Abstract

Background. Tango is a dance that holds potential as a therapeutic intervention to improve gait, balance, and quality of life, particularly in populations with locomotor impairments. Despite growing clinical interest, quantitative evidence integrating biomechanical and metabolic aspects of tango walking remains scarce. Tango walking, especially in the leader role, involves aesthetic and technical modifications of normal gait, including altered posture, which may affect locomotor economy. This study aimed to quantify the metabolic cost, mechanical work, and center-of-mass (CoM) dynamics of tango walking, and to compare these variables with those of self-selected walking performed at similar speeds. We hypothesized that (i) tango walking would increase the cost of transport (CoT) and reduce locomotor efficiency, and (ii) these changes would be associated with modifications in CoM mechanics, joint kinematics, and spatio-temporal gait parameters.
Methods. Seventeen tango dancers participated in the study, performing two 5-minute trials: self-selected walking and tango walking in the leader role to a Milonga music. Oxygen consumption was measured using a portable metabolic system to compute net metabolic power and CoT. Whole-body kinematics were recorded using a 3D motion capture system to reconstruct CoM trajectories and compute spatio-temporal parameters, mechanical work, energy recovery, and related metrics. Statistical comparisons between conditions were performed using paired tests for discrete variables and Statistical Parametric Mapping (SPM) for time-series data.
Results. Walking speed and basic spatio-temporal parameters did not differ significantly between conditions. However, tango walking elicited a significantly higher metabolic power and CoT (≈ +50%) and a lower locomotor efficiency compared with self-selected walking. Mechanical work variables did not differ significantly between conditions, although tango walking exhibited substantially higher variability, particularly in the internal work, energy recovery indices, and temporal gait parameters. SPM analyses revealed significant differences in CoM trajectories, with reduced lateral CoM oscillations during tango walking, especially during mid-stance. Knee joint kinematics showed significantly greater flexion throughout the stance phase in tango walking.
Conclusions. The aesthetic variations within Tango, particularly at milonga rhythm, significantly increase metabolic demands without a proportional increase in mechanical work. Notable changes in the lower limb kinematics and CoM trajectory align with this increased metabolic demand. The increased variability suggests that the Tango gait requires more balance control than walking, potentially leading to greater muscle activity, primarily due to co-contractions. Our findings support Tango's use in rehabilitation; however, further research is needed to fully understand the underlying reasons for these changes.