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Comparison of different passive knee extension torque-angle assessments
Sandro R Freitas1, João R Vaz, Paula M Bruno
1Universidade de Lisboa, Faculdade de Motricidade Humana, CIPER, P-1100, Portugal.
Physiological Measurement
|October 24, 2013
Summary
This study found that both the measurement method and subject positioning significantly impact passive knee extension torque-angle measurements. Reliability of torque measurements was higher than for other parameters, highlighting the importance of standardized protocols for knee extension analysis.
Area of Science:
- Biomechanics
- Kinesiology
- Human Movement Science
Background:
- Isokinetic dynamometry is commonly used to assess knee joint torques and angles during passive extension.
- Previous studies often lack detailed reporting on methodological errors and reliability outcomes for passive knee extension assessments.
- The influence of subject positioning on the reliability of passive knee extension torque-angle measurements remains unclear.
Purpose of the Study:
- To analyze the intra- and inter-session reliability of two distinct methods for assessing passive knee extension torque-angle relationships.
- To investigate the effect of non-tested thigh position on passive knee extension torque-angle measurements and reliability.
- To compare the reliability of direct torque measurements versus derived parameters (slope, mathematical model) in passive knee extension analysis.
Main Methods:
- Two methods were employed: (A) 2D kinematic analysis with a custom device for direct resistance measurement, and (B) isokinetic dynamometry.
- Method B utilized two subject positions: non-tested thigh flexed at 45° and in a neutral position.
- Intra-class correlation coefficients (ICCs) were calculated for torque, torque-angle curve slope, and mathematical model parameters in 16 healthy males.
Main Results:
- Method A and Method B yielded significantly different torque-angle responses.
- The passive torque-angle relationship and stretch tolerance were demonstrably influenced by the non-tested thigh's position.
- Intra-class correlation coefficients for direct torque measurements were higher compared to those for the slope and mathematical model parameters.
Conclusions:
- The choice of measurement method critically affects passive knee extension torque-angle outcomes.
- Subject positioning, specifically the non-tested thigh's placement, is a significant factor influencing these biomechanical measurements.
- Standardized protocols considering both measurement technique and subject positioning are essential for reliable and comparable passive knee extension data.
