Tibial torsion measured in normal adults.

A mobile fluoroscope was used to measure tibial torsion bilaterally in a random sample of 100 adults without a medical history of injury to the lower extremities. From a chosen neutral position, the difference in torsion between the right and the left tibia in the same subject ranged from -11 to 15 degrees, with a mean value of +2.1 degrees, indicating greater outward rotation of the right tibia in two thirds of the subjects. A difference in torsion of more than 6 degrees was found in a fourth of the subjects.