Comparison of Static Lower Extremity Alignment in Female Ballet Dancers and Non-ballet Dancer

Abstract

PURPOSE This study aimed to: 1) compare the differences in static lower-extremity alignment (SLEA) between female ballet dancers (BD) and non-ballet dancers (NBD); 2) investigate the differences among gesture leg (GL) and supporting leg (SL) in BD and dominant leg (DL) in NBD; and 3) compare limb asymmetry between groups.METHODS Twenty-nine female BD and 20 NBD were recruited for this study. The quadriceps, tibiofemoral, rearfoot, and genu-recurvatum angles, tibial torsion and varum, and navicular drop height were measured. An independent t-test was conducted to compare SLEA and limb asymmetry between groups. One-way analysis of variance with Bonferroni post-hoc tests were performed to determine the differences among the GL, SL and DL.RESULTS BD showed lower quadriceps and rearfoot angles, less tibial varum and navicular drop, and greater tibiofemoral angle (p<.005) than NBD. BD showed less quadriceps angle asymmetry but greater tibial torsion asymmetry (p<.01) than NBD. GL and SL in BD showed differences in quadriceps, tibiofemoral, rearfoot angle, tibial torsion and navicular drop compared to NBD.CONCLUSIONS Repetitive dance movements can transfer varying forces to the GL and SL, potentially contributing to SLEA asymmetry. An intervention strategy that can reduce SLEA asymmetry in BD is needed, as is the identification of elements of ballet training that contribute to maintaining a normal SLEA.