Acupuncture Points and Myofascial Trigger Points: Overlap Analysis

Overview of Acupuncture Points and Trigger Points – Anatomical and Functional Alignment

Acupuncture Points: In traditional Chinese medicine (TCM), acupuncture points are specific spots on the body along meridians (energy channels) where needles or pressure are applied to affect the flow of Qi (vital energy)​. These points were charted thousands of years ago; by the 3rd century CE nearly 95% of the classical points in use today had been described​. Anatomically, many acupuncture points coincide with neuro-muscular junctions or high concentrations of nerves and blood vessels (motor points), even if classical theory described them in energetic terms. For example, modern anatomic studies show many acupoints lie near where nerves enter muscles, which is also where trigger points often develop​. Acupuncture points can be classed as fixed named points on meridians, extra points (recognized points outside the main meridians), or ashi points, which are pragmatic “tender spots” elicited on palpation (the term ashi means “Ah yes!” – indicating the point of pain)​.

Myofascial Trigger Points (MTrPs): Trigger points, in contrast, are a concept from modern musculoskeletal medicine (developed in the mid-20th century by Travell and Simons) referring to hyperirritable nodules in a tight band of skeletal muscle or fascia​. An active trigger point is tender to touch and can produce referred pain in specific patterns distant from the nodule, along with local twitch responses and tightness. Functionally, trigger points often result from muscle overuse, injury, or stress, leading to localized muscle fiber contractures and sensitized nerves. Notably, ancient Chinese medicine recognized similar tender spots; the TCM classic Ling Shu (ca. 1st century BCE) describes that when an area is diseased or strained, certain points become extremely tender (“...when pressed, there should be pain...”)​. These correspond to what TCM calls ashi points, which strongly parallels the concept of trigger points. In fact, all trigger points can be considered ashi points in acupuncture, though not all ashi points are typical trigger points​. This indicates that ancient practitioners were likely palpating and treating the same tender knots that we today label as myofascial trigger points.

Anatomical Overlap: There is a remarkable anatomical overlap between many classical acupuncture points and common myofascial trigger point locations. Early studies by Melzack et al. (1977) found that 100% of the 48 trigger point locations they examined had a nearby (<3 cm) acupuncture point, and about 71% of those pairs also shared similar pain referral patterns​. Later, much more extensive mapping by modern researchers showed that over 90% of the common trigger points correspond anatomically with established acupuncture points​. For example, many trigger points are located at the center of muscle bellies or at musculotendinous junctions, which often coincide with acupuncture loci. These include points like GB-21 (on the upper trapezius muscle), SI-11 (in the infraspinatus muscle), or GB-30 (in the piriformis/gluteal region) – all known acupuncture points that correspond to classic trigger point locations in those muscles (as detailed later in Table 1). Moreover, both trigger points and acupuncture points tend to exhibit lowered electrical resistance and heightened sensitivity when active, implying a physiological similarity​. Imaging and microanatomy studies have also found that trigger points often occur near nerve entry zones or motor endplates in muscles​. Interestingly, many acupuncture points are located in exactly these anatomically significant sites (e.g. nerve bifurcations or muscle motor points), providing a biological rationale for why stimulating those spots (whether by an acupuncturist’s needle or a clinician’s dry needling) can modulate musculoskeletal function.

Functional Alignment: Functionally, both systems recognize that stimulating these special points can alleviate pain and dysfunction. Acupuncture’s framework attributes this to unblocking stagnant Qi and restoring balance, whereas trigger point therapy explains it by releasing muscle contracture, improving local circulation, and reducing localized nerve sensitization. In essence, though born from very different medical paradigms, acupuncture points and trigger points often “represent the same phenomenon” in the context of pain relief​. As Melzack et al. noted in 1977, the discovery that so many painful trigger points correspond to known acupuncture pain-relief points was likely not a coincidence, but rather indicates that both traditions found the same effective spots on the body through independent paths​. Modern experts agree: a comprehensive review of 255 common trigger points found that 238 of them (93%) could be directly mapped to specific acupuncture points in the same muscle location​. This overlap is far too high to be due to chance (~1 in 7 trillion odds, statistically)​. It suggests that ancient practitioners, by palpating for tender “ashi” spots and observing results, were empirically treating the same myofascial phenomena that modern trigger point therapists target. Today, this alignment allows a productive integration of knowledge – we can discuss musculoskeletal pain in terms of both trigger point locations and acupuncture meridians, often describing the very same spots on the body​.

