Kinematics Analyses Related to Stretch-Shortening Cycle during Soccer Instep Kicking After Different Acute Stretching

Abstract

The purpose of this study was to examine the effects of static and dynamic stretching within a preexercise warm-up on angular velocity of knee joint, deepest knee flexion (DKF), and duration of eccentric and concentric contractions, which are relative to the stretch-shortening cycle (SSC) during instep kicking in professional soccer players. The kicking motions of dominant legs were captured from 18 Olympic professional male soccer players (height: 180.38 ± 7.34 cm; weight: 69.77 ± 9.73 kg; age: 19.22 ± 1.83 years) using 4 digital video cameras at 50 Hz. There was a significant difference in the DKF after the dynamic stretching (-3.22 ± 3.10°) vs. static stretching (-0.18 ± 3.19°) relative to the no-stretching method with p < 0.001. Moreover, there was significant difference in eccentric duration after the dynamic stretching (0.006 ± 0.01 seconds) vs. static stretching (-0.003 ± 0.01 seconds) relative to the no-stretching method with p < 0.015. There was a significant difference in the concentric duration after the dynamic stretching (-0.007 ± 0.01 seconds) vs. static stretching (0.002 ± 0.01 seconds) relative to the no-stretching method with p < 0.001. There was also a significant difference in knee angular velocity after the dynamic stretching (4.08 ± 3.81 rad·s) vs. static stretching (-5.34 ± 4.40 rad·s) relative to the no-stretching method with p < 0.001. We concluded that dynamic stretching during warm-ups, as compared with static stretching, is probably the most effective way as preparation for the kinematics characteristics of soccer instep kick, which are relative to the SSC.

Comparison of the Maximum Angular Velocity of Lower Limb Joints in Different Methods of Zenkutsu-dachi in Karate

“…This pattern is similar to walking or running. The main flexor muscle of the foot is iliopsoas muscle [9], and plays a role in swinging the foot forward when walking or running [10]. Therefore, considering the similarity of the movement pattern in this technique with the that of walking and running, it can be said that the hip joint and psoas muscles are the main and most important factors for performing the forward movement of Zenkutsu-Dachi.…”

The Effect of Tapering Period with and without Creatine Supplementation on Hormonal Responses of male football Players

“…Studies have shown that a 7-21 day tapering period improves performance. Among the factors that play a role in this case, hematological, biochemical, and hormonal factors, immune system, and mentalpsychological factors are mentioned (2,3,7,8). The levels of testosterone and cortisol in the plasma indicates the anabolic and catabolic reactions of tissues.…”

“…In a soccer match, the reliance on each energy system is constantly changing. Getting the desired training balance is complex and depends on special knowledge about the metabolism and physiological changes of the athletes of that sport (2,3).…”