Acupuncture and the Peripheral Nervous System
A Radiculopathy Model
By Dr. C. Chan Gunn
Varieties of Acupuncture
Intramuscular Stimulation - A contemporary scientific version of acupuncture
Proposed Radiculopathy Model
� II. � Spondylosis and Radiculopathy Radiculopathy and denervation supersensitivity
Spondylosis and degeneration
� III. � Effects of Radiculopathy
Contracture and concurrent muscle shortening
Radiculopathy and segmental autonomic reflexes
Radiculopathy and chronic pain
The Shortened Muscle Syndrome
� IV. � Central Role of the Needle
Acupuncture and the current of injury
The needle’s role in healing
Needle-grasp, Deqi and muscle proprioceptors
� V. � Challenges of Diagnosis and Treatment
The needle as a powerful diagnostic tool
� VI. � Discussion
� VII. � Conclusion
Acupuncture and the Peripheral Nervous System:
A Radiculopathy Model by Dr. C. Chan Gunn
I -- Introduction:
Western research into acupuncture has focused on the neurochemical basis of acupuncture analgesia and the
Central Nervous System (CNS). In doing so, it has ignored the Peripheral Nervous System (PNS), and overlooked
some important clues to acupuncture’s effectiveness.
This paper reviews the relationship of acupuncture to the PNS, and proposes a model based on radiculopathy
(which is peripheral neuropathy occurring at the nerve root). This model helps clarify many of the mysteries
surrounding acupuncture and how it works in so many different conditions, including chronic pain. The model also
shows that many Traditional Chinese concepts can be reconciled with today’s understanding of physiology.
Before describing the proposed radiculopathy model, the term ‘acupuncture’ will be examined. ‘Acupuncture’ is a
word of Western origin which was coined in the 16th century to describe the Chinese use of a needle to promote
healing in certain diseases. The Chinese, themselves, referred to this technique by many different names (e.g., ‘needle
effect’, ‘needle skill’, or ‘needle therapy’) all of which indicate the central role of the needle. ‘Acupuncture’ can
be confusing because it is used in medical literature to refer to a number of related, but not necessarily identical,
modalities. The span of acupuncture’s effectiveness depends on the modality used, combined with the knowledge
and skill of the practitioner.
Varieties of acupuncture:
It should be emphasized that classical or traditional acupuncture in China is only part of the whole philosophy
of Traditional Chinese Medicine (TCM).20 All Western medical doctors practicing acupuncture, or medical
acupuncturists, have had training in classical acupuncture, but most of them do not practice the ancient principles
of TCM, even though they continue to use TCM nomenclature and terminology. Medical acupuncturists,
for instance, do not use TCM techniques, such as pulse diagnosis, for examination. They accept, instead, the
neurochemical explanation for acupuncture analgesia; consequently, many of them restrict their practice to pain
management. Many medical acupuncturists, in effect, use acupuncture as a form of trigger point therapy;2 or as a
procedure for electric stimulation.15 Some Western researchers call electrical stimulation with surface electrodes
applied over acupuncture points as ‘acupuncture’, but this is incorrect as a needle is central to the procedure.
Acupuncture becomes perplexing when all versions, despite different methodologies and rationales, are claimed
to be effective for a wide range of applications -- everything from asthma to allergic rhinitis, from addiction to
chronic pain. If these claims are true, how can such a simple procedure have such a prolific range of benefits? By
what mechanism is needling effective? Western research, which concentrates on pain, has thrown some light on
the neurochemical basis of acupuncture analgesia,12 but has not produced a satisfactory explanation for all of
Intramuscular Stimulation (IMS):
In recent years, more and more medical doctors have replaced TCM concepts to practice a contemporary version
that is better attuned to neuroanatomic principles. The Multidisciplinary Pain Center, University of Washington
School of Medicine, uses and teaches a system of dryneedling that relies entirely on neuroanatomy. Examination,
diagnosis, treatment, as well as progress of therapy are all determined according to physical signs of peripheral
neuropathy.8 The system, referred to as Intramuscular Stimulation (or IMS) to distinguish it from other forms of
needling, is now used at many pain centres throughout the world.