Comparison of Acupuncture Point Indications and Trigger Point Symptoms

One compelling aspect of the overlap is that not only are the locations similar, but the subjective symptoms or effects associated with those locations are often strikingly similar between TCM literature and trigger point medicine. Classical acupoints each have documented indications – centuries of clinical observations about what symptoms or conditions pressing or needling that point can alleviate. Myofascial trigger points, similarly, have well-documented referred pain patterns and symptom profiles (as mapped by Travell and Simons). When researchers compare these, the concordance is remarkable: in a 2006 analysis of the 255 “most common” trigger points, 94% of anatomically corresponding acupuncture points shared similar pain referral regions or clinical indications with the trigger point​. In other words, if a trigger point in a muscle causes pain in a particular distal pattern, the acupuncture point at that same location is very likely to have been used traditionally to treat pain in that same region​. This provides strong evidence that the two systems, though using different language, have been addressing the same clinical entities.

Pain Referral and Indications: Trigger points are known for causing referred pain – e.g. a trigger point in the upper trapezius might refer pain to the temple and jaw, a sternocleidomastoid (SCM) trigger can cause frontal headaches and dizziness, or a gluteus medius trigger can send pain down the leg. Acupuncture texts, on the other hand, might say a point on the shoulder (like GB-21) treats headaches and jaw tension, or a neck point (GB-20 at the skull base) alleviates dizziness and head pain, or a hip point (GB-30) is indicated for sciatica (leg pain). These parallel descriptions align with what we now know are the myofascial pain referral patterns:

  • Upper Trapezius (GB-21 “Jianjing”): A classic trigger point in the upper trapezius causes neck/shoulder pain and can refer pain to the side of the head (temple) causing tension headaches. GB-21, the acupuncture point located in the upper trapezius muscle, is traditionally indicated for neck stiffness, shoulder tension, and headaches​. Clinically, acupuncturists often find this point tender (ashi) in patients with neck pain and head pain, just as a trigger point therapist finds a trapezius TrP there​. Needling or pressing GB-21 often reproduces the referred ache towards the head – a sign of hitting the trigger point – and relieves the headache after treatment. This one-to-one match of trigger point symptom (headache) and acupoint indication (“clears head pain”) is observed repeatedly.

  • Infraspinatus (SI-11 “Tianzong”): An active trigger point in the infraspinatus (a rotator cuff muscle) typically presents as a deep ache in the shoulder blade that can radiate down the arm or up the neck. Small Intestine 11, located in the center of the infraspinatus fossa, is a major local acupuncture point for shoulder and upper back pain. TCM texts note it is used for pain in the scapular region and inability to raise the arm. Indeed, SI-11 corresponds precisely to common infraspinatus TrPs​. Patients with a frozen shoulder or rotator cuff injury often have exquisite tenderness at SI-11. Stimulating this point (by acupuncture or deep pressure) can reproduce the arm referral (signaling the TrP) and alleviate shoulder pain and motion restriction thereafter. The overlap in indication – relieving shoulder/scapula pain and improving arm mobility – aligns with the trigger point’s effect.

