Biomechanics of Competitive Swimming Strokes - Essay Example

Swimming An assignment submitted by Winter Swimming Swimming is not only a good choice of exercise and essential in times of emergency but also a competitive sport that is immensely popular worldwide. Unlike other recreation sports, swimming is largely a technique-based sport that requires skill and proper technique to improve swimmer’s speed and power. Practicing on pure mileage could be less efficient and is more likely to put the learners’ energy out rather than making them any faster. With efficient choice of swimming strokes and appropriate technique-based training, swimmers can achieve desired results. A good swimming technique relies on the efficiency of one’s power transfer process by overcoming drag. Moreover, deriving maximum energy output from the effort put in is mainly the essence for swimmers to improve their performance in competitive swimming. The discussion provides a detailed technical analysis of swimming strokes – freestyle, backstroke, and butterfly, along with a review of the biomechanical principles related to each of those strokes. Furthermore, suggestions of drills or exercises for improving the favorite stroke of backstroke, based on the technical and biomechanical aspects, will also be critiqued. The basic swimming strokes of Freestyle, Backstroke, and Butterfly stroke are taken for analysis focusing on its biomechanics and technical aspects. Freestyle is generally the fastest and most popular stroke, with front crawl being the most commonly chosen among swimmers. That is, although swimmers or in particular ones in competition can choose whatever stroke they wish during the freestyle, mostly they choose front crawl which involves the swimmer circling his/her arms forward in alternation even while kicking their foots up and down. Next, the Backstroke, or otherwise the elementary backstroke is perfect for recreational and competitive arena. In this swimming stroke, the individual lies right on his back in the supine position on water and the strokes are done with one arm at a time. Last, the butterfly stroke is done on the breast, by moving both the arms and is accompanied by the dolphin kick. Unlike the other strokes, butterfly stroke is quite difficult and requires adequate practice with proper technique and strong muscle coordination. Freestyle, being the fastest stroke, would clearly improve one’s speed in swimming and this stroke is quite essential for lifeguard practices. As above-mentioned, it is characterized by stroking of the arms alternatively over the water surface, accompanied with alternating flutter kick in an up-and-down manner. The technique involves the body position to be streamlined along with the arms extending over the head. This would lengthen the body posture while swimming, even as the back and legs has to be kept straight, except during the flutter kick. The head position has to be in line with the water in a downwards angle, in order to maintain the body’s streamlined position and reduce frontal resistance. In the Freestyle technique, body roll action increases the power of the stroke, beginning with the arm action entering the water in front of the head between a parallel line from the shoulders and the midline of the body. It is important for the hand to accelerate throughout the ‘pull through’ phase for gaining maximum speed. This would technically reduce the ability to pull and the drag. Finally, in the propulsive phase, the hand is swept backwards, upwards, and outwards to finish the stroke. It is important to learn this swimming technique by focusing on actions that would possibly increase the swimming speed and thereby decrease impedances to progress. Coming to the biomechanical aspects of the Freestyle stroke, there are three forms of resistance involved - skin or frictional resistance, Eddy or turbulence resistance, and the frontal or wave resistance. When the water comes in contact with the swimmer’s body, frictional form of resistance occurs and that could be managed by making the body smoother as well as carrying a thin layer of surface water on the body surface. In Freestyle, surface friction is determined by the amount of surface area of the body, the speed of water compared to that of the swimmers, the smoothness of the body, as well as the quality of the water. The frontal resistance occurs when the swimmer’s body moves forward in the water, causing a wave-making drag, which impedes their forward motion. “The swimmers’ forward momentum causes a buildup of moving pressure disturbances in the water in front of the body, which results in frontal resistance” (Colwin, 2002, p.39). The Eddy resistance, on the other hand, is caused by the forward acceleration of water, creating eddies and water turbulence for the swimmer. Each of the resistance has a considerable impact on the swimmer’s movement and so if these are minimized, it would maximize the propulsive effects of the swimmers movements. In Backstroke style swimming, an alternating motion of the arms is involved, accompanying with a flutter kick while lying on the back. On turns, the swimmers rotate to their stomach and perform a flip turn, with some part touching the wall and finishing it on the back. The arm stroke has a major role in forward movement, and consists of two parts - the power phase and the recovery phase. The starting position for the swimmer is to float on the back with the heads in a neutral position and face above the water surface. While the head is in line with the spine and the hand in line with the shoulder, the legs have to execute the flutter kick, alternatively upwards then downwards. In the recovery phase, the arms are positioned in a semicircular movement and then straight, while the other arm sweeps underwater providing enough propulsion. The two basic techniques involved in the backstroke are: the arms have to move in an equal force, to increase the resistance of the water turbulence; and the body has to roll on the either sides for the arms to extend to their