Concept and Terminology

TM (in Chinese: 患肌) refers to the condition in which a normal muscle remains semicontracted for a prolonged period of time. This condition results in a tight, hard band felt in a part of the muscle or throughout the entire muscle, but most commonly in the area of the muscle belly. TrPs are in embedded in TM. Fu developed the term ‘TM’ in 2014 with collaboration by other practitioners of Fu’s subcutaneous needling (FSN) in China. In one of his Chinese FSN books, he translated ‘患肌’ into ‘pathological tight muscle’, but after the recommendation by Dr. Jidong Wu in Cambridge, UK, Dr. Fu agreed to the term ‘tightened muscle’ instead (Fu, 2016).

Before answering the question why the term TM is preferred over TrP, an introduction to the FSN technique is indicated. FSN is a therapeutic approach for musculoskeletal painful disorders and some chronic benign visceral disorders, which originated from traditional acupuncture. This procedure is performed by inserting a solid needle, usually a special trocar needle, into the subcutaneous layer around a TM to achieve a desired effect (Fig. 16.1). Different from traditional acupuncture, FSN has no special insertion point. The FSN needle is inserted anywhere in the vicinity of a TM with the needle tip pointing towards the TM. Apart from not having fixed insertion points, other aspects of FSN also contributed to the need to replace the more traditional TrP construct and terminology.

1. 1. The term ‘myofascial’ is an adjective referring to skeletal muscle and its fascia. Fascia has been described in detail in Chapter 3. Myofascial refers not only to muscle tissue. The perception with palpation is that TM is mostly muscle tissue, especially in the muscle belly. Fascia does not have the same TM quality with palpation.
   
2. 2. The word ‘trigger’, as used in TrP, is more or less meaningless in the practice of FSN. The trigger reaction is felt when a needle touches muscle fibres. In FSN, needles do not touch the muscles as the technique is strictly used subdermally.
   
3. 3. The word ‘point’, as used in TrP, is also not suitable in the practice of FSN because FSN targets what is perceived as a slice or band.

The name FSN, or Fu Zhen (浮针, in simplified Chinese; 浮針, in Traditional Chinese), has some profound implications. ‘Fu Zhen‘ is the Chinese pronunciation for FSN. Fu is the surname of the inventor, who is also the first author of this chapter. In Chinese, ‘Fu, 浮’ means floating, and it could also mean superficial. ‘Zhen’ means acupuncture or needling. Therefore in some English-language papers, FSN is also called ‘floating acupuncture‘ (Huang et al., 1998), Fu’s acupuncture (Zhang, 2004), Fu needling (Xia & Huang, 2004), and floating needling (Fu & Huang, 1999). However, neither floating nor superficial are precise translations; the word ‘subcutaneous’ is a better substitute in terms of demonstrating the manipulation features of FSN.

Although FSN originated from classic acupuncture, FSN’s manipulation and theory have nothing to do with the concepts of traditional acupuncture such as meridians, acupoints, Yin-Yang, and Qi. Therefore FSN is not some variety of acupuncture and should not be referred to as acupuncture. Fig. 16.2 shows the FSN needle in a subcutaneous layer of a human cadaver. Another approach, called intradermal needle therapy, is easily confused with FSN. The intradermal needle (Fig. 16.3) is a type of short needle made of stainless steel wire, especially used for embedding in the skin rather than in the subcutaneous layer (Cheng, 1987).

