Hainsworth S V, Delaney R J, Rutty G N
Department of Engineering, University of Leicester, Leicester, UK.
Int J Legal Med. 2008 Jul;122(4):281-91. doi: 10.1007/s00414-007-0202-6. Epub 2007 Sep 27.
Stabbing is the most common method for violent death in the UK. As part of their investigation, forensic pathologists are commonly asked to estimate or quantify the degree of force required to create a wound. The force required to penetrate the skin and body by a knife is a complex function of the sharpness of the knife, the area of the body and alignment with cleavage lines of the skin, the angle of attack and the relative movement of the person stabbing relative to the victim being stabbed. This makes it difficult for the forensic pathologist to give an objective answer to the question; hence, subjective estimations are often used. One area where some degree of quantification is more tractable is in assessing how sharp an implement (particularly a knife) is. This paper presents results of a systematic study of how the different aspects of knife geometry influence sharpness and presents a simple test for assessing knife sharpness using drop testing. The results show that the radius of the blunt edge at the tip is important for controlling the penetration ability of a kitchen knife. Using high-speed video, it also gives insight into the mechanism of knife penetration into the skin. The results of the study will aid pathologists in giving a more informed answer to the question of the degree of force used in stabbing.
在英国，刺伤是暴力死亡最常见的方式。作为调查工作的一部分，法医病理学家通常会被要求估算或量化造成伤口所需的力的大小。刀具刺入皮肤和身体所需的力是一个复杂的函数，它取决于刀具的锋利程度、身体部位、与皮肤纹理的对齐情况、攻击角度以及持刀者相对于被刺受害者的相对运动。这使得法医病理学家很难对该问题给出客观的答案；因此，常常采用主观估计。在评估工具（尤其是刀具）的锋利程度时，某种程度的量化处理相对更容易一些。本文展示了一项关于刀具几何形状的不同方面如何影响锋利程度的系统研究结果，并提出了一种使用跌落测试来评估刀具锋利程度的简单方法。结果表明，刀尖钝边的半径对于控制菜刀的穿透能力很重要。通过高速视频，该研究还深入了解了刀具刺入皮肤的机制。研究结果将有助于病理学家更全面地回答刺伤所用的力的大小这一问题。
