TRIGGER POINTS

The Evidence

Peter Brukner

Sports Physician

Melbourne, Australia

OUTLINE

• Definition

• Diagnosis

• Theories

• Treatment

– Vapocoolant spray

– Injections

– Dry needling

Historical perspective

• 1938 - Kellgren identified referred pain from points in muscle

• 1938 – Gutstein (Good)

• 1941 – Kelly (Australia)

• 1940s onwards – Janet Travell

• Travell & Rinzler (1951)

• Travell & Simons (1983)

• Smythe & Moldofsky (1965, 1977) – Fibrositis syndrome

• Fibromyalgia – Yunus et al, 1981

– Wolfe et al, 1990

DEFINITION

Presence of exquisite tenderness at a nodule in a

palpable taut band. …..if the patient recognises the

pain elicited by digital pressure on (or needle

penetration of) the trigger point, the trigger point is

clinically active, not just latent.

(Travell & Simons 1983)

What are trigger points?

• Localised areas of deep tenderness and

increased resistance within a tight band

of muscle

• Local Twitch Response or “Jump sign”

in response to pressure

• Some positional similarities to

acupuncture points for the relief of pain

SYMPTOMS

Active vs latent trigger points

Local or referred

Muscle dysfunction that may perpetuate the

phenomenon

Active vs Latent Trigger Points

• Latent points cause increased muscle

tension and shortening only

• Active points present with pain that is

reproducible with pressure +/- referred

symptoms

• Latent points may be activated by a

number of influences

Active vs Latent Trigger Points

ACTIVE LATENT

Local tenderness + +

Taut band + -

Local twitch response + -

Referred pain + -

ACTIVE TRIGGER

POINTS

Responsible for presenting complaint

PAIN

Weakness/ parasthesia/ temperature changes

+/- referred sensations

+/- satellite trigger points

LATENT TRIGGER

POINTS

Present with muscle shortening or restriction

Pain occurs on application of external pressure

May become activated by a variety of stimuli

Distal Effects of Trigger Points

• Satellite trigger points

• Muscle spasm - agonist, antagonist or

distal

• Muscle inhibition

• Sensory symptoms

• Autonomic changes

TP development

Thought to develop after:

• Unaccustomed eccentric and concentric

loading

• Low-load repetitive tasks

• Sustained postures

• Respiratory stress such as over-breathing

• In association with visceral pain and

dysfunction

POSSIBLE PRECIPITANTS

Perpetuating factors

Stress

Overuse

Poor postural control/ core stability

EXAMINATION

FINDINGS

Local tender spot within tight muscle

band

Reproduction of the patient’s

symptoms

Local twitch response to snapping

palpation or dry needling

EXAMINATION

RELIABILITY

Inter and intra rater assessment by palpation

unreliable (Lew et al 1997)

4 clinicians could reliably identify TP’s after

training extensively together (Sciotti et al 2001)

Unreliable in untrained, marginally reliable after

training (Hsieh et al 2000)

Local twitch response least reliable feature

(Gerwin et al 1997)

Presence of taut band, tenderness, jump sign highly

reliable in r.c. tendinitis (Al-Shenqiti & Oldham, 2005)

MYOFASCIAL PAIN

SYNDROMES

Pain or autonomic phenomena

referred from active TrPs with

associated dysfunction

Probably fit under CRPS type II

criteria

•Trigger points

•Generalised hyperalgesia

•Psychological disturbance

MYOFASCIAL PAIN SYNDROMES

Presentations

Regional muscle disturbance

Generalised muscle pain

+/- inciting factor

(Injury/overuse/joint disease)

Defined by presence of tender points

and trigger points

Pain

MYOFASCIAL PAIN SYNDROMES

Psychological Impact

Unsure if part of the pathology or secondary

to the chronic pain state.

Some indication that treating chronic pain

improves psychological state (Bogduk 2000)

Disturbance can impact a patient’s

interpretation of pain and the response to

treatment

PATHOLOGY

There is no gold standard

pathological test for the

identification of trigger points

PATHOLOGY

Histology

Most studies negative

(Yunus et al 1986, Russell et al 1992)

Non specific fibrosis and absence of

inflammatory cells have been noted

PATHOLOGY

EMG

SPONTANEOUS ELECTRICAL ACTIVITY

(SEA)

Low amplitude background noise

Superimposed high amplitude spike activity

PATHOLOGY

EMG

Examples of spontaneous electrical

activity

Reproduced from Simons et al

PATHOLOGY

EMG

Said to represent motor end plate noise (EPN)

(Travell & Simons 1983)

May reflect stimulation of intrafusal muscle fibres (Hubbard et al 1993)

Endplate noise characteristic of, but not restricted to,

the region of a MTrP (Simons 2002)

Irritability of an MTrP highly correlated with

prevalence of EPN in upper trap muscle (Kuan et al, 2007)

PATHOLOGY

EMG

Noise may represent excessive ACH release at

nerve terminals

Spikes are said to be pathological, but are likely

to represent the response of muscle to needle

stimulation (ie physiological).

BIOCHEMISTRY

No theory has been conclusively proven.

