Neuromusculoskeletal Pain: Lessons from the Myofascia

Jay P. Shah, MDRehabilitation Medicine Department

National Institutes of Health

Disclosures

•

Nothing to disclose

NIH Clinical Research Center “Bench to Bedside -

Bedside to Bench”

LaboratoriesLaboratories

Inpatient Care

Outpatient Care

Pattern-generating mechanism (Neuromatrix)

Brain areas encoding pain experience and behaviorsCultural,

past experience,personality

attention

Autonomic endocrine, immune variables

CNS Plasticity

Sensitization

Pathogenic inputs

Visceral inputs

Somatosensory inputs

Melzack, Trends Neurosci 1990; 13:88-92

Perception

Adapted from Butler, DS The Sensitive Nervous System

Pain Mechanisms

• Review the diagnostic criteria for myofascial pain and demonstrate the referral patterns of common myofascial trigger points (MTrPs)

• Examine the unique neurobiology of muscle pain

• Discuss the dynamic interplay of muscle nociceptors and endogenous biochemicals in the initiation, amplification and perpetuation of peripheral and central sensitization

• Demonstrate that an active myofascial trigger point (MTrP)

in the upper trapezius has elevated levels of inflammatory mediators, neuropeptides, and cytokines, etc. –

substances

known to be associated with persistent pain states, sensitization and inflammation

Goals of Discussion

•

Introduce novel applications of ultrasound techniques to visualize MTrPs, measure their stiffness properties and local blood flow

•

Demonstrate that MTrPs in the upper trapezius are stiffer than surrounding tissue and that active MTrPs can be distinguished from latent MTrPs by their high-resistance blood flow

Goals of Discussion

Myofascial Trigger Points

A Very Common, Complex and Overlooked Cause of Non-articular Musculoskeletal Pain

Hans-Werner Weisskircher www.trigger-point.com

Essential Clinical Criteria for Myofascial Pain

•

Palpation of a taut band•

Exquisitely tender spot (a myofascial trigger point) in the taut band

•

Reproduction of the subject’s symptomatic painGerwin et al. Interrater reliability in myofascial trigger point examination. Pain. 1997;69(1-2):65-73

Hans-Werner Weisskircher www.trigger-point.com

•

Palpation of a taut band•

Exquisitely tender spot (a myofascial trigger point) in the taut band

•

Reproduction of the subjects symptomatic painGerwin et al. Interrater reliability in myofascial trigger point

examination. Pain. 1997;69(1-2):65-73

Courtesy Marta Imamura

Essential Clinical Criteria for Myofascial Pain

Myofascial Trigger Points

2-5 areas in hard, palpable bands of skeletal muscle:

Active –

cause a clinical pain complaint or other abnormal sensory symptoms

Latent –

show all the other characteristics of active MTrPs, except that they’re pain free

Travell JG, Simons DG. Myofascial pain and dysfunction: the trigger point manual. Baltimore: Williams & Wilkins; 1992.

Upper Trapezius

Medial Pterygoid

Lateral PterygoidSCM (sternal division)

Masseter

Orofacial Pain 2º Myofascial Trigger

Points

Hans-Werner Weisskircher

www.trigger-point.com

Release of Inflammatory mediators, Neuropeptides and Cytokines

Release of Inflammatory Release of Inflammatory mediators, Neuropeptides mediators, Neuropeptides and Cytokines and Cytokines

Courtesy Marta Imamura

Muscle Muscle InjuryInjury

Muscle Pain, Inflammation, and Sensitization

Sensitize wide dynamic range neurons and higher centers leading to allodynia, hyperalgesia and…

Sensitize wide dynamic range Sensitize wide dynamic range neurons and higher centers neurons and higher centers leading to allodynia, hyperalgesia leading to allodynia, hyperalgesia andand……

Courtesy Marta Imamura

Muscle Muscle InjuryInjury

Muscle Pain, Inflammation, and Sensitization

Courtesy Marta Imamura

… expansion of the receptive field of pain and referral of pain ……

expansion of the receptive expansion of the receptive

field of pain and referral of pain field of pain and referral of pain

Muscle Pain, Inflammation, and Sensitization

Travell JG, Simons DG. Myofascial pain and dysfunction: the trigger pointmanual. Baltimore: Williams & Wilkins; 1992.

