Fu Subcutaneous Needling (FSN)

Meridian chart


1. Introduction 

Fu Subcutaneous Needling (FSN), originating from traditional Chinese acupuncture, is a therapeutic approach for localised diseases, especially for painful musculoskeletal disorders. This procedure is performed by inserting a special trocar needle into the subcutaneous layer around the afflicted (dysfunctional muscles) spot to achieve the desired effect. In some cases, FSN can provide immediate and significant relief of the pain in trigger points (TrPs) more effectively than anaesthesia.


This technique, along with the FSN needle, was invented by Dr. Zhonghua Fu in 1996. FSN does not follow the rules and principles of Traditional Chinese Medicine (TCM) and the chosen insertion points do not coincide with traditional acupuncture points. 


FSN abstains from the muscle and deep fascia layers and is confined to only the subcutaneous layer where collagen fibers are most abundant. 


As the subcutaneous layer (connective tissue immediately beneath the skin) has a low nerve supply, there is less pain than with other needling therapies.

2. Mechanism

FSN and traditional acupuncture both share the same mechanism of action in terms of the measurable or physiological effects they relate on the body.

The effects that FSN emits on the body are by means of mechanotransduction as the swaying of the needle triggers a response on the connective tissue, specifically the collagen fibers by stimulating signal transduction and gene expression in fibroblasts of the subcutaneous tissue.

A drawing or magnetic effect on connective tissue has been observed upon needle manipulation as the contraction and shape changes of fibroblasts (type of cell) cause pulling of collagen fibers and secondary alignment of fibroblasts and collagen fibers. During manipulation of the needle, collagen fibers wind and tighten around the needle shaft, and dispersing of nociceptive substances and PH balance has also been observed in skeletal muscles.

3. The FSN needle

The FSN needle is a modified trocar needle similar to an I.V. Catheter. There are 3 parts to the needle: soft tube, protecting sheath, and needle core. The needle core is 31 mm in length and 1 mm in diameter. Each needle is individually packaged and sterilized with ethylene oxide gas.