IMS and the proposed model have been developed from the writer’s conclusions following clinical observations and
research carried out over a period of more than twenty years (first, at the Workers’ Compensation Board of British
Columbia, and subsequently, at the writer’s pain clinic). Some salient conclusions that led to the radiculopathy model
proposed in this paper are:
� Acupuncture points are nearly always situated close to known neuroanatomic entities, such as, muscle motor
points or musculotendinous junctions; 5
� Points that are found to be effective for treatment belong, more often than not, to the same segmental
level(s) as presenting symptoms, or the injury; 11
� These points usually coincide with palpable, muscle bands (sometimes called trigger points) that are tender
to digital pressure;
� Tender points are distributed in a segmental or myotomal fashion, in muscles supplied by both anterior and
posterior primary rami -- indicating radiculopathy; 6
� Muscles with tender points are unfailingly shortened from spasm and contracture;
� Virtually all conditions that respond to needling demonstrate signs of peripheral neuropathy;7,10 these signs
are not well known, and therefore frequently missed. 10
� Symptoms and signs typically disappear when the tender and tight muscle bands are needled. 11
IMS practitioners therefore purposely seek out tender and tight muscle bands in affected segments for needling.
Following needling, physical signs of peripheral neuropathy, such as muscle spasm, vasoconstriction and tenderness
often disappear within seconds or minutes, and it is extremely satisfying to see these signs disappear before one’s
eyes. Other signs, like trophedema diminish gradually, maybe taking days or even weeks to disappear. Ultimately,
however, all signs vanish following successful treatment. IMS practitioners, with extensive training in anatomy and
neurophysiology, thus freed from the limited number of empirical points available in classical acupuncture, can be
many times more effective than traditional acupuncturists.
Proposed radiculopathy model This paper reviews the specific effects of the needle on the PNS, and offers a model
in which it is proposed that:
• 1. The many and various conditions amenable to needle therapy, including chronic pain, are essentially
epiphenomena (or signs and symptoms) of abnormal physiology in the PNS which occur with
• 2. These various conditions (including any accompanying pain) improve when normal function is restored.
• 3. The needle is a simple, yet unique tool, able to access the PNS to restore normal function.
In other words, although the needle in ‘acupuncture’ helps many conditions, they are but different facets of a single
underlying condition -- i.e., radiculopathy. Needle therapy does not treat individual diseases. Rather, it aims to
restore homeostatis to the entire patient. It helps many conditions by a single expedient -- restoring normal function
to the PNS.
II -- Spondylosis and radiculopathy
Radiculopathy and denervation supersensitivity
Traditional Chinese Medicine places great emphasis on Ch’i, the ‘flow of energy’.20 Its physiologic equivalent is
probably the flow of nerve impulses in the PNS. When the flow of nerve impulses is blocked, innervated structures
are deprived of the trophic factor. This factor (thought to be a combination of axoplasmic flow and electrical input)
is normally delivered by the intact nerve. It is needed for the regulation and maintenance of cellular function and
integrity. Structures deprived of the trophic factor become highly irritable and develop supersensitivity according to
Cannon and Rosenblueth’s Law of Denervation1:
• When a unit is destroyed in a series of efferent neurons, an increased irritability to chemical agents develops
in the isolated structure or structures, the effect being maximal in the part directly denervated.
Not all physicians are familiar with the condition of peripheral neuropathy. It may be defined as a disease that
causes disordered function in the peripheral nerve. Although sometimes associated with structural changes, a
neuropathic nerve can, deceptively, appear normal. It still conducts nerve impulses, synthesizes and releases
transmitted substances, and evokes action potentials and muscle contraction. Muscle cells innervated by the
axon, however, become supersensitive and behave as if the muscle had indeed been denervated. They generate
spontaneous electrical impulses that can trigger false pain signals or provoke involuntary muscle activity.3
Supersensitivity also affects nerve fibres. These become receptive to chemical transmitters at every point along their
length, instead of at their terminals only. Sprouting may occur, and denervated nerves are prone to accept contacts
from other types of nerves, including autonomic and sensory nerve fibres. Short circuits are possible between
sensory and autonomic (vasomotor) nerves and may contribute to reflex sympathetic dystrophy or causalgic pain.
