Influence of foot position and vision on dynamic postural strategies during the “grand plié” ballet movement (squatting) in young and adult ballet dancers

Abstract Purpose To analyse dynamic postural strategies during the “grand plie” in two different foot positions (parallel or turned out), with and without vision, and as a function of age in ballet dancers. Method Twenty young dancers (YD) aged from 8 to 16 years, and 20 adult dancers (AD) aged from 17 to 30 years were recruited. Center of pressure (CoP) and ground reaction forces (GRF) were recorded (500 Hz) during the grand plie (lowering, squatting and rising). This movement was tested with the feet parallel and with both lower limbs turned out (foot angle >140°), with eyes open (EO) and eyes closed (EC). Groups were compared using Student t -tests. Repeated analysis of variance was used to examine the effects of eyes and foot conditions, with a significance level of p  Results The results of this study showed that dynamic postural strategies during the “grand plie” ballet movement are influenced by age, foot position and visual condition. CoP displacement length (p  Conclusion The effect of foot position was greatest with EO. The parallel position was less stable. The YD were more unstable in the parallel position, particularly with EC. For both groups, the lack of vision increased instability. These results show the importance of integrating balance training in a variety of foot positions and visual conditions, particularly during the initial stages of training to prevent injury.