Inhibitory Effect of Acupuncture on Vibration-Induced Finger Flexion Reflex in Humans: Comparisons Among Radial, Median, and Ulnar Nerve Stimulation.
Vibration-induced finger flexion reflex (VFR) is inhibited with acupuncture to TE 5 or LI 4 at the skin innervated by the radial nerve.



The aim of this study was to determine if acupoints in regions innervated by the radial nerve are specific to inhibit VFR.



This experiment was performed using a crossover design with 3 acupuncture groups (needle insertion to the right LU 11, PC 9, or SI 1) and a control group (no needle treatment). Each acupoint was randomly needled on separate days. Ten healthy volunteers were recruited for this study. VFR was induced by applying vibration on the volar side of the right middle fingertip. An acupuncture needle was inserted in the acupoint and retained for 5 minutes. For the main outcome measure, maximum finger flexion force (MFFF) was measured during vibration and was compared among four groups.



MFFFs in the acupuncture groups were significantly lower (p<0.05) than that in the control group. However, no significant difference was observed in MFFFs in the three intervention groups after acupuncture to LU 11, PC 9, and SI 1.



Acupuncture to the right LU 11, PC 9, or SI 1 point inhibited the ipsilateral VFR, which suggests that afferent inputs from the radial nerve with needle insertion were not specific, compared with those from the median and ulnar nerves to suppress neuronal activities in the VFR reflex circuits.
Department of Acupuncture and Moxibustion, Faculty of Health Sciences, Tokyo Ariake University of Medical and Health Sciences , Tokyo, Japan . ; Second Department of Physiology, Showa University School of Medicine , Tokyo, Japan . ; Japan School of Acupuncture , Moxibustion, and Physiotherapy, Tokyo, Japan .
Hiroyoshi
H
Yajima
Department of Acupuncture and Moxibustion, Faculty of Health Sciences, Tokyo Ariake University of Medical and Health Sciences , Tokyo, Japan . ; Second Department of Physiology, Showa University School of Medicine , Tokyo, Japan . ; Japan School of Acupuncture , Moxibustion, and Physiotherapy, Tokyo, Japan .
Miho
M
Takayama
Second Department of Physiology, Showa University School of Medicine , Tokyo, Japan . ; Japan School of Acupuncture , Moxibustion, and Physiotherapy, Tokyo, Japan . ; The Foundation for Oriental Medicine Research , Tokyo, Japan .
Akiko
A
Kawase
Department of Acupuncture and Moxibustion, Faculty of Health Sciences, Tokyo Ariake University of Medical and Health Sciences , Tokyo, Japan . ; Second Department of Physiology, Showa University School of Medicine , Tokyo, Japan . ; Japan School of Acupuncture , Moxibustion, and Physiotherapy, Tokyo, Japan .
Nobuari
N
Takakura
Second Department of Physiology, Showa University School of Medicine , Tokyo, Japan . ; Japan School of Acupuncture , Moxibustion, and Physiotherapy, Tokyo, Japan .
Masahiko
M
Izumizaki
Department of Acupuncture and Moxibustion, Faculty of Health Sciences, Tokyo Ariake University of Medical and Health Sciences , Tokyo, Japan . ; Second Department of Physiology, Showa University School of Medicine , Tokyo, Japan . ; The Foundation for Oriental Medicine Research , Tokyo, Japan .
Ikuo
I
Homma
Acupuncture; Flexion Reflex; Median Nerve; Radial Nerve; Stiff Muscles; Ulnar Nerve; Vibration