Common Referral Diagnoses for Pain Found to be of Myofascial Origin

•

Angina Pectoris (atypical)

•

Appendicitis

•

Atypical Migraine•

Tension Headache

•

Occipital Headache

•

Pectoralis Major

•

Lower Rectus Abdominis

•

Sternocleidomastoid, Temporalis, Mastic. Musc, Post. Cervicals,

Travell JG, Simons DG. Myofascial pain and dysfunction: the trigger point manual. Baltimore: Williams & Wilkins; 1992.

“Since no specialty claims skeletal muscle as their organ, it

is often overlooked”David G. Simons, MD

Muscle –

The “Orphan Organ”

•

NO specialty claims muscle as its organMuscle is ½ of the bodyNo organized emphasis on muscle pain (MTrP) research or student trainingClinicians focus primarily on treating the SYMPTOMS of myogenic pain, not the CAUSE of the pain (MTrPs)

Active MTrPs can only be diagnosed by systematic palpation

Hans-Werner Weisskircher

www.trigger-point.com

Apply Firm Pressure

Hans-Werner Weisskircher www.trigger-point.com

Palpation, Palpation, Palpation•

Careful palpation of the surface of the body reveals distinct differences in the quality and density of the underlying tissue. Many of these areas or points will be tender:

•

A Shi points in Traditional Chinese Medicine

•

Kori in Japanese system•

Muskelharten in German system

Nociceptor Function•

Encode Noxious Stimuli•

Possibly leading to pain

•

Maintain Tissue Health•

Initiate and maintain reaction to injury

Nociceptors are Dynamic “Two-way”

Structures

A Critical Efferent Nociceptor Function: Neuropeptide (Substance P, CGRP) Production

Courtesy Jan Dommerholt

Muscle pain is NOT skin pain

Unique Neurobiology of Muscle Pain

Muscle Pain is often Overlooked

“I’ll beBack!”

“Ohhh, my

Back!”

Unique Characteristics of Muscle Pain

• Aching, cramping pain, difficult to localize and referred to deep and distant somatic tissues

• Muscle pain activates unique cortical structures Svensson P et al. Cerebral processing of acute skin and muscle pain in humans. J Neurophysiology July 1997; 78: 450-460.

• Inhibited more strongly by descending pain-modulating pathways XianMin Y, Mense S. Response Properties and descending control of rat dorsal horn neurons with deep receptive fields.

Neuroscience 1990; 39:823-831.

• Activation of muscle nociceptors is much more effective at inducing neuroplastic changes in dorsal horn neuronsWall PD, Woolf CJ.

J Physiol 1984 Nov;356:443-458.

Distant Referral Patterns

Hans-Werner Weisskircher www.trigger-

point.com

Powerful Descending Inhibition on Muscle Pain

Fields HL, Basbaum AI: Central nervous system mechanisms of pain modualtion. In Textbook of Pain; 1999:309-329.

Afferent Bombardment of Muscle Nociceptors: 2nd

Messenger Cascades, Induction of Immediate Early

Genes and Protein Synthesis, Excitotoxicity and Cell Death

Activity Dependent PlasticityWall PD, Woolf CJ. Muscle but not cutaneous C-afferent input produces prolonged increases in the excitability of the flexion reflex in the rat. J Physiol. 1984 Nov;356:443-58.