  • Sternocleidomastoid (sternal head): Trigger points in the SCM muscle can produce a constellation of symptoms: frontal or periorbital headaches, vertigo, tinnitus (ringing in ears), and even nausea. There is no single classical acupuncture point that exactly matches the mid-belly of the SCM where these TrPs reside; such spots would be treated as ashi points. However, the GB-20 “Fengchi” point is at the insertion of these neck muscles (near the occiput) and is indicated for headache, dizziness, ear issues, and neck stiffness​– highly similar to the SCM trigger point’s symptom pattern. Pressing or needling GB-20 often refers sensations to the head or ear (like a trigger point does) and relieves those symptoms; in fact, GB-20 lies at the junction of trapezius and SCM insertions and can address suboccipital muscle TrPs as well. This is an example of how acupuncture channels account for referred effects: the gallbladder meridian (running through GB-20 and down the neck) mirrors the referral pattern of the SCM trigger (head/ear), suggesting a clinical equivalence recognized in TCM practice​.

  • Jaw Muscles (Masseter, Temporalis): Trigger points in the jaw muscles refer pain to the teeth, jaw, and temple. Acupuncture points ST-6 “Jiache” (on the masseter belly at the jaw angle) and ST-7 “Xiaguan” (just above the jaw joint in front of the ear) are classical points for jaw pain, toothache, and TMJ disorders. They coincide with common masseter trigger points. Needling ST-6 often elicits dull pain in the lower teeth or jaw – precisely the referred pain a masseter TrP produces – and is very effective for jaw tension and toothache​. Likewise, deep needling at ST-7 can treat earache and upper tooth pain by deactivating lateral pterygoid triggers that refer to the ear region​. The traditional indications (“toothache, lockjaw, ear pain”) match the myofascial referral zones of these masticatory muscle trigger points​.

  • Gluteal Region (Piriformis/Gluteus Medius – GB-30): A trigger point in the piriformis or deep gluteus medius/minimus can cause sciatica-like pain – radiating down the back or side of the leg. Gallbladder 30 (“Huantiao”), located in the buttock where the piriformis crosses the sciatic nerve, is a staple acupuncture point for sciatica, hip and leg pain. Anatomically, GB-30 lies deep to the gluteus maximus at the piriformis muscle – precisely where a common trigger point causes nerve impingement​. Stimulation of GB-30 often reproduces the shooting pain down the leg (indicative of the trigger point) and helps release the piriformis spasm, relieving sciatic pain​. The TCM description for GB-30 includes “disinhibits the hip and leg, treats lumbar and leg pain,” which aligns perfectly with the referral of gluteal TrPs and their treatment effects.

Numerous such examples exist. In Travell and Simons’ trigger point manuals, each TrP entry often has a diagram overlapping a spinal nerve referral pattern with muscle locations. It has been noted that these referred pain patterns bear a strong resemblance to acupuncture meridian pathways​. A quantitative study found 76% of trigger point pain referral patterns corresponded closely to TCM meridian distributions (the pain radiates along the same path as a known channel)​. For instance, a trigger point in the soleus (calf muscle) refers pain to the heel – following the Bladder meridian down the leg to the foot; appropriately, Bladder-channel acupuncture points (like BL-57 in the calf) are used for heel pain and calf cramps. In the large majority of cases, traditional acupuncture indications for a point encompass the typical pain caused by a trigger point in that location​. This extends beyond pain to other phenomena: about 24% of common trigger points also produce autonomic or “visceral” symptoms (e.g. dizziness, nausea, tearing, cough, arrhythmia)​. Remarkably, 93% of those cases had analogous descriptions in acupuncture lore for the corresponding acupoint​. For example, a trigger point in the sternocleidomastoid that causes dizziness corresponds to acupuncture point GB-20, which is used for dizziness and vertigo; a trigger point in the jaw muscle that causes ringing in the ears corresponds to points near the ear (SJ-17, GB-2) used for tinnitus. This high concordance in indications strongly reinforces that both paradigms are dealing with the same physiological effects.

