Comparison of the ground reaction force and changes in center of mass to pressure and time to reach stabilization during landing jump (start) and selected muscle function in young professional and semiprofessional karate girls

Poster Presentation
Paper ID : 1750-12THCONG
Oral / Poster Presentation File: 1750-12THCONG.jpg 
1Tehran markaz
2Professor,Kharazmi University, Tehran, Iran
3member of science board of Faculty of Sari University of Medical Sciences
In karate, the skill level is directly related to the person's ability to perform the technique, and regardless of experience, it can lead the athletes to the championship level. On the other hand, foot dancing is one of the most important skills for a strong, purposeful beginning of techniques consisting of high-speed, continuous jump-landing functions.
Objective: This study aimed at comparing some bio-mechanical parameters such as ground reaction forces, changes in center mass to pressure center, time to rech stabilization of jump-landing and performance of selected muscles between karate tasks.
The study population included young karate girls of national team (professional group) and selected young karate girls of Mazandaran province (semi-professional group) (9 persons per group). Force plate was used to measure bio-mechanical parameters. Electromyographic and image signals were recorded using electromyography and video recorder. Then, the data were evaluated by parametric and nonparametric statistical methods.
Descriptive statistics showed that all biomechanical parameters in both professional and non-professional groups occurred more in left leg than the right leg and inferential statistical results showed that between there were significant differences between ground reaction forces and center of mass-pressure changes with gastrocnemius muscle, vastus medialis, biceps femoris muscle and anterior tibia. However, there was no significant difference between their time to stabilization.
The study data showed that biomechanical parameters that are involved in equilibrium and performance improvement can play an important role in skill level implementation. One can also increase speed and power by focusing on improving muscle performance through specific exercises for each muscle.