Muscle PainPeripheral Mechanisms

BRADYKININRECEPTOR

BRADYKININRECEPTORBradykinin Receptor

Muscle Nociception

–

Binding of Substances to Matched Chemoreceptors

(B2→B1)

Muscle PainSpinal Mechanisms

• REDUCED SPATIAL RESOLUTION–

Due to lower density of muscle sensory afferents compared to the skin

• CONVERGENCE OF SENSORY INPUT–

Input from skin, bone, viscera, periosteum

Characteristics of Muscle Nociceptor Projections to Dorsal Horn

• Sustained noxious stimulation (of Group IV fibers in muscle) leads to the opening of previously ineffective connections in dorsal horn neurons

• Intramuscular injection of various biochemicals (e.g., bradykinin, prostaglandins, serotonin, acidic saline, etc.) activates muscle nociceptors and causes allodynia and hyperalgesia

Dorsal Horn Changes in Pathologic Conditions –

Central Sensitization

DIVERGENCE OF SENSORY INPUT

Expansion of Receptive Field by a Painful Muscle Stimulus

Hoheisel U, Mense S, Simons DG. Appearance of new receptive fields in rat dorsal horn neurons following noxious stimulation of skeletal muscle: a

model for referral of muscle pain? Neurosci lett 153:9-12, 1993

Selected neuron responds only to deep pressure in biceps femoris muscle

Biceps Femoris

Courtesy Jan Dommerholt

Hoheisel U, Mense S, Simons DG.

Neurosci lett 153:9-12, 1993

5 min after BK injection in TA, the selected neuron can now be excited by additional RF’s located in deep

muscle that normally have high threshold

Expansion of Receptive Field by a Painful Muscle Stimulus

Courtesy Jan Dommerholt

Hoheisel U, Mense S, Simons DG.

Neurosci lett 153:9-12, 1993

Expansion of Receptive Field by a Painful Muscle Stimulus

Hoheisel U, Mense S, Simons DG.

Neurosci lett 153:9-12, 1993

Expansion of Receptive Field by a Painful Muscle Stimulus

Hoheisel U, Mense S, Simons DG.

Neurosci lett 153:9-12, 1993

Expansion of Receptive Field by a Painful Muscle Stimulus

Hoheisel U, Mense S, Simons DG.

Neurosci lett 153:9-12, 1993

Expansion of Receptive Field by a Painful Muscle Stimulus

Hoheisel U, Mense S, Simons DG

Neurosci lett 153:9-12, 1993

15 min after BK injection in the TA the selected

neuron responds to moderate (innocuous) pressure in its original receptive field -

biceps femoris

Expansion of Receptive Field by a Painful Muscle Stimulus

Allodynia (light pressure and muscle

movement)

Hyperalgesia

Glutamate Substance P

Nociceptive Bombardment causes

Central Sensitization and Neuroplastic

Changes in Dorsal Horn Neurons

Pain begins in Calf, Heel and Foot

Then Develops Pain in SI Joint too

Then Develops Pain in SI Joint too

TrP3

Ineffective Synapse

Dorsal horn

Neuron for SI Joint is Initially Inactive

TrP3

Effective synapse

Expansion of the Receptive Field

TrP3

Wide Dynamic Range Neuron

++----

Excitatory tonus via nociceptors

Inhibitory tonus

Dynorphin

Met Leu- enkephalin

SP

Galanin

VIP

NPY

SOMGABA, Glycine, Glutamate, ACh, DA, 5-HT, Nitric Oxide

Immune system

Neurotrophins

Neurosteroids

Cytokines

Glia and Astrocytes

Substances Dynamically Modulating Dorsal Horn Neurons

MTrPs and the Local Twitch Response

Courtesy Joseph Audette

FibrositisMyositis

MyofascialPain

MyofascitisMyofibrositis

Muscularrheumatism Myelosis

Radiculitis

Myofascial Pain Historical and Regional Confusion

Historical Context of Trigger Points

•

Steindler coined the term “trigger points” when he found he was able to relieve

sciatica by injecting Novocain into tender points in muscles in the lumbar and gluteal regions

•

Travell added the term “myofascial”

after performing a biopsy of the infraspinatus muscle and observed that pinching the fasciae produced the same referral pattern as the muscle

