The Malleolar Valgus Index (MVI) is a static measurement taken with a flatbed computer scanner. An MVI value is helpful in catogorizing the structure of a foot along a spectrum containing planus (flat-foot), rectus (ideally-aligned), and cavus (high-arched). The MVI reference values for rectus and planus are 7.31 and 17.88 respectively.

To make an MVI measurement a plexiglass platform is placed over a scanner bed and a custom-made MVI jig is fitted to the medial malleolus and lateral malleolus (the ankle bones)--as shown above. A scan of the foot is then made in grayscale and posterized to 8 levels which allows for a better view of the foot's contact with the ground.

The scan is then printed and measurements are made to determine the following:

ML: Length between the lateral jig marker and the medial jig marker

BC: Length between the foot bisection line and the midpoint of the malleolar bisection line (ML). The foot bisection line is determined by finding the midpoints of the lines A1-A2 (the most anterior border) and P1-P2 (the most posterior border). These two lines are drawn at right angles to the medial border line and end at the lateral border line.

MOV=Constant measuring the distance between the jig and the medial malleolus and lateral malleolus.