Do Technical Skills and Natural Predispositions in Ballet Influence Muscle Activity in Turnout? The Pilot Study

Turnout is the base for classical ballet positions. Dancers with no anatomic predispositions often force turnout by excessively rotating their knees, ankles and feet compensating for insufficient hip external rotation. The aim of this research was to examine the electromyographic (EMG) signal from selected muscles of the trunk and lower extremities during standing in five classical ballet positions in female dancers with different technical skills and predispositions. Two professional and two student female ballet dancers participated in the study. EMG activity of selected muscles: lumbar erector spinae, rectus abdominis, gluteus maximus, sartorius, tibialis anterior, peroneus and medial head of gastrocnemius was recorded bilaterally in five classical ballet positions. The recorded EMG signal was analyzed in three ways: “RMS analysis”, “ratio analysis” and “temporal analysis”. Main findings concern little or no abdominal and back muscles activation in classical ballet positions compared to straight standing posture in all dancers regardless of skills or predispositions, greater activation of hip external rotators in professional dancers and greater ankle muscles activity in those without predispositions in classical ballet positions. Presented EMG analysis could complement training session as it would make the technical skills progress assessment more objective.