Opening of Previously Ineffective Synapses

Treatments for Myofascial Pain

•

Spray/Stretch•

Strain/counterstrain

•

Muscle energy•

Myofascial release

•

Medications•

Dry Needling

•

Trigger point injections•

Botox injections

•

Orthotics, shoe modification

•

Counseling•

Behavioral management

•

Relaxation•

Imagery

•

Hypnosis•

Coping skills

•

Acupressure

“Dry needling MTrPs and eliciting LTRs is as effective as

lidocaine injection in inactivating a MTrP and relieving pain”

Hong CZ. Lidocaine injection versus dry needling to myofascial trigger point. The importance of the local twitch response. Am J Phys Med Rehabil. 1994;73(4):256-63.

Recent studies comparing MTrP injections with a syringe and MTrP needling with an acupuncture needle showed that MTrP needling with an acup

needle does not cause more post-needling soreness

Ga H, Choi JH, Park CH, Yoon HJ. Acupuncture needling versus lidocaine injection of trigger points in myofascial pain syndrome in elderly patients - a randomised trial. Acupunct Med. 2007 Dec;25(4):130-6.

Ga H, Koh HJ, Choi JH, Kim CH. Intramuscular and nerve root stimulation vs lidocaine injection to trigger points in myofascial pain syndrome. J Rehabil Med. 2007 May;39(5):374-8.

Trigger Point Needling: Trigger Point Needling: Proper Technique to Elicit Local Twitch Proper Technique to Elicit Local Twitch

Responses is EssentialResponses is EssentialHong CZ

Arch Phys Med Rehab 1994;73:256

Courtesy Joseph Audette

How does dry needling work?

What is the Pathophysiology of Myofascial Pain?

UNKNOWN

Simons’ Integrated Hypothesis

Increased Miniature Endplate Potentials

(Endplate Noise)

Increased Fiber Tension (Taut Band)

Release of Sensitizing

Substances? (Pain)

Pathophysiology Histopathology

Histochemistry

What is the Biochemical Milieu of MTrPs?

Clinical findings

Underlying milieu?

Myofascial Trigger Points: A Unique Perspective at the NIH

In Vivo Microdialysis –

A Technique For Analysis of the Biochemical Milieu of MTrPs

MicrodialysisLow or no solute

High concentration solute

Semi-permeable membrane

Courtesy Terry Phillips

Microdialysis/Acupuncture Needle

Courtesy Terry Phillips

Microdialysis/Acupuncture Needle –

30 Gauge Hypodermic

Fluid in

Fluid outSolute exchange

surface –

dialyzer membrane set 0.2 mm from the needle tip

Delivery tubes

Courtesy Terry Phillips

Comparison of Needle Tips

25G syringe needle

32G acupuncture needle

Courtesy Terry Phillips

Comparison between a Standard Acupuncture Needle and

our Needle/Probe

Acupuncture needle

Needle/Probe

Courtesy Terry Phillips

Comparison of Needle Tips

Rounded acupuncture needle tip pushes cells aside rather than piercing them

Sharp beveled hypodermic needle tip acts like a miniature scalpel capable of piercing, cutting and tearing cells

Courtesy Terry Phillips

Microdialysis Sampling

Courtesy Sagar Parikh

Microdialysis System

Fraction collector

Soft tissue

Needle

In-flow catheter

Microdialysis pump

Out- flow

catheter

Courtesy Terry Phillips

computer

detector

CE chamber

capillary

Power supply

Co-investigators

•

Terry Phillips, PhD, DSc

•

Jerome Danoff, PT, PhD

•

Lynn Gerber, MD

Hans-Werner Weisskircher www.trigger-

point.com

Design, Setting, and Patients

Three healthy subjects were selected to be in each of three groups (total 9 subjects) based on history and physical examination of upper trapezius:

•

Group 1)

Normal (no neck pain, no trigger point)•

Group 2)

Latent (no neck pain, trigger point

present)•

Group 3)

Active (neck pain present [<

3months],

trigger point present).

