Dynamic Knee Brace Hinges for Side Load Stability
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Solution Overview
Problem
Existing knee braces with pre-formed or pre-adjusted static angulation often roll circumferentially around the user's leg, particularly at greater angulation settings, failing to provide an effective and comfortable side load during knee movement.
Innovation Solution
A dynamic orthopedic knee brace with adjustable hinges that change length as the knee moves through its range of motion, applying a side load during extension and removing it during flexion, utilizing four-bar linkages or polycentric mechanisms to maintain stability and comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If pre-formed or pre-adjusted static angulation is used to create side load, then side load is provided at full extension, but the brace rolls circumferentially around the user's leg
Solution Approach 1:
The patent applies dynamics by transitioning from static angulation to dynamic hinges that change length during knee movement. The hinges extend during extension to increase side load and contract during flexion to decrease side load, preventing circumferential rolling while maintaining effective force application throughout the range of motion
Solution Approach 2:
The patent implements parameter changes by making the hinge length a variable parameter that changes with knee angle. The hinges are designed to extend and contract based on knee position, dynamically adjusting the geometric parameters of the brace structure to maintain optimal side load without causing rolling
2Force
If greater pre-set angulation is used to increase side load, then greater side load is provided, but the rolling effect increases
Solution Approach 1:
The patent uses dynamics to make the angulation adjustable in real-time. The hinges dynamically change their effective length based on knee position, allowing the brace to provide greater side load when needed (during extension) while automatically reducing the angulation effect during flexion to prevent rolling
Solution Approach 2:
The patent applies preliminary anti-action by designing the hinge mechanism to counteract the rolling effect before it occurs. The dynamic adjustment of hinge length preemptively reduces the side load component that would cause rolling during flexion, while maintaining it during extension when rolling is less problematic
3Force
If dynamic hinges that extend and contract are used, then side load is optimized during extension, but hinge complexity increases
Solution Approach 1:
The patent applies asymmetry by designing the medial and lateral hinges with different characteristics. One hinge is designed to extend while the other contracts during knee movement, creating an asymmetric dynamic system that optimizes side load application while the asymmetry itself helps prevent rolling by creating balanced moments
Data Source
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AI summary
An orthopedic knee brace includes at least one hinge; at least one upright connected rotatably to the at least one hinge; and wherein the at least one hinge and the at least one upright are configured and arranged to apply a force to a user's knee when moved from a flexion position to an extended position and to relax the force applied to the user's knee when moved from the extended position to the flexion position.