## 4 Discussion  
This review aimed to use foot ulcers as a prognostic tool to analyse the response of plantar tissue to daily physical activity while considering different plantar pressure and temperature variables in healthy and diabetic patients. The results of the various studies indicated that the quantity and type of activities examined to date were heterogeneous [28; 30], resulting in significant inter-individual variations in accumulated load within plantar tissues. The research considered here [28; 30] reached a consensus that plantar pressure and temperature increase during walking and other weight-bearing actions. This activity can be studied via thermography, which may facilitate the evaluation of skin degradation and the prevention of injuries in plantar tissues. [PERSON] et al. [30] observed a weak association between the maximum pressures recorded during walking and those recorded in the same participant during other daily activities. This finding indicates that foot pressure during walking may not accurately reflect the loads on plantar tissues during other activities of daily living. The authors argue that the magnitude and distribution of pressures in healthy individuals vary with different types of activity and walking speeds. This may explain why patients at risk of skin ulceration could not be identified based on a predetermined pressure threshold during ambulation and other physical activities. [PERSON] et al. [31] registered the foot temperature in two different age groups of participants (eighteen healthy volunteers: a group of eight subjects aged between 30 and 40 years old, and another group of ten subjects aged over 40 years old) while walking on a treadmill for 45 min. It was observed that there was a progressive increase in temperature as a result of walking cadence (5 \({}^{\circ}\)C over the first 23 min at a cadence of 80, 100 and 120 steps/minute). However, after 45 min of walking, the final temperature did not vary when compared with the baseline. This result was consistent with the findings of a subsequent study by [PERSON] et al. [32], although the majority of the participants in the latter study were older (mean = 70 years) and the increase in temperature observed after walking for 30 min at 3 km/h was also lower (4 \({}^{\circ}\)C). Nevertheless, both studies indicate that there was a notable stabilisation or plateau effect on foot temperature during walking. The concept of a foot temperature plateau appears to be a reasonable assumption, given the physiological mechanisms that support heat generation, including muscle contractions, friction forces or viscoelastic heating, as well as factors that control heat loss, such as radiation, conduction and evaporation. However, further investigation would be required to confirm this hypothesis and explore its underlying mechanisms. Regardless, blood flow can either increase or dissipate temperature in different contexts. In this line of research, [PERSON] et al. [33] developed a model to describe the phenomenon of heat transfer in shed feet. This model was designed to predict the temperature of the sole of the foot, with a particular focus on the plantar arch and metatararsal area. Furthermore, the authors considered the impact of heat loss due to sweating during walking and running. They observed a maximum increase in foot temperature of 6 \({}^{\circ}\)C, 8 \({}^{\circ}\)C and 11.5 \({}^{\circ}\)C, respectively, after 30 min at speeds of 3, 6 and 9 km/h. The mean age of the participants in this latter study was 23.8 years. As observed in previous studies [31; 32], the increase in temperature during walking and running was greater in younger participants. [PERSON] et al. [33] demonstrated that the cooling of the plantar arch and metatararsal area as a thermoregulatory mechanism through sweating was minimal at a speed of 3 km/h. However, this mechanism became apparent in the plantar arch area after 15 min at 9 km/h and at 20 min at 6 km/h, although sweat in the metatararsal area was negligible at all of these speeds.