Segmented Shoe Sole for Forefoot Running Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing shoe soles are not adequately structured to support a natural and sustainable forefoot running style, leading to inefficiencies and discomfort due to heel sinking and loss of power and time.
Innovation Solution
A shoe sole design that maintains a stable posture by contacting the ground at specific points (C and D), ensuring the heel and toe portions are separated from the ground, and forming an angle of at least 5 degrees between the heel central position and the metatarsophalangeal joint position, promoting a heel-up condition and forefoot posture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a high-rigidity plate is incorporated in the sole to support the heel during sinking, then heel support is improved, but the sole cannot naturally urge forefoot running and sustainability is reduced
Solution Approach 1:
The sole is divided into multiple independent regions with different thicknesses and rigidities. The heel region has greater thickness for support, while the forefoot region has smaller thickness for natural ground contact. This segmentation allows each region to perform its specific function independently, resolving the contradiction between heel support and forefoot running sustainability.
Solution Approach 2:
Different portions of the sole are designed with locally optimized properties. The heel portion has increased thickness and rigidity for support during heel sinking, while the forefoot portion has reduced thickness to enable natural ground contact and rolling. This local differentiation allows the sole to provide both heel support and promote sustainable forefoot running.
2Strength
If the sole thickness at the heel region is increased to support heel sinking, then heel support is improved, but ground contact stability and forward rolling smoothness are reduced
Solution Approach 1:
The sole is segmented into heel region, midfoot region, and forefoot region with progressively decreasing thickness. This segmentation creates a gradient structure where the heel region provides support while the forefoot region ensures stable ground contact and facilitates smooth forward rolling during the gait cycle.
3Adaptability or versatility
If the sole is designed to maintain forefoot posture with heel elevated, then forefoot running is promoted, but ground contact stability during transition is reduced
Solution Approach 1:
The sole is pre-shaped with a curved ground-contact surface that guides the foot through the transition from heel contact to forefoot contact. This preliminary geometric configuration ensures that as the runner transitions, the sole naturally rolls forward along the curved surface, maintaining stability throughout the transition while promoting forefoot posture.
Solution Approach 2:
The ground-contact surface of the sole features a downwardly convex curved shape at the forefoot region. This curvature facilitates smooth forward rolling during the gait cycle, allowing the sole to transition naturally from heel contact to forefoot contact while maintaining ground contact stability and promoting sustainable forefoot running.
Data Source
AI summary
Path length L is a distance from the origin to the tip toe position along the sole top surface, intersection C is a point between the sole bottom surface and a line perpendicular to the reference line S through the position of 0.45 L, and intersection D is a point between the sole bottom surface and a line perpendicular to the reference line S through the position of 0.60 L. In a sole stable posture in which the sole is in contact with the ground at points C and D, the sole bottom surface is separated from the ground at the heel and tip toe portions. Inequality, θ≥5 degrees is satisfied in the sole stable posture, wherein θ is an angle between the ground and a line connecting the heel central position of 0.15 L and the metatarsophalangeal joint position of 0.68 L.