High-Intensity Focused Electromagnetic Therapy Combined With Foot Core Training for Pronated Foot

The objective of this trial is to assess the effects of high-intensity focused electromagnetic therapy combined with foot core training targeting the intrinsic foot muscles on plantar load, static foot posture, intrinsic foot muscle morphology and intrinsic foot muscle activation in individuals with pronated foot.

The main questions it aims to answer are:

Question 1: To compare changes in plantar load following interventions of high-intensity focused electromagnetic therapy combined with foot core training, high-intensity focused electromagnetic therapy alone, and sham high-intensity focused electromagnetic therapy combined with foot core training.

Question 2: To compare changes in static foot posture, intrinsic foot muscle morphology, and intrinsic foot muscle activation following interventions of high-intensity focused electromagnetic therapy combined with foot core training, high-intensity focused electromagnetic therapy alone, and sham high-intensity focused electromagnetic therapy combined with foot core training.

Question 3: To assess the effects of each intervention on plantar load, static foot posture, intrinsic foot muscle morphology, and intrinsic foot muscle activation in individuals with pronated foot.

Eligible participants will be randomly assigned to one of three groups: the high-intensity focused electromagnetic therapy combined with foot core training group, the high-intensity focused electromagnetic therapy group, or the sham high-intensity focused electromagnetic therapy combined with foot core training group.

High-intensity focused electromagnetic therapy sessions will last for 20 minutes each, while the foot core training program will comprise 4 exercises, with 10 repetitions per set and 3 sets per session for each exercise. Participants will undergo these interventions twice a week over a 6-week period.

Plantar load and electromyographic signals of the abductor hallucis muscle during gait, ultrasonography for morphological analysis of the intrinsic foot muscles, and static foot posture will be evaluated at baseline and 6 weeks following the intervention.

Inclusion criteria

• Age ≥ 20 years old
• Navicular drop test ≥ 10 mm
• Foot Posture Index ≥ 6
• Foot and ankle range of motion within normal limits

Exclusion criteria

• Rigid flatfoot
• Any congenital deformity of lower extremity
• Leg length discrepancy > 10 mm
• Lower extremity injuries or surgeries in recent 6 months
• Neurological deficits
• Contraindications of high-intensity focused electromagnetic therapy: pregnancy, unhealed wound, implanted electronic devices or other metal implants