Question

Should the maximum angular velocity of the shank coincide with ball contact? Explain why or why not.

Answer 1

Good kicking technique is an important aspect of a soccer player. Therefore, understanding the biomechanics of soccer kicking is particularly important for guiding and monitoring the training process. The purpose of this review was to examine latest research findings on biomechanics of soccer kick performance and identify weaknesses of present research which deserve further attention in the future. Being a multiarticular movement, soccer kick is characterised by a proximal-to-distal motion of the lower limb segments of the kicking leg. Angular velocity is maximized first by the thigh, then by the shank and finally by the foot. This is accomplished by segmental and joint movements in multiple planes. During backswing, the thigh decelerates mainly due to a motion-dependent moment from the shank and, to a lesser extent, by activation of hip muscles. In turn, forward acceleration of the shank is accomplished through knee extensor moment as well as a motion-dependent moment from the thigh. The final speed, path and spin of the ball largely depend on the quality of foot-ball contact. Powerful kicks are achieved through a high foot velocity and coefficient of restitution. Preliminary data indicate that accurate kicks are achieved through slower kicking motion and ball speed values.

The effects of age and gender on soccer kick technique and biomechanics received a little attention in the literature. In general, it appears that soccer kick indicators differ with age and gender. Particularly, previous studies reported that maximum ball speed and knee angular velocity increase with age . Ball speed values reach 32.1 m·s^-1 for 15-18 year players (Table 3). Ball speed increases with age probably due to the increased muscle mass and technique improvements

Maximum knee angular velocities during the kick range from 1014 deg·s^-1 for 4.6 year-old children to 1204 deg·s^-1 for 14 year-old players (Table 4). Improvement in kicking performance is partly because of the higher levels of muscle strength of the players (due to growth and maturation).

ref -https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3786235/