Eight week short-term effects of military training on foot structure and function in young adults

Foot structure and function may change over time. Different foot types have been associated with a higher incidence of certain foot pathologies. Injury prevalence in the military can affect readiness for deployment and effectiveness in combat. It is currently unknown if measures of foot structure and function change in response to intensive exercise or aggressive military training in young adults.

Does foot structure and function change longitudinally from baseline (onset of intensive basic military training) to 8-week follow-up on a sample of United States Military Academy (USMA) cadets?

Measures of foot structure (arch height index (AHI), arch height flexibility (AHF)) and function (center of pressure excursion index (CPEI), peak pressure (PP), maximum force (MF), pressure time-integral (PTI), force-time integral (FTI), and contact area (CA)) were obtained at baseline and after 8-weeks in 106 USMA cadets. Foot function variables were measured with a plantar pressure measuring device using a 12-region masking algorithm. Generalized estimation equation (GEE) models were used for statistical analysis to account for potential dependence in bilateral foot data.

AHI for sitting and standing significantly increased. PP significantly reduced beneath the overall foot, hallux, and 2nd metatarsal head. MF significantly increased beneath the 3rd metatarsal head and decreased beneath the lateral heel. PTI significantly increased beneath the overall foot and the 1st-5th metatarsal heads, medial heel, and medial arch. FTI significantly increased beneath the overall foot, 1st-5th metatarsal heads, and the medial heel. After co-varying for body weight, all these findings remained, suggesting changes in weight had no effect on foot structure and function.

Foot structure changed to a higher arch while foot function demonstrated less over-pronation. Future research should investigate changes in foot structure and function over larger time frames and examine the risk for subsequent musculoskeletal injuries.