Contributed By Derek R. Austin, MS, CMT, April Neufeld, BS, LMT, NCTMB, Sandra K. Anderson, BA, LMT, ABT

In this month's Massage Therapy Foundation Research Column, we are taking a critical look at the effects of acupressure. Widely accepted in Japan, many Americans are unaware of the many benefits of manual acupressure. It is a noninvasive technique in which, instead of needles, the practitioner's fingers press on traditional acupuncture points. Acupressure has been shown to be calming, relieve pain and induce relaxation.

Lead author Dr. Takako Matsubara, PT, an Associate Professor in the Department of Rehabilitation at Nihon Fukushi University, Japan, and his colleagues studied an area of interest to most massage therapists - chronic neck pain. Their research article, "Comparative Effects of Acupressure at Local and Distal Acupuncture Points on Pain Conditions and Autonomic Function in Females with Chronic Neck Pain" was published in the journal Evidence-Based Complementary and Alternative Medicine.

Matsubara and colleagues randomly allocated 33 female subjects (n=33) to three groups. Group one subjects received acupressure at three tender points consistent with local acupuncture points (LP) "Jianjing" (GB 21), "Jianwaishu" (SI 14), and "Jianzhongshu" (SI 15). These local acupuncture points align with tender points in the trapezius muscle with acupressure (see Figure 1). Group two subjects received acupressure at three distal acupuncture points (DP); in this study, distal meant points distal to the location of the neck pain. These points were "Hegu" (LI 4), "Shousanli" (LI 10), and "Quchi" (LI 11). These distal acupuncture points are traditionally associated with neck-shoulder-arm disorders in Chinese/Japanese traditional medicine (see Figure 2). A third group, termed the control, received no acupressure at all.

Subjects were assessed about pain intensity using a verbal rating scale (VRS); the intensity of neck pain or stiffness was evaluated on a numerical scale from 0 to 3 (0: no pain, 1: mild pain, 2: moderate pain, and 3: severe pain). Subjects were also assessed about pain-related disability using the Neck Disability Index (NDI), pain-related anxiety using State-Trait Anxiety Inventory-I (STAI-I), and about muscle hardness (MH) on bilateral trapezius muscles. Pain-associated stress was assessed using salivary alpha-amylase (sAA) activity and heart rate variability (HRV) to determine parasympathetic and sympathetic activity. Low electrical frequency fluctuations in heart are indicators of sympathetic and parasympathetic activity, and high electrical frequency fluctuations are indicators of parasympathetic activity.

Parasympathetic and sympathetic activity in the test subjects was measured because several previous reports showed that the effects of acupuncture and acupressure are due to influencing the autonomic nervous system. The acupressure treatment lasted about ten minutes per session. Three sets of acupressure were applied with thumb pressure in a rotary fashion at 20-25 cycles per minutes for 30 seconds on each of the three assigned local or distal points on the right side of the subject's body; the same procedure was followed on the left side. The same investigator applied acupressure in all cases.

There were no significant differences among the three groups pre-treatment. There were no measured changes in pain, stiffness or autonomic activity in the control group throughout the study. However, in the LP and DP groups, the VRS, STAI-I, and MH significantly decreased immediately following treatment, indicating a decrease in pain and stiffness. The next day, the NDI was significantly lower compared with pre-treatment in the LP and DP groups. The subjects' heart rates significantly decreased and high frequency component of HRV significantly increased, indicating a parasympathetic autonomic response, only in the LP group.

This study is notable for its use of both local and distal acupressure therapy. Both appear to be effective in relieving chronic neck pain in only a single ten minute session, with significant next-day effects on the NDI, a validated measure of pain-related disability. Interestingly, reduction in pain in the LP and DP groups as assessed by the VRS were not significantly different from the control group at the one day follow-up.

This study by Matsubara et al., is limited by the lack of longer term follow-up beyond one day, the small sample size of 11 participants per group, and the inherent inability to blind the practitioner and participants from knowing which treatment was administered or received. As a primary measurement of pain intensity, the authors could have used a 10-cm visual analog scale (VAS), which may have been more sensitive to differences between groups at the one-day follow-up. Also, the addition of a "sham acupressure" group would have helped rule out the possibility of placebo effects or effects stemming from touch, not acupressure per se. Finally, the sample used in this study only included women; men might respond differently to acupressure applied to the points used in this study.

In conclusion, acupressure to both local and distal acupuncture points significantly reduces chronic neck pain in this randomized, controlled trial. The researchers point out that most clinicians combine local and distal acupuncture points in clinical practice, and they suggest that further research should assess combinatorial effects. This Open Access journal article is freely available in PubMedCentral at www.ncbi.nlm.nih.gov/pmc/articles/PMC2952311/.

Author's Note: For additional research about accupressure, please see Robinson et al.'s 2011 Open Access review entitled, "The Evidence for Shiatsu: a systematic review of Shiatsu and acupressure" published in BMC Complementary & Alternative Medicine and available at www.biomedcentral.com.proxy.library.vcu.edu/1472-6882/11/88.

Editor's note: For more information about massage therapy research, visit the Massage Therapy Foundation at www.massagetherapyfoundation.org.