The basic examination technique used in Applied Kinesiology (AK) is a manual muscle test 1. Applied Kinesiology is a system of evaluating body reactions to different stimuli that interact with the nervous system 2. Recent reviews highlight historical, practical and methodological aspects of manual muscle testing 345. During the development of AK 1, Goodheart described an association between meridians and individual muscles. The sedation and tonification acupoints of the corresponding meridian were used in a similar way as in acupuncture. These effects are based on the relations defined by the Five Elements (wuxing): Water (shui), Wood (mu), Fire (huo), Earth (tu) and Metal (jin) (Table 1). Tonification is based on the generating or mother-child relation, i.e. the sheng cycle 6. Sedation is based on the inverse or child-mother relation 6. In clinical practice, the use of these acupoints induces changes in the strength of the muscle being examined which can be perceived by the examiner as well as by the patient. When sedation is applied, muscle tone will diminish; when tonification is applied, muscle tone will increase.

A further development of AK was made by Burtscher et al. 7 leading to a technique called AK meridian therapy (AKMT). While the name AKMT is similar to that of Goodheart 1 and Walther 2, Burtscher expands the regulatory possibilities of AK through the use of element acupoints of associated meridians according to the Five Elements 6 in order to achieve sedation or tonification (Table 2).

While there is abundant literature on the use of manual muscle tests for the evaluation of musculoskeletal disorders, only few studies have evaluated the effects of acupuncture on muscle function in clinical situations similar to those of AK. Costa and de Araujo 8 recently described the local effects of acupuncture on the tibialis anterior muscle. By needling the ST36 and SP9 acupoints, they observed a diminution of root mean square (RMS) signal of the tibialis anterior.

Since 2003, we have used the AKMT techniques for the evaluation of musculoskeletal diseases at our institute (WOMED, Innsbruck Austria), and used surface electromyography (sEMG) to investigate the functional correlations between manual muscle tests and AKMT points. The aim of this article is to report these sEMG data.

Figures 1, 2, 3, 4, 5 and 6 show amplitude graphs of the sEMG data of each of the selected procedures. Table 3 displays the acutal RMS data obtained in each procedure. The dimension of RMS signal change following sedation, tonification or scar manipulation was greater than the basal value for repeated measures at ten seconds interval (variation 5–8%). In each graph the right inset shows the initial muscle signal on the left-most column.

The most common and basic situation in AK, i.e. the use of the sedation acupoint within the same meridian (SI8), led to a diminution of signal amplitude (Figure 1). A more graded pattern of response was observed when other sedating acupoints were used (Figures 2 and 3). Each subject showed, however, an individual response pattern. In the tonifying procedure, a constant increase in signal amplitude was recorded (Figure 4).

In subject 5, manual stretch stimulus of each of the three abdominal scars tested led to a diminution of signal intensity of the rectus femoris (Figure 5). Correction of this sedating effect could not be achieved by the use of tonification acupoints. In such situations, selective NT (a specific anesthetic agent for each scar) 13 was carried out as needed. In our routine work, mostly for treating hypertrophic scars, the three most commonly used agents are procaine, mepivacaine and lidocaine, in 34.8%, 30.4% and 26.1% of cases (n = 115) respectively (time period 2002–2005). The selective NT was carried out effectively in subject 6. Manipulation of the two shoulder scars produced initially a diminution of the RMS signal. Already ten minutes after NT, scar manipulation did not alter the muscle tone. Surprisingly, the 'new' basal RMS value improved compared to the initial basal value (Figure 6).

Caruso and Leisman described the AK test as one that evaluates a transitory state named 'quality of resistance' 9. The sEMG analyses we did support this notion of change in the 'quality of resistance', i.e. diminution of RMS amplitude under sedation and the opposite during tonification. These effects can be achieved via acupoints of the same meridian or of associated meridians according to the theory of the Five Elements. The use of additional acupoints of tonification or sedation show slight differences in the absolute RMS signals; however the use of sEMG is not mandatory for clinical practice. Experienced AK practitioners can still rely on the good practice for conducting manual muscle tests 4. In a similar study based on AK principles, Zampagni et al. 14 used a tailor-made device equipped with a load cell in order to evaluate the strength of the tensor fascia lata in different conditions. The changes in the recorded signals are in agreement with the principles of AK in relation to sedation and tonification.

It must be stressed that the conduct of manual muscle tests must follow good practice guidelines in order to obtain reliable results 4. The combination of manual muscle testing and acupuncture principles results in a unique and simple examination procedure when compared with other methods such as electroacupuncture 15, laser acupuncture 16 or computer-based meridian diagnosis 1718. In clinical practice, changes of the 'quality of resistance' of the test muscle are also felt by the patient. Understanding the examination procedure adds a psychological dimension to the treatment 19. Manual contact and interaction has the potential of improving the patient-doctor communication 20.

According to a recent study by Costa and de Araujo, functional changes of the tibialis anterior muscle can be induced via needling ST36 and SP9 acupoints 8. We would like to offer an acupuncture-based interpretation of their results. According to AK, the tibialis anterior muscle corresponds to the Bladder meridian. The sedating effect of ST36 corresponds to the grandparent relation between the ST and BL meridians. The sedation effect seen when SP9 was needled could be explained by the inner-outer relation that exists between these two acupoints. According to AKMT 7, the needling of inner-outer related meridians will reinforce the complementary partner, in this case ST36, which then shows effects corresponding to the grandparent relation between ST and BL. We feel that this explanation based on principles of Chinese medicine is more appealing than the term 'reflex loop' used by Castro and de Araujo in their publication.

Traditional acupuncture concepts of tonification and sedation are applicable to clinical studies based on manual muscle techniques of AK. Tonification leads to an improved function of any meridian while sedation reduces the excess. In terms of muscle signals derived from sEMG, signals increase in tonification and decrease in sedation. Surgical scars can cause interferences in manual muscle tests as well as in muscle tone and require treatment by means of selective NT.

AK: Applied Kinesiology; AKMT: Applied Kinesiology meridian therapy; NT: neural therapy; RMS: root-mean-square; sEMG: surface electromyography.

The authors declare that they have no competing interests.

Both RM and HM designed the study and wrote the manuscript. RM performed the sEMG studies. Both authors read and approved the final version of the manuscript.