In summary, the symptomatic “maps” drawn by Eastern acupuncturists and Western myofascial pain specialists align to a striking degree. Acupuncture points that have been empirically used for specific pain syndromes are often located exactly where a trigger point can reproduce that syndrome. The overlap in referred pain pathways and in therapeutic indications is well above random chance​. This convergence provides a valuable cross-validation: it suggests that one can use the rich diagnostic framework of either system to inform treatment in the other. For instance, an acupuncturist can use trigger point charts to decide which points might be tender and in need of needling; conversely, a physician can use acupuncture meridian theory to understand why a trigger point is referring pain along a particular nerve route.

 

Needling Techniques and Physiological Effects: Acupuncture vs Dry Needling

When it comes to treating these overlapping points, practitioners of acupuncture and trigger point dry needling sometimes employ different techniques, yet there are also similarities in the physiological outcomes. Here we compare how each approach needles the point and what effects result:

Technique and Needle Manipulation: Traditional acupuncture involves inserting a very fine needle to a specific depth at the acupoint and manipulating it to elicit the characteristic sensation known as Deqi. Deqi is described as a dull ache, heaviness, or tingling that radiates from the point; obtaining this sensation is considered crucial in TCM for effective treatment​. The acupuncturist may twirl or lift-thrust the needle gently until the patient (and practitioner) feel the Deqi, but they generally avoid vigorous movements that cause sharp pain. In trigger point dry needling (sometimes called intramuscular stimulation), the technique is more direct and aggressive on the trigger spot: the needle is often inserted into the taut muscle band and moved (pistoned or coned) to try to provoke a local twitch response – a brief involuntary contraction of the muscle fibers​. This twitch is considered a sign that the trigger point has been accurately hit and is releasing. Dry needling practitioners are less concerned with the subjective Deqi feeling; they focus on the twitch and often expect the patient to feel a reproduced “familiar pain” (the referred pain) and some cramping twitch, which can be momentarily sharp or uncomfortable​. In essence, acupuncture’s manipulation is geared toward achieving a neural sensation (without excessive pain), whereas trigger point needling seeks a muscular release event (even if it causes a brief painful twitch).

Despite these differences, both methods insert the same stainless-steel filiform needles into the body’s soft tissues, and in many cases they are actually needling the very same spots. An acupuncturist treating low back pain, for example, might insert needles into the lumbar erector spinae muscle trigger points – but he/she may call them by acupuncture names like BL-23 or ashi points in the low back. Meanwhile, a physical therapist performing dry needling for back pain will insert into those same taut bands in the erector spinae. The immediate mechanical action – a needle disrupting contracted muscle fibers and nerve endings – is similar. Both approaches cause local micro-trauma that triggers the body’s healing responses: increased blood flow, release of neurotransmitters, and a reset of muscle spindle activity. After needling, a successful treatment in both paradigms often results in reduced muscle tension and improved range of motion in that area.

Needle Retention and Treatment Duration: In TCM acupuncture, needles are typically retained for a period (often ~15–30 minutes) once inserted, to allow the therapeutic effects to build​. The practitioner might insert 10–20 needles over multiple points (local and distal) and let the patient rest with them. Dry needling usually is more brief and focused – the needle may be pistoned in and out a few times and removed once the trigger point’s twitch/response is obtained, often within seconds to a couple of minutes; prolonged retention is not usually necessary in trigger point release (though some practitioners do leave needles in for a short time)​. Additionally, acupuncturists sometimes apply supplemental techniques during retention, such as mild electrical stimulation (electroacupuncture) on the needles or warming (moxibustion), whereas trigger point therapy may simply involve the needling alone or combined with stretching after needle removal​. These differences reflect the underlying philosophies: acupuncture views points within an integrative system and often treats multiple points in combination, while dry needling is a more localized, lesion-centered approach.

