The effects of loaded, unloaded, dynamic, and static activities on foot volumetrics

Do the feet of male and female netball players differ in shape? Implications for shoe design

A large proportion of netball players suffer foot-related problems and pain and are dissatisfied with current netball-specific footwear. To improve the fit and functionality of netball-specific shoes, we must understand the shape of these players' feet and determine whether any sex differences exist. Five hundred and two representative-level netball players (n = 251 male; n = 251 female) had their feet three-dimensionally scanned. We then used a validated MATLAB code to automatically extract 10 measurements to characterise each participant's foot shape. Differences between men and women for the absolute values and those normalised to foot length and stature were identified using independent samples t-tests with a Bonferroni adjusted alpha level. The size and shape of male netball players' feet differed significantly from their female counterparts. Males had significantly larger absolute and normalised foot measurements than females, notably at the ball of the foot, heel and instep (p < 0.001). Netball shoe manufacturers should develop unique lasts for each sex and foot size and should offer a more extensive range of shoe lengths and widths to netball players. Such considerations will help optimise shoe fit and comfort and, in turn, reduce foot-related problems and pain associated with ill-fitting footwear.

Influence of badminton practice on calcaneal bone stiffness and plantar pressure

Objectives: The aim of this study was to analyze the plantar pressures and bone stiffness of the calcaneus in badminton players compare to healthy participants, as well as to detect possible asymmetries and chronic adaptations derived from the prolonged practice of badminton.Methods: Twenty-two badminton players (35.2 ± 13.6 years, 169.4 ± 8.2 cm, 67.6 ± 13.7 kg) and 30 healthy controls (32.2 ± 12.8 years, 170.7 ± 9.5 cm, 66.25 ± 14.84 kg) volunteered to participate in this investigation. A Footwork® Pro pressure platform was used to study plantar pressures and an Achilles® bone scanner was used to record the bone stiffness of the calcaneus. The variables analyzed were plantar surface, percentage of force per area (forefoot and hindfoot), distance between the center of pressure and the projection of the center of mass in standing, and calcaneal bone stiffness.Results: The values of bone stiffness of the calcaneus were higher in badminton players than control group in the dominant lower limb (Badminton = 114.32 ± 18.97 U.A. vs. Control = 102.07 ± 16.36 U.A.; p = 0.019) and non-dominant lower limb (Badminton = 115.12 ± 21.95 U.A. vs Control = 101.37 ± 15.72 U.A.; p = 0.014). Badminton players showed asymmetric values in mean pressure (dominant = 35.41 ± 6.05 Kpa vs. non-dominant = 39.21 ± 6.54 Kpa; p = 0.011) and distance among center of pressure of each foot and center of mass (dominant = 11.28 ± 1.65 cm vs. non-dominant = 10.48 ± 1.63 cm; p = 0.025).Conclusions: The calcaneal stiffness of the badminton players was higher than control group, which places badminton in the category of osteogenic sports. The badminton players showed an asymmetric pattern during the static balance, which may be an indicative of asymmetries derived from the continued practice of badminton.

[Does a Physical Education lesson affect the foot morphology in school-aged children?]

BACKGROUND

To analyze the changes in foot morphology in school-age children, after a Physical Education lesson.

METHODS

A total of 10 school-age children (5 girls and 5 boys) were recruited with a mean age of 9.3 ± 0.5 years that voluntary participated in this study. Measurements of both feet were obtained using a 3D foot digitizer model IFU-S-01 (Japan) in two different moments, before and after a physical education lesson (per-exercise and post-exercise), where different activities involving displacements, jumps and landings were performed.

RESULTS

By comparing foot morphology before and after exercise, significant differences in the arch height were found, which increased after exercise (p<0.05). The ball width shows greater changes after exercise but without significant differences (p= 0.07; effect size [ES] = 0.2). Furthermore, a positive correlation between the ball width and the arch height (p<0.05) and negative correlation between the distance from the heel to the first metatarsal and the ball width (r = - 0.7; p<0.05), were observed.

CONCLUSIONS

The type of activities undertaken during physical education lesson (displacements, jumps and landings) increased the pressure on the forefoot, which would lead to a lager arch height. Development of children's sport footwear systems should take into account the foot lengths, widths and heights, for a better fit, preventing future musculoskeletal injuries.