Acupuncture needle grasp

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Acupuncture needle grasp: Ultrasound analysis and clinical

implications

 

Helene M Langevin, Junru Wu, David L Churchill, Gary J Badger and

Jason A Yandow

Department of Neurology, University of Vermont, Burlington, VT

 

The insertion and manipulation of acupuncture needles is associated

with a measurable biomechanical phenomenon termed " needle grasp " ,

characterized by an increase in the force necessary to pull the

acupuncture needle out of the skin (pullout force). Needle grasp is

not due to a muscle contraction, and histological observations in

rat tissue explants suggest that needle grasp involves connective

tissue. We used high frequency (50 MHz) ultrasound scanning acoustic

microscopy to further confirm quantitatively that changes in

connective tissue architecture occur as a result of acupuncture

needle rotation. Using this technique, we obtained high-resolution

images of viable rat abdominal wall tissue explants into which an

acupuncture needle had been inserted and either rotated for 32

revolutions, or not rotated. We hypothesized that the acoustic

pattern generated by the main components of connective tissue

(collagen, elastic fibers, fat, extracellular matrix) is more

ordered after acupuncture needle rotation, compared with needle

insertion alone without rotation.

 

A Fourier Transform analysis was performed on standardized polar

coordinate lines (using the center of the needle as the origin) from

the bitmap gray scale images created by the scanning acoustic

microscope. For each line, this analysis yielded spatial frequency

peaks corresponding to spatial periodicity in the image. The maximum

peak gray level at a significantly low spatial periodicity (0.3-1.4

mm) was significantly higher with needle rotation (vs. p<) compared

with acupuncture needle insertion alone without rotation (mean ± SE:

28.7 ± 2.2 vs. 21.9 ± 1.4, p=0.02). This indicates that connective

tissue architectural order increased with acupuncture needle

rotation. The images also suggest that this increased order is due

to tissue winding around the needle and reorganization of tissue

structures relative to the needle. Changes in connective tissue

architecture may be perceived by the acupuncturist holding the

needle, and therefore may be important clinically. This perception

may constitute important feedback affecting how the acupuncturist

chooses to further move (or not move) the needle.

 

During their training, acupuncturists learn to apply needle

stimulation that is quantitatively and qualitatively appropriate to

each clinical situation. Before needling, the acupuncturist will

usually decide roughly what type of manipulation will be used (e.g.

reducing method, reinforcing method, deep or shallow needling). Once

the needle is inserted, the acupuncturist will carefully observe and

feel for changes in the patient, and modify his/her behavior

accordingly. This response to the feedback provided by the patient

during needling is a key component of the acupuncturist's skills.

This feedback includes verbal communication of sensations

experienced by the patient during needling, and also includes direct

observation of changes such as skin color, facial expression, as

well as local changes in the area of the needle. Local changes in

the area of the needle can be perceived by acupuncturists with

extremely small amounts of needle movement (less than one revolution

of the needle, or up-and-down movements of a few millimeters). These

changes can be very subtle, leading some authors to suggest that

they occur on an " energetic " plane. Another possibility is that

subtle material changes in the tissues are taking place, perhaps

accompanied by related energetic phenomena.

 

In this study, we describe pronounced tissue architectural changes

occurring as a result of a relatively large amount of acupuncture

needle rotation (corresponding to pullout forces of the order of 500

grams in related experiments). Smaller amounts of needle

manipulation are likely to be associated with more subtle tissue

architectural changes. Whether large or small in magnitude, these

changes in connective tissue architecture may have profound

downstream effects. Mounting evidence suggests that mechanical

deformation of tissue can lead to mechanical signal transduction

into cells, polymerization of cellular actin cytoskeleton,

activation of intracellular signaling pathways, changes in gene

expression and cell contraction. These biochemical events may

further contribute to the sensation perceived by the acupuncturist,

and also may be components of acupuncture's therapeutic effect.

Modification of the acupuncturist's skilled behavior in response to

tissue changes caused by needle manipulation therefore may be a key

to the treatment's outcome.

 

Funded by the National Center for Complementary and Alternative

Medicine, Grant #R21 AT00300.

 

regards

H.peter