Initial Analyte Values in TrapeziusAnalyte Active Latent Normal *P value

pH (pH units) 5.4 6.3 6.5 P<.03

Bradykinin (pm/l) 69 49.6 47.5 P<.01

NE (nmol/l) 3.1 2.0 1.8 P<.01

Serotonin (nmol/l) 6.6 4.7 4.1 P<.01

Substance P (pg/ml) 187 50 34 P<.01

CGRP (pg/ml) 172 37.4 25.5 P<.01

TNF-α

(pg/ml) 173.5 26.5 21.2 P<.001

IL-1β

(pg/ml) 133.7 19.5 17.7 P<.001

*Active >

Latent, Normal (except pH)

0

50

100

150

200

250

300

350

400

0:00 2:24 4:48 7:12 9:36 12:00 14:24 16:48

Time

pg/m

lConcentration of Substance P over time

I = SEEI

II

Active

Latent

Normal

• Collect near real-time samples from soft tissue with minimal system perturbation and without harmful effects on subjects

• Proof-of-principle of the system’s ability to distinguish among subjects who have clinically distinct soft tissue findings

• Active MTrP in the upper trapezius has elevated levels of inflammatory mediators

(bradykinin,

protons, etc.), catecholamines

(norepinephrine and serotonin), neuropeptides

(substance P, CGRP)

and pro-inflammatory

cytokines

(TNF-α, IL-1β)

First Phase: What We’ve Demonstrated

Shah J, Phillips T, Danoff J, Gerber L. An in vivo microanalytical technique for measuring the local biochemical milieu of human skeletal muscle. J Appl Physiol. 2005

99(5): 1977-84.

1) Determine whether these findings are unique to the upper trapezius when compared to a remote uninvolved site in the medial gastrocnemius muscle

2) Measure additional analytes (e.g., IL-6 and IL-8) known to be associated with pain, inflammation and intercellular signaling.

Purpose of Second Phase

9 subjects, all of whom had no calf pain or calf MTrPs, were divided into 3 groups based on the following findings in the trapezius:

1) Active (painful MTrP present; 3 subjects) 2) Latent (non-painful MTrP present; 3 subjects) 3) Normal (no pain, no MTrP present; 3 subjects)

Design, Setting, and Patients

Hans-Werner

Weisskircher

www.trigger-

point.com

3 Groups of Subjects with following findings in upper trapezius muscle:

1) Active MTrP, 2) Latent MTrP, 3) No MTrP

No MTrP

Exclusion Criteria

•

Fibromyalgia•

Cervical radiculopathy

•

Atypical facial neuralgia•

History of previous trigger point injections in the upper trapezius and upper medial gastrocnemius

•

Knee pain•

History of cervical spine or shoulder surgery

•

On any medications

•

Other concurrent pain syndromes

•

Use of tobacco products•

Any aspirin within 3 days of needling

•

History of bleeding diatheses•

Being on anticoagulation therapy

•

An inordinate fear of needles•

Lumbosacral radiculopathy

Procedure and MeasuresProcedure :Samples were obtained continuously from the trapezius site at regular intervals for 14 minutes, and then from the upper medial gastrocnemius site for 10 minutes.

Measures :Levels of protons (H+), bradykinin, SP, CGRP, serotonin, norepinephrine, TNF-α, IL-1β, IL-6 and

IL-8.

Initial Analyte Values in TrapeziusAnalyte Active Latent Normal *P valuepH (pH units) 5.2 6.6 6.7 P<.001Bradykinin (pm/l) 71.3 39.9 41.5 P<.003NE (nmol/l) 3.0 1.9 1.5 P<.0001Serotonin (nmol/l) 6.9 4.2 3.9 P<.0001Substance P (pg/ml) 169.3 46.7 30.8 P<.0001CGRP (pg/ml) 157.3 49.3 25.8 P<.0001TNF-α

(pg/ml) 181.8 30.0 8.9 P<.001IL-1β

(pg/ml) 121.9 20.8 9.9 P<.001IL-6 (pg/ml) 130.2 16.7 10.5 P<.0001IL-8 (pg/ml) 61.7 7.7 6.9 P<.0001

