Electromyographic Comparison of the Développé Devant at Barre and Centre

Abstract

This investigation compared the electromyographic (EMC) activity of selected muscle groups of skilled dancers executing the développé devant at barre and in centre. A four-channel Nicolet-Viking Biomedical electrograph system was used to assess muscular activity. Surface electrodes were placed over four muscles: quadriceps femoris, hamstrings, tibialis anterior, and abductor hallucis. The participants performed five trials of the développé devant at barre and centre in randomized order. The dancers performed the six phases of the développé devant (coupé, passé, attitude, full extension, tendu, closure to fifth position) in time with a metronome set in three-quarter time at 144 beats per minute. EMC amplitude was recorded at each of the six time phases (1200, 2400, 3600, 4800, 6000, and 7200 msec, respectively). The EMC values (mV) of the raw amplitude of each phase of the développé devant for each subject were “standardized” by dividing by their respective maximum voluntary contraction (MVC). A four-way ANOVA was used to assess the effects and interactions of subjects, trials, phases, and “treatment” (barre versus centre). Results indicated no significant difference (p < 0.05) between barre and centre for either the quadriceps femoris or hamstring muscle of the gesture leg. The main effect of phase was significant (p < 0.05). There was a significant difference in EMC activity (p < 0.05) between barre and centre for the tibialis anterior and abductor hallucis of the standing leg across phases. Post-hoc analysis indicated that EMC activity of the tibialis anterior and abductor hallucis muscles was significantly greater at centre compared to barre during all phases of the développé devant. It was concluded that the training at barre is an acceptable way of preparing the muscles of the gesture leg, but not the standing leg, for the demands of centre.