Cannon and Rosenblueth’s original work was based on total denervation or decentralization for supersensitivity to
develop. Accordingly, they named the phenomenon denervation supersensitivity.1 Today, however, it is known that
physical interruption and total denervation are not necessary. Any circumstance that impedes the flow of motor
impulses for a period of time can rob the effector organ of its excitatory input, and can cause disuse supersensitivity
in that organ and in associated spinal reflexes.19
The importance of disuse supersensitivity cannot be overemphasized. When a nerve malfunctions, the structures it
supplies become supersensitive and will behave abnormally. These structures over-react to many forms of input --
not only chemical, but physical inputs including stretch and pressure. Disuse supersensitivity is basic and universal,
yet not at all well known or credited.
Spondylosis and degeneration
It is not unusual for the flow of nerve impulses to be obstructed. Peripheral neuropathy, which is often
accompanied by partial denervation, is not exceptional in adults. There are innumerable causes of peripheral nerve
damage, such as trauma, inflammation, and infection; they may be from metabolic, degenerative, toxic, and other
conditions. The nerve’s response to any agent, however, is always the same, dysfunction of the nerve.
Spondylosis is probably the most common cause of peripheral neuropathy.6 The spinal nerve root, because of its
vulnerable position, is notably prone to injury from pressure, stretch, angulation, and friction. Because spondylosis
follows wear and tear, radiculopathy is typically seen in middle-aged individuals.
Ironically, radiculopathy itself contributes to degenerative conditions (including spondylosis!). Radiculopathy
degrades the quality of collagen, causing it to have fewer cross-links; it is therefore frailer than normal collagen.14
The amount of collagen in soft and skeletal tissues is also reduced. Because collagen lends strength to ligament,
tendon, cartilage, and bone, neuropathy can expedite degeneration in weight-bearing and activity-stressed parts of
the body -- which include the spine and joints.
III -- Effects of Radiculopathy
This section reviews some of the repercussions of radiculopathy on the PNS. The effects of radiculopathy
vary according to the type (sensory, motor, autonomic, or mixed) and distribution of nerve fibres involved. All
denervated structures can develop supersensitivity (including skeletal muscle, smooth muscle, spinal neurones,
sympathetic ganglia, adrenal glands, sweat glands, and brain cells).
Contracture and concurrent muscle shortening
Contracture, commonly referred to as ‘spasm’, is the evoked shortening of a muscle fibre in the absence of action
potentials. It cannot be satisfactorily explained without reference to denervation supersensitivity.
Of the structures that develop supersensitivity, the most critical is striated muscle. Neuropathy can cause muscle
contracture, with concurrent muscle shortening. These constant companions of musculoskeletal pain can be
palpated as ropy bands in muscle (Fig. 1). Although shortened muscles are no longer believed to cause pain
and tenderness by compressing normal nociceptors,17 pain and tenderness may result when nociceptors are
supersensitive. Thus, muscle bands, although usually pain-free, can become focally tender and painful as trigger
When trigger points are numerous and widespread in the body, the condition has been called ‘fibrositis’,
‘fibromyositis’, or ‘fibromyalgia’. This common condition causes much grief and distress because it is frequently
misunderstood and therefore incorrectly treated.
Muscle shortening can cause further pain through mechanical pull. Such syndromes are discussed later in this paper
under the heading ‘The shortened muscle syndrome’.
Contracture is not maintained by volitional contraction, and cannot be ended by voluntary relaxation. When
examined in the EMG, it is silent, as in a completely relaxed muscle: there are no motor units. The only findings are
miniature endplate potentials (mepps) caused by the release of small packages or quanta of acetylcholine (ACh).
This model postilates that these tiny potentials, although incapable of initiating contraction in normal muscle
(which is sensitive to ACh only at the endplate region), can indeed initiate contraction in a supersensitive muscle that
reacts to ACh along the entire surface of the fibre membrane. ACh slowly depolarizes the muscle membrane, and
this induces electromechanical coupling.