*Active >

Latent, Normal (except pH)

0.00

100.00

200.00

300.00

400.00

500.00

600.00

0.00 5.00 10.00 15.00

Time (min)

pg/L

Set 1 Active

Set 1 Latent

Set 1 Normal

Set 2 Active

Set 2 Latent

Set 2 Normal

Combined Data for Substance P Concentration in Trapezius over Time

Concentrations of Analytes in the Active Group at Initial Needle Insertion

Analyte Trap GS *P valuepH 5.5 5.7 NS

Bradykinin 63.7 39.7 P<.001

NE 2.8 2.4 P<.001Serotonin 6.5 6.0 P<.001Substance P 140.9 52.9 P<.001

CGRP 129.9 46.7 P<.001TNF-α 143.9 45.5 P<.001 IL-1β 97.1 44.8 P<.001 IL-6 102.5 39.6 P<.001IL-8 48. 8 21.5 P<.001

*Trapezius >

Gastrocnemius

Analyte GS (Act) GS (Lat) GS (Nor) *P valuepH 5.7 6.7 6.8 P<.01

Bradykinin 39.7 37.4 35.3 P<.01(A>N)

NE 2.4 1.8 1.5 P<.01

Serotonin 6.0 4.4 3.7 P<.01

Substance P 52.9 18 13.8 P<.01

CGRP 46.7 16.1 12.1 P<.01

TNF-α 45.5 17.1 8.6 P<.01

IL-1β 44.8 23.1 8.5 P<.01

IL-6 39.6 14.9 9.5 P<.01

IL-8 21.5 10.5 5.5 P<.01

Concentrations of Analytes at Initial Needle Insertion in Gastrocnemius Muscle

*Active >

Latent, Normal (except pH)

Active

Latent

NormalActive group

I = SEE

(Normal Muscle)

Active

Latent

Normal

I = SEE

(Normal Muscle)

Active group

I = SEEActive

(Normal Muscle)

Active grou

ActiveI = SEE

(Normal Muscle)

Active group

I = SEE

Active

e

(Normal Muscle)

Active group

e

I = SEE

Active Active group

(Normal Muscle)

• An active MTrP has a unique biochemical milieu of substances known to be associated with pain states and inflammation

• The biochemical milieu of an active MTrP in the upper trapezius differs quantitatively from a remote, uninvolved site in the gastrocnemius muscle.

Second Phase: What We’ve Learned

• Subjects with an active MTrP in the upper trapezius have elevated levels of these analytes in a remote, uninvolved muscle compared to latent and normal subjects. This suggests that substances associated with pain are not limited to local areas of MTrPs or a single anatomical locus.

• In the trapezius, the concentration of specific analytes dramatically changes in response to initial needle insertion and also following a local twitch response, particularly in active MTrPs

Second Phase: What We’ve Learned

Shah JP, Danoff JV, Desai MJ, Parikh S, Nakamura LY, Phillips TM, Gerber LH. Biochemicals assoicated with pain and inflammation are elevated in sites near to and

remote from active myofascial trigger points. Archives of Physical Medicine & Rehabilitation 2008 Jan;89(1):16-23

Biochemical Considerations

H+

“Pro-inflammatory cytokines increase the sensitivity of all

peripheral neural structures and their afferent cell bodies, causing

hyperalgesia and the development of neuropathic pain

states”Cytokines and Pain. Watkins

and Maier, eds. 2000

Hypernociceptive role of cytokines and chemokines:

Targets for analgesic drug development?

