The most common way to classify arch height among the general public is by appearance, which roughly divides arches into three types: normal arches, low arches, and high arches. Besides appearance-based classification, you can also judge your arch type by creating a simple foot pressure map yourself: wet the soles of your feet, step evenly on a piece of paper to leave a footprint (a simplified foot pressure map), then divide the footprint into regions and calculate the proportion of the sole area in contact with the ground to determine your arch type based on the resulting index range.
1. Normal Arches
- The normal arch index ranges from 0.21 to 0.28.
- When observing the foot’s appearance, the Achilles tendon is roughly perpendicular to the ground.
- Foot pressure is evenly distributed across all areas of the sole, and shoe sole wear is relatively uniform.
- Recommendation: No special pressure reduction is needed; regular insoles are sufficient.
2. Low Arches
- If the arch index is greater than 0.28, the arch curve is flat or indistinct.
- Foot pressure is significantly increased or concentrated on the medial (inner) arch.
- The Achilles tendon appears concave inward in appearance, and shoe sole wear is concentrated on the inner side of the foot.
- Recommendation: Choose arch support insoles that prioritize "support" (with a sufficiently high curve or high hardness).
3. High Arches
- When the arch index is less than 0.21, the arch curve is prominent and distinct.
- Foot pressure is significantly increased or concentrated on the lateral (outer) arch and heel.
- The Achilles tendon appears concave outward in appearance, and shoe sole wear is concentrated on the outer side of the foot.
- Recommendation: Select arch support insoles for high arches that prioritize "shock absorption".