RESUMO
[Objectives]The purpose of this study is to clarify the effect of acupuncture sensation on the body sway during a one-legged stance.[Methods] The study participants were 16 healthy adults (mean age 21.8±1.6 years). The study design was a crossover method, wherein the same individuals participated in the acupuncture stimulation condition and the control condition at intervals of more than one week. Evaluation was performed before and after each intervention by holding a one-legged stance for 40 seconds on a force plate. A total of six items of body sway were measured, including: circumferential area, rectangular area, effective value area, total trajectory length, unit trajectory length, and unit area trajectory length. In addition, Visual analog scale (VAS) was used to evaluate the ease with which the lower leg was subjected to force during measurement. In the acupuncture stimulation condition, single acupuncture was performed on the lower limb muscle group of the measuring leg, and the VAS of the acupuncture sensation was evaluated at the time of stimulation and at the end of measurement. Stainless steel disposable acupuncture needles (length: 50 mm, diameter: 0.20 mm.) were used for stimulation. The stimulation sites were the ST32, ST37, BL37, BL57, and GB37 of the test leg, and acupuncture needles were inserted to the desired depth and removed when sensation was felt. The control condition was the supine position for five minutes. Comparisons were made between the pre- and post-acupuncture stimulation conditions and the pre- and post-control conditions(body sway, lower leg VAS, acupuncture sensation VAS). [Results] There was no significant difference between the two conditions in terms of body sway. However, the VAS of lower limb effort was significantly lower, from 78.0±14.9 mm to 63.1±17.0 mm before and after the intervention (p<0.05). On the other hand, in the control condition, there was no significant difference from 79.5±12.3 mm to 75.2±12.7 mm before and after rest. The VAS of acupuncture sensation was 50.4±14.3 mm during stimulation and 9.8±9.0 mm at the end of measurement, which was significantly lower (p<0.05). [Conclusion] Acupuncture sensation did not affect the body sway before and after acupuncture stimulation. However, the subjective sensation of weakness appeared, suggesting that acupuncture stimulation may cause a transient sensation of weakness.