Verri WA, Cunha TM, Parada CA et alPharmacology and Therapeutics 2006

TNF-α, IL-1β,

IL-6 and IL-8 were among the first cytokines described as participating in the development of

inflammatory and neuropathic pain

Cg, LPS or Ag

Nociceptor Sensitization

IL-1β

↔IL-6

Cytokine Cascade and Pain

TNF-α

Prostaglandins

IL-8 ↔CINC-1

Sympathetic amines

Ag

IL-18 ↔ IL-12

ET-1

Verri WA et. alPharmacology and Therapeutics 2006

Cox enzyme β-Blocker

50-μm laser-drilled hole for embedding hydrogel

Second Generation Needle with Hydrogel

First Generation Microdialysis Needle

Moving Ahead: Microanalytic Systems for in-vivo Measurement of the Biochemical Milieu of Muscle

Shah et al. J. Appl. Physiol. 2005 99:1977-94

30-gauge needle~0.5 μL sample

The Next Phase: A Natural History Study

• Does the biochemical milieu at and around the MTrP change with respect to the natural history of myofascial pain in the upper trapezius?

• Does the biochemical milieu of the upper trapezius correlate with changes in the severity of pain, presence or absence of physical findings or degree of local tenderness over time?

• What are the levels of anti-inflammatory substances (e.g., IL-4, IL-10), neurotrophins (e.g., NGF, NT-3), analgesic substances (e.g., β-endorphin) and substances associated with muscle metabolism and physiology (e.g., creatine kinase, aldolase, ACh esterase, etc.)?

Treatment TrialsAssess the local biochemical milieu of MTrPs as an outcome measure

of efficacy in clinical treatment trials utilizing

pharmacologic and physical medicine approaches

A New Direction

To Address an Old Controversy

Obstacles

•

There are currently no imaging criteria for the diagnosis of trigger points or for assessing clinical outcome of treatments.

•

It remains a clinical diagnosis based exclusively on history and physical examination.

Our Research Question

In the long term, we want to understand the pathophysiology of myofascial pain and develop

clinical outcome measures.

Can ultrasound imaging be used to develop objective descriptions of the tissue and blood flow characteristics of

myofascial trigger points (MTrPs) and the immediately adjacent structures?

Hypoechoiec trigger point

3 cm

Fascia

Uppertrapezius

Upper Trapezius Muscle with MTrP

Vibration Sonoelastography

30 kPa

63 kPa 44 kPa

Vibration Applicator

Hypoechoeic trigger 

point 

Focal decrease of color 

variance indicates a 

localized stiffer region 

upper trapezius

Vibration Sonoelastography of Muscle with MTrP

Uniform echogenecity in 

uninvolved muscle 

Uniform color  variance 

indicates homogeneous  

stiffness

upper trapezius

Vibration Sonoelastography of Uninvolved Muscle

Vibration Sonoelastography of Uninvolved Muscle

Sonoelastography Imaging

Objective diagnostic test

Outcome measure to evaluate tissue changes in response to treatment

Describe natural history

Sikdar et al. Arch. Phys. Me Rehabil., 2009 (in press)

Imaging blood flow near MTrPs in the Upper Trapezius

B BFS=1

A BFS=0

BFS=2D

BFS=2C

• Ultrasound is feasible for imaging MTrPs

• MTrPs exhibit different echogenecity compared to surrounding muscle.

• Vibration sonoelastography shows differences in relative stiffness between trigger points and normal (uninvolved) muscle. Sikdar et al. Assessment of Myofascial Trigger Points (MTrPs): A

New Application of Ultrasound Imaging and Vibration Sonoelastography. Conf Proc. IEEE Eng Med Biol Soc. 2008

Observations

Observations•

Blood flow waveform characteristics can be used to differentiate Active and Latent MTrPs

•

Retrograde flow in diastole indicating a very high resistance vascular bed and possible blood vessel compression is associated with Active MTrPs Sikdar S, Shah JP, Gebreab T, Yen R, Gilliams E, Danoff J, Gerber L. Novel Applications of Ultrasound Technology to Visualize and Characterize Myofascial Trigger Point and Surrounding Soft Tissue. Archives of Physical Medicine and Rehabilitation. In press. 2009

XXInflamatory

Mediators, BK,NE, SP,

Serotonin, Cytokines

Integrated

Neuromuscular

Theory

Courtesy Bryan O’Neill

Injection Therapies

What?Where? Why?