The term ‘Fu’s subcutaneous needling’ was first mentioned in a 2005 article by Fu and Xu, in which they described the treatment method (Fu & Xu, 2005), followed by several other research papers (Fu et al., 2006, 2007). FSN should be clearly distinguished from dry needling (DN), which involves the insertion of a fine single-use sterile needle into a TrP for the treatment of myofascial pain. DN has been in use since the 1970s and differs from the use of needling from an Oriental paradigm (Baldry, 1995, 2000, 2002; Hsieh et al., 2007; Hong, 2000, 2002, 2004, 2006; Simons, 2004, 2008). TrP DN is based on a Western anatomical and neurophysiological paradigm and has been increasingly utilised in the Western world, especially in the US, UK, The Netherlands, Canada, Belgium, Norway, Australia, Switzerland, Ireland, Brazil, South Africa, and Spain, among others (Dommerholt et al., 2006). Unlike traditional acupuncture, DN does not consider ancient Chinese philosophy and traditional ideas. Traditional acupuncture is based on prescientific ideas such as meridians, Qi (a kind of invisible energy), and Yin–Yang (Ellis & Wiseman, 1991; White & Ernst, 2001; Kim, 2004), whereas DN is entirely based on the recent understanding of scientific neurophysiology, anatomy, and pain sciences (Ghia et al., 1976; Melzack et al., 1977; Melzack, 1981). The manipulation method used in acupuncture differs from that used in DN and is based on different theoretical foundations and principles.

Contemporary research and the emergence of DN have reduced the sense of mystique surrounding noninjection therapies for pain (Amaro, 2008). Although acupuncture and DN have different theoretical bases, they are similar in some aspects.

1. 1. Nothing is injected into the body.
   
2. 2. Needles may target the same points known as either a trigger point in DN or an Ah-shi point in Chinese medicine.
   
3. 3. Many of the pain indications overlap.

Further, in TrP DN the importance of the local twitch response is emphasised, which is a reaction during needling with some resemblance to the ‘De-Qi’ effect in acupuncture (Hong, 1994). Chou and associates (2008, 2009, 2011, 2014) have modified the technique used in acupuncture into a procedure similar to Hong’s DN technique. Therefore in a ‘broad sense’ acupuncture can be considered as one type of DN.

FSN borrowed some ideas from traditional acupuncture, but the essential features are different from those of traditional acupuncture. Acupuncture and FSN are based on different theories and techniques and manipulations are employed with entirely different kinds of needles. Traditional acupuncture theory is mystical, even to Chinese doctors. FSN is a much easier approach, which does not consider the traditional theories. Compared with the current practice of DN, FSN has several unique features. There are at least two differences between FSN and DN. FSN needles are inserted into nondiseased areas and FSN is confined to subcutaneous layers, whereas DN inserts the needles into TrPs and often deep into the muscles. FSN is considered a particular type of DN. FSN shares the same scientific neurophysiological and anatomical foundation as TrP DN.

Contemplation of De-Qi

De-Qi or Qi is an acupuncture phenomenon that occurs during needle manipulation, experienced by the patient as a particular sensation (e.g., soreness, aching, numbness, or ‘needle grasp’) or by the acupuncturist as a pulling sensation (Cheng, 1987; Lin, 1997; Langevin et al., 2006; White et al., 2008). Traditionally, De-Qi must be achieved in the process of acupuncture regardless of the manipulation used; otherwise, the therapeutic results are poor (Cheng, 1987). In every textbook on acupuncture in Chinese, the importance of De-Qi is always emphasised and reiterated and acupuncturists repeatedly highlight De-Qi. As a result, most Chinese patients believe in the adage, ‘no De-Qi, no effect.’ Sometimes patients will be disappointed in the acupuncturist if they fail to acquire De-Qi, even though it may cause discomfort to the patient.

Acupuncturists and patients are not the only ones who consider De-Qi to be pivotal. Some scientists also believe that De-Qi plays an important role in acupuncture analgesia (Cao, 2002; Park et al., 2005). Acupuncture needling may activate afferent fibres of peripheral nerves to elicit De-Qi, the signal that ascends to the brain, activates the antinociceptive system, including certain brain nuclei, modulators (opioid peptides) and neurotransmitters, and through the descending inhibitory pathway, which results in analgesia (Cao, 2002).

However, occasionally acupuncture does work without De-Qi and could fail even when the patients achieve strong De-Qi. Furthermore, many acupuncture substitutes, such as cupping, moxibustion, transcutaneous electrical nerve stimulation (TENS), and so on, do not elicit De-Qi, but they appear to be effective nevertheless (Chen & Yu, 2003).

