Internal and Imagined External Foci of Attention Do Not Influence Pirouette Performance in Ballet Dancers.

Ballet dancers need to constantly improve their performance. Several studies show that an internal focus (on body movements) leads to inferior motor performance relative to an external focus of attention (on the movement effects), but the majority of dancers usually adopt an internal focus. It is not clear if the benefits of an external focus are relevant for form-based tasks performed in a ballet. Purpose: Test whether an imagined external focus of attention can improve ballet dancers' performance of a form-based task, the en dehors double pirouette (EDDP). Method: 23 experienced amateurs and 17 professional dancers between 18 and 35 years old performed three EDDP under each of three attentional focus instruction conditions (No Focus, Internal, Imagined External). Order of presentation of Internal and Imagined External focus instructions was blocked and balanced across participants. Movement quality was assessed by three experts with a customized observational scale. Movement kinematics were measured by the angle of inclination of the trunk and inclination of the rotation axis with respect to the global vertical during the EDDP. Results: Movement quality and trunk inclination were significantly different between amateurs and professionals, but the rotation axis inclination was not. No quantitative or qualitative effects of focus were found for the performance of the EDDP across focus conditions. Conclusions: There appears to be no differential effects of using an internal or imagined external focus on the immediate performance of the EDDP for amateur and professional ballet dancers. Personal and task factors might account for the lack of effects.

Muscular performance characterization in athletes: a new perspective on isokinetic variables

Background: Isokinetic dynamometry allows the measurement of several variables related to muscular performance, many of which are seldom used, while others are redundantly applied to the characterization of muscle function. Objectives: The present study aimed to establish the particular features of muscle function that are captured by the variables currently included in isokinetic assessment and to determine which variables best represent these features in order to achieve a more objective interpretation of muscular performance. Method: This study included 235 male athletes. They performed isokinetic tests of concentric knee flexion and extension of the dominant leg at a velocity of 60º/s. An exploratory factor analysis was performed. Results: The findings demonstrated that isokinetic variables can characterize more than muscle torque production and pointed to the presence of 5 factors that enabled the characterization of muscular performance according to 5 different domains or constructs. Conclusions: The constructs can be described by torque generation capacity; variation of the torque generation capacity along repetitions; movement deceleration capacity; mechanical/physiological factors of torque generation; and acceleration capacity (torque development). Fewer than eight out of sixteen variables are enough to characterize these five constructs. Our results suggest that these variables and these 5 domains may lead to a more systematic and optimized interpretation of isokinetic assessments. .