Abstract des Autors

Flexibility (FL) defined as the scope of movement of one or several joints is a factor of sport performance, which is determined by age, gender, training, anthropomorphic characteristics and genetic factors, of which very little has been studied. Method: To establish the relative importance of genetic and environmental influence on flexibility, we have studied the genetic component, using the Hereditability Index (HI at a value of 1.0 indicates that 100% of the variation would be due to genetic variation) in 24 sportsment split into 12 pairs of twin brothers (6 monozygotes and 6 dizygotes), who did not have any significant perinatal or environmental differences. Zygosity was determined by genetic analysis of the leukocyte human antigen system (LHA), especially the Class I and II loci, and other genetic variants. To calculate the FL, the subjects underwent an indirect flexometric test for the trigonometric calculation of the angle of aperture of the scapulohumeral (FL, SHA) and coxofemoral joints (FL, CFA), the latter broken down into the horizontal and sagittal fields, for active and forced passive movements and for both legs. Results: We do not find significant differences in the age and anthropomorphic measurements between the two groups (MZ and DZ). The HIs which were statistically significant for F6,6 (DZ MZ-I) over 4.2 and P<0.05, are the FL, CFA in the transversal plane for open legs and active (0.82) and forced passive (0.77) movement, and in the sagittal plane for the right leg in active movement (0.78). Conclusions: We conclude that the genetic influence of flexibility is substantial, especially of the coxofemoral joint (75%) and mainly of the right leg, and our study corroborates the previous results yielded by familiy studies, at least for the target public of our research. Verf.-Referat