Evidence-Based Complementary and Alternative Medicine / 2011 / Article / Figbox 2

Review Article

Paradoxes in Acupuncture Research: Strategies for Moving Forward

Box 2

Acupuncture-related definitions.
Acupuncture Treatment Versus Acupuncture Needling
The term “acupuncture” in and of itself is ambiguous. It has been used to refer to either a specific procedure involving
acupuncture needling or a multicomponent treatment that also involves history taking, physical examination, diagnosis, and
education. In some cases, nonneedling procedures (e.g., laser, TENS) conducted at acupuncture points are also referred to as
acupuncture. In order to minimize ambiguity, the term “acupuncture” will not be used in this paper. Rather, we will refer to
“acupuncture needling” or “acupuncture treatments”. We will not discuss techniques using stimulation of acupuncture points
without needles.
Components of Acupuncture Treatments
An underlying assumption of this paper is that acupuncture treatments are multicomponent interventions [54].
Accordingly, for research purposes, we divide the components of acupuncture treatments into four groups
(Figure 1): (1) needling components (i.e., needle size, depth, stimulation, location), (2) specific (acupuncture
theory-related) nonneedling components that are traditionally considered to have therapeutic value such as
Traditional Chinese Medicine (TCM) diagnosis and palpation, and (3) generic, nonspecific nonneedling components
that are not unique to acupuncture treatments such as belief and expectancy of the practitioner and patient, therapeutic
setting, time and attention. These distinctions become relevant in the discussion of issues related to the interpretation of
studies using sham controls, and the distinction between specific versus nonspecific effects. These distinctions are
further complicated by the fact that we do not fully understand which components of acupuncture have “active”
physiological effects.
Sham Acupuncture
The term “sham” acupuncture is used to refer to procedures controlling for the designated acupuncture treatment
components that are being evaluated. In human clinical trials, the aim of sham acupuncture is usually to perform a
“mock treatment” that the subject believes is an acupuncture treatment, but which in theory is missing all relevant
needling and/or specific nonneedling components that are hypothesized to be active. Examples of components that
have been controlled for (alone or in combination) in clinical trials to date include needle location (e.g., use of
nonacupuncture points or acupuncture points believed to be therapeutically irrelevant) [55], degree of needle insertion
(e.g., no penetration or depths believed to be suboptimal) [56], needle stimulation (e.g., no or suboptimal manual or
electrical stimulation) [57], and components of patient/practitioner interactions traditionally considered integral to
acupuncture therapy (e.g., limited palpation or restricted dialog related to traditional Chinese medicine) [16]. In animal
experiments, the aim of a sham control is to perform a procedure that controls for the effects of the general handling of the animal
plus some of the needling components listed above.
Acupuncture Points
Based on historical texts, acupuncture points are locations on the body that are the focus of acupuncture needling,
acupressure, and other procedures. According to acupuncture theory, there are several hundred acupuncture points
that are distributed along “meridians” or “channels” connecting these points as well as numerous other “extra points”
that are not associated with a particular meridian. Although there is general consensus among acupuncturists regarding
the approximate location of major acupuncture points, experimental studies have shown considerable variability in the
precise location of points across practitioners [58, 59]. Moreover, there is yet little scientific evidence supporting
the distinction between acupuncture points and nonacupuncture points. Acupuncture points have been hypothesized
to have some anatomical correlations (e.g., nerves, connective tissue, gap junctions), as well as bioelectrical properties,
but limited systematic research is available to support these theories [35]. This lack of understanding of what is and
what is not an acupuncture point impacts our ability to interpret the results of clinical trials that compare needling
at acupuncture and nonacupuncture (i.e., sham) points.