Effect of prefabricated thermoformable foot orthoses on plantar surface temperature after running: A gender...

There is a lack of evidence about the effect of different type of foot orthoses on plantar surface temperature. Moreover, that effect could be different depending on gender due to anatomical and physiological differences between men and women. The aim of the study was to analyze the effect of a prefabricated thermoformable foot orthosis on plantar surface temperature after running and taking gender differences into account. Thirty recreational runners (15 males, mean (standard deviation): 28 (7) years, 69.7 (6.5) kg, 1.74 (0.05) cm and 22.9 (1.7) kg/m²; and 15 females: 35 (7) years, 55.2 (6.9) kg, 1.63 (0.06) cm and 20.6 (1.9) kg/m²) carried out a maximum incremental test as pre-test, and two running tests on a treadmill at the laboratory wearing previously randomized different foot orthoses (thermoformable and prefabricated generic). The plantar surface temperature of the dominant foot sole in ten regions of interest was assessed before and immediately after 30-min running at 75% of VO_2max. The use of thermoformable foot orthoses produced lower temperatures only in men after the run in medial heel (P = 0.033, ES = 0.7), which then disappeared in temperature variation (after - before) (P = 0.910). Regarding gender, women showed lower temperatures before the run in both orthosis conditions (P < 0.039, ES > 0.8), but no differences in temperatures after the run (P = 0.910) in comparison with men. Moreover, absolute temperatures after running were always greater than before the run (P < 0.001, ES > 5.0). In conclusion, the thermoformable foot orthoses do not modify plantar surface temperature after running in healthy runners of either gender, compared to prefabricated generic foot orthoses. Although women present lower baseline plantar temperatures than men, these differences disappear after exercise.