Characterisation of dynamic couplings at lower limb residuum/socket interface using 3D motion capture.

Area of Science:

• Biomechanics
• Prosthetics and Orthotics
• Rehabilitation Engineering

Background:

• Current artificial limb socket design relies heavily on prosthetist's subjective judgment.
• A deeper scientific understanding of the residuum/socket interface dynamics is needed for improved prosthetic fitting and design.

Purpose of the Study:

• To develop and validate a novel method for characterizing three-dimensional (3D) dynamic coupling at the residuum/socket interface.
• To quantify the angular and axial couplings in a trans-femoral amputee.

Main Methods:

• Utilized 3D motion capture technology for dynamic analysis.
• Developed a biomechanical model incorporating a Virtual Residuum Segment (VRS) and a Socket Segment (SS).
• Quantified angular and axial couplings at the residuum/socket interface in a single case study.

Main Results:

• Identified significant non-rigid angular coupling (>10°) in the quasi-sagittal plane.
• Measured axial coupling ranging from 21 to 35 mm.
• Estimated smaller angular couplings (<4° and <2°) in the quasi-coronal and quasi-transverse planes, respectively.

Conclusions:

• The proposed experimental and analytical approach provides objective data for the residuum/socket interface.
• This method can assist in the iterative socket fitting process for lower limb prosthetics.
• Findings suggest potential for developing novel prosthetic socket designs based on dynamic coupling characteristics.