Abhängigkeit der Stichkraft von der Klingenform – Entwicklung eines experimentellen Setups und erste Ergebnisse

Abstract

Abstract Background In court proceedings, forensic and biomechanical experts frequently have to estimate the stabbing forces necessary for a certain pattern of injury. Studies on this topic are rare. Objective Development and calibration of an experimental set-up for quantification of dynamic stabbing kinematics and forces. Investigation of the influence of different shaped blades on stabbing forces. Material and methods We developed and calibrated a handle with an integrated force sensor and an accelerometer. Different blades can be attached to the handle. A total of 27 stabbings were performed by 1 volunteer at medium intensity and preferably reproducible stabbing velocities. We used three blades with different shapes. Gelatine served as tissue simulant. Maximum stabbing velocities were captured via two-dimensional high-speed videography. Results The force sensor calibration resulted in a nearly perfect linear regression. Stabbing velocities ranged between 2.7 and 5.0 m/s with stabbing forces between 54.8 and 129.3 N. Stabbing with the blunt blade resulted in significantly higher stabbing forces compared to pointed and serrated blades. A similar trend was observed for serrated versus pointed blades, but without statistical significance. A significant dependency of the stabbing velocity on stabbing force could only be proven for the serrated blade. Conclusion Blade shape and stabbing velocity are factors that can influence the resultant stabbing force. Reliable case evaluation needs the consideration of case-specific knives and circumstances.