Introduction

In the era of recent researches, no two individuals are comparable in their observable qualities. Even genetically identical twins can have some minor differences. Dayananda R, et al. 1 defined anthropometry as a collection of systematic procedures that quantitatively depict the dimensions of the human skeleton. It is considered to be a fundamental instrument of biological anthropology and is finding greater usage in medical science, particularly in the field of forensic medicine. Forensic studies of unidentified human remains have consistently using anthropometry 2.

The determination of a person's gender is a crucial and vital factor in determining their identity 3.

Gender refers to the culturally defined characteristics of a human being, by which it gets associated with the society. Gender determination is a significant and vital factor in determining the identity of an individual. If the entire skeleton is present, determining the sex of an individual becomes very simple. Although the pelvis and skull are the most dependable bones for this purpose. It is becoming crucial to determine the sex from other areas of the skeleton as well because in medico-legal cases, one does not always have a fully developed pelvis or skull 4. DNA technology may be the most precise method for identifying body parts in the event of mass disasters where it is possible to examine numerous dismantled body parts. But still, it is not an affordable method as it is expensive, time-consuming and extensive. The identification by anthropometry becomes more significant, affordable and convenient methods in such massive catastrophes.

Partially damaged bodies and human remains are often encountered in fields, where dismantling, explosion, or other mass disasters took place. The main purpose of investigating the damaged remains is to develop a biological profile that identifies individuals by estimating the age, and gender, which is of prime prerequisite nowadays. Foot dimensions have not been frequently used in investigating these areas. But generally the human foot is mostly shielded by shoes, so the recovery of undestroyed foot becomes more evident at these explosive and disaster sites, making the investigation possible. Hence feet can be an excellent clue regarding personal identity. Also, the foot dimensions vary between populations around the globe which is attributed to factors such as genetics, environment and climatic, different habitat and social conditions. Thus, the present study was conducted to find association of the left foot index in gender determination.

Aim

The aim of the study was to determine gender from the Left Foot Index in Rajasthan adult population.

Materials and Methods

The present study was a cross-sectional, observational and descriptive study. It was conducted in the Department of Anatomy, RUHS College of Medical Sciences (RUHS-CMS), Jaipur.

The study was carried on 407 (207 Males & 200 females) healthy, asymptomatic adults, residing in Rajasthan University of Health Sciences of Rajasthan origin in the age group of 17 to 25 years. The study was approved by Ethical Committee of the institute. Written Informed consent was taken from each subjects.

Inclusion Criteria

Healthy, asymptomatic male and female subjects who were willing to participate and of the age group between 17 and 25 years were included in the study.

Exclusion Criteria

Subjects with apparent physical foot anomalies, inflammation, deformities and surgery (if any), the history of accident or fracture, congenital foot deformity like vertical talus, club foot and systemic chronic illness were excluded for the study.

Measurement of foot dimensions

Digital Sliding caliper was used to measure the foot dimensions.

Foot dimensions included foot length and foot breadth.

Foot Length

It was measured as the distance from the most posterior point of the heel (pterion) to the most anterior point of the longest toe-first or the second toe (accordion) 5.

Foot Breadth

The distance between the most prominent point on the medial aspect of the head of the first metatarsal and the most prominent point on the lateral aspect of head of fifth metatarsal was measured 6.

Left foot was selected for measurement according to the recommendation of the international agreement for paired measurements 7 [Figure 1, Figure 2, Figure 3, Figure 4].

Foot dimensions were measured in centimeters up to two decimal places. All the measurements were recorded thrice and then their mean was calculated for accuracy.

To eliminate the discrepancies due to diurnal variation, the measurements were taken between 2 to 5 p.m. To minimize instrument and inter-observer errors, the same observer carried out all the measurements with the same instrument.

Foot Index (FI)

It was calculated by using the measured foot parameter foot length and foot breadth.

Statistical Analysis

Data collected was entered in Microsoft excel 2010 worksheet in the form of a master chart. The data were subjected to statistical analysis using a statistical package for social sciences (SPSS) version 20. Standard deviation, p-values were obtained. Comparison of mean in two groups was done with an independent t-test.

