Weak TGS Correlates with Hallux Valgus in 10–12 Year Old Girls: A Cross- Sectional Study

Objective: Hallux valgus is one of the most common foot deformities. It is considered that hallux valgus is associated with foot arch height, footwear, sex and so on. Toe grip strength (TGS) is important for developing foot posture because it attributes to foot arch height. The relationship between hallux valgus and TGS in children is unknown, although childhood is a key period for developing foot posture. The objective of this study is to investigate the relationship between hallux valgus angle (HVA) and TGS in children. Methods: A total of 671 (1342 feet) 10-12 year old children (boys, n = 317, age = 10.3 ± 0.7; girls, n = 354, age = 10.2 ± 0.7; means ± standard deviation [SD]) participated in this study. HVA, the angle between the first metatarsal axis and the proximal phalangeal axis, was measured using a goniometer. TGS was measured using a toe grip dynamometer. Differences in the data between boys and girls were analyzed using the Mann-Whitney U test. According to sex, single and multiple linear regression analyses with generalized estimating equations were performed for the relationship between HVA and TGS. The level of statistical significance was set at p ˂ 0.05. Results: The TGS and HVA of participants’ feet were 13.3 ± 4.0 kg (boys, 13.4 ± 3.9 kg; girls, 13.1 ± 4.1 kg) and 7.9 ± 5.0° (boys, 6.7 ± 4.5°; girls, 9.2 ± 5.1°, p ˂ 0.001). The multiple linear regression analysis in girls indicated a correlation between TGS and HVA (β = -0.098, p = 0.045), whereas in boys, there was no correlation. Conclusions: HVA is greater in girls than in boys, and in girls, weak TGS correlates with hallux valgus. Weak TGS may attribute to hallux valgus in potential stage or early stage. Strengthening TGS may be as promising tool for preventing the onset of hallux valgus and for developing good foot posture.