Cannon described four types of increased sensitivity:
� (1) Superduration of response, where the amplitude of responses is unchanged, but their course is
� (2) Hyperexcitability, where the threshold for the stimulating agent is lower than normal;
� (3) Increased susceptibility, where lessened stimuli that do not have to exceed a threshold produce responses
of normal amplitude; and
� (4) Super-reactivity, where the ability of the tissue to respond is augmented. Contracture may thus represent
muscle shortening of superduration, launched by miniature endplate potentials, in a super-reactive and
Trophedema, or neurogenic edema, is a frequent companion of underlying muscle contracture. It may result
from increased capillary permeability and impaired lymphatic drainage. Trophedema is easily confirmed by the
“peau d’orange” effect, or the Matchstick Test: trophedema cannot be indented by digital pressure, but when a
blunt instrument is used, like the end of a matchstick, the indentation produced is clear-cut and persists for many
Radiculopathy and segmental autonomic reflexes:
The actions of the sympathetic and parasympathetic systems are generally mutually antagonistic. The sympathetic
system helps maintain a constant internal body environment, or homeostasis. It commands reactions that protect
the individual, such as increase of blood sugar levels, temperature, and regulation of vasomotor tone. The
parasympathetic system lacks the unitary character of the sympathetic, and its activity increases in periods of rest
and tranquility. The TCM term ‘Rebalancing the Yin and Yang’ (Yin and Yang represent opposing forces) probably
parallels restoration of the balance between the two autonomic systems.
Sympathetic fibres in spinal nerves innervate the blood vessels of skin and muscle, pilomotor muscles, and
sweat glands. In emergency situations, there is a generalized sympathetic discharge, and fibres that are normally
silent at rest are activated: sweat glands, pilomotor fibres, adrenal medulla, and vasodilator fibres to muscles. In
radiculopathy, comparable reactions occur in the affected segment, which indeed behaves as if it were in a state
of emergency. Vasoconstriction gives radiculopathy its cardinal feature -- affected parts are discernibly colder, as
may be shown by thermography. The pilomotor reflex is alerted, which may be manifested as ‘goose bumps’ in the
involved dermatome; sudomotor activity may be profuse too.
Sympathetic fibres in visceral nerves innervate the intestine, intestinal blood vessels, heart, kidney, spleen, and other
organs (Fig. 2). As with the somatic system, afferent impulses from the viscera connect with motor efferent neurons
of the autonomic system in the spinal cord and brain stem. Fibres to the different visceral effectors are independent
and discrete, and are carried out in reflex fashion. (Early TCM workers undoubtedly noticed the association between
the autonomic system and viscera -- thus naming meridians after them.)
Although modulation of autonomic reflexes is carried out in the CNS, supersensitive segmental autonomic reflexes
can be influenced and restored to normal by releasing muscle contractures in involved segments. For example,
epiphenomena (or manifestations) of radiculopathy, such as tension headache, cluster headache, even migraine, and
allergic rhinitis, improve when supersensitive sympathetic nerve fibres are restored to normal (Cervical 1--3, Fig. 2).
Upper gastrointestinal (GI) complaints are common, but symptoms like heartburn, gastroesophageal reflux,
nonulcer dyspepsia, and peptic ulcer disease are often difficult to differentiate from those of the irritable bowel
syndrome (abdominal pain, abdominal distention, relief of pain with defecation, frequent stools with pain onset,
loose stools with pain onset, mucus passage, and the sensation of incomplete evacuation or tenesmus). The two
groups of symptoms may indicate, respectively, dysfunction in the greater and the lesser splanchnic nerves (Fig. 2).
Upper GI complaints are usually associated with mid-dorsal back pain and signs of spondylotic radiculopathy (such
as tenderness and trophedema) in the mid-dorsal back (T2--5). The irritable bowel syndrome is generally associated
with the lower dorsal back (T5--L1), but it is not uncommon for a patient to suffer from both groups. Dorsal
spondylosis commonly remains silent until symptoms are precipitated by emotional stress or physical strain (lengthy
air travel and carrying heavy baggage, for instance).
There is a tendency to over-investigate these symptoms because they can suggest something benign or something
serious. Since these symptoms respond quickly to the release of paraspinal muscle contractures in affected
segments, however, it is feasible and probably preferable to try IMS first.
Parasympathetic fibres traveling in the vagus nerve are abundant in the thorax and abdomen; they slow the heart,
enhance digestion, and produce bronchial constriction. Problems of bronchial constriction and secretion may be
relieved with treatment to the cervical and upper dorsal spine.
