Individual and Task-Specific Variability in Violin-Playing Kinematics Among Professional and Amateur Performers: A Pilot Motion-Capture Study.

Background Violin performance requires coordinated multi-joint and postural control, and performers may adopt different movement strategies. This pilot study primarily described participant-level heterogeneity and task-specific kinematic patterns in professional and amateur violinists, with secondary exploratory screening for nonoverlapping group ranges. Methods Six violinists (three professional and three amateur) were assessed using a 16-camera Vicon motion-capture system (Vicon Motion Systems Ltd., Oxford, UK) during a standardized phase using the same violin, bow, and shoulder rest. Three tasks with complete data were analyzed: a four-note slurred scale, a spiccato scale, and a concerto excerpt. Ten kinematic outcomes were derived from right upper-limb geometric proxy angles, pelvic-center displacement variability, and wrist path length. Analyses were descriptive and hypothesis-generating. Thirty task × outcome combinations were screened for complete nonoverlap between groups; with three participants per group, approximately three such combinations are expected by chance. Results Substantial interindividual heterogeneity was observed within both groups. Three of 30 task × outcome combinations showed nonoverlapping ranges, matching the number expected by chance, and none recurred across tasks. During spiccato, anteroposterior and vertical pelvic-center displacement variability were higher in all professionals; during the concerto excerpt, right wrist proxy-angle temporal variability was lower in all professionals. The 0.15-mm vertical pelvic-center separation was not interpreted as meaningful because study-specific measurement precision was not established. Conclusions No kinematic pattern consistently distinguished professional from amateur performers across tasks. The dominant finding was substantial participant-level heterogeneity and task-specific kinematic variation. Larger studies with repeated measurements and prospectively assessed playing-related musculoskeletal symptoms are needed to evaluate the clinical relevance of individualized movement profiles.