An association between excessive valgus hindfoot alignment and postural stability during single-leg standing in adolescent athletes

Yasunari Ikuta; Tomoyuki Nakasa; Hironori Fujishita; Hiromune Obayashi; Kouki Fukuhara; Tetsuhiko Sakamitsu; Kai Ushio; Nobuo Adachi

doi:10.1186/s13102-022-00457-7

An association between excessive valgus hindfoot alignment and postural stability during single-leg standing in adolescent athletes

BMC Sports Sci Med Rehabil. 2022 Apr 11;14(1):64. doi: 10.1186/s13102-022-00457-7.

Authors

Yasunari Ikuta^{1

2}, Tomoyuki Nakasa^{3

4}, Hironori Fujishita⁵, Hiromune Obayashi⁵, Kouki Fukuhara⁵, Tetsuhiko Sakamitsu⁵, Kai Ushio^{5

6}, Nobuo Adachi³

Affiliations

¹ Department of Orthopaedic Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan. yikuta@hiroshima-u.ac.jp.
² Sports Medical Center, Hiroshima University Hospital, Hiroshima, Japan. yikuta@hiroshima-u.ac.jp.
³ Department of Orthopaedic Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, 734-8551, Japan.
⁴ Medical Center for Translational and Clinical Research, Hiroshima University Hospital, Hiroshima, Japan.
⁵ Sports Medical Center, Hiroshima University Hospital, Hiroshima, Japan.
⁶ Department of Rehabilitation Medicine, Hiroshima University Hospital, Hiroshima, Japan.

Abstract

Background: Diminished balance is associated with the incidence of ankle and lower extremity injuries in adolescents. Although flexible flatfoot is a common foot condition in pediatric and adolescent populations, the association between balance control and foot morphology remain unclear in adolescent athletes.

Methods: Rearfoot angle in the double-limb standing position, body mass index (BMI), and isometric muscle strength related to the knee joint were retrospectively reviewed in 101 adolescent athletes (75 boys and 26 girls) with a mean age of 14.0 years (range 12-17). Postural stability during single-leg standing on static and dynamic platforms was investigated using Balance System SD in 119 feet without functional ankle instability. The participants were divided according to their rearfoot angle into control (less than 7°) and valgus (greater than or equal to 7°) groups. The measured parameters were compared between the control and valgus groups using Welch's t-test, and P values < 0.05 were considered statistically significant. Multiple regression analysis was conducted to identify the factors that significantly influenced postural control.

Results: The average rearfoot angle was 4.6° in all participants. An excessive valgus rearfoot angle was detected in 53 feet (26.2%). No significant difference was found between the groups in terms of BMI and isometric knee muscle strength. Although no statistical differences were observed in postural stability on the static platform between the control and valgus groups, the valgus group demonstrated poorer postural stability for single-leg standing on the dynamic platform. Multiple regression analysis revealed that BMI and rearfoot angle were significantly associated with a poor postural control on the dynamic platform.

Conclusions: Our findings suggest that excessive rearfoot valgus specifically contributes to the deterioration of postural stability in adolescent athletes, and that rearfoot alignment should be evaluated for the adolescent population to prevent sports-related lower extremity injury.

Keywords: Adolescent; Athletes; Foot; Postural balance.