Effect of medial arch-heel support in inserts on reducing ankle eversion: a biomechanics study

Area of Science:

• Biomechanics
• Sports Medicine
• Orthotics and Prosthetics

Background:

• Excessive ankle eversion is linked to lower extremity overuse injuries.
• Orthotic inserts are commonly used to limit pronation and prevent injuries.
• The effectiveness of orthotics is product-specific, necessitating targeted research.

Purpose of the Study:

• To investigate the impact of medial arch-heel support in shoe inserts on reducing ankle eversion.
• To evaluate the effectiveness of varying levels of medial arch-heel support during standing, walking, and running.

Main Methods:

• Thirteen pronators and 13 normal subjects participated in trials.
• Motion capture system recorded ankle eversion in barefoot and shod conditions with varying insert support.
• Statistical analysis (ANOVA) was used to compare eversion across conditions.

Main Results:

• Medial arch-heel inserts reduced ankle eversion in dynamic (walking, running) but not static (standing) conditions.
• In walking, inserts reduced maximum eversion by 2.1-3.0 degrees.
• In running, low medial arch support significantly reduced maximum eversion by 3.1-3.6 degrees.

Conclusions:

• Medial arch-heel inserts are effective in reducing ankle eversion during walking and running.
• The inserts showed a trend towards normalizing eversion in over-pronated individuals during walking.
• In running, the inserts helped restore normal eversion range in 84% of pronators.