The relationship between the linear distance from the finger tip to the cardinal line of the hand and loss of flexion of the individual interphalangeal and metacarpophalangeal joints was studied using mathematical techniques. Mathematical functions were developed and a table was prepared from which impairment values could be derived directly. The results by this method correlate well with those by the time-consuming angular method for the measurement of impairment, and it was concluded that this procedure offers a simple, valid alternate method useful in some circumstances.