Bilateral Effect of Unilateral Electroacupuncture on Muscle Strength

Abstract

Objectives: This study aimed to examine the bilateral effect of 4 weeks of unilateral electroacupuncture on leg muscle strength.Design: The effect of unilateral electroacupuncture at two selected acupoints, Zusanli (ST-36) and Xiajuxu (ST-39), which are located on the anterior tibialis muscle, on dorsiflexion strength was evaluated by statistical analyses of the interactions between the muscle strength pre and post 4 weeks of intervention, between the two legs, and between an experimental and a control group.Settings/location: The trial was carried out in the exercise rehabilitation laboratory at Tianjin University of Sport.Subjects: Thirty (30) healthy men with an average age of 20.9 Ϯ 2.98 (SD) years were randomly allocated into an electroacupuncture group (EG) and a control group (CG). They were physically active, but without specific strength training or previous experience of acupuncture.Interventions: Participants in the EG were given 3 sessions of electroacupuncture per week. In each session, the electroacupuncture was applied to the right leg at the acupoints with 8 duty cycles of 1 minute on and 1 minute off, pulse width of 1 millisecond, frequency of 40 Hz, and intensity of 30-40 V. Participants in the CG group kept their normal daily activities without additional intervention.Outcome measures: The maximum strength in dorsiflexion of each leg was examined by having participants lift weights in the range of motion of ϳ20°at the ankle joint.Results: Repeated-measures analysis of variance with Bonferroni adjustment detected significant increase in strength of both legs (right 21.3%, left 15.2%) in the EG (p Ͻ 0.05) and the increase was significantly higher than that of the CG (p Ͻ 0.05). The CG showed no significant change (right 3.0%, left 4.8%), post-treatment.Conclusions: Unilateral electroacupuncture at the selected acupoints improved muscle strength of both limbs. These findings may have implications in physical therapy and rehabilitation settings. 539

Immediate Response Gain in Handgrip Strength With Acupuncture: An Experimental Study

“…Results indicate that acupuncture was able to significantly and immediately increase gain of handgrip strength measured by the dynamometer. This result is consistent with the studies of Yim et al (2007) and Huang et al (2007) who concluded that there are ergogenic effects of some acupoints. It is possible that the lost of strength found in GCRT may be due to muscle relaxation, considering that the volunteers of this group received no intervention.…”

An fMRI Investigation on Brain Activity in Response to Unilateral Acupuncture, Electroacupuncture and Electromyostimulation on ST36 and ST39

“…Electric stimulation has been widely used as a supplementary training method for improving muscular strength and fitness as well as a means of rehabilitation (Maffiuletti, 2010;Paillard, 2008). Electroacupuncture has recently been shown to be able to improve muscle strength as well (Huang et al, 2007). Although the electric stimulation and electroacupuncture can directly activate peripheral nerve and muscle fibres and by-pass the central nervous system, recent evidence has suggested that the training/therapeutic effects of electric stimulation may also include neural plasticity (Chae et al, 2008;Maffiuletti, 2010;Wolpaw, 2007).…”

“…This appears to be similar to the concept of cross education. A recent investigation in our laboratory has demonstrated that four weeks of electroacupuncture on tibialis anterior muscle (TA) of one limb can significantly increase dorsiflexion muscle strength in both the stimulated limb and the contralateral limb (Huang et al, 2007). The exact mechanism of cross education is not clear.…”

“…However, the neural mechanisms for the cross education induced by electric stimulation or electroacupuncture may not be the same as that induced by voluntary exercise because the stimulation is applied to a peripheral nerve or muscle that by-passes the corticospinal pathway. It has been speculated that the sensory afferents may play an essential role in mediating cross-education effect induced by electric stimulation and electroacupuncture (Hortobagyi, 2005;Huang et al, 2007). Furthermore, whether the cross-education effect caused by electrical stimulation on surface or via needling at the acupoint involves similar or different neural mechanisms has not been examined.…”

Effects of Acupuncture Therapy on the EMG Activity of the Rectus Femoris and Tibialis Anterior during Maximal Voluntary Isometric Contraction in College Students

“…5 Moreover, Huang et al demonstrated that the dorsi and plantar flexion strengths of the ankle improved by 21.3% following a 4-week acupuncture treatment compared with another ankle without any treatment. 6 Larisa et al also reported increased isometric strength and electromyography (EMG) activation after acupuncture stimulation. 7 Nevertheless, studies on the immediate effects of one-time acupuncture treatment that is directly applied in the field on the muscles of athletes are still significantly lacking.…”