Radiculopathy and chronic pain:
Chronic pain can be the outcome of any (or a combination of) the following:
� (1) continuous stimulation of A-delta and C-fibres from ongoing nociception (such as an unhealed fracture),
or from ongoing inflammation (rheumatoid arthritis, for instance);
� (2) psychogenic factors (which are outside the present discussion)
� (3) functional disturbances in the nervous system, when there may be supersensitivity in the pain sensory
system, but no actual excitation of nociceptors from extrinsic sources. Radiculopathic (and neuropathic)
pain belongs to category (3); it typically occurs in the absence of ongoing tissue injury, nociception, or
inflammation. It is secondary to a functional disturbance in the nervous system (radiculopathy), and is
always, therefore, accompanied by signs of neuropathy,22 which resolve after successful treatment. When
radiculopathic pain involves primarily the musculoskeletal system, it is commonly called myofascial pain.
Radiculopathic pain in this model: is deemed to be the sensory expression of the mixed manifestations (sensory,
motor, autonomic, and mixed) that can occur with radiculopathy; and pain is not a feature unless nociceptive fibres
are involved. Other features of neuropathic pain4 include:
� (1) delay in onset after precipitating injury (supersensitivity takes at least five days to develop);
� (2) unpleasant sensations such as dysethesiae, or deep, aching pain;
� (3) pain felt in a region of sensory deficit;
� (4) paroxysmal, brief shooting or stabbing pain. Mild stimuli can be very painful (allodynia). Significantly,
additional pain may be produced mechanically by muscle shortening.
The shortened muscle syndrome:
Physical force generated by a shortened muscle can give rise to many painful conditions,9 as in the following
examples, which are motor manifestations of neuropathy:
� Shortening gives rise to tension in tendons and their attachments -- when protracted, tension can cause
such syndromes as epicondylitis, tendonitis, tenosynovitis, or chondromalacia patellae (Table I, and Fig. 3).
Because these syndromes appear dissimilar and occur at different anatomical sites, they are presently not
recognized as having the same etiology.
� When muscles acting on a joint shorten, they limit the joint’s range. An example is acute torticollis which
results from shortening of the splenius capitis and cervicis muscles; an extreme example is the frozen
shoulder, in which all muscles acting on the joint have shortened.
� Muscle shortening from contracture can upset joint alignment -- hallux vulgus, for example, is due to
shortening of the extensor hallucis longus muscle; the bunion is a secondary development.
� Increased pressure on the articular surfaces of a joint can cause arthralgia -- as in medial knee joint pain.
This pressure can lead also to a torn meniscus.
� Chronic restriction of joint range, misalignment and increased pressure on articular surfaces can eventually
lead to degenerative arthritis or osteoarthritis.
� Pressure on a nerve can produce an entrapment syndrome -- shortening in the pronator teres or pronator
quadratus, for example, can give rise to symptoms of a carpal tunnel syndrome.
The most critical of all the muscles that can shorten and press on, or pull upon, supersensitive structures to cause
pain, are the paraspinal muscles that act across an intervertebral disc space. They draw adjacent vertebrae together,
compress the disc, and narrow the intervertebral foraminae. The nerve root can be compressed by a bulging disc; or
it can be irritated after it emerges from the intervertebral foramen (Fig. 4). A vicious circle can thus arise: pressure
on a nerve root causes radiculopathy; radiculopathy leads to shortening in muscles, including paraspinal muscles;
and shortening in paraspinal muscles further compresses the nerve root.8
Key to treating:
All radiculopathic conditions is releasing the shortened paraspinal muscles that pull adjacent vertebrae together and
cause pressure on the disc and nerve root. And here is where the acupuncture needle plays its unsurpassed role.
IV -- Central role of the needle:
Acupuncture owes its full capabilities to the needle. The needle is the most effective instrument devised for
stimulating the PNS through muscle receptors. (At least 40% of nerve fibres innervating a muscle subserve sensory
rather than motor end organs.) A primary object of treatment is to release muscle shortening, and the needle does
this more swiftly and precisely than any other physical therapy, including transcutaneous electric stimulation, or
shallow percutaneous procedures (in which a needle is used to pierce skin to overcome skin resistance).
