Changes in pressure pain threshold (PPT) values after acupuncture. Pressure pain threshold was measured with a finger type pressure algometer consisting of a strain gage and a processing unit. Changes in the resistance caused by strain in the gage was converted to changes in the voltage via Wheatstone bride in the processing unit which enables quantitative indication of the pressure as an arbitrary units (AU). A significant decrease in the PPT two days after exercise was found in all groups while recovery was observed after application of acupuncture at the skin and the muscle with statistical significance when compared with that in the control at the end of the trial. (P = 0.020 and P < 0.001 for skin and muscle respectively). Asterisks indicate significant differences compared with two days after the exercise (* P < 0.05, ** P < 0.001). Data are shown as mean ± SD.