Background: Posturography is a diagnostic technique that quantifies postural control through Centre of Pressure (CoP) displacement analysis on a force platform. Footwear characteristics, particularly heel-to-toe drop, may influence balance by modifying plantar pressure distribution and proprioceptive feedback. The aim of this study was to evaluate the impact of different footwear drops (0 mm, 5 mm, 10 mm) on postural control in healthy young adults, considering sex, BMI, and shoe size. Methods: A cross-sectional study was conducted in 117 participants (56 men, 61 women) using the Dinascan/IBV ^® platform and the Romberg test. CoP displacement and velocity were analyzed. Results: Significant differences were observed in CoP total displacement ( p < 0.001), mean velocity ( p < 0.001), and medio-lateral dispersion ( p = 0.024) when comparing 0 mm to 5 mm and 10 mm drops. Sex differences were significant at 0 mm drop for maximum medio-lateral force ( p < 0.001) and mean velocity ( p = 0.042), with men exhibiting greater values. At 5 mm drop, men showed significantly higher swept area ( p = 0.029) and anteroposterior displacement ( p = 0.007) than women. Conclusions: Small variations in footwear drop can affect postural control, particularly in the medio-lateral plane. Sex and BMI significantly influence CoP behavior, suggesting the need to consider these factors in footwear design and clinical balance assessments.

Introduction and Objectives: The thickness of the plantar fat pad (PFP) beneath the metatarsal heads may play a protective role in preventing forefoot disorders such as metatarsalgia. However, reference values for plantar adipose tissue thickness in this region among healthy individuals are currently unavailable. Therefore, the aim of this study was to determine, by means of ultrasound imaging, the thickness of the PFP beneath the five metatarsal heads and to analyze its possible relationship with body mass index (BMI). Materials and Methods: Thirty-five young adults (17 males and 18 females) with neutral feet, free from deformities or pain, participated in the study. Using a VINNO E35 ultrasound device, the thickness of the PFP beneath each of the five metatarsal heads was quantified. A linear transducer was positioned longitudinally along the axis of each metatarsal. The distance between the dermis and the flexor tendon was measured from the second to the fifth metatarsal heads, and from the fibular sesamoid for the first metatarsal head. Results: The central forefoot showed the greatest PFP thickness (2nd metatarsal head, 7.1 ± 0.9 mm; 3rd metatarsal head, 6.9 ± 0.9 mm). No significant differences in PFP thickness were found between sexes. However, a positive correlation was observed between BMI and PFP thickness at the fourth metatarsal head (r = 0.358, p = 0.035). Conclusions: The study demonstrated greater PFP thickness beneath the second and third metatarsal heads, with no significant sex-related differences. These findings indicate a consistent anatomical pattern independent of sex in young, healthy individuals. Moreover, a moderate influence of BMI was identified at the fourth metatarsal head, which could represent a potential protective mechanism against forefoot overload.

Sports footwear is widely used across a range of physical activities. A key factor distinguishing running shoes from other types of footwear is the “drop,” the millimeter difference between the heel and the forefoot. This study aimed to analyze the influence of different drops (0, 5, and 10 mm) on ground reaction forces during walking and to examine the effects of sex and body mass index (BMI) under these conditions. An observational, descriptive, and cross-sectional study was conducted with 117 participants (56 men and 61 women). The Dinascan/IBV^® dynamometric platform (Instituto de Biomecánica de Valencia, Valencia, Spain) was used to measure ground reaction forces during walking (braking, take-off, propulsion, and swing forces), walking speed, and stance time. The descriptive analysis revealed comparable values for the left and right limbs, with slightly higher values observed in the right limb. Statistically significant differences were found in stance time, braking force, and swing force between the 0 mm and 10 mm drop conditions. Take-off force showed highly significant differences when comparing the 0–5 mm and 0–10 mm drop conditions. Sex-based differences were observed in all variables at the initial proposed drop condition of 0 mm, except for walking speed, possibly due to anatomical and physiological differences. Significant differences were found in stance time at 0 mm drop, braking force, and propulsion force. Highly significant values were obtained for take-off force and during the swing phase. A strong correlation was found between ground reaction forces and BMI with the different proposed drops in all forces studied, except for the support force, where a moderate correlation was obtained. Although shoe drop was found to influence ground reaction forces in this study, it is one of several factors that affect gait biomechanics. Other footwear characteristics, such as sole stiffness, material composition, weight, and elasticity, also play important roles in walking performance. Therefore, shoe drop should be considered an important but not exclusive parameter when selecting footwear. However, these results are limited to healthy young adults and may not be generalizable to other age groups or populations.