A multisegmental foot model with bone-based referencing: sensitivity to radiographic input parameters

Area of Science:

• Biomechanics
• Orthopedics
• Kinesiology

Background:

• Accurate measurement of foot and ankle kinematics is essential for understanding biomechanical function and diagnosing pathologies.
• Existing models may not fully account for the complex 3D orientation of multiple foot and ankle segments.
• Integrating bony anatomy with skin marker data is critical for precise kinematic analysis.

Purpose of the Study:

• To present a novel kinematic model for measuring the 3D orientation of multiple foot and ankle segments.
• To establish neutral alignments based on underlying bony segment orientations.
• To index skin-mounted marker orientation to bony anatomy using weight-bearing X-ray data.

Main Methods:

• Development of a new 3D kinematic model for the foot and ankle.
• Utilizing weight-bearing X-rays to align skin markers with bony anatomy.
• Performing sensitivity analysis of the model using walking trial data to assess radiographic input parameter influence.

Main Results:

• Kinematic output in each plane was most sensitive to radiographic measurements within that same plane.
• Perturbations in coronal and transverse planes showed significant carry-over effects into other planes.
• The model's sensitivity analysis underscores the importance of accurate anatomical data.

Conclusions:

• Accurate accounting for underlying bony anatomy is paramount for precise intersegmental kinematic measurements.
• The developed model provides a framework for improved 3D foot and ankle motion analysis.
• Understanding cross-plane sensitivities is vital for robust kinematic modeling in the foot and ankle.