 - 6.75) Finishing the armstroke too early 6 (6 - 7) Elbow drop during entry 7 (6 - 7) BREATHNIG AND COORDINATION Holding the head unnaturally high 5 (3.25 - 6) Turning the head too late 5 (4.25 - 6) Turning the head too soon 5 (5 - 6) The arm in front glides too long before starting downsweep 5 (2 - 6) Shallow breathing 5.5 (4 - 6.75) Pulling the head back and out of alignment 5.5 (5 - 6) Gliding hand is not extended during inhalation 6 (4 - 6) Breathing through the nose 6 (4 - 7) Downsweep started too soon 6 (5 - 6) Breath holding 6 (4.25 - 7) Taking a breath twice during each stroke cycle 6 (5 - 7) Lifting the head forward during inhalation 6 (5 - 7) Head up swimming 7 (6 - 7) Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 11 Based on the mistakes' median scores, we established the FCTA (Table 4) We assigned the points to the mistakes in relation to their impact on FC swimming performance. Despite the scale range spanning from 1 to 7 the coaches evaluated the mistakes mostly with scores ranging from 3 to 7 only (Table 2 and Table 3). Therefore, the points assigned in the FCTA varied from 1 (for mistakes with lower than moderate impact) to 5 (for mistakes with severe impact). Table 4. The FCTA tool based on FC mistakes in relation to their impact on swimming performance. Lower than moderate impact Moderate impact Higher than moderate impact High impact Severe impact 1 point 2 points 3 points 4 points 5 points BODY POSITION  The head is too deep  No long-axis rotation,  Too much hip rotation,  Hips are too deep,  Disruption of the lateral alignment  Not keeping the whole body in a straight line KICKING  Kicking too high  Kick amplitude too small,  Feet not turned in,  Kicking is not rhythmical,  Extending the ankles too little at the end of kick  Feet not extended,  Kick amplitude too large,  Kicking not continuous,  Kicking from the hip only,  Kicking too deep,  Crossover kicking,  Kicking from the knee  Bicycle kicking  Asymmetrical kicking with one leg to the side,  Dorsiflexing the feet ARMSTROKING  Keeping fingers too wide apart  Wrist drop during stroke,  Finger-tips do not enter the water first,  No acceleration throughout the stroke,  Swing arm over the water low and wide,  Entering the hand far outside the shoulder line,  Entering the hand across the centre line,  Insweep too short,  Insweep too long  Wrist drop during entry,  Underreaching during entry,  Finishing the armstroke too early  Elbow drop during entry BREATHING AND COORDINATION  Holding the head unnaturally high,  Turning the head too late,  Turning the head too soon,  The arm in front glides too long before starting downsweep,  Shallow breathing,  Pulling the head back and out of alignment  Gliding hand is not extended during inhalation,  Breathing through the nose,  Downsweep started too soon,  Breath holding,  Taking a breath twice during each stroke cycle,  Lifting the head forward during inhalation  Head up swimming Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 12 STUDY 2 – The FCTA Tool Validation METHODS Participants 147 males and 89 females, aged from 18 to 20 years, participated in the study. They were candidates for enrolment in the university study programme at the University of Ljubljana, Faculty of Sport. Therefore, the participants could be classified as intermediate or advanced swimmers. They received written and verbal instructions before the beginning of the study. They provided an informed written consent. Procedures The participants swam maximal 50-meter FC. The swim test was part of the selection process (test of motor abilities and skills) for the candidates who applied to the study at the University of Ljubljana, Faculty of Sport. The candidates had to swim 50-meter as fast as possible with voluntary start (start from the water or jump from the edge or from starting block), swimming technique and turn. There were no other technical requirements for the test. In this study, we selected the candidates who swam the entire 50-meter distance in FC. The test was conducted in a 25-meter swimming pool with both shallow water (120 cm) and deep water (180 cm) sections, with a water temperature of 28ºC, and with eight laines. Eight participants swam in the same time. We recorded their performances for further technical analyses. Statistical analyses Two swim experts identified the mistakes made during participants’ swimming. Their professional qualifications provided by Slovenian Swimming Federation were instructors (level two) and had at least ten years of experience in teaching swimming. Additionally, we numerically evaluated the mistakes based on the FCTA tool and made a summary for each participant. Validity of the FCTA tool was determined by examining Pearson correlations between and the amounts of numerically evaluated mistakes made by the participants theirs times achieved at maximal 50-meter swim test. The data were analysed using SPSS package (version 15.0, SPSS Inc., Chicago, USA). Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 13 RESULTS On the basis of the observations (table 5), the most common mistakes during the maximal 50- meter FC swimming in both groups were: finishing the armstroke too early, downsweep started too soon, feet not turned in, swing arm over the water low and wide. These mistakes were made by 50% of participants or more. Table 5. The most common mistakes made at participants' maximal 50-meter FC swimming. The data are presented in percentage (incidence of the mistake per number of male or female participants, respectively) for each group. MISTAKES MALES FEMALES BODY POSITION Hips are too deep 40 31 Too much hip rotation 32 27 Not keeping the whole body in a straight line 15 15 The head is too deep 2 0 KICKING Feet not turned in 61 51 Kicking not continuous 42 30 Kicking too deep 37 33 Bicycle kicking 33 42 Kicking too high 32 34 Kicking is not rhythmical 32 28 Kick amplitude too large 24 24 Kicking from the knee 22 26 Feet not extended 12 6 Dorsiflexing the feet 9 2 ARMSTROKING Finishing the armstroke too early 74 63 Swing arm over the water low and wide 51 49 Entering the hand across the centre line 44 49 Underreaching during entry 36 31 Insweep too short 20 24 Wrist drop during entry 19 19 No hand acceleration during the pull 12 20 Elbow drop during entry 10 21 Keeping fingers too wide apart 15 11 BREATHING AND COORDINATION Downsweep started too soon 76 60 Pulling the head back and out of alignment 40 31 Lifting the head forward during inhalation 23 19 Head up swimming 18 15 Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 14 The average time of the maximal 50-meter FC swimming was 41.88 ± 5.79 and 46.67 ± 6.65 seconds for male and female participants, respectively. By using Pearson’s correlation coefficient, we confirmed a linear correlation between the times achieved and the amounts of numerically evaluated mistakes made by participants maximal 50-meter swim test (Figures 1 and 2). The correlations between variables were positive, r(145)= 0.74, p<0.01 and r(87)=0.69, p<0.01, for male and female participants, respectively. Figure 1. The correlation between the times achieved and the amounts of numerically evaluated mistakes made by male participants at maximal 50-meter swim test. Figure 2. The correlation between the times achieved and the amounts of numerically evaluated mistakes made by female participants at maximal 50-meter swim test. Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 15 DISCUSSION The aim of this pilot study was to develop and to validate the FCTA tool. In the study 48 FC mistakes were evaluated and arranged according to the perceptions of experienced swimming instructors and coaches. Mistakes were ranked on a scale from 1 (for mistakes with lower than moderate impact) to 5 (for mistakes with severe impact). By using the FCTA tool, we numerically evaluated the mistakes that were made during participants’ maximal 50-meter swim test. Validity of the FCTA tool was determined by examining Pearson correlations between and the amounts of numerically evaluated mistakes made by the participants theirs times achieved at maximal 50-meter swim test. We found a strong correlation between these variables. Thus, we believe that the FCTA tool could be useful for the technique assessment of FC performance. Despite the scale range spanning from 1 to 7 the coaches evaluated the mistakes mostly with scores ranging from 3 to 7 only (Tables 2 and 3). This was expected due to the fact that we have chosen mistakes already discussed in existing literature (Maglischo, 2003). Swimmers can apply a particular swimming technique in a slightly different way. This is known as an individual¢s style. However, there are specific aspects in each swimming technique performance that are categorically wrong. These were referred to as mistakes in the present study. The technique mistakes that appear during swimming increase drag and consequently energy expenditure of swimmers (Pyne, & Sharp, 2014). Mistakes in the FC body position usually mean that swimmers disturb their horizontal or lateral alignment i.e. disruption of the lateral alignment and not keeping the whole body in a straight line (Table 2). Indeed, the swimmers produce less resistance when their bodies are streamlined horizontally and laterally (Maglischo, 1993). The major mistakes that cause a loss of streamlined horizontal alignment were lifting the head up during inhalation or even holding the head completely out of the water during the entire cycle. Both are results of problems concerning breathing during swimming. Indeed, breathing during swimming is one of the most challenging skills that beginner swimmers should learn. The exhalation should be performed against extra hydrostatic pressure exerted by the water and completed when the face is submerged, thus the breathing should be in accordance with stroke technique as well. Due to the short duration of the inhalation phase, i.e. not more than 0.49 seconds (Cardelli, Lerda, & Cholet, 2000), the problems regarding breathing could be expected at FC learning, for example mistakes such us: shallow breathing, breath