Friday, May 04, 2012

Foot forensics: Gender?

Dimensions of the human foot can be used for the determination of sex and stature of an individual in forensic investigations. This is especially important in cases when the common skeletal elements used to assess sex are absent or damaged. What may appear to the layperson a simple task is very complex and experts have developed several ways in which to discriminate gender including a foot index. The formula involves dividing the foot breadth by foot length then multiplying it by hundred. On average the foot index is slightly higher in females in the right foot and males in the left foot. Despite apparent foot length and foot breadth showing significant sex differences, critics believe sex determination cannot be made conclusively from the foot index. Another method involves careful measurement of the calcaneus (heel bone). Measuremens include maximum length, load-arm length, load-arm width, and posterior circumference of the bone. Using a discriminant function, based on all four variables, the overall cross-validated classification rate of 86.69% was established. In studies females were classified correctly in 88.64% of the cases and males were correctly classified in 84.75% of the cases. This method has proven useful but not full proof. Other anthropodmeric studies have also found different patterns of morpological variation of the calcaneus and cuboid can also be used to discriminate gender.

Further Reading

Dimichele DL, Spradley MK. 2012 Sex estimation in a modern American osteological sample using a discriminant function analysis from the calcaneus. Forensic Sci Int. 2012 Apr 16.
Moudgil R, Kaur R, Menezes RG, Kanchan T, Garg RK. 2008 Foot index: Is it a tool for sex determination? J Forensic Leg Med. 2008 May;15(4):223-6.

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