ORIGINAL ARTICLE Biomechanical assessment of various punching techniques Jiri Adamec 1 & Peter Hofer 2 & Stefan Pittner 2 & Fabio Monticelli 2 & Matthias Graw 1 & Jutta Schöpfer 1 Received: 19 August 2020 /Accepted: 2 October 2020 # The Author(s) 2020 Abstract Punches without the use of instruments/objects are a common type of body violence and as such a frequent subject of medicolegal analyses. The assessment of the injuries occurred as well as of the potential of the assault to produce severe body harm is based on objective traces (especially the documented injuries of both parties involved) as well as the—often divergent—descriptions of the event. Quantitative data regarding the punching characteristics that could be used for the assessment are rare and originate mostly in sports science. The aim of this study was to provide physical data enabling/facilitating the assessment of various punching techniques. A total of 50 volunteers took part in our study (29 males and 21 females) and performed severe punches with the fist, with the small finger edge of the hand (karate chop), and with the open hand with both the dominant and the non-dominant hands in randomized order. The strikes were performed on a boxing pad attached to a KISTLER force plate (sampling frequency 10,000 Hz) mounted on a vertical wall. The punching velocity was defined as the hand velocity over the last 10 cm prior to the contact to the pad and ascertained by using a high-speed camera (2000 Hz). Apart from the strike velocity, the maximum force, the impulse (the integral of the force-time curve), the impact duration, and the effective mass of the punch (the ratio between the impulse and the strike velocity) were measured/calculated. The results show a various degree of dependence of the physical parameters of the strikes on the punching technique, gender, hand used, body weight, and other factors. On the other hand, a high degree of variability was observed that is likely attributable to individual punching capabilities. In a follow-up study, we plan to compare the “ordinary” persons with highly trained (boxers etc.) individuals. Even though the results must be interpreted with great caution and a direct transfer of the quantitative parameters to real-world situations is in general terms not possible, the study offers valuable insights and a solid basis for a qualified forensic medical/biomechanical assessment. Keywords Punch . Impulse . Fist . Open hand . Forensic biomechanics Introduction Punches are a common kind of body violence and are being assessed on a regular basis in expert witness testimonies. Apart from the correspondence between the asserted assault and the documented injuries, often questions are raised regarding the punch intensity (both the actual and the hypothetically possible for the involved individual and the particular kind of assault) and other biomechanical aspects regarding the specific act of violence (oftentimes with significant differences among the participants and/or witnesses). Considering any rank order of violent acts, there seems to be a general agreement that a strike with the palm is less violent than a fist punch [1], though suf- ficiently objectifiable biomechanical data to support or dismiss this opinion are missing. However, in the current literature, there are also (mostly) individual cases in which comparatively serious injuries are said to have occurred as a result of blows with the open hand so that such a statement must at least be critically questioned [2, 3]. Although there is some knowledge regarding punching ca- pabilities in different settings, mostly related to sports and/or martial arts with punch intensity measured by different methods [4–9], to our knowledge there is no comprehensive study concentrating on forensic aspects of various kinds of strikes and punches with intraindividual and interindividual comparisons. Jiri Adamec and Peter Hofer contributed equally to this work. * Jiri Adamec jiri.adamec@med.uni-muenchen.de Peter Hofer peter.hofer@sbg.ac.at 1 Institute of Legal Medicine, Ludwig-Maximilian-University, Nussbaumst. 26, 80336 Munich, Germany 2 Department of Forensic Medicine, Paris-Lodron University of Salzburg, Ignaz Harrer St. 79, 5020 Salzburg, Austria https://doi.org/10.1007/s00414-020-02440-8 / Published online: 14 October 2020 International Journal of Legal Medicine (2021) 135:853–859