holding, lifting the head forward during inhalation and head up swimming (Table 3). Head position mistakes result in kicking that is too deep whereas the body inclines too far Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 16 downward. The need of keeping the head out of water leads to an increase of trunk incline, thus to an increase of frontal area and hydrodynamic resistance (Zamparo, & Falco, 2010). This leads to an increase of energy requirement albeit indirectly by higher heart rate during FC swimming with the head above the water in comparison to the FC with proper head movements (Zamparo, & Falco, 2010). Furthermore, most of the mistakes that disturb lateral alignment are related to armstroke mistakes such as entering the hand far outside the shoulder line, entering the hand across the centre line and underreaching during entry (Table 3). The mistake with severe impact at FC armstroke is the elbow drop during entry (Table 3). The reason for this mistake lies in the fact that swimmers try to apply propulsive force before the arms are oriented backward (Maglischo, 2003). This causes pushing water down, disturbing horizontal and lateral alignment and decreasing forward speed. Additionally, it could put the swimmer in a poor position to use the latissimus dorsi muscle during the stroke (Troup, 1992). Another important (i.e. severe impact) mistake such us finishing the armstroke too early (with hand exit before extension) could be a result of beginning the downsweep with the other arm too soon (Maglischo, 2003). This mistake shortens the propulsive phase, i.e. shortens stroke length, which is usually correlated with the decrease of the swimming speed (Hay, & Guimares, 1983). Indeed, Yanai (2003) suggested that swimmers improve their FC performance over a period of training in order to be able to attain a faster speed with an increased stroke length. The FCTA tool was developed according to the perceptions of experienced swimming instructors and coaches. For the validation of this tool, we deliberately chose the swimming performances of candidates for the enrolment at the University of Ljubljana, Faculty of Sport. There were at least two reasons for choosing these candidates. Firstly, they swam 50-meter as fast as they could because the achieved time was one of the selection criteria for enrolment. Secondly, they were mostly swimmers at intermediate or advanced levels without any experience with competitive swimming. In terms of physical, technical and psychological preparation for the swim test they did all the preparation themselves, most of them without any expert help. In the light of the above, they swam 50-meter FC maximally, however with more or less technical mistakes (Table 5). Great heterogeneity was observed between them regarding swim times and mistakes occurrence (Figures 1 and 2), however, these two variables were related to each other. Regardless to gender, we obtained a positive correlation between the times achieved and the amounts of numerically evaluated mistakes made by the participants at maximal 50-meter swim test. R of 0,69 and 0,74 obtained by female and male participants, respectively, was moderately strong with very high statistical significance (p < 0,01) (Akoglu, Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 17 2018). This means that candidates with fewer mistakes made achieved faster times, i.e. better results at the swim test. In view of the above, we assumed that the times that the participants achieved at the swim test depended mainly on their FC technical skills and, to a lesser extent, on other factors. We could not exclude the effects of the starting and turning performance (Veiga, & Roig, 2017) as well as the influences of anthropometrical (Rozi, Thanopoulos, Geladas, Soultanaki, & Dopsaj, 2018), physiological (Lätt, et al., 2010), energy (Pyne, & Sharp, 2014) and psychological (Sheard, & Golby, 2006) attributes. It seems that the FCTA tool discriminated the participants due to their degree of technical skills in a similar way as the measured time did. Limitations and Directions for Further Research The generalisability of the findings is limited for several reasons. In retrospect, our failure to collect retest data regarding swimming instructors' assessments was a missed opportunity to determine internal consistency of their perceptions of common FC mistakes. Future investigators should redress this omission thus, determine the reliability of the tool. Moreover, we investigated the validity of the FCTA tool using the times of the maximum 50-meter swim test of adult participants. One might suspect that we would obtain different results if we tested younger participants for this validation. CONCLUSION In conclusion, these results indicated that the FCTA could be a valid tool to effectively assess the technical skills of intermediate and advanced level swimmers in front crawl. It could help instructors and coaches classify swimmers according to their FC technique performance. However, this was a pilot study, so all conclusions are preliminary and require further research. Acknowledgment This research was supported by the Slovenian Research Agency (ARRS) (project No. P5-0147 entitled “THE KINESIOLOGY OF MONO-STRUCTURED, POLY-STRUCTURED AND CONVENTIONAL SPORTS”). Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 18 Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. REFERENCES Akoglu H. (2018). User's guide to correlation coefficients. Turkish Journal of Emergency Medicine, 18(3), 91–93. Barbosa, T.M. (2005). Observación, identificación e intervención del profesor de natación sobre las faltas más usuales durante la enseñanza de las técnicas de crol y espalda. In XXV Congreso Internacional de Técnicos de Natación y VIII Congreso Ibérico. Madrid. Barbosa, T.M., Costa, M.J., Cardoso, L., Garrido, N.D., Marinho, D.A., da Costa, A.M., Queiros, T.M., & Silva, A.J. (2013). Reference Manual for Teaching and Technical Improvement in Swimming. Lausanne: FINA. Cardelli, C., Lerda, R., & Chollet, D. (2000). Analysis of breathing in the crawl as a function of skill and stroke characteristics. Perceptual and Motor Skills, 90 (3), 979-987. Campaniço, J., & Silva, A. (1998). Observação qualitativa do erro técnico em Natação. In A.J. Silva, & J. Campaniço (Eds.), Seminário Internacional de Natação (pp. 47-92). Vila Real: Edições da Universidade Trás-os- Montes e Alto Douro. Coleman, S. (1998). Biomechanics and its application to coaching practice. In N. Cross, & J. Lyle (Eds.), The coaching process: Principles and practice for sport. Oxford: Butterworth Heinmann. Hay, J.G., & Guimaraes, A.C. S. (1983). A quantitative look at swimming biomechanics. Swimming Technique, 20, 11-17. Hynes, G., O'Grady, M., & O'Hare, G., (2013). Towards accessible technologies for coaching. International Journal of Sports Science & Coaching, 8 (1), 105-114. Lätt, E., Jürimäe, J., Mäestu, J., Purge, P., Rämson, R., Haljaste, K., Keskinen, K. L., Rodriguez, F. A., & Jürimäe, T. (2010). Physiological, biomechanical and anthropometrical predictors of sprint swimming performance in adolescent swimmers. Journal of Sports Science & Medicine, 9(3), 398–404. Lees, A. (2002). Technique analysis in sport: a critical review. Journal of Sports Science, 20 (10), 813-828. Maglischo, E. W. (2003). Swimming fastest. California: Mayfield Publishing Company. Maslovat, D., & Franks, I. M. (2008). The need for feedback. In M. Hughes, & I. M. Franks (Eds.), The essentials of performance analysis: An introduction. Oxon: Routledge. Mooney, R., Corley, G., Godfrey, A., Osborough, C., Newell, J., Quinlan, L.R., & Olaighin, G. (2016). Analysis of swimming performance: perceptions and practices of US-based swimming coaches. Journal of Sports Sciences, 34 (11), 997-1005. Pion, J., Devos, P., & Dufour, W. (1988). A rating scale for the evaluation of the breaststroke technique in pedagogical situations. In B.E. Ungerechts, K. Wilke, & K. Reischle (Eds.), Swimming Science V: Proceedings of the Vth International Symposium of Biomechanics and Medicine in Swimming (pp. 369-373). Champaign, IL: Human Kinetics. Pyne, D. B., & Sharp, R. L. (2014). Physical and energy requirements of competitive swimming events. International Journal of Sport Nutrition and Exercise Metabolism, 24(4), 351–359. Reischle, K. (1993). Biomecanica de la Natatión. Madrid: Editorial Gymnos. Kinesiologia Slovenica, 28, 2, 5-19 (2022), ISSN 1318-2269 Front Crawl Swimming Mistakes 19 Rozi, G., Thanopoulos, V., Geladas, N., Soultanaki, E., & Dopsaj, M. (2018). Anthropometric characteristics and physiological responses of high level swimmers and performance in 100 m freestyle swimming. Movement & Sport Sciences (101)3-7. Sanders, R. H., Psycharakis, S., McCabe, C. B., Naemi, R., Connaboy, C., Li, S., & Spence, A. (2006). Analysis of swimming technique: State of the art applications and implications. Portuguese Journal of Sport Sciences, 6(2), 20–24. Sheard, M., & Golby, J. (2006). Effect of a psychological skills training program on swimming performance and positive psychological development. International Journal of Sport and Exercise Psychology, 4(2), 149-169. Stibilj, J., Košmrlj, K., & Kapus, J. (2020). Evaluation of Mistakes in Backstroke Swimming. Kinesiologia Slovenica, 26(2), 5–15. Troup, J.P. (1992). Studies by the International center for Aquatic Research 1991-92. Colorado Springs: U.S. Swimming Press. Veiga, S., & Roig, A. (2017). Effect of the starting and turning performances on the subsequent swimming parameters of elite swimmers. Sports Biomechanics16 (1), 34–44. Wilson, B. D. (2008). Development in video technology for coaching. Sports Technology, 1 (1), 34–40. Yanai, T. (2003). Stroke frequency in front crawl: its mechanical link to the fluid forces required in non-propulsive directions. Journal of Biomechanics 36, 53-62. Zamparo, P., & Falco, S. (2010). Head out swimming in Water polo: a comparison with front crawl in young female players. In P.L. Kjendlie, R.K. Stallman, & J. Cabri (Eds.), Biomechanics and medicine in swimming 11 (187-189). Oslo: Norwegian School of Sport Sciences.