Frequency of Therapy: Acupuncture for chronic pain might be done twice or three times a week, or even daily for acute issues, following TCM protocols​. Dry needling in a physical therapy context is often done once a week or once every 2 weeks as an adjunct to exercise therapy​. This is partly because acupuncture clinics operate on an oriental medicine model of frequent treatments to rebalance the system, whereas rehabilitation clinics space treatments to allow tissue recovery from the aggressive needling. There’s also a practical regulatory aspect: some jurisdictions limit dry needling frequency or the contexts in which it’s applied. Nonetheless, when comparing outcomes, studies have found that both high-frequency acupuncture and lower-frequency dry needling can yield improvements in pain and function, and it’s not clear that one approach is universally superior for musculoskeletal pain​.

Physiological Effects and Mechanisms: Both acupuncture and trigger point needling ultimately produce overlapping physiological effects, especially when applied to the same points. These include:

  • Localized Muscle Release: Inserting a needle into a knotted muscle produces a localized contraction (twitch) followed by reflexive relaxation of that taut band. This is a well-documented effect in dry needling, but acupuncturists treating myofascial pain also report feeling the muscle “grasp” the needle and then loosen. The result is a reduction in muscle tone and a restoration of normal length and blood perfusion to the tissue​.

  • Neural Modulation – Pain Gate and Endorphins: Both techniques stimulate A-delta and C fibers which send signals to the spinal cord and brainstem that can disrupt pain circuits. This relates to the “Gate Control Theory” of pain modulation. Acupuncture has been shown to trigger release of endogenous opioids (endorphins, enkephalins) and neurotransmitters like serotonin in the central nervous system, leading to generalized pain relief. Dry needling, through intense stimulation of a trigger point, likely activates similar descending inhibitory pathways. Essentially, needling a trigger point or acupoint can increase pain threshold in that segment via spinal gating and also induce a systemic pain relief response through central mechanisms​. Both approaches exploit these neurophysiological effects, even if acupuncture also frames it as unblocking meridians.

  • Circulation and Healing: The physical act of needling causes a minor inflammatory response that brings blood flow and immune activity to the area. In a tight, ischemic trigger point nodule, this helps wash out metabolites and relieve hypoxia. Acupuncture in TCM terms “moves Blood and Qi” – which biomedically corresponds to improving circulation. The end result is accelerated healing and reduced irritability of the trigger point. Studies measuring biochemical changes have found both acupuncture and dry needling can reduce the concentration of nociceptive substances (like substance P, CGRP) around a painful locus while increasing anti-inflammatory cytokines locally​.

  • Segmental and Suprasegmental Effects: An interesting aspect is that acupuncture often uses distal points along a nerve segment or meridian to affect a painful area, whereas trigger point needling is very focal. However, when acupuncture needles are placed even away from the pain, they often correspond to other musculature in the same myotome or spinal segment or to a related referral pattern. From a biomedical standpoint, needling remote points can still modulate pain via central neural networks. For instance, acupuncture might treat low back pain by needling the back of the knee (BL-40) – which could be seen as activating a reflex that relaxes the lumbar muscles. Dry needling rarely uses such distal points purely for neuromodulation (it sticks to the trigger spots themselves), but in practice, many acupuncturists will also needle local tender points (which are triggers). Thus, a comprehensive TCM treatment might include both local and distal points, addressing both the immediate trigger point and the broader pain pathway. Dry needling typically focuses only on local triggers, but some practitioners combine it with other therapies (stretching, posture correction) to address functional patterns.

Outcomes and Differences: In terms of patient outcomes, research comparing acupuncture and trigger point dry needling has yielded mixed but generally convergent results. Several randomized controlled trials by Itoh et al. in Japan compared trigger point needling versus traditional acupuncture for chronic low back pain, neck pain, and knee osteoarthritis​. They found no significant difference in pain relief – trigger point dry needling was not more effective than properly chosen acupuncture points for these conditions​. Both provided improvement, suggesting that stimulating key points (whether exactly at the trigger or along the relevant meridian) achieves similar clinical benefit in many cases. Another trial using injections at either acupoints or trigger points for back pain actually found a slight edge for the acupuncture point approach​. A systematic review would likely conclude that both methods are effective for musculoskeletal pain, and differences may come down to the practitioner’s skill and approach rather than an inherent superiority of one method​.

