Thermal Asymmetries and Mean Foot Temperature

Foot problems can cause pain and discomfort, limiting the activities of many individuals. Infrared thermography may be useful for early detection of abnormal temperatures using various ways of calculating the mean foot temperature (MFT) to analyze asymmetries and differences between different groups. The aim of this study was to compare two protocols for calculating the MFT, identifying the magnitude of asymmetries in several regions and their correlations with the forehead temperature and brain temperature tunnel(BTT).Nineteen healthy volunteers of both genders aged between 18 and 55 years participated in the study.Data collection included anamnesis, body mass measurement, stature, glycaemia, body core temperature and acquisition of thermal images of the feet and face. The Wilcoxon test revealed that the mean foot temperature calculated using hallux, 2^nd, 3^rd, 4^th and 5^th toes, 1^st, 3^rd and 5^th metatarsal heads and heel, was lower than that calculated without the four lesser toes (Z = -2.636, p = 0.008).However, the asymmetry between the two feet was the same in both cases (medianof 0.4 °C). The correlations of the MFT with the forehead temperature and BTT were positive and significant for the two forms of calculation, and the correlation was stronger when all toes were used to calculate the mean (forehead: ρ = 0.654, p = 0.002, BTT: ρ = 0.617, p = 0.005). The study showed the relevance of the toes in the analysis of the MFT, and it may be important to evaluate asymmetries in the toes to detect abnormal thermal patterns. This finding suggests that it is preferable to use MFT calculated with all toes.