Therefore De-Qi may be not as relevant as traditionally is often suggested. To prove the insignificance of De-Qi, the best method is to stimulate the tissue without obvious direction and then observe what will happen. The elicitation of De-Qi is related to the needling depth (Lin, 1997). There are few free nerve endings and proprioceptive receptors in the subcutaneous layer, whereas free nerve endings are abundant in the epidermis and dermis. Proprioceptive receptors do exist in the muscular layer (Tortora, 1989). Therefore there should be no occurrence of De-Qi even if the subcutaneous layer is stimulated. Under such a condition, does the needling effect still exist? For an acupuncturist, it is easy to verify the existence of the needling effect, and this simple trial was one of several factors resulting in the discovery and development of FSN. One example of a form of acupuncture where achieving De-Qi has been shown to not be critical is wrist–ankle acupuncture.

Clinical Application of Wrist–Ankle Acupuncture

Wrist–ankle acupuncture (WAA) (Jiang et al., 2006) is also called wrist–ankle needling (Song & Wang, 1985). Dr Xinshu Zhang, a neurologist who has worked at the Second Military Medical University in Shanghai, developed WAA in 1972. WAA divides the whole body into 12 longitudinal regions, six for each half of the body (Fig. 16.4). There are six points 2 cun (about 50 mm) above the wrist joint corresponding to the six regions above the diaphragm, and there are six points 3 cun (about 75 mm) above the ankle joint corresponding to the other six regions (Fig. 16.5). A cun is a measure of distance relative to a person’s body dimensions that is commonly used in traditional Chinese medicine. If a disorder occurs in one of the regions, the corresponding point should be chosen. Unlike conventional acupuncture, WAA inserts an acupuncture needle only superficially in the subcutaneous layer; some authors claim that WAA is effective in the treatment of pain with various origins (Zhu & Wang, 1998). Needling superficially in WAA wrist or ankle points to treat distant disorders often has a good effect (Song & Wang, 1985; Chu & Bai, 1997), leading to the idea that needling close to the afflicted area could be at least as effective as needling in an area remote from that which is afflicted, and that needling closer may be preferable. These thoughts motivated the principle author to seek answers through clinical trials.

Ancient Techniques

Fu attempted to treat a patient with tennis elbow, or lateral epicondylitis, by needling the patient near the painful spot, which caused a positive response, and as such became the first successful case of FSN. From then on, a series of clinical trials were completed, and positive results were commonly achieved. In the same year, Fu wrote a brief introduction to FSN, which was published in a Chinese health newspaper (Fu, 1996). The next year Fu published his first research paper in Chinese in the Journal of Clinical Acupuncture and Moxibustion (Fu, 1997).

Innovation of the Fu’s Subcutaneous Needling Needle

Increase of Fu’s Subcutaneous Needling Indications

Structure of the Fu’s Subcutaneous Needling Needle

FSN needles, individually packaged and presterilised with ethylene oxide gas, are designed for single use. The FSN needle is made up of three parts (Fig. 16.6): a solid steel needle core (bottom), a soft casing tube (middle), and a protecting sheath (top).

The needle core consists of a needle and the needle core handle. The needle is made of stainless steel with a beveled tip. When the needle enters the skin, the bevel of the tip should face upward. The handle is made of plastic and square-shaped, and one of the four sides has 10 protuberances. The protuberances are on the same side as the bevel of the tip. If the protuberances face upward, the bevel will also face upward. The needle core allows the FSN needle to have sufficient rigidity to quickly go through the skin, go forward along the superficial layer, and smoothly sway from side to side. A soft casing tube encases the FSN needle.

The soft casing tube consists of two parts, namely a fluoroplastic body and the tube’s hub, which is made of regular plastic. The two parts are connected to each other by a metal wedge. The tip of the casing tube is about 3 mm beyond the tip of the needle core when the needle core is embedded inside the casing tube. The casing tube has two functions. It covers the tip of the needle until the needle is pulled back by 3 mm; thus the tip of needle stick will not damage surrounding organs or tissues during the swaying movement. The casing tube can substitute for the steel needle core beneath the skin and reduce the patient’s pain during retention.

The protective sheath covers the needle core and the casing tube and keeps the FSN needle sterile.