Department of Clinical Engineering, Faculty of Human Care at Makuhari, Tohto University, 1-1 Hibino, Mihama-Ku, Chiba, 261-0021, Japan.
Department of core informatics, Graduate School of Informatics, Osaka Metropolitan University, Osaka, Japan.
Biomed Eng Online. 2024 Aug 21;23(1):83. doi: 10.1186/s12938-024-01282-4.
The structures around the navicular bones, which constitute the medial longitudinal arch, develop by 10 years of age. While navicular bone height is often emphasized in the assessment of flatfoot, three-dimensional (3D) evaluations, including those of structural parameters during inversion, have rarely been investigated. If the development of flatfoot during the growth process could be predicted, appropriate interventions could be implemented. Therefore, in this longitudinal cohort study, we developed a system, utilizing smartphones, to measure the 3D structure of the foot, performed a longitudinal analysis of changes in midfoot structures in 124 children aged 9-12 years, and identified factors influencing the height of the navicular bone. The foot skeletal structure was measured using a 3D system.
Over 2 years, foot length and instep height increased during development, while navicular height decreased. The 25th percentile of the instep height ratio and navicular height ratio at ages 9-10 years did not exceed those at ages 11-12 years, with percentages of 17.9% and 71.6%, respectively, for boys, and 15.8% and 49.1%, respectively, for girls. As the quartiles of the second toe-heel-navicular angle (SHN angle) increased at ages 9-10 years, the axis of the bone distance (ABD) and SHN angles at ages 11-12 years also increased, resulting in a decrease in the navicular height ratio. A significant inverse correlation was found between changes in SHN angle and navicular height ratio. These findings indicate that the navicular bone rotation of the midfoot is a predictor of the descent of the navicular bone.
This study revealed that some children exhibit decreases in navicular bone height with growth. As a distinct feature, the inversion of the navicular bone promotes flattening of the midfoot. Thus, this study provides insights into changes in midfoot development in children and provides an effective evaluation index.
构成内侧纵弓的舟骨周围结构在 10 岁时发育完成。虽然在评估扁平足时经常强调舟骨高度，但很少有研究对其进行三维（3D）评估，包括足内翻时的结构参数评估。如果能预测儿童在生长过程中扁平足的发展情况，就可以实施适当的干预措施。因此，在这项纵向队列研究中，我们开发了一个系统，利用智能手机来测量足部的 3D 结构，对 124 名 9-12 岁儿童的中足结构进行了纵向分析，并确定了影响舟骨高度的因素。使用 3D 系统测量足部骨骼结构。
在 2 年的时间里，足部长度和足背高度在发育过程中增加，而舟骨高度则降低。9-10 岁时足背高度比和舟骨高度比的第 25 百分位数均未超过 11-12 岁时的水平，男孩分别为 17.9%和 71.6%，女孩分别为 15.8%和 49.1%。随着 9-10 岁时第二趾跟舟骨角（SHN 角）四分位的增加，11-12 岁时的骨距轴（ABD）和 SHN 角也增加，导致舟骨高度比下降。SHN 角的变化与舟骨高度比之间存在显著的负相关关系。这些发现表明，中足舟骨的旋转是舟骨下降的预测指标。
本研究表明，随着生长，一些儿童的舟骨高度会下降。舟骨的内翻是中足变平的一个显著特征。因此，本研究揭示了儿童中足发育的变化特征，并提供了一个有效的评估指标。
