Comparison of the kinematics of the full-instep and pass kicks in soccer

PURPOSE: The goal of this study was to gain a better understanding of the mechanics of the inside-of-the-foot passing shot used in soccer ("pass kick"). METHODS: The motions of the pass kick were compared with those of the full-instep kick ("full kick"). The study followed an inverse dynamics approach, using three-dimensional cinematographic techniques. RESULTS: At impact, the pelvis and the thigh-shank plane pointed more toward the right in the pass kick; the shank-foot plane also pointed further outward relative to the thigh-shank plane. Knee extension accounted for most of the speed of the foot in both kicks (86% in the full kick; 67% in the pass kick). In the pass kick, pelvis tilt toward the right and hip adduction contributed to a medial component of foot velocity (8.4 m.s-1) normal to the thigh-shank plane, which made the resultant foot velocity vector more oblique to the plane than in the full kick. This facilitated ball impact with the medial aspect of the foot. The slower ball speed in the pass kick was because of a slower foot speed (18.3 m.s-1 vs 21.6 m.s-1). Limitations in the maximum medial velocity that can be generated may force players to restrain the within-plane (and therefore also the resultant) velocity of the foot to be able to impact the ball squarely with the medial aspect of the foot. CONCLUSIONS: To impact the ball with the medial aspect of the foot in the pass kick, the player orients the pelvis, the right leg, and the foot more toward the right and introduces a medial component of foot velocity. However, most of the speed of the foot is still generated through knee extension.