When the needle is inserted, it is deftly tapped through the skin to avoid alerting A-delta nociceptive fibres
located close to the surface. The needle is then eased through subcutaneous tissue and into muscle. The fine,
pointed needle (unlike the cutting edge of a hollow needle used for injecting medications) pushes tissues aside and
produces minimal tissue injury. Under normal circumstances, when there is no muscle shortening, the patient feels
practically no sensation or pain. (C-fibres sense pain only when there is cellular damage followed by the release of
inflammatory, algogenic substances such as histamine, prostaglandin, or bradykinin.)
Acupuncture and the current of injury:
When the needle pierces muscle, it disrupts the cell membrane of individual muscle fibres, mechanically discharging
a brief outburst of injury potentials referred to as ‘insertional activity’. Less insertional activity occurs where muscle
tissue has been replaced by fibrosis or necrosis, or where there is trophedema. Insertional activity is greater where
muscle cell membrane has become hyper-irritable.
Needle injury also generates long-lasting currents that are involved in repair and regeneration. The current of injury,
first described by Galvani in 1797, has been shown (using a vibrating probe which can measure steady extra-cellular
currents as small as 0.1 microamperes/cm2) to generate up to 500 microampere/cm2 in a freshly amputated finger-
tip.13 Unlike externally applied, short-lived, forms of stimulation like massage or heat, the current of injury can
provide stimulation for several days until the miniature wounds heal. Stimulation by using the body’s response-to-
injury is an important resource, as desensitization of supersensitivity can take many days.16,21
The needle’s role in healing:
Needle therapy has another unique advantage that other physical modalities do not: it causes local bleeding.
Bleeding promotes healing by delivering numerous growth factors, including the platelet-derived growth factor
(PDGF)18. PDGF attracts cells, induces DNA synthesis, and stimulates collagen and protein formation. PDGF is,
in fact, the principle mitogen responsible for cell proliferation. Body cells are normally exposed only to a filtrate of
plasma (interstitial fluid); they do not normally come in contact with the platelet factor, except in the presence of
injury, hemorrhage, and blood coagulation.
Needle-grasp, Deqi and muscle proprioceptors:
When the needle penetrates a shortened muscle, it can provoke the muscle to fasciculate and release quickly -- in
seconds or minutes. A shortened muscle that is not quickly released, however, will invariably grasp the needle.
This needle-grasp can be perceived by the physician when an attempt is made to withdraw the needle. Leaving
the grasped needle insitu for a further period (typically 10 to 30 minutes) generally leads to objective release of a
persistent contracture. Failure of a correctly placed needle to induce needle-grasp signifies that spasm is not present
and therefore not the cause of pain -- in which case, the condition will not respond to this type of treatment.
When there are several muscles, each with many muscle bands or fasciculi requiring treatment, it may be necessary
to hasten contracture release by augmenting the intensity of stimulation. The traditional method is to twirl the
grasped needle -- a motion that specifically stimulates proprioceptors. All forms of stimuli have their specific
receptors -- massage excites tactile and pressure receptors; heat and cold activate thermal receptors; traction,
exercise, or manipulation stimulate muscle proprioceptors, and so on. As an alternative to twirling the needle, heat
(moxibustion) or electrical stimulation is sometimes used.
How does twirling the needle work? When a muscle is in spasm, muscle fibres cling to the needle, and twisting
causes these fibres to wind around its shaft. This coiling of muscle fibres shortens their length, converting the
twisting force into a linear force. Unlike traction or manipulation, this stimulation is very precise and intense
because the needle is precisely placed in a taut muscle band.
The needle-twirling maneuver vigorously stimulates muscle proprioceptors and gives rise to a peculiar, subjective
sensation known in TCM as the Deqi (formerly written as Teh Ch’i) phenomenon. This distinctive sensation is
an extreme version of the muscle-ache felt in myofascial pain. Patients have variously described the sensation
as ‘cramping’, or ‘grabbing’, or a ‘dull, heavy ache’. Deqi is outside any normal experience of pain, and must be
experienced in person in order to fully comprehend the unmistakable quality of myofascial pain. The muscle’s grasp
on the needle and the sensation the patient feels are both intensified as the needle is twirled to increase stimulation
-- until some moments later the shortened muscle is released with coincident disappearance of pain.