That said, patients often report different sensations during the treatments. Acupuncture, especially in the hands of a gentle practitioner, may be more comfortable – patients often describe a dull, spreading sensation (Deqi) and then relaxation. Trigger point needling can be more painful during the procedure – the twitch response can feel like a cramp, and there may be post-treatment soreness akin to intense exercise. However, trigger point dry needling can sometimes yield very rapid relief after an initial soreness, especially if a longstanding trigger was released. Acupuncture’s effects might be more subtle and cumulative across sessions, particularly if distal points and general balancing are used in addition to local points.

In physiological endpoints, though, both share a lot of common ground: reduced muscle EMG activity in the affected muscle, increased range of motion, normalized chemical environment in the tissue, and pain reduction. Modern imaging like functional MRI even shows that stimulating an acupoint or a trigger point in the same area can light up similar brain regions related to pain modulation. One notable difference is conceptual: acupuncturists will treat the whole channel or region if multiple trigger points are implicated, whereas a trigger point therapist might methodically needle each active TrP in a muscle. For example, for a patient with tension-type headache, an acupuncturist might needle several points along the neck and shoulders (GB-20, GB-21, LI-4, etc., including both sides) whether or not each is a palpable trigger, to release the entire pathway of tension. A dry-needler might specifically target two or three palpable triggers (say in upper trapezius and suboccipital muscles). Despite this difference in approach, the overlapping points they choose (GB-20 and GB-21 in this case) will produce similar local and systemic effects.

In conclusion, while acupuncture and trigger point dry needling differ in technique and theory, at overlapping point locations they likely produce very similar therapeutic effects. Both relieve pain by neurophysiological mechanisms (segmental inhibition, endogenous opioids), reduce muscle spasm, and improve circulation. The distinctions lie in style: acupuncture integrates the point into a holistic treatment framework (with specific needle manipulations like tonification or sedation and longer retention), whereas dry needling zeroes in on the myofascial dysfunction with rapid in-and-out pricks. Importantly, one approach does not preclude the other. In fact, many modern clinicians combine both: an acupuncturist might perform aggressive trigger point releases for a portion of the session and also do gentler distal needling, or a physiotherapist might learn some acupuncture points to enhance their dry needling outcomes. The convergence of these methods on the same anatomical targets underscores their shared therapeutic substrate. As one review succinctly concluded, “although separated by 2000 years of history, the acupuncture and myofascial pain traditions have fundamental clinical similarities in the treatment of pain disorders”​. Their union can help demystify acupuncture in western terms and enrich trigger point therapy with time-tested knowledge.

Well-Documented Overlaps Between Acupuncture Points and Trigger Points (Table)

Researchers have identified numerous one-to-one correspondences between classical acupuncture points and common myofascial trigger points. Table 1 below lists several well-documented overlaps, including the anatomical location, the muscle involved, and the shared pain indications. Each example is supported by sources from clinical research or authoritative texts. These overlaps are widely accepted and have been corroborated by multiple studies or clinical observations.

