Walking cadence affects rate of plantar foot temperature change but not final temperature in younger and older adults

This study examined the relationship between (1) foot temperature in healthy individuals and walking cadence, (2) temperature change at different locations of the foot, and (3) temperature change and its relationship with vertical pressures exerted on the foot. Eighteen healthy adult volunteers (10 between 30 and 40 years - Age: 33.4±2.4years; 8 above 40 years - Age: 54.1±7.7years) were recruited. A custom-made insole with temperature sensors was placed directly onto the plantar surface of the foot and held in position using a sock. The foot was placed on a pressure sensor and the whole system placed in a canvas shoe. Participants visited the lab on three separate occasions when foot temperature and pressure data were recorded during walking on a treadmill at one of three cadences (80, 100, 120steps/min). The plantar foot temperature increased during walking in both age groups 30-40 years: 4.62±2.00°C, >40years: 5.49±2.30°C, with the rise inversely proportional to initial foot temperature (30-40 years: R²=-0.669, >40years: R²=-0.816). Foot temperature changes were not different between the two age groups or the different foot locations and did not depend on vertical pressures. Walking cadence affected the rate of change of plantar foot temperature but not the final measured value and no association between temperature change and vertical pressure was found. These results provide baseline values for comparing foot temperature changes in pathological conditions which could inform understanding of pathophysiology and support development of evidence based healthcare guidelines for managing conditions such as diabetic foot ulceration (DFU).