Acupuncture sensation during ultrasound guided acupuncture needling

This innovative pilot study scientifically investigated one of the foundations of traditional acupuncture: the sensations experienced during treatment, known as 'de qi' (得氣). Using a revolutionary approach combining real-time ultrasound with validated sensation questionnaires, the researchers mapped, for the first time, the specific sensations associated with different anatomical depths during needling. The study enrolled five healthy volunteers who received needling at four distinct tissue levels: epidermal (skin surface), dermal (skin layer), fascial (connective tissue surrounding muscle), and intramuscular (within muscle). The researchers tested both traditional acupuncture points (LI-13 and LU-4) and control points located 3 cm distant from the classical meridians.

The methodology included two needle manipulation techniques: simple oscillation (vertical movement) and oscillation combined with rotation. The results revealed distinct, statistically significant patterns of sensation at different depths. In the more superficial layers (epidermal and dermal), sensations described as 'pricking' and 'sharp' predominated (p = 0.007), while in the deeper layers (fascial and intramuscular), sensations of 'heaviness,' 'dull ache,' and 'radiation' were more common (p = 0.002). Surprisingly, there were no significant differences between traditional acupuncture points and control points at most depths tested, except in the deepest intramuscular layer (p = 0.006).

The needle rotation technique significantly increased deep sensations in the fascial layer (p = 0.021) but did not affect superficial sensations, suggesting that needle manipulation may have specific effects depending on depth. These findings challenge traditional concepts of acupuncture point specificity and suggest that anatomical depth may be more important than the exact location of the point. The study also provides scientific evidence to explain why different acupuncture schools (Chinese with deep needling versus Japanese with superficial needling) report distinct sensations. The clinical implications are significant, as they may lead to the development of more standardized and objective treatment protocols.

The research opens the way for future studies that combine objective measures (force and torque) with subjective sensation assessments. Limitations include the small sample size, the purely subjective nature of sensation measures, and the lack of data on real clinical efficacy. Larger studies are needed to confirm these preliminary findings and to investigate whether these differences in sensation translate into different therapeutic outcomes.