One method for assessing the effectiveness of fast brushing

The purposes of this study were to determine if fast brushing of the skin overlying a muscle is effective in increasing the sensitivity of the stretch reflex of that muscle and to detect the optimal rate and duration of brushing to elicit this effect in healthy adults. The stretch sensitivity of the right lateral gastrocnemius muscle was measured by EMG activity and force produced by the abrupt tap of the Achilles tendon before and after fast brushing. Peak-to-peak EMG and force from 10 taps were established. Eight different conditions (two control and six experimental brushing) were applied to 10 healthy adult subjects (age range, 30 to 46 years). The experimental conditions included rotary brushing at 5 Hz, 180 Hz, or 360 Hz for 5 seconds or at 5 Hz, 180 Hz, or 360 Hz for 30 seconds. Postbrushing taps began 30 seconds after the brush was turned off and continued every 5 minutes for 30 minutes. This method of fast brushing did not increase the stretch sensitivity of the muscle in healthy adults. Possible factors influencing the results of the study and recommendations for future studies are presented.