A MR imaging procedure to measure tarsal bone rotations

Area of Science:

• Biomechanics
• Medical Imaging
• Orthopedics

Background:

• Magnetic Resonance Imaging (MRI) provides valuable 3D insights into foot bone motion.
• Accurate devices for controlled foot loading and positioning are essential for MRI studies of foot mechanics.

Purpose of the Study:

• To evaluate a novel MRI procedure for quantifying 3D tarsal bone motion during pronation and supination.
• To assess the transfer of motion from a loading device to the calcaneus and estimate required degrees for distinguishing tarsal joint rotations.

Main Methods:

• A new MR imaging procedure was developed for measuring tarsal bone positions.
• Three healthy subjects underwent repeated measurements in pronated and supinated foot positions under bodyweight.
• Quantification of motion transfer and estimation of rotational degrees were used for evaluation.

Main Results:

• 45-70% of pronation and 75-95% of supination were transferred to the calcaneus.
• The talonavicular joint exhibited the largest rotation (up to 20 deg), followed by the subtalar joint.
• Minimal rotation was observed between the calcaneus-cuboid and navicular-cuboid joints.

Conclusions:

• The developed MRI procedure is applicable for investigating 3D tarsal bone mechanics.
• Findings align with existing literature, validating the method's reliability.
• This technique may offer new insights into the foot function-morphology relationship by combining kinematic and morphological data.