Foot Muscle Cross-Sectional Area and Recurrent Falls: A Preliminary MRI-Based Evaluation

Foot muscle strength reduction is common in older adults experiencing falls, yet the link between foot muscle radiological characteristics and fall recurrence remains unexplored. This study investigated the association between foot muscle cross-sectional area (CSA), as quantified through MRI, and a history of recurrent falls.

A retrospective case-control study included patients aged ≥60 years with a history of repeated falls (≥2) and age- and sex-matched controls without falls. Foot muscle CSA at the first tarsometatarsal joint was measured on T1-weighted (n=8) or proton density (n=18) MRI images. Measurements were performed by two independent raters, with inter-rater agreement assessed via the intraclass correlation coefficient (ICC). Multiple regression analysis was performed, adjusting for potential confounding variables. Statistical significance was set at P < 0.05.

Thirteen case subjects with recurrent falls and 13 age-sex matched controls were included. The baseline demographic and physical characteristics were comparable between groups except for foot muscle CSA, which was significantly smaller in the case group (P = 0.006). Regression analysis revealed that a decrease in foot muscle CSA significantly increased the likelihood of recurrent falls, independent of other variables (odds ratio =0.99, 95% CI: (0.98, 0.99), P = 0.03). The interrater agreement was calculated to be excellent (ICC = 0.92, P < 0.01)  Conclusion: Reduced foot muscle CSA may be associated with an increased risk of falls in older adults. This feasibility study lays the foundation for future work investigating fall-risk stratification using this relatively simple quantitative imaging technique.