Fall from a balcony--accidental or homicidal? Reconstruction by numerical simulation.

In the case presented, conflicting witness accounts and the subject's injuries were highly suspicious of an assault that might have caused the balcony fall. For the reconstruction, a simulation software, originally designed for motor vehicle accident reconstruction, was used. Three scenarios were simulated using the PC-Crash multibody pedestrian model: (S1) Subject was pushed against and fell over balcony rail, (S2) subject fell off from a seated position, (S3) subject fell off from a prone position on the rail. (S1) could be ruled out due to inconsistent results in terms of landing area and minimum velocity. Realistic results were obtained for (S3) with a fall off from a prone position on the rail. After a few months, the comatose subject awoke and gave an account of what had happened being consistent with the simulation results. This case demonstrates the feasibility of multibody simulations also in cases of nontraffic incidents.

[The numerical Hatze-model: also qualified for calculations on children?]. / Das numerische Hatze-Modell: Auch für Berechnungen an Kindern geeignet?

The aim of this study was to find out whether the Hatze-model, which is specifically designed for adults, is suitable for calculations on children as well. By means of that program it is possible to calculate various parameters of the human body. After the collection of data and analysis of the results according to Hatze it becomes evident that this model provides good results only for the calculation of the total body mass. As regards the body segments, there are significant under- and overestimations. The same applies to the calculation of mean body density. Indeed there is a significant gender dimorphism indicating that girls have a higher fraction of body fat than boys. However, the values are far below those described in the literature. Due to the formula, the values of the centres of gravity are linear and congruent in both sides of the body. Interpretation of the results is difficult, as there are no valid reference values. Furthermore the program is not able to take characteristic shapes and proportions of children into account. For this reason 88% of the children are defined as either pregnant or obese. In summary, the study shows that the present model should not be used to calculate children and the human models have to be designed specifically for children.