Knee Flexor Assessment Apparatus for Bilateral Hamstring Strength Measurement
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Solution Overview
Problem
Existing methods for assessing knee flexor muscle strength, particularly hamstring strength, are limited by high costs, requirement for skilled operators, limited portability, and inability to simultaneously assess both legs during a bilateral exercise.
Innovation Solution
An apparatus comprising a support, two securing members to fix the subject's lower legs, and at least one sensor to measure the force indicative of knee flexor muscle strength during eccentric contractions, allowing for simultaneous assessment of both legs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If isokinetic dynamometer is used for hamstring strength assessment, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the essential measurement function from the complex isokinetic dynamometer system. Instead of using the full dynamometer apparatus, it isolates the force sensing capability and applies it to a simplified setup where force sensors measure hamstring force during Nordic curls, maintaining measurement precision while eliminating unnecessary complexity
Solution Approach 2:
The patent creates a simplified copy of the measurement function. Rather than replicating the entire isokinetic dynamometer system, it copies only the essential force measurement capability using force sensors and strain gauges, achieving comparable assessment results with a much simpler apparatus
2Measurement precision
If isokinetic dynamometer is used for hamstring strength assessment, then measurement precision is improved, but ease of operation deteriorates
Solution Approach 1:
The apparatus enables self-service operation where the subject performs the Nordic curl exercise independently while the force sensors automatically record and process the hamstring force data. The system self-calibrates and self-measures without requiring skilled operators to control movement velocity or interpret complex dynamometer readings
Solution Approach 2:
The patent replaces the complex mechanical control system of the isokinetic dynamometer with simple force sensing. Instead of mechanically controlling movement velocity and sensing torque through complex linkages, it uses electronic force sensors to directly measure hamstring force, eliminating the need for skilled mechanical operation
3Measurement precision
If isokinetic dynamometer is used for hamstring strength assessment, then measurement precision is improved, but productivity deteriorates
Solution Approach 1:
The patent merges the assessment of both hamstrings into a single simultaneous measurement. The force sensors are positioned to measure both hamstrings during a bilateral Nordic curl exercise, allowing both legs to be assessed at the same time rather than requiring separate unilateral tests, thereby doubling productivity while maintaining precision
Solution Approach 2:
The apparatus enables continuous measurement of hamstring force throughout the entire range of motion during the Nordic curl. Force is measured continuously from the starting position through the lowering phase and return, capturing the full eccentric and concentric phases without interruption, maximizing the information obtained from each assessment
4Reliability
If isokinetic dynamometer is used for hamstring strength assessment, then reliability is improved, but portability deteriorates
Solution Approach 1:
The patent segments the assessment system into separate, lightweight components: force sensors, strain gauges, and data processing equipment. This modular approach replaces the single large, heavy isokinetic dynamometer with distributed sensing elements that can be easily transported and set up in various locations while maintaining reliable measurements
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 apparatus provides a cost-effective, portable, and efficient means to assess hamstring strength, offering improved reliability and sensitivity in measuring between-limb strength imbalances, thus enabling more accessible and comprehensive assessments.
Implementation Method 1
at least one sensor, which in use detects a force indicative of the strength of the at least one knee flexor muscle
Data Source
AI summary
An apparatus for use in assessing strength of at least one knee flexor muscle of a subject, the apparatus including a support, two securing members, each securing member securing a respective lower leg of the subject in a position that in use is substantially fixed relative to the support and at least one sensor, which in use senses a force indicative of the strength of the at least one knee flexor muscle in at least one leg of the subject while the subject performs an eccentric contraction of the at least one knee flexor muscle.