EFFECTIVENESS OF DIFFERENT FORMS OF HEATING BY

It is generally stated that diathermy and penetrating short-wave infra-red radiation are more effective for heating deep subcutaneous tissues than are the non-penetrating rays of long-wave infra-red or the heat derived from direct contact, but there are few experimental studies on the extent of the difference involved. We report here some observations on the temperature changes produced in the lumbar region by these different methods of heating. Methods Tests were made in the lumbar area of one subject on different days. The area was made flat by having the subject prone with pillows packed under the abdomen, and temperatures were measured at the centre point of the area, 2-5 cm. to the right of the second lumbar vertebral spine. Skin temperature was recorded with two copper-constantan wire thermocouples (Whyte, 1951), and subcutaneous temperatures with needle thermocouples passed vertically into the region (Whyte and Reader, 1951). (a) Short-Wave Infra-Red Radiation.-This was supplied from a 1,000-watt tungsten filament lamp; * it was applied to a 12 x 12 cm. area in the maximum intensity whic