Layered Midsole Structure Reduces Muscle Load
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Solution Overview
Problem
Conventional shoe soles lack a structured midsole design that effectively reduces the load on muscles and tendons during running, particularly in relation to ankle angle and angular velocity, which affects muscle tension and tendon strain.
Innovation Solution
A layered midsole structure featuring a low-hardness foamed material in the upper layer and a high-hardness foamed material in the lower layer, with specific thickness and distribution patterns to manage compressive deformation and flexural rigidity, thereby reducing ankle angle changes and muscle load during running.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional single-layer foamed material sole is used, then the structure is simple and easy to manufacture, but the load on muscles and tendons during running cannot be effectively reduced
Solution Approach 1:
The midsole is divided into two distinct layers: an upper layer made of low-hardness foamed material and a lower layer made of high-hardness foamed material. This segmentation allows each layer to perform its specific function - the upper layer reduces muscle load through increased ankle angle while the lower layer provides structural support - thereby reducing the load on muscles and tendons during running
Solution Approach 2:
The invention uses a composite structure combining two different foamed materials with distinct hardness properties. The low-hardness upper layer and high-hardness lower layer work together to achieve both comfort (reduced muscle load) and structural integrity, resolving the contradiction between ease of manufacture and harm reduction
2Object-affected harmful factors
If a thick layer of low-hardness foamed material is arranged in the forefoot portion, then the ankle angle increases and muscle extension decreases, but the compressive deformation of the forefoot portion becomes excessively large
Solution Approach 1:
The midsole employs different hardness characteristics in different regions: the upper layer uses low-hardness foamed material specifically in the forefoot portion to increase ankle angle and reduce muscle load, while the lower layer uses high-hardness foamed material to provide structural support and limit excessive compressive deformation. This local differentiation of material properties resolves the contradiction between reducing muscle load and controlling forefoot deformation
3Object-affected harmful factors
If a high-resilience foamed material is used in the upper layer, then the recovery speed increases and muscle load reduces, but the manufacturing complexity increases compared to conventional materials
Solution Approach 1:
The midsole is segmented into two layers with the upper layer specifically using high-resilience foamed material to reduce muscle load through faster recovery speed, while the lower layer uses conventional high-hardness foamed material. This segmentation allows the complex material to be used only where needed for performance optimization
Solution Approach 2:
The invention combines high-resilience foamed material in the upper layer with high-hardness foamed material in the lower layer, creating a composite structure that achieves reduced muscle load while managing the complexity through functional differentiation of materials
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 layered midsole design reduces muscle and tendon strain by increasing ankle angle and decreasing ankle angular velocity, leading to improved comfort and reduced fatigue during running.
Implementation Method 1
the amount of compressive deformation of the forefoot portion is larger than that of the rear foot portion
Implementation Method 2
a higher speed at which to recover to an original shape after being deformed than that of the high-hardness foamed material N
Data Source
AI summary
A midsole includes an upper layer and a lower layer made of a foamed material; the upper layer is a low-hardness foamed material; the lower layer is a high-hardness foamed material; the low-hardness foamed material of the upper layer is a low-hardness, high-resilience material that has a higher specific gravity than the high-hardness foamed material, that has a low hardness that is lower than the hardness of the high-hardness foamed material, and that has a higher speed at which to recover to an original shape after being deformed than that of the high-hardness foamed material.