Ultrasonography in Acupuncture Uses in Education and Research

The present study represents an important advance in the pursuit of greater precision and standardization in acupuncture practice, an ancient therapy that traditionally relies on the practitioner's experience and the patient's subjective sensation. Conducted in Singapore, this innovative research investigated how ultrasonography can be used to locate acupuncture points with greater precision and to determine the appropriate depth for needle insertion, using as a model the BL-32 point, located at the second posterior sacral foramen.

Acupuncture faces significant challenges related to the precise location of points and the determination of correct insertion depth. Traditionally, practitioners locate points through palpation and determine whether the needle has reached the appropriate depth through the patient's report of "de qi"—a sensation of numbness, tingling, or heaviness indicating adequate stimulation. However, this approach is subjective and can vary considerably across patients and practitioners. Traditional manuals present significant variations in depth recommendations, reaching differences of up to 50% for the same point, which can compromise treatment efficacy.

The researchers developed a four-step experimental protocol to assess the utility of ultrasonography in acupuncture. First, a certified practitioner located the BL-32 point through traditional palpation, using anatomical landmarks such as the posterior superior iliac spine. Next, they used an ultrasound device to visualize the anatomical structures around the point and measure the distance from the skin to the sacral foramen. In the third step, an acupuncture needle was inserted at a 30-degree angle while the study participant reported the sensations experienced.

Finally, a new ultrasound examination confirmed the needle's position and its proximity to the desired sacral foramen.

The results demonstrated that ultrasonography was able to clearly visualize all relevant anatomical structures, from the skin to the sacral bone, including the gluteus maximus muscle and ligaments. The distance from the skin to the sacral foramen was measured at 2.1 cm on both sides of the participant. During needle insertion, the participant reported the first sensation of "de qi" when the needle reached 3.5 cm depth, still within the gluteus muscle. A more intense sensation was experienced at 4.0 cm, when the needle effectively reached the surface of the sacral foramen.

Using mathematical calculations based on the Pythagorean theorem, considering the 30-degree insertion angle, the researchers estimated a perpendicular depth of 1.8 cm, which was confirmed by ultrasonography with notable precision at 1.85 cm.

These findings have important implications for both clinical practice and acupuncture education. For patients, this means more precise and potentially more effective treatments, especially in people with greater amounts of adipose tissue, where locating deep points can be more challenging. Sacral foramen points such as BL-32 are particularly important in the treatment of urological, digestive, reproductive, and pelvic pain problems, but they are frequently underused due to the difficulty of precise location. With the assistance of ultrasonography, these points can be used with greater confidence and safety.

For novice practitioners, this technology offers a valuable learning tool, allowing real-time visualization of anatomy and confirmation of correct needle positioning.

In the research arena, ultrasonography can contribute significantly to the standardization of treatment protocols, a critical need for rigorous scientific studies on acupuncture. The ability to objectively quantify insertion depth and confirm precise needle placement can improve the quality and reproducibility of research in this field. In addition, visualization of nearby vascular structures may increase procedural safety, although vascular complications are extremely rare in acupuncture.

It is important to recognize the limitations of this study. It was conducted in only one participant, which limits the generalizability of the results to different body types and individual anatomical variations. The study focused exclusively on the BL-32 point, although the principles may be applicable to other points. The need for ultrasound equipment and specialized training may limit practical applicability in all clinical contexts.

Future studies with larger samples and various acupuncture points are needed to fully validate this approach.

In conclusion, this pioneering research demonstrates the promising potential of ultrasonography as a complementary tool in acupuncture practice, offering greater precision, safety, and objectivity to a therapy traditionally based on subjective experience. Although more studies are needed, these results pave the way for a productive integration between modern technology and traditional medicine.