A comprehensive exercise program improves foot alignment in people with flexible flat foot: a randomised trial

Question: In people with flexible flat foot, what is the effect of a comprehensive exercise program on navicular drop height and medial longitudinal arch angle compared with a control regimen of brief active range of motion exercises?

Design: Randomised controlled trial with concealed allocation, blinding of assessors and intention-to-treat analysis.

Participants: Fifty-two people with flexible flat foot.

Intervention: The experimental group undertook 30-minute exercise sessions three times per week for 6 weeks. The exercises involved active dorsiflexion and plantarflexion, foot shortening exercises, gluteal muscle strengthening, and stretching. The control group performed active dorsiflexion and plantarflexion only for 6 weeks.

Outcome measures: Navicular drop height and longitudinal arch angle.

Results: Randomisation allocated 26 participants to each group. One participant from the experimental group and two from the control group did not complete the study. After 6 weeks, the participants in the experimental group improved their navicular drop height by 0.4 cm (95% CI 0.4 to 0.5) more than those in the control group. These participants also improved their longitudinal arch angle by 16 deg (95% CI 13 to 19) more than those in the control group.

Conclusion: In people with flexible flat foot, a comprehensive 6-week exercise program improved the navicular drop height and longitudinal arch angle more than active dorsiflexion and plantarflexion alone. This improved the cosmetic appearance of the foot and reduced progression towards more severe flat foot, which typically becomes symptomatic.

Trial registration: CTRI/2021/07/034599.