Comprehensive biomechanical characterization of feet in USMA cadets: Comparison across race, gender, arch flexibility, and foot types

Abstract

Lower extremity musculoskeletal injuries are common, complex, and costly problems. Literature supports associations between static foot structure and dynamic foot function, as well as between overuse injury and demographic characteristics. Previous studies failed to provide a comprehensive biomechanical foot characteristics of at-risk military personnel. In this study, foot structure, function, and arch height flexibility (AHF) were objectively measured in 1090 incoming cadets (16.3% female, mean age of 18.5years and BMI of 24.5kg/m) of the United States Military Academy at the start of their training. A Generalized Linear Model with an identity link function was used to examine the effects of race, gender, foot types, and AHF while accounting for potential dependence in bilateral data. Planus and flexible feet independently demonstrated over-pronation, as measured by reduced Center of Pressure Excursion Index (CPEI). When comparing across race, Black participants showed a significantly lower arch height index (AHI), a larger malleolar valgus index (MVI), and a higher prevalence of pes planus (91.7% versus 73.3% overall). However, Asian participants with flexible arches, rather than Black with low arch, displayed over-pronation in gait. Females showed no significant difference in standing AHI and MVI but demonstrated a significantly greater AHF and a reduced CPEI than male participants. This was the first large scale investigation that comprehensively characterized biomechanical foot in a cohort of young at-risk individuals with lower limb musculoskeletal injuries. Long-term goal is to examine the relationship between these biomechanical features and injuries, ultimately to develop effective preventive measures.

Morphological variations of the human talus investigated using three‐dimensional geometric morphometrics

“…Therefore, the female talus with a larger torsion of the head surface could result in higher arch of female foot. However, another study showed that the arch height is significantly lower in females than in males (Lee & Wang, 2015), whereas others reported no significant differences in the arch height between sexes (Song et al, 2018; Zifchock, Davis, Hillstrom, & Song, 2006). Hence, further studies are certainly necessary to clarify the relationship between the talar head torsion angle and the arch height in the human foot.…”

The biomechanical effects of pronated foot function on gait. An experimental study

“…The CPEI was computed from data collected from 2 pressure distribution platforms during gait (see experimental protocol). This index is reliable with an ICC above 0.95 23 and is a very useful tool for the assessment of foot function during gait both in clinical practice and research 24‐26 . It is calculated from the concavity of the center of pressure curve in the metatarsal head region, normalized to foot width, 23 and represents the mediolateral deviation of the center of pressure under the one‐third trisection of the foot.…”

“…This index is reliable with an ICC above 0.95 23 and is a very useful tool for the assessment of foot function during gait both in clinical practice and research. [24][25][26] It is calculated from the concavity of the center of pressure curve in the metatarsal head region, normalized to foot width, 23 and represents the mediolateral deviation of the center of pressure under the one-third trisection of the foot. A cutoff of 19.4% was used to determine the foot type 23,27 ; values below this percentage indicated FP and values above indicated a neutral or supinated foot.…”

Influence of Medial Longitudinal Arch Deformation on Body Characteristics, Muscle Strength, Locomotive Function in the Community-Dwelling Elderly: A cross-section study

“…The mean foot measurements in this study may be smaller than those previously reported because of bony structure differences based on race and age. Song et al reported that Asians have exible feet that are prone to pronation at the subtalar joint [31] and that foot measurements in the Japanese population tend to have a smaller AHR than those in Western countries.…”