title: Interaction of ACTN3 gene polymorphism and muscle imbalance effects on kinematic efficiency in combat sports athletes.
abstract: OBJECTIVE
  The purpose of this study was to determine the interaction of ACTN3 gene polymorphism and muscle imbalance effects on kinematic efficiency changes in combat sports athletes.
  
  
  METHODS
  Six types of combat sports athletes (Judo, Taekwondo, boxing, kendo, wrestling, and Korean Ssi-reum) participated in the study. ATCN3 gene polymorphism and muscle imbalance in lower extremity were evaluated followed by analysis of differences of moment in hip, knee, and ankle joint during V-cut jumping and stop. To examine the moment difference due to an interaction of ATCN3 polymorphism and muscle imbalance, all participants were divided into 4 groups (R+MB, R+MIB, X+MB, and X+MIB).
  
  
  RESULTS
  There was no significant difference of hip, knee, and ankle joint moment in R allele and X allele during V-cut jumping and stop based on ACTN3 gene polymorphism. Otherwise, muscle imbalance of knee moment in X-axis and ground reaction force of knee in Z-axis showed a higher significance in muscle imbalance during V-cut jumping and stop compared to muscle balance (p<0.05). In addition, joint analysis showed that muscle imbalance in X allele group had significantly higher knee moment of V-cut ground reaction force in X-axis and higher ankle moment of jumping ground reaction force in X and Z-axis compared to muscle balance with R and/or X group (p <0.05).
  
  
  CONCLUSIONS
  This study confirmed that muscle imbalance in lower extremity of combat athletes might induce higher risk factors of sports injury incidence than genetic factor and training might reduce the ratio of sports injury risk incidence.
authors: College of Sports Science, Kangnam University, Yongin-si, Gyoenggi-do Republic of Korea.
authors: Hansang
authors: H
authors: Jung
authors: Department of Sports Health Medicine, School of Sports Science, Jungwon University, Goesan-gun, Chungbuk Republic of Korea.
authors: Namju
authors: N
authors: Lee
authors: Department of Sports Leadership, College of Natural Science, Kwangwoon University, Seoul Republic of Korea.
authors: Sok
authors: S
authors: Park
keywords: ACTN3; Athletes; Muscle imbalance