2025 ISAKOS Biennial Congress Paper
Dynamic Rasterstereography Improves the Detection of Movement Delays and Dynamic Asymmetries in the Scapulothoracic Kinematic of Healthy Subjects
Davide Cucchi, MD, Bonn, Deutschland GERMANY
Jonas Moss, MD, Bonn GERMANY
Jan-Marek Meyer, cand. med., Bonn GERMANY
Luisa Nystroem, cand. med., Bonn GERMANY
Filippo Maria Piana Jacquot, MD, Milan ITALY
University Hospital Bonn, Bonn, GERMANY
FDA Status Not Applicable
Summary
Dynamic rasterstereography improves the detection of movement delays and dynamic asymmetries in the scapulothoracic kinematic of healthy subjects
Abstract
Assessing scapulothoracic kinematics typically involves visually observing patients during movement, which has limited inter- and intra-observer reliability. Dynamic rasterstereography (DRS) records, measures, and visualizes surface structures in real-time, using a curvature map to colour-code convex, concave, and saddle-shaped structures on the body surface. This study aimed to evaluate the diagnostic efficacy of DRS-assisted observation in identifying dyskinetic scapulothoracic patterns.
Healthy participants performed shoulder abduction/adduction and flexion/extension cycles without additional weight, recorded using both DRS and a conventional video camera. A metronome ensured consistent timing, and for DRS a grid of parallel light rays projected onto the back surface was captured using indirect optical measurement techniques. The mean surface curvature was converted into a colour scale. The diagnostic performance of conventional and rasterstereography videos in detecting dyskinetic patterns, including static asymmetries, dynamic asymmetries, motion delays, and rapid compensatory movements, was compared. Two investigators independently evaluated the videos twice in a blinded and randomized sequence to assess intra- and inter-rater reproducibility.
Analysis of 118 videos showed good-to-excellent intra-rater and inter-rater reproducibility for both techniques (ICCs 0.727 to 0.949). DRS outperformed conventional videos in detecting movement delays (p=0.0008) and dynamic asymmetries (p=0.0016). However, no differences were found in static asymmetry and rapid compensatory movement detection.
DRS can create a real-time model of the trunk surface, proving superior to conventional observation in detecting movement delays and dynamic asymmetries during shoulder movement. It is a reliable and promising digital technology for enhancing scapular kinematics and dyskinesis assessment in clinical and research settings.