STUDIES ON PAIN. A NEW METHOD FOR MEASURING PAIN THRESHOLD: OBSERVATIONS ON SPATIAL SUMMATION OF PAIN

Abstract

The purpose of these studies has been to pre-sent a new method for measuring pain thresholds, together with experimental observations on the physiology of pain and on the effect of various chemical agents upon pain thresholds. Methods for estimating the intensity of the stimulus required to evoke a painful sensation in the skin may be classified under the headings: mechanical, chemical, electrical, and thermal. The mechanical devices as used by von Frey (1) and by Eddy (2), involving production of pain by pressure, empirically correlated the amount of pressure and the pain threshold. The deforma-tion and internal stresses in the tissues responsible for the sensation were not investigated, and it may