Can positional MRI predict dynamic changes in the medial plantar arch? An exploratory pilot study.

Area of Science:

• Biomechanics
• Medical Imaging
• Orthopedics

Background:

• Positional MRI (pMRI) enables 3D assessment of navicular bone position.
• A stretch sensor device measures medial plantar arch movement.
• This study aimed to validate pMRI against stretch sensor measurements.

Purpose of the Study:

• To validate positional MRI (pMRI) against a stretch sensor device for assessing navicular bone displacement.
• To investigate the correlation between combined pMRI measures and stretch sensor readings under various loading conditions.

Main Methods:

• 10 participants underwent pMRI and stretch sensor measurements.
• Measurements were taken in supine, standing, and standing with 10% body weight loading positions.
• Stretch sensor measurements were also performed during barefoot walking.

Main Results:

• Total navicular displacement by pMRI was 10.3 mm.
• No significant additional displacement occurred with 10% body weight loading.
• Total navicular displacement correlated with stretch sensor measurements under static loading (rho=0.66, P=0.04) but not during walking (rho=0.58, P=0.08).

Conclusions:

• Positional MRI demonstrated concurrent validity with stretch sensors for navicular bone displacement under static loading.
• The combined pMRI measure did not predict dynamic changes in the medial foot arch during walking.
• Further research is needed to understand dynamic foot arch behavior during gait.