Twirling the grasped needle elicits the stretch or myotatic reflex (seen clinically in the knee-jerk). The reflex is
activated by the muscle stretch and causes a contraction in that same muscle. Twirling the grasped needle is like
stretching the muscle: it stretches muscle spindles, causing Group-Ia fibres from the annulospiral endings to
monosynaptically excite skeletomotor neurons that supply homonymous and synergist muscles. The same afferent
volley disynaptically inhibits skeletomotor neurons that supply antagonist muscles.
Group-Ia and group-Ib fibres work together in close association; whereas the muscle spindle signals the velocity
of muscle stretch and muscle length, the Golgi tendon organ (GTO) signals the velocity of muscle tension
development as well as steady tension. Group-Ib fibres from the GTO make disynaptic inhibitory connections with
both homonymous and synergist skeletomotor neurons.
By stipulating the needle-grasp and the Deqi phenomenon as requirements for diagnosis and treatment, TCM has
perceptively recognized the central role of muscle proprioceptors in chronic neuropathic pain . Inserting a needle
into normal muscle does not produce needle grasp or Deqi. A-delta and C-fibres, carriers of injury signals, are not
primarily involved in chronic neuropathic pain; their incitement produces nociception, which elicits a different reflex
-- the flexion or withdrawal reflex.
The important observation is this: when a shortened muscle is released, all associated epiphenomena of peripheral
neuropathy (including pain, tenderness, vasoconstriction) vanish from the treated area -- sometimes from the entire
segment. Simultaneous resolution of the different epiphenomena by reflex stimulation may be explained by the
overlap of neuronal circuits in the periphery (where two reflexes may share the same afferent receptor population),
and in the spinal cord (where the same interneuronal circuit and/or motor neuron may serve more than one reflex
-- see Fig. 5).
It is important to note too that the end-product of any single spinal reflex, such as a muscle contraction, will itself
initiate other reflexes.
V -- Challenges of diagnosis and treatment:
Diagnosing pain and dysfunction caused by radiculopathy can be difficult. A history gives little assistance. Pain often
arises spontaneously, with no history of trauma; or else the degree of reported pain far exceeds that consistent with
the injury. Laboratory and radiologic findings are generally not helpful either. Thermography can reveal decreased
skin temperature in affected dermatomes but does not itself indicate pain or identify individual painful muscles.
Signs of neuropathy are subtle, and differ from those of outright denervation (such as loss of sensation and
reflexes). Radiculopathies are difficult to document with routine nerve conduction studies, which measure only the
few fastest-conducting and largest fibres and take no account of the majority of smaller fibres. In focal neuropathy,
nerve conduction velocities remain within the wide range of normal values, but F-wave latency can be prolonged.
Electromyography is not specific either.
In view of these considerations, diagnosis depends almost entirely on the examiner’s clinical experience and
acumen. A careful inspection for signs of motor, sensory, trophic, or autonomic dysfunction in the skin and
affected muscles is necessary. Because changes in these conditions are primarily in muscle, even when symptoms
appear to be in joints or tendons, signs in the muscles are the most consistent and relevant: increased muscle tone;
tenderness over motor points; taut and tender, palpable contracture bands; and associated restricted joint range.
It is important to remember that in radiculopathy, signs are generally present in the territories of both the posterior
primary division and the anterior primary division of the affected nerve root or the formed nerve. Consequently,
the symptoms are projected onto the dermatomal, myotomal, and sclerotomal target structures supplied by the
affected neural structure. Knowledge of the segmental nerve supply to muscles and bones is essential for diagnostic
treatment. Each constituent muscle must be palpated and its condition noted. The most effective sites of dry
needling are at muscle motor points and musculotendinous junctions. The procedure requires detailed knowledge
of anatomy, and clinical skill comes only with practice. Moreover, because many paraspinal muscles are compound
(e.g. the longissimus) and extend throughout most of the length of the vertebral column, the entire spine must be
examined even when symptoms are localized to one region.
