Understanding the relationship between movement variability and body image is essential in disciplines where motor control and body perception are closely linked, such as dance. The present study with 24 ballet dancers presents a computational approach for detecting moments of loss of control in elbow movement fluidity. This serves as an objective proxy for body image and body awareness, as subtle disruptions in movement, especially in joints that are not the primary focus of technical training, can reflect increased self-monitoring or discomfort, factors commonly associated with negative body image in dancers. Through movement analysis during two common rehearsal contexts (i.e., marking choreography and full execution with music) we examined how movement variability differs based on task demands. Our findings show that loss of control moments are more frequent during marking, underscoring the influence of rehearsal context on both motor performance and body-related self-perception. Furthermore, we demonstrate that movement instability in the elbow joint can be associated with self-reported measures of body image and awareness, reinforcing the connection between motor variability and psychological well-being. By identifying the elbow as a sensitive and reliable indicator of instability during ballet practice, our approach offers a lightweight alternative to full-body kinematic analysis, supporting practical applications beyond laboratory settings. From a Human-Computer Interaction (HCI) and Ubiquitous Computing (Ubicomp) perspective, this work contributes design insights for systems that integrate body image and movement behavior metrics. These findings open new possibilities for interactive technologies aimed at enhancing body image and improving movement precision in dancers and other movement practitioners. • A computational approach to detect moments of loss of control in elbow movement fluidity, offering an objective proxy for assessing body image factors during ballet practice. • Loss of control differs between marking and choreography execution with music. • The isolation of the elbow joint can reliably capture motor variability and psychological influences during ballet practice, providing an efficient alternative to full-body assessments. • Key insights into how moments of loss of control in movement relate to body image disturbances.

In ballet, synchronizing movement with music is essential for both technical precision and expressive performance. However, younger dancers often struggle with abstract concepts such as timing due to the lack of continuous, personalized feedback in traditional instruction. This paper introduces KneeEcho Box, an interactive sonification interface for ballet training that uses real-time computer vision to track knee movements during the plié and translates them into MIDI-based xylophone tones, reminiscent of a music box. KneeEcho Box was evaluated in a between-subjects study with 22 young ballet dancers. Results show that sonification enhanced movement precision, spatiotemporal awareness, and user engagement, particularly among younger participants. These findings suggest that integrating interactive auditory feedback into ballet practice can enrich traditional instruction and open new avenues for research at the intersection of human–computer interaction and the performing arts.

Sensory technologies alter how we perceive our body, which can have profound implications for multiple domains. Prior work has contributed a myriad of artefacts and evaluative studies, but we still lack design knowledge to design meaningful body perception alterations facilitated by sensory technologies. To address this gap, we draw from soma design to propose a methodological approach centered on body sensations as design material. We articulate our approach based on a project on co-designing wearables to alter body perception together with professional dancers. Our approach involves engaging participants in articulating and sharing body sensations to others, and exploring somatically sensory stimuli to co-design concepts for future technologies. We contribute experiential facets of body sensations, movement and sensory potentials to alter sensations, methods and design strategies, and a collection of ideas. Our work can be relevant to design communities interested in sensory technologies, perceptual alterations and body sensations as material.