Medial longitudinal arch development of children aged 7 to 9 years: Longitudinal investigation

Abstract

Background. It is unclear at what age the medial longitudinal arch (MLA) of the foot becomes stable in children. The influence of footwear on MLA development also is unknown. Objective. The purpose of this study was to examine the MLA development of children using a longitudinal approach. The relationship between wearing different types of footwear and MLA development also was explored longitudinally. Design. This was a longitudinal cohort observational study. Methods. The MLA of 111 healthy children (mean age = 6.9 years, SD = 0.3) was evaluated using 3 parameters (arch index [AI], midfoot peak pressure [PP], and maximum force [MF]) extracted from dynamic foot loading measurements at baseline (t0), 10-month follow-up (t1), and 22-month follow-up (t2). Information on footwear usage was surveyed. Linear mixed modeling was used to test for differences in MLA over time. Results. The MLA of the children remained stable over time (AI: t0/t1/t2 = 0.25 [95% confidence interval (CI) = 0.24, 0.26]/0.25 [95% CI = 0.24, 0.26]/0.25 [95% CI = 0.24, 0.26]; P = .95). When the children’s sex was considered, the AI of boys decreased (higher arch) with age (0.26 [95% CI = 0.24, 0.27]/0.25 [95% CI = 0.24, 0.27]/0.25 [95% CI = 0.23, 0.27]; P = .02). Boys also displayed a flatter MLA than girls at age 6.9 years (AI: mean difference = 0.02 [95% CI = 0.01, 0.04]; P = .02). At baseline, children who wore closed-toe shoes displayed the lowest MLA overall (AI: closed-toe shoes/sandals/slippers = 0.26 [95% CI = 0.24, 0.28]/0.24 [95% CI = 0.23, 0.25]/0.25 [95% CI = 0.24, 0.26]; P