Variability in the precision of acupoint location methods

The ability to precisely locate appropriate acupoints is, according to both traditional and contemporary theories, essential to deliver acupuncture treatments. More than half of the acupoints defined in acupuncture literature are sufficiently distant to anatomical landmarks, to require the use of specialised techniques in order to locate them. However no research has been conducted to investigate the precision of any manual method (electrical detection is discussed at detail with reference to numerous conflicting research papers). This thesis details the design, conduct and results of experimentation carried out to measure the precision of four methods (named the directional, proportional, elastic and ruler methods) used to locate acupoints. The methods include two based upon the traditional Chinese anatomical unit of measurement, the cun, and two based upon the traditionally reported lengths of areas of the human body. The reasons for selecting these methods, and for excluding others, are explained. Seventy two subjects were involved in testing the precision of the four methods by applying them when locating a fictitious acupoint. The subjects marked the attempts to locate the fictitious acupoint with invisible ink. The marks were transferred to plastic films and measurements made from reference points. A significant difference was found between the methods (F3,120 = 11.74, p less than 0.0001). No significant difference was found between the two traditional methods of point location (directional mean = 11.35, and proportional mean = 11.17) (p less than 0.998), nor between the two variant methods of point location (elastic mean = 7.63, and ruler mean = 6.34) (p less than 0.68). Significant differences were found between the two traditional methods and the two variant methods. The directional method was less precise than both the elastic method (F3,120 = 11.74, p less than 0.007) and the ruler method (p less than 0.00009). The proportional method was also less precise than both the elastic method (F3,120 = 11.74, p less than 0.011) and the ruler method (p less than 0.0002). Each subject also completed a short questionnaire regarding ease and comfort of use of the four methods. The two more precise methods were generally not well received by subjects in this study. Their two primary concerns were not with precision, but rather of application of the method, and its perceived appearance to patients. An analysis was also carried out to describe any variation in acupoint location descriptions reported by prominent authors. 151 clinical research papers reporting acupuncture studies were selected according to a number of criteria. The five most frequently prescribed acupoints in these papers comprised the sample used in the examination of seven acupuncture texts. Variability was found between the texts, and is discussed in consideration of the presently poor understanding of the anatomical make-up of an acupoint. Also examined was the usefulness of measures of sensitivity to palpation used when locating acupoints. No statistically significant difference was found between any of the acupoints tested and the related control points. The thesis discusses the implications for acupuncture practice, research and education in light of the lack of precision measured, the subjects' preference for the more imprecise methods, the inability to locate or even verify the location of an acupoint using pressure, variability in reported acupoint locations between reference texts, and the related short-comings in published acupuncture research