Abstract: A finger tip sensitivity-testing instrument consisting of a tunnel-shaped track member used as a support for the hand and forearm of a patient, the track member having a longitudinal cavity slidably receiving a feeler bar which is formed on its top surface with surface profile structure varying progressively longitudinally in sensible magnitude. The patient's finger is received in a notch in the edge of the tunnel top wall so as to allow the finger to engage the surface profile bar as it is extended from the tunnel. Graduations are inscribed along the side margin of the feeler bar which represent specific increments of differential surface profile relative to the mouth of the tunnel. The feeler bar rests slidably on a spring-supported plastic thin plate, thus simulating a floating support surface for the feeler bar.