The Littler line method and the area under a Gaussian curve: a new method of assessing digital range of motion.

A new method of measuring digital range of motion (the Littler line method) is presented. When a Gaussian curve is centered over the Littler line and the appropriate area under the curve is computed, this area can provide a measure of the functional range of motion regained by an injured digit. Seventeen children (24 digits) with flexor tendon injuries were evaluated at an average follow-up period of 58 months (range, 12-121 months). The Littler line/Gaussian curve method was found to be more reproducible than total active motion, particularly in zone I and II injuries. This method can serve as a more meaningful functional assessment tool than a linear measurement such as total active motion, because it emphasizes digital motion in the mid-ranges of digital motion. (J Hand Surg 2001;26A:23-30.