Raya Stoyanova1, Metodi Goshev2, Georgi Chingov3
1Department of Mechanical Engineering, Faculty of Engineering, South-West University Neofit Rilski, Blagoevgrad, Bulgaria.
2Department of Forensic Medicine and Deontology, Faculty of Medicine, Medical University of Sofia, Bulgaria.
3Resident Doctor in Thoracic Surgery at University Hospital of Zurich, Zurich, Switzerland
ORCID IDs: 10000-0001-9633-4467, 20000-0002-7244-3973, 30009-0000-0104-4468
Corresponding Author: Raya Stoyanova, E-mail: rajkach@swu.bg
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https://doi.org/10.63711/ijdr.net20260401
ABSTRACT
Motorcycle road crashes are a specific subject of technical and forensic-medical reconstruction. Unlike occupants of enclosed vehicles, the rider and pillion passenger may become separated from the motorcycle and acquire independent translational and rotational motion. Their subsequent trajectories can involve primary and secondary contacts with another vehicle, the road surface, roadside safety equipment, or fixed objects. Consequently, the injury mechanism is determined not only by the initial collision configuration but by the complete sequence of body motion and contacts.
This study examines pulmonary trauma as a potential linking element between technical reconstruction and forensic-medical assessment. Published clinical, forensic, biomechanical, and transport-safety evidence is structured for pulmonary contusion, pulmonary laceration, pneumothorax, haemothorax, haemopneumothorax, associated rib fractures, and their morphological characteristics. Rider and passenger kinematics are considered separately because their positions on the motorcycle produce different separation times, contact opportunities, and loading pathways.
A bidirectional integrated reconstruction model is proposed. In the forward analytical direction, the sequence is traced from crash mechanism through rider or passenger kinematics, contacts, mechanical loading of the thorax, and pulmonary injury. In the reverse direction, the medical findings are used as an independent consistency criterion for testing the mechanical compatibility of the technically reconstructed mechanism. The model does not treat a single pulmonary lesion as a deterministic marker of one crash mechanism. Across the analysed clinical series, comprising 8,372 injured motorcyclists, the reported frequency of pulmonary contusion or pulmonary injury ranged from 1.47% to 12.5%, pleural complications from 1.61% to 23.6%, and rib fractures from 11.29% to 19.4%. Owing to differences in sample selection and diagnostic grouping, the results are interpreted comparatively and no pooled overall frequency is calculated.
The proposed approach increases the traceability of complex road-accident reconstructions by requiring agreement among technical traces, body kinematics, contact chronology, thoracic loading, and the distribution of injuries. It can also identify injurious contact configurations relevant to motorcycle protection systems and transport safety.
Keywords: Motorcycle crash, Reconstruction, Rider kinematics, Pillion passenger, Pulmonary trauma, Injury biomechanics, Forensic medicine
Research Area: Transportation Engineering, Forensic Medicine, Injury Biomechanics
Copyright © 2026 The Author(s). This article is licensed under CC BY 4.0.
