Kicking

The mechanics of kicking is influenced by numerous factors, including the position of the ball (e.g. in the air vs on the ground), its relative proximity to the body, and/or the athlete’s desired outcome (e.g. striking the ball with different parts of the foot to elicit a specific outcome). Although each of these factors will affect the kicking action, the overall movement sequence can be sub-divided into three distinct phases: i) the preparation phase; ii) the driving phase; and iii) the follow-through. The preparation phase moves the kicking foot away from the eventual direction of the kick, which increases the range that the limb must move through before contacting the ball and, hence, improving the opportunity to accrue foot velocity. During the early driving phase, the hip of the kicking leg rapidly flexes while the knee remains flexed; however, once the hip achieves peak angular velocity, the knee extends to accelerate the foot towards the ball. The follow-through begins after ball contact and is a vital part of the kicking action, as it serves to protect the muscles and joints from injury by allowing mechanical loads to be dissipated over a greater timeframe. Performing the kicking action exposes the knee to a complex array of stresses that include compressive, shear and torsional forces. When combined with the physical pressure provided by opposition players, these forces have the potential to lead to significant knee injuries, such as anterior cruciate ligament rupture.