Transverse Plane Determination Of The Tibial Torsion Angle
This measurement technique has the advantage of obtaining the “transmalleolar angle” without instrument or skin slippage encountered with the use of other devices. A calibration graph (by Staheli & Engel) is reproduced on an acrylic “back-plate” positioned beneath the supine subject’s foot and ankle. Vertical bisection of the medial and lateral malleoli are initially marked and the device is placed with its vertical arms at both sides of the ankle.
With the foot and ankle brought to their neutral position attitudes, the upright millimeter scales are read and their difference in height from the back-plate is determined. After removing the subject’s limb from the device, the ankle width is measured from the caliper scale of the instrument.
With the malleolar height differential plus the width of the ankle, the degree of “malleolar (tibial) torsion” is plotted from the backplate grid and recorded.