Relationship between Buckling of Acupuncture Needles and the Handle Type

Abstract

Background

Most popular single-use acupuncture needles consist of a stainless steel shaft with a handle made of copper coil or plastic stick.

Objectives

To determine the strengths and weaknesses of these two handle types for needle buckling.

Methods

The buckling load for acupuncture needles with these two different handle types was determined using a digital scale, and the stiffness of stainless steel wires used in different types of acupuncture needles was measured using a Dynamic Mechanical Analysis machine.

Results

This study showed that an acupuncture needle with a copper coil handle was far more susceptible to buckling than a needle with a plastic stick handle. The average buckling force of acupuncture needles with plastic stick handles was 46.7% higher than that with copper coil handles for needles of 0.25 mm×30 mm, and 30.8% higher for needles of 0.25 mm×60 mm. Replacing a copper coil handle with a plastic stick handle could save about 100 tonnes of copper wires and 20 million metres of medical grade stainless steel wire a year worldwide.

Conclusions

The results from this study suggest that the common practice of using coiled copper for handles on acupuncture needles should be re-evaluated. Replacing a copper coil handle with a plastic stick handle would significantly reduce needle buckling and improve patient comfort and safety. This would also reduce the consumption of copper and medical grade stainless steel wire considerably.