Introduction: Transmalleolar axis (TMA) measurements are frequently used as a means of determining tibial torsion.

Material & Methods: The agreement between the prone, Edinburgh footprint and Dundee jig methods of measuring the TMA, and the repeatability of each method were investigated. The left and right limbs of 12 normal subjects (3 male, 9 female age range 21–61 years, mean age 38) were measured using the following three methods. The measurements were repeated for 6 subjects between 5 and 10 days later. All measurements were undertaken by the same assessors. The mean TMA values and repeatability of each method, and the agreement between the measures was as follows:

Results: Negative is external.

Discussion: Clinical methods will always include measurement errors, and a true TMA value may only be obtained from radiological or ultrasound methods. The position of the foot when marking the line for the prone method was very critical. The jig method produced lower values than those found previously. The Edinburgh footprint method proved the most repeatable of all three methods. There was poor agreement between the methods suggesting they should not be used interchangeably.