Asymmetric Sole Structure for Thenar Kick Repulsion
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Solution Overview
Problem
Existing running shoes fail to provide sufficient repulsive force to assist the wearer's foot movement during a kick, particularly in the thenar portion, due to uneven pressure distribution upon landing.
Innovation Solution
A sole design with a first-inner-foot-side-stepping portion that projects downward and is thicker than adjacent portions, enhancing repulsive force by concentrating compressive forces and facilitating smoother foot movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the midsole and outsole are shaped with substantially the same thickness to achieve uniform ground contact, then grip is enhanced and weight is reduced, but insufficient repulsive force is provided in the thenar portion to assist foot movement during a kick
Solution Approach 1:
The sole applies local quality by creating a thickness difference between the inner foot side stepping portion (thicker) and outer foot side stepping portion (thinner). This localized variation in thickness concentrates compressive forces in the thenar portion to generate sufficient repulsive force for kick assistance while maintaining overall sole functionality.
Solution Approach 2:
The sole employs asymmetry by designing the inner foot side stepping portion with greater thickness than the outer foot side stepping portion. This asymmetric thickness distribution optimizes the repulsive force generation in the thenar portion, addressing the specific need for kick assistance without requiring complete structural redesign.
2Force
If the inner foot side stepping portion is made thicker to increase repulsive force, then kick assistance is improved, but the overall weight of the shoe increases
Solution Approach 1:
The thickness increase is localized only to the inner foot side stepping portion where repulsive force is needed, rather than increasing the thickness of the entire sole. This localized approach provides kick assistance while minimizing the overall weight penalty.
Solution Approach 2:
The invention applies partial action by increasing thickness only in the specific region (inner foot side stepping portion) where it is most needed for repulsive force generation, rather than uniformly thickening the entire sole. This partial thickening achieves the required force while keeping weight increase minimal.
3Force
If pressure is concentrated on the thenar portion during landing, then repulsive force can be generated, but the sole structure must be more complex to manage pressure distribution
Solution Approach 1:
The sole uses local quality by designing the inner foot side stepping portion with greater thickness to naturally concentrate pressure in the thenar portion during landing. This structural feature guides pressure distribution without requiring complex active control mechanisms.
Solution Approach 2:
The thicker inner foot side stepping portion is designed in advance to pre-establish the pressure concentration path. This preliminary structural configuration ensures that pressure naturally flows to the thenar portion during landing, eliminating the need for complex active pressure management systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The sole design increases repulsive force, stabilizes foot posture, and assists in smooth movement by concentrating compressive forces on the thenar portion, improving the wearer's kicking motion.
Implementation Method 1
A sole for a shoe composed of an elastic body... The first-inner-foot-side-stepping portion is at least partially curved and projects in a downward direction... One embodiment of the present teaching can increase a repulsive force supplementing a force with which a wearer moves their foot during a kick
Data Source
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AI summary
Provided are a sole capable of increasing a repulsive force supplementing a force with which a wearer moves their foot during a kick, and a shoe including the sole. The front foot portion 1F includes a first-inner-foot-side-stepping portion 2 that is a range A1 overlapping with a placement portion on which a foot of the wearer is placed and includes at least a part of a range A2 overlapping with the thenar portion of the wearer and a first-outer-foot-side-stepping portion that is the range A1 and includes at least a part of a range A3 overlapping with the hypothenar portion of the wearer when viewed in the top-bottom direction. The first-inner-foot-side-stepping portion 2 is at least partially curved and projects in a downward direction, and is thicker than the first-outer-foot-side-stepping portion 3 on an imaginary line L1 passing through the thenar portion and the hypothenar portion of the wearer.