Acupuncture Point (Meridian) Corresponding Muscle & Trigger Point Shared Indications/Symptoms Source(s)
GB-21 – Jianjing
(Gallbladder 21)		 Upper Trapezius trigger point (mid-fiber of trapezius muscle, top of shoulder) Neck and shoulder pain; tension headaches referring to temple/jaw; shoulder stiffness Overlapping location noted in neck pain cases; GB-21 used for trapezius spasm & headache relief
GB-20 – Fengchi
(Gallbladder 20)		 Suboccipital trigger points at insertions of trapezius and sternocleidomastoid (occiput region) Occipital headaches, migraines; dizziness/vertigo; neck stiffness and shoulder tension Anatomy: between attachments of SCM and trap at skull base. Indicated for headache, vertigo, neck pain
SI-11 – Tianzong
(Small Intestine 11)		 Infraspinatus trigger point (scapula, mid infraspinatus fossa) Shoulder blade pain; deep shoulder ache; limited arm rotation or “frozen shoulder” pain SI-11 lies in infraspinatus muscle. Used for scapular/shoulder pain and arm movement issues (matches infraspinatus TrP referral)
ST-6 – Jiache
(Stomach 6)		 Masseter (jaw muscle) trigger point (near jaw angle) Jaw pain, TMJ dysfunction; lower toothache or gum pain; jaw clenching (bruxism) ST-6 is on masseter belly; needling it hits common masseter TrP. Masseter TrP refers pain to lower molars and jaw, aligning with ST-6’s use for toothache/jaw tension
GB-30 – Huantiao
(Gallbladder 30)		 Piriformis/Gluteus Medius trigger point (deep lateral hip/buttock) Sciatica – radiating hip and leg pain; buttock pain; difficulty walking due to hip pain GB-30 is located over piriformis and gluteal trigger spots. Indicated for sciatica, hip and leg pain. Trigger here (piriformis) causes sciatic nerve pain, which GB-30 relieves
BL-57 – Chengshan
(Bladder 57)		 Gastrocnemius (calf) trigger point (mid calf belly) Calf cramps and spasm; Achilles tendon pain or plantar fasciitis (heel/arch pain); tension in calf BL-57 lies at the gastrocnemius mid-belly (common calf TrP). Calf TrPs cause posterior leg cramps, heel pain, plantar foot pain. BL-57 traditionally treats calf spasm and heel pain (hemorrhoid point in TCM but also used for leg pain)

Table 1: Selected examples of well-documented correspondences between acupuncture points and myofascial trigger points. Each acupuncture point (with meridian and common name) is paired with the muscle and trigger point that occurs in the same location. The typical pain or symptom patterns are described, showing the alignment between trigger point referral pain and the traditional acupuncture point indications. Sources provide evidence of the anatomical overlap and clinical use. (GB = Gallbladder channel, SI = Small Intestine, ST = Stomach, BL = Bladder, etc.)

Key: GB-21 and GB-20 are on the neck/shoulder region; SI-11 is on the shoulder blade; ST-6 is on the jaw; GB-30 is in the buttock; BL-57 is in the calf. All of these illustrate how a trigger point in a muscle corresponds to an acupuncture point that has been used for similar pain in that region.

Less-Documented and Proposed Overlaps (Ashi Points and Novel Points)

While most common trigger points coincide with established acupuncture points, there are a few trigger points that do not clearly map to named classical points. These often fall into the category of “extra points” or ashi points in acupuncture – locations that are used when tender, but not formally listed on the standard meridians. Some of these “orphan” trigger points have noteworthy clinical effects (often viscerosomatic reflexes) that weren’t explicitly described in old acupuncture literature, or were described differently. Researchers and clinicians have proposed correlations for these as well, albeit with less historical documentation. Table 2 lists a few such examples of trigger points that have only tentative or minor correspondence in acupuncture, including notes on their effects. These overlaps are less substantiated in TCM texts (sometimes only mentioned in passing, if at all) but are observed in practice.

