56 studies [10, 14–18, 28, 35, 38, 42, 43, 50, 53, 55, 57, 58, 61, 64, 66, 68, 69, 71, 73, 75–77, 87, 89–91, 93–96, 99–101, 103, 104, 106–111, 115, 117, 120, 124, 127–130, 140, 166, 169] have evaluated needle sensation after acupuncture stimulation. The 10-point Visual Analogue Scale (VAS), the Massachusetts General Hospital Acupuncture Sensation Scale (MASS), the Subject Acupuncture Sensation Scale (SASS), the 6-point Likert scale, the Park questionnaire, the Psychophysical Rating of Needling Sensation, and the Needle Sensation Questionnaire (NSQ) were used to evaluate the needle sensation (Figure 4).