A fatal fall from a balcony? A biomechanical approach to resolving conflicting witness accounts.
An adult male was found below a third floor balcony having sustained fatal head injuries. An account provided by a witness described how the deceased had been in high spirits and had engaged in swinging from the third floor balcony rail in an attempt to swing onto a lower second floor balcony and whilst doing so had lost his grip and fallen (10.67 metres) to the ground below. A conflicting account was provided, some weeks later, by a second witness, who claimed to have observed an argument between two men on a third floor balcony, during which one had vigorously pushed the other over the balcony rail. The push, it was alleged, caused the man to move very quickly over the balcony rail and fall in an 'upturned crucifix' position to the ground. This paper describes a series of biomechanical experiments, conducted on a reconstruction of the third floor balcony and the second floor balcony rail, during which a volunteer was subjected to the two fall scenarios, in an attempt to resolve the conflicting witness accounts. Analysis of human movement was performed using a 3-D motion analysis system, markers were placed at the volunteer's key joint centres and were tracked to determine physical parameters. The parameter values were used to calculate what dynamic movements may have occurred had the volunteer been allowed to fall, not just a distance equivalent to the lower balcony rail but a greater distance, equivalent to that between the balcony and the ground. Calculations indicate that during the hanging-fall scenario a range of body rotation was produced between 159 degrees and 249 degrees, that is, an upturned head-first body orientation, consistent with that required to produce the described injuries and consistent with the description provided by the first witness. The push-fall scenario, however, produced a greater estimated body rotation of between 329 degrees and 530 degrees, equal to the body rotating, from the point of free-fall to the moment of impact, between almost 1 and 1.5 times. This was consistent with the described injuries but inconsistent with the description provided by the second witness. It was therefore concluded that although both the accidental and inflicted-push scenarios could produce a body orientation consistent with the reported injuries, only the accidental scenario produced a fall which could be described as an 'upturned crucifix', since the push scenario produced a significantly greater body rotation. The witness who alleged that the deceased had been pushed later retracted his statement.
Jones
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MD
Institute of Medical Engineering and Medical Physics, Cardiff School of Engineering, Cardiff University, P.O. Box 685, The Parade, Cardiff CF24 3TA, Wales, UK. Jonesmd1@Cardiff.ac.uk
Cory
C Z
CZ
D000058:Accidental Falls; D001696:Biomechanical Phenomena; D005554:Forensic Medicine / Q000379:methods*; D006801:Humans; D008297:Male; D008954:Models, Biological