SENSITIVITY OF THE HAND TO SURFACE PRESSURE

A new method of measuring pain-pressure threshold (PPT) of the hand ha s been developed. Externally applied surface pressure (EASP) was exert ed at a certain rate of increase and the level where the feeling of pr essure turned into pain was recorded. Also, the effects of sustained E ASP were elucidated. Sixteen healthy right-handed subjects (eight fema le, eight male) participated. The distribution of the hand's sensitivi ty to EASP is presented. The most sensitive areas were the thenar area , the skinfold between thumb and index finger and the area around os p isiforme. When the hand was repeatedly exposed to EASP, the PPT decrea sed with increasing number of pressure incidents. For sustained EASP, the time of exposure was found to be important also for the quality of the sensation. Our results show that sustained EASP does not hurt at once, but becomes painful after a short time. On average, the female P PT corresponded to two-thirds of the male PPT. Females experienced pai n faster than males when exposed to sustained EASP, and chose lower le vels when estimating acceptable sustained EASP.