Investigating the Influence of ACTN3 R577X Polymorphism on Performance and Angular Kinematics Using Motion Capture Technology

The ACTN3 gene is known as the “sprinter gene” due to the increased frequency of the R allele of the gene in various cohorts of elite sprinters compared to the general population. In situ muscle fibers that express α-actinin-3 protein can produce more force than the muscle fibers that are α-actinin-3 deficient. In vivo analysis showed that individuals lacking the R variant of the gene (ACTN3 XX genotype) encoding α-actinin-3 demonstrated slower running times and lower peak knee torque at higher angular speeds (30–180 deg/s). The aim of this study is to investigate the influence of the ACTN3 gene on performance and angular kinematic characteristics by comparing ACTN3 RR+RX and ACTN3 XX individuals during explosive jumps and sprints using motion capture technology. The kinematic and force data were obtained using a Qualisys Track Manager (QTM) system, and DNA was isolated from white blood cells using standard procedures. The 291-bp PCR fragment was electrophoresed, visualized under UV light, and finally, digested with Hpy8 restriction endonuclease. ACTN3 RR+RX individuals demonstrated statistically significant differences (P<0.05) in SJ, CMJ, and DJ jump height, greater mean values of peak vertical ground reaction force (PVGRF), increased angular velocity at the knee joint during the DJ jump, and greater torque production at higher angular speeds during 5-m sprints. In conclusion, our study allowed us to deepen our knowledge regarding the role of α-actinin-3 protein in human locomotion. The results indicate that the ACTN3 gene influences force production and certain angular kinematic characteristics during explosive jumps and sprints.