The needle as a powerful diagnostic tool:
The needle is more than a therapeutic tool, it is a powerful diagnostic tool as well. Indeed, deep contracture can only
be discovered by probing with a needle. Contracture is invisible to X-rays, CT scans, or MRI, and contracture in
deep muscles is beyond the finger’s reach. The fine, flexible needle transmits feedback on the nature and consistency
of the tissues it is penetrating. When it penetrates normal muscle, the needle meets with little hindrance; when it
penetrates a contracture, there is firm resistance, and the needle is grasped; and when it enters fibrotic tissue, there
is a grating sensation (like cutting through a pear). Sometimes, the resistance of a fibrotic muscle is so intense (the
hardness can be mistaken for bone) that extreme pressure may be required to force the needle in.
Guided by the needle-grasp and the Deqi, an examiner is able to identify the distressed segment quickly, and with
greater accuracy than with X-rays, scans, or MRIs. Indeed, radiological findings may mislead by showing older, non-
When irritation to a nerve is minor, neuropathy can be a transient condition, and releasing shortened muscles
may be all that is necessary to restore function while the nerve heals. When shortened muscles are released, pain
and joint range improve. Treating the several most painful shortened bands in the muscle is usually followed by
relaxation of the entire muscle.
In recurrent or chronic pain, fibrosis generally becomes a feature of the contractures, and response to treatment
is then much less dramatic and less effective. The extent of fibrosis is not necessarily correlated with chronologic
age; scarring occurs after injury or surgery, and many older individuals have less wear and tear than younger ones
who have subjected their musculature to repeated physical stress. Treatment of extensive fibrotic contractures
necessitates more frequent and extensive needling, and release of the contracture is often limited to the individual
muscle band treated. To relieve pain in such a muscle, therefore, all tender bands require treatment. In chronic
myofascial conditions, the needle can be used to disperse fibrotic tissue entrapping a nerve.
For long-lasting pain relief and restoration of function, it is essential to release shortened paraspinal muscles that
are compressing a disc and irritating the nerve root. Surgical intervention is rarely necessary, as the needle can reach
almost all shortened muscles.
The efficacy of IMS therapy for chronic low back pain was demonstrated by a randomized clinical trial involving
a large group of patients in the British Columbia Workers Compensation Board. At their seven-month follow-
up, the treated group was clearly and significantly better than the control group.11 It is worth noting, however, as
examination skill improves, any physical change in the patient condition becomes self-evident and unmistakable.
VI -- Discussion
Health and disease are perceived differently by Western medicine and TCM. Western medicine has a narrow and
specific definition of disease as being a definite morbid process, often with a characteristic train of symptoms.
Numerous distinct diseases require numerous distinct treatments.
Traditional Chinese philosophy, on the other hand, has a holistic concept of health. It regards good health as the
ideal state where total harmony and equilibrium exist within the body, and where the body is in harmony too with
its environment. This concept of health agrees with the modern epidemiologic view that illness is caused by the
loss of equilibrium in the simultaneous interaction of host, agent, and environment. It is consonant too with the
World Health Organization’s definition of health as a state of complete physical, mental, and social well-being -- not
merely the absence of disease and infirmity.
In illness, TCM seeks to restore equilibrium in the body. When the upset is caused by an overwhelming agent such
as an acute infection, TCM is ineffective and inferior to modern methods of intervention like antibiotics. When
equilibrium is lost, however, through such dysfunction in the host as the neuropathic disorders discussed in this
paper, TCM may then be able to stimulate the body to regain normal balance.
Many Western researchers are unaware of neuropathic pain. They generally assume chronic pain to be ongoing
signals of tissue damage (nociception or inflammation) conveyed to the CNS via a healthy nervous system. As a
consequence, they are preoccupied with analgesia and the suppression of nociception. When endogenous opioids
were discovered, these researchers assumed that acupuncture worked as a neuro-modulating technique, activating
multiple analgesia systems in the spinal cord and brain, and stimulating the endogenous pain suppression system to
release neurotransmitters and endogenous opioids. However, neurochemicals are most likely to be released under
stressful conditions (including drug and smoking withdrawal) which do not even necessarily produce pain. Their
role may be to modulate the various homeostatic mechanisms and act as an endocrine-endorphin stress system that
complements the neuronal regulatory system.