Trigger Point & Muscle Approximate Acupuncture Correspondence Notable Symptoms/Effects Notes/Reference
Pectoralis Major “cardiac arrhythmia” TrP
(in left chest, 5th intercostal space medial to nipple)		 No classical acupoint at exact spot (ashi point near **PC-1** region on chest) Can induce cardiac arrhythmia or palpitations when active (triggering premature heartbeats) Identified by Travell as capable of causing heart rhythm disturbances. TCM pericardium channel has a point (PC-1) nearby, but classical texts emphasize it for chest pain and cough, not arrhythmia specifically.
“Belch Button” TrP
(upper abdominal trigger point, possibly diaphragm or epigastric region)		 No formal acupoint (midline ashi near **Ren-14/15** area or phrenic nerve) Pressing causes burping (gastric air release) and relieves epigastric bloating; associated with reflux symptoms Named in Travell’s Trigger Point Manual for eliciting burping. Overlaps the epigastric region innervated by phrenic nerve. Nearest acupuncture points Ren-14/15 address “rebellious Qi” (burping, nausea) – a possible conceptual link, though the trigger point itself is not a defined acupoint.
Lower Abdomen “causes diarrhea” TrP
(trigger point in abdominal wall, possibly near right lower quadrant)		 No specific acupoint (could be treated ashi or near **ST-25 Tianshu**) Can trigger intestinal motility leading to sudden loose stools or abdominal cramping Reported by Travell et al. as a point that when active can cause diarrhea urgency. ST-25 (adjacent on mid-abdomen) is the classical front-mu of the colon for diarrhea, but this TrP doesn’t exactly match a known point – it represents a visceral-somatic reflex not explicitly mapped in TCM.
Lateral Pterygoid TrP
(deep jaw muscle, behind maxilla)		 No surface acupoint; accessed via intra-oral ashi or through **ST-7 Xiaguan** deep needling Jaw clicking, TMJ pain; referred pain to ear (earache) or upper molar tooth pain; sinus congestion sensation Laterally pterygoid triggers are treated by needling behind the TMJ. Travell noted injections at the region of ST-7 to treat these deep muscle TrPs. ST-7 is an acupoint for jaw and ear pain; deep angle needling of ST-7 reaches the pterygoid, showing an overlap, though classical texts didn’t describe the muscle, just the symptom (ear/toothache).

Table 2: Examples of trigger points that have less clearly documented acupuncture equivalents. These tend to be special cases often involving viscerosomatic reflexes or deep muscles not directly covered by the primary meridians. In acupuncture, such points would be treated as ashi points (tender spots) or fall near existing points (e.g. PC-1 for the pectoral trigger, or ST-25 for the abdominal trigger), but the classical literature may not mention the specific symptom that the trigger point elicits (like arrhythmia or belching). The notes indicate the nature of each trigger point and any tentative linkage to acupuncture concepts. These overlaps are considered “less-documented” simply because they are not part of the common 361 classical points, yet they highlight areas where modern trigger point therapy could expand the acupuncture point repertoire (or vice versa) by acknowledging effective tender points outside the well-trodden pathways.

It should be noted that even when a trigger point does not correspond to a formal acupuncture point, acupuncturists can still treat it by palpation (identifying it as an ashi point). The concept of ashi points in acupuncture is essentially an acknowledgment that not all therapeutic points have names – some are taken wherever a pathological spot is found. This is very much in line with trigger point therapy. As research continues, some of these less-documented overlaps may become better established. For instance, modern acupuncturists now frequently treat pectoral trigger points to help cardiac arrhythmia or anxiety chest tightness, effectively blending Travell’s findings with acupuncture practice, though historically this wasn’t in TCM texts​​.

In conclusion, the overlap between acupuncture points and myofascial trigger points is extensive and supported by anatomical, clinical, and physiological evidence. The two paradigms, despite arising from entirely different worldviews, converge on a common map of the body’s key loci for pain and healing. Traditional acupuncture provides a rich context and time-tested knowledge base for why stimulating these points can have broad effects, while myofascial trigger point science offers precise insights into muscular and neural mechanisms. By understanding their overlap, practitioners can leverage the strengths of both – improving assessment (through palpation of ashi/trigger points) and treatment (through versatile needling techniques and holistic point selection). This integrated perspective ultimately benefits patients, as it widens the toolkit for relieving pain and dysfunction by targeting the body’s most potent spots for recovery​.

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