A novel assessment technique for measuring ankle orientation and stiffness

Area of Science:

• Biomechanics
• Rehabilitation Engineering
• Medical Device Development

Background:

• Ankle assessment is crucial for monitoring rehabilitation progress.
• Current methods like dynamometers have limitations in manual manipulation and single degree-of-freedom (DOF) measurement.
• Accurate measurement of ankle orientation and stiffness is needed for effective patient monitoring.

Purpose of the Study:

• To propose and evaluate a novel ankle assessment technique for multiple DOFs.
• To develop a device capable of both manual and automatic operation for ankle assessment.
• To validate the accuracy and reliability of the new assessment method.

Main Methods:

• A novel ankle assessment device was constructed using a position sensor and a multi-axis load cell.
• The device was evaluated for measuring ankle dorsiflexion and plantarflexion.
• Nine subjects participated in the study to assess device effectiveness.

Main Results:

• Measured ankle orientation showed consistency with the NDI Polaris optical tracking system.
• Measured ankle torque and stiffness correlated well with existing published data.
• High test-retest reliability was observed, with ICC2,1 > 0.846 and SEM < 1.38.

Conclusions:

• The novel ankle assessment technique is effective for measuring ankle orientation and stiffness.
• The developed device demonstrates high accuracy and reliability for use in rehabilitation.
• This technique offers a promising tool for objective monitoring of ankle function.