Segmented Midfoot Sole Structure for Plantarflexion and Stability

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Solution Overview

Problem

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

Innovation Solution

A sole structure with a midfoot portion designed to bend anisotropically, featuring distinct bending stiffnesses in plantarflexion and dorsiflexion directions, and comprising multiple segments connected by hinges and connectors to allow for modular adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the midfoot portion is made stiff to maintain stability during running, then stability is improved, but plantarflexion capability deteriorates

Engineering Contradiction:
Improvestability during runningVSAvoidplantarflexion capability
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The midfoot portion is divided into multiple segments (first segment, second segment, third segment) that can move relative to each other through hinges. This segmentation allows the structure to adapt its stiffness dynamically - maintaining stability when segments are locked together during running, while enabling plantarflexion when segments can pivot relative to each other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The hinge mechanism introduces dynamic adaptability to the midfoot portion. The hinge allows the structure to transition between a stiff configuration (for running stability) and a flexible configuration (for plantarflexion during kicking), enabling the sole to optimize its mechanical properties based on the athletic activity being performed.

Inventive Principle:
Principle #15Dynamics

2Speed

If the midfoot portion is made flexible to increase plantarflexion, then kicking velocity is improved, but stability during running deteriorates

Engineering Contradiction:
Improvekicking velocityVSAvoidstability during running
Core Design Contradiction:
SpeedVSStability of the object's composition

Solution Approach 1:

By segmenting the midfoot portion into movable sections connected by hinges, the structure can achieve high flexibility during plantarflexion (improving kicking velocity) while maintaining stability during running through the geometric arrangement and locking behavior of the segmented structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The hinge is positioned asymmetrically within the midfoot portion, creating different mechanical behaviors for plantarflexion versus dorsiflexion. This asymmetric placement allows greater range of motion in the plantarflexion direction (enhancing kicking velocity) while providing inherent stability during dorsiflexion-based activities like running.

Inventive Principle:
Principle #4Asymmetry

3Ease of operation

If a hinge is added to enable segment movement, then plantarflexion capability is improved, but device complexity increases

Engineering Contradiction:
Improveplantarflexion capabilityVSAvoidstructure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The hinge connects segmented portions of the midfoot, enabling controlled movement between segments. This segmentation approach achieves enhanced plantarflexion capability through a relatively simple mechanical division of the sole structure, avoiding the need for complex actuation systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The hinge mechanism operates passively, utilizing the natural forces generated during athletic movement (body weight, muscle force) to enable segment rotation. This self-service approach allows the hinge to function without requiring external power sources, control systems, or complex actuation mechanisms, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #25Self-service

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

Enhances kicking velocity by allowing increased plantarflexion while maintaining stability during running and other athletic activities.

Implementation Method 1

the midfoot portion configured to bend in a plantarflexion direction and a dorsiflexion direction, the midfoot portion comprising: a first bending element disposed at a ground-facing side of the midfoot portion... a second bending element disposed at an upper-facing side of the midfoot portion

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4684676A1Sole structure for a shoe
Publication Date: 2026.01.28 ADIDAS AG
  • EP4684676A1 patent drawingFigure 1~2
  • EP4684676A1 patent drawingFigure 3
  • EP4684676A1 patent drawingFigure 4A~4B

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 is configured to bend in a plantarflexion direction and a dorsiflexion direction. The midfoot portion comprises various elements disposed at a ground-facing side of the midfoot portion that can alter bending characteristics of the midfoot portion.