Midfoot Sole Structure With Asymmetric Bending for Kicking Stability

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Solution Overview

Problem

Existing shoe soles do not effectively balance increased plantarflexion for enhanced kicking performance with stability during running and other athletic movements.

Innovation Solution

A sole structure with a midfoot portion featuring connectors and a resilient component that allows for differential bending stiffness in plantarflexion and dorsiflexion directions, enabling increased plantarflexion for kicking while maintaining stability during running.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the midfoot portion is made stiff to provide stability during running, then stability is improved, but plantarflexion range of motion deteriorates

Engineering Contradiction:
ImprovestabilityVSAvoidplantarflexion range of motion
Core Design Contradiction:
Stability of the object's compositionVSLength of moving object

Solution Approach 1:

The midfoot portion transitions from a static, uniformly stiff structure to a dynamic structure with differential stiffness characteristics. The resilient component enables the midfoot to adapt its stiffness based on the direction of bending: stiff during dorsiflexion for stability, and flexible during plantarflexion for increased range of motion. This dynamic behavior resolves the contradiction between stability and flexibility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The midfoot portion is designed with asymmetric bending stiffness: higher dorsiflexion bending stiffness for stability during running, and lower plantarflexion bending stiffness for enhanced kicking performance. This asymmetric design allows the same structure to provide different mechanical properties in different directions, simultaneously achieving stability and increased plantarflexion range of motion.

Inventive Principle:
Principle #4Asymmetry

2Length of moving object

If the midfoot portion is made flexible to increase plantarflexion for kicking, then plantarflexion range of motion is improved, but stability during running deteriorates

Engineering Contradiction:
Improveplantarflexion range of motionVSAvoidstability
Core Design Contradiction:
Length of moving objectVSStability of the object's composition

Solution Approach 1:

The resilient component is positioned at a specific location within the midfoot portion, creating a localized flexible region. This allows the midfoot to exhibit flexibility only where needed (at the resilient component location during plantarflexion) while maintaining overall structural integrity and stability during dorsiflexion. The local modification resolves the contradiction between flexibility and stability.

Inventive Principle:
Principle #3Local quality

3Device complexity

If a single resilient component is used, then device complexity is reduced, but adaptability for different athletic performance needs deteriorates

Engineering Contradiction:
Improvedevice complexityVSAvoidadaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The resilient component system is divided into multiple independent resilient components (first resilient component for medial-lateral stability, second resilient component for fore-aft flexibility). Each component can be independently configured with different stiffness characteristics, allowing the midfoot portion to provide differentiated mechanical properties in different directions. This segmentation enables high adaptability while maintaining relatively simple device complexity.

Inventive Principle:
Principle #1Segmentation

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 structure enhances kicking velocity by allowing greater plantarflexion while providing stability during dorsiflexion, addressing the limitations of traditional soles that prioritize either stiffness or flexibility.

Implementation Method 1

a resilient component coupled to the first connector and the second connector, wherein the midfoot portion has a resting state in which the resilient component has a first length, wherein, when the midfoot portion bends in a dorsiflexion direction, the first connector and the second connector move away from each other and pull the resilient component to a second length longer than the first length

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4684677A1Sole structure for a shoe
Publication Date: 2026.01.28 ADIDAS AG
  • EP4684677A1 patent drawingFigure 1~2
  • EP4684677A1 patent drawingFigure 3A
  • EP4684677A1 patent drawingFigure 3B

AI summary

A sole structure for a shoe comprises a forefoot portion and a heel portion. A midfoot portion can be coupled to the forefoot portion and the heel portion. The midfoot portion comprises a plurality of connectors disposed on a ground-facing side of the midfoot portion. The midfoot portion comprises a resilient component coupled to the first connector and the second connector. The resilient component and connectors can alter bending characteristics of the midfoot portion.