How Biomechanics has influenced Soccer
Biomechanics is the application of mechanical principles in the study of living organisms. (J. Hall, 1991, p. 524). For the purpose of this essay I will focus on how biomechanics has influenced soccer. Soccer is a worldwide sport that is played right from elite level all the way down to children playing in the school playground just for fun. Soccer is a popular sport in most countries, but it is just considered a sport to most people, they do not focus on the true biomechanics related to it. Biomechanics has an important role right from the Goalkeeper up the forwards. Throughout this essay I will focus on biomechanical factors related to the skills involved in the game, the equipment used in soccer, the surfaces played on and Injuries which are related to the sport.
In soccer the main action which is involved is the kicking of the ball. I have researched many journal articles, books etc. but the main focus seems to be on the instep kick. According to Wickstrom’s (1975) there are four main stages to the motion in mature kicking:
(1) The withdrawal of the thigh and shank during the backswing
(2) The rotation of the thigh and shank forwards, which occurs as a result of hip flexion
(3) When the thigh angular velocity reduces, there is a corresponding increase in shank angular velocity up to impact with the ball
(4) The follow-through.
The graphs in Fig. 3 can be interpreted in relation to the progression of the kicking skill suggested by Wickstom’s (1975). During stage 2, both the shank and thigh increase their angular velocity. In stage 3, just before impact, there is an increase in shank angular velocity and a decrease in thigh angular velocity. A large angular velocity of the shank results in a high foot speed, and this is important for a well-hit kick. To achieve a high foot speed, energy must be built up in the early stage of the movement. About half of the shank angular velocity at impact is built up during stage 2, and the remaining half appears to be transferred from the thigh during stage 3. Therefore, the movement at the hip and knee, and the muscular strength applied during stage 2, will determine the maximal speed of the foot at impact. (Lees and Nolan, 1998, pp. 211-234)
A biomechanical factor of soccer kicking that is of high importance is the angled approach that the player takes to kick a stationary ball. Isokawa and Lees (1988) investigated the effect of the approach angle on the velocity of the ball. They took 6 male subjects and looked at the approach angles of 0° 15° 30° 45° 60° and 90° while the angle of the knee was at 0°. The maximum velocity of the shank was achieved with an approach angle of 30° and the maximum ball speed with an approach angle of 45°. Therefore, an approach angle of 30-45° would appear optimum.
Players that would be free takers for example or penalty takers would need to focus hugely on this in order to get the optimum angle to get the best possible shot...