A study of limb asymmetry and its effect on estimation of stature in forensic case work.

Estimation of stature is an important parameter in identification of commingled, mutilated and skeletal remains in forensic examinations. Bilateral asymmetry is defined as the difference between the measurements of the left and right sides of the human body. While estimating stature from skeletal material as well as from body parts in forensic anthropology case work, asymmetry of the human body may result in erroneous estimates due to bilateral variations present in dimensions of the human body and bones. The purpose of the present study was to evaluate asymmetry in upper and lower extremity dimensions in a north Indian population and to see its effect on the estimation of stature from these dimensions. The study was based on a sample of right-handed 967 adult male Gujjars, an endogamous group of North India. Bilateral asymmetry was assessed in six limb dimensions i.e. total upper extremity length, upper arm length, forearm length, hand length, total lower extremity length and lower leg length using a paired t-test. The results indicated that statistical significant bilateral asymmetry exists in total upper extremity length, upper arm length, forearm length, total lower extremity length and lower leg length (p<0.01). Correlation coefficients of various dimensions of upper and lower extremities with stature were found to be highly significant (p<0.001). Regression equations were calculated for estimation of stature from these limb dimensions using both left and right sides. The study concludes that there is a higher possibility of obtaining erroneous results while estimating stature from those body dimensions which show statistically significant bilateral asymmetry when formula developed from one side is used on the other side. Although, there seems to be a little possibility of obtaining erroneous results while estimating stature from those body dimensions which showed statistically insignificant asymmetry, it is strongly recommended that the examiner must first identify the side to which the limb part or bone belongs to, and then apply the appropriate formula derived for that particular side.