RESULTS

There were a total of 407 participants in this study (207 males and 200 females). Mean foot length in males was 25.21 (SD±1.1) and in females was 22.83 (SD±1.08). Similarly, mean foot breadth in males was 9.55cm (SD = 0.46) and that in females was 8.72 cm (SD = 0.43). This gender-wise difference in mean foot length and mean foot breadth was statistically significant(p<0.001).

Foot Index was calculated.

Mean foot index in males was 37.89(SD±1.37) and that in females was 38.24 (SD±1.54) This gender-wise difference in Foot Index was found statistically significant(p < 0.001). A significant positive correlation was found in both genders. (Table 1, Table 2).

DISCUSSION

Gender is the key in defining the human being. It is when this is known one gets acceptance, recognition, differentiation in the society. Gender determination thus, became a very important role in knowing the unknown.

With the increase in calamities, and massive disasters where our forensic experts deal with unidentified and dismantled human remains. It becomes essential to analyze the human remains and to whom it belongs.

In the present study, attempts have been made to establish the association of Foot dimensions in predicting gender of a person. For this purpose, Mean foot length, Mean foot breadth and Foot Index of left foot in males and females were calculated.

It was observed that Mean left foot length in males was 25.21 (SD±1.1) and in females was 22.83 (SD±1.08). Similarly, mean left foot breadth in males was 9.55cm (SD = 0.46) and that in females was 8.72cm (SD = 0.43). A positive correlation was found between foot dimensions and gender. Males had an average foot length of 2.38 cm greater than females. Foot breadth in males was also about 1 cm greater as compared to females. This gender wise difference in mean foot length and mean foot breadth was statistically significant (p<0.001).

The Overall Left foot index was more in females greater than 38 (LFI>38) than in males (LFI <38). (Table 3). Thus, this value 38 can be used as a deviation point for gender determination in the adult population. In our study though LFL and LFB was more in males than females in all the age groups. But the difference in Foot Index was observed in both males and females at different age groups. This states that although foot parameters are interdependent on each other still they differ in gender at different age groups, this can be related to the growth pattern of the individual.

Our study was in accordance with Agnihotri et al., 8 study on Mauritius population where LFI was greater than 37 in females and less in males, and Singla R et al., 9 study on Haryanvi and North Indian populations where LFI was greater than 37 in females and less in males.

While in other studies, conducted by Jaydip Sen et al 10 on Bengal population LFI was greater than 41 in males and less in females, Kewal Krishan et al 11 on Himachal population LFI was greater than 38 in males and less in females, and Barnabas et al 12 on Nigerian population, LFI was greater than 34 males and less in females. Shaifaly Madan Rustagi et al 13 on medical students, LFI was almost equal in males and females. (Table 4)

It can be attributed to genetic, and environmental factors as one moves to different geographical regions. Also, in areas where survival is dependent on adaptation under climatic and biological changes, the morphological variations are more diverse. Thus these parameters can be utilized for identifying an individual in that particular geographical population. Foot dimensions have a wide range of variations around the globe thus, they can be used as good predictors of gender of an individual in cases of massive disaster, where dismantled foot remains are recovered. By determining a gender one can ease the identification procedure by the experts in less time.

By devising the references point i.e. Mean left foot index, one can easily predict the gender of the unknown person. So, this study will be useful to forensic experts and anthropologists in analyzing foot remains and also by surgeons in reconstructive surgeries.

Limitations of study

The study was conducted on young adults between age group of 17 to 25 years, we hope that this age range covers the age at which fusion of foot bones occurs in population.¹⁶ A wider age group of participants might have produced a different and more accurate prediction of gender from foot index. Similarly, we measured only the left foot as per the recommendation for paired measurements. The results would have been more refined if both feet were considered for measurements.

CONCLUSION

The present study established a definite relationship in determining gender from the Left Foot Index.

Acknowledgement

The author is grateful to Dr. Gireesh Gupta for his constant support & guidance throughout the study.

Financial Support and Sponsorship

The authors declare that they have no funding support for this study.

Conflicts of Interest

The authors declare that there are no conflicts of interest.