Effects of human variation on foot and ankle pain in rural Madagascar

Abstract

Objectives: Foot and ankle dysfunction in barefoot/minimally shod populations remains understudied. Although factors affecting musculoskeletal pain in Western populations are well-studied, little is known about how types of work, gender, and body shape influence bone and joint health in non-Western and minimally shod communities. This study examines the effect of human variation on locomotor disability in an agrarian community in Madagascar.Materials and methods: Foot measurements were collected along with height, weight, age, and self-report data on daily activity and foot and ankle pain from 41 male and 48 female adults. A short form revised foot function index (FFI-R), that measures functional disability related to foot pain, was calculated. Raw and normalized foot measurements were compared by gender and used in a multiple linear regression model to determine predictors of FFI-R.Results: Compared to men, women reported higher FFI-R scores (p = 0.014), spent more time on their feet (p = 0.019), and had higher BMIs (p = 0.0001). For their weight, women had significantly smaller and narrower feet than men. Bimalleolar breadth (p = 0.0005) and foot length (p = 0.0223) standardized by height, time spent on feet (p = 0.0102), ankle circumference standardized by weight (p = 0.0316), and age (p = 0.0090) were significant predictors of FFI-R score.Discussion: Our findings suggest that human variation in anatomical and behavioral patterns serve as significant explanations for increased foot and ankle pain in women in this non-Western rural population. Foot and ankle pain were prevalent at similar levels to those in industrialized populations, indicating that research should continue to examine its effect on similar barefoot/minimally shod communities.