utmost stretch, which would help propelling. In order to make your backstroke movement properly executed, the biomechanics behind it has to be learnt. Coordination between the lower and upper body is the key to successful backstroke swimming. In order to achieve the fluid movement of the body, both the upper and lower body has to work together simultaneously. Similarly, kicking from the knee by flexing the tibio-femoral joint would create drags, causing the swimmer’s legs to sink lower. Also, it is important to keep the ankle plantar flexed as this will push the water to the anterior position, slowing down swimmer’s velocity drastically. Butterfly Stroke, one of the beautiful strokes, features a difficult technique that needs a fair amount of muscular strength and precise timing control. This stroke technique is performed with the legs moving together with downward thrusting movement and the feet whipping downwards. The arms have to push the water downwards first and then to the backwards in a sweeping movement. Meanwhile, the torso has to move forward in an undulating manner. It is important for this butterfly stroke technique to keep the head under water unless while breathing, which has to be done at alternate stroke of the arms. The main biomechanical aspect of the butterfly stroke is its trunk angle, full extension of the arms during upsweep and the second kick intensity. A higher trunk angle is expected to increase the drag force and the projected surface area. In order to decrease this tendency, the swimmers have to adopt an alternative breathing technique. Also, higher extension of the arms during upsweep would increase the propulsive phase duration, while the reduced kick intensity and increased kick frequency would increase the swimmer’s velocity. “Considering the lower limbs kinematics, the reduction of the kick amplitude plus the increase of kick frequency, combined with the increase of the knee’s angle during the downbeat, seems to be the best way to increase the swimmer’s velocity” (Barbosa, Marinho, Costa & Silva, n. d, p.370). The higher velocity of the lower limbs during the downbeats would decrease the speed fluctuations of the swimmers. The arm’s recovery phase in butterfly stroke is when the velocity decreases instantaneously. Similarly, the trunk movement is associated to the legs action, providing a greater activity for the rectus abdominus and spine erector. Backstroke is one among the favorite strokes and possibly requires improvement through continued practice and understanding of the key techniques. “Knowledge of specific muscle activity is an important factor in understanding neuromuscular coordination and effective force production during the different phases of the backstroke start” (Jesus, Fernandes, Vilas-Boas, and Sanders, 2014, p.36). Since the backstroke needs to maintain a streamlined body position, it is not as efficient and fast as the freestyle. Moreover, it requires the limbs to apply constant propulsive motion which is achieved through the alternating action of the arms and the continuous fluttering action of the legs. This technique “generates momentum by rotating your shoulders and your hips. As one arm lifts out of the water, the other starts the propulsive phase underneath the surface” (“Improving your backstroke”, 2014). The reason for the backstroke swimmers not reaching the potential power is that the stroke is done with the arms out and so he could not pull them directly to the body, resulting in reduced power. Some of the common errors in backstroke swimming can reveal the importance of the stroke’s biomechanics in performance. Overreaching for the arms would increase the drag force or the frontal resistance considerably on the body due to the lateral movement of the hips. Also, entering with the back of the hand would result in water smashing which would increase the drag again causing the swimmers to reduce efficiency. Additionally, ankle flexibility is required for gaining propulsion from the kick, while pointing the toes can increase the surface area for pushing water back easily. There are certain drills and exercises that would help improving this backstroke swimming technique further. Backstroke kick performed by holding board on sides and the ends, each done in multiples of 25s and 50s, would help in balancing and doing flutter kick in a supine position (“Improving Your Backstroke Technique”). Similarly, L-drill is done with a kick on sides with the bottom arm extended and swung to the top, forming the ‘L’ shape against the body. Pause in this position for a count of three or four and repeat the sequence after rolling on to the arms. The 6/3/6 drill is done by pushing off the wall and taking kicks on the side with the bottom arm extended. The 3/3/3 drill includes alternate three strokes using the right arm and then with the left, altering both the arms (Jesus et al., 2014). Hands by side, overhead, at 45 degrees, and 90 degrees can possibly help in improving the stroke efficiency. Double arm and single arm backstroke by rolling opposite shoulders, as well as focus on hand entry would help progress in training. The key aspect to improve any stroke, including backstroke, is to have patience and willingness to adapt while learning the technique. Moreover, appropriate drills and exercises can help the swimmer learn how to keep the balance in water as well as to use the hips and core instead of just muscling through the stroke. Actually, this is what will make efficient and faster swimmers. References: Barbosa, T. M., Marinho, D. A., Costa, M. J. & Silva, A. J. (n. d). Biomechanics of competitive swimming strokes. Retrieved from http://www.intechopen.com/download/pdf/19665> Colwin, C. (2002). Breakthrough Swimming. Human Kinetics. Jesus, K., Fernandes, R. J., Vilas-Boas, J. P. and Sanders, R. (2014). “The backstroke swimming start: state of the art.” Journal of Human Kinetics 42 (1): 27-40. “Improving Your Backstroke Technique.” (2014). In Masters Swimming Hub. 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