BIOCHEMISTRY

Higher concentrations of protons, bradykinin,

calcitonin gene-related peptide, substance P, tumor

necrosis factor-alpha, interleukin-1 beta, serotonin

and noradrenaline in active TrP, lower pH.

Shah et al, 2005

Increased 5-HT and glutamate, increased anaerobic

metabolism in TrP

Rosendal et al, 2004

BIOCHEMISTRY

Muscle contraction

Trigger points - ? Primarily muscle or neurologic

phenomenon

Basic understanding of muscle contraction required to

understand popular theories of formation

BIOCHEMISTRY

Muscle contraction

IMAGING

We have no reliable method of imaging trigger

points to date

IMAGING

Thermography

Can We See Them?

Thermography

Technique of detecting heat emission from the body

Thought that it may be increased over trigger points

Blinded trials showed no significant difference in

reliability compared with controls (Diakow, 1992 Swerdlow & Dieter 1992)

Probably just measuring skin blood flow

IMAGING

Thermography

Hot spots do not necessarily correspond to trigger

points

No difference in imaging findings patients vs

controls (Swerdlow et al 1992, Diakow, 1992)

NOT VALID

Can We See Them?

Ultrasound

One study

Experienced operator unable to determine any

difference between trigger points and control points (Lewis et al 1999)

IMAGING

31P NMR

Early research indicated some promise, but has not

been followed up. (Kushmerick 1989, Mather 1988)

Based on detecting the different forms of phosphate

(energy compounds) in the muscle, thus giving an

idea of the metabolic status of the muscle.

No clear indication of changes expected in

myofascial pain.

Can We See Them?

MRI

????

IMAGING

MRI

No data to date.

Pilot investigation revealed no imaging evidence of

changes in the region of clinically detected trigger

points.

(unpublished data)

ACUPUNCTURE

Traditional

Chinese Medicine

has many

similarities with

trigger points and

the therapies used

today

ACUPUNCTURE

Acupuncture & trigger points

71% correlation between trigger point locations

and acupuncture points described for the relief

of pain

(Melzack 1977)

TRIGGER POINT THERAPY

Non-Invasive

Spray and stretch, TENS,

ultrasound, laser, iontophoresis

Invasive

Injection, dry needling

Vapocoolant spray

• Travell & Simons (1992) • “Single most effective non-invasive method”

• Jaegar and Reeves (1986) • Improved pain threshold (p<0.01)

• Improved VAS (p<0.004)

• No correlation between the two

Vapocoolant spray

• Originally ethyl chloride spray

• Alternatively …..

• Dichlorodifluoromethane-trichloromono-

fluoromethane (Fluori-Methane)

Massage

Massage Techniques

• Ischemic compression therapy (Trapezius)

effective for immediate pain relief

• Combination with hot pack plus active ROM

and stretch with spray, hot pack with active

ROM and stretch with spray and TENS or

interferential current are most effective for

easing MTrP pain and increasing cervical

ROM Hou et al, 2002

TRANSCUTANEOUS

ELECTRICAL NERVE

STIMULATION (TENS)

• TENS vs placebo (Graff Redford, 1989)

– No change with low frequency TENS

– High frequency (100Hz) reduced pain

without change in pressure threshold

(p<0.05)

– Postulated for pain relief only

TENS

Hsueh (1997)

– ENS (60Hz) – 57% improvement in pain intensity

– 46% pain threshold

– 15% ROM

– EMS – 15% pain intensity and threshold

– 83% ROM

– p<0.05

Ultrasound

Gam (1998) » massage, exercise, U/S

» massage, exercise

» no intervention

• Reduction in number and sensitivity of

tp’s in intervention groups (p<0.05)

• No change in VAS

Laser • Thorsen (1992)

– LLLT not different from placebo on functional or resting VAS (6 treatments)

– 43% reported subjective benefits of placebo, 17% of laser

• Cecchereli (1989)

– Diode laser reduced pain (p<0.001)

– Significant only at sessions 7,10,11,12 and at 3 months

• Hakguder et al (2003)

– LLLT beneficial for pain in MPS

Botulinum Toxin A

Systematic review (Ho & Tan, 2006)

• effective in one trial

• not effective in four trials

Kuan et al (2002)

• Suppressed EPN in MTrP of rabbit

skeletal muscle

Local Anaesthetic Injection

• Frost (1980)

– Saline better than mepivicaine

• Hameroff (1981)

– Bupivacaine vs etidocaine vs saline

– At 24 hours, LA better (p<0.05)

– 7 days, average pain better (p<0.005)

– Some extra benefits from etidocaine, but

most parameters not significantly different

Local Anaesthetic Injection

• Frost (1986) single blinded trial

comparing lidocaine with diclofenac.

– Non significant trend to better results on

VAS with NSAID over 5 hour follow up

– Became significant only at 3 hours

(p<0.05)

• May indicate significant inflammatory

contribution

Local Anaesthetic Injection

• Carlson (1993)

– 2% lidocaine reduced pain and EMG

activity. (p<0.001)

– No correlation between the two.

Local Anaesthetic Injection

• Fine (1988) - naloxone vs placebo in

reversing effects of local anaesthetics • return of pain (VAS) from 5 minutes (p<0.002)

• relapse in ROM from 30 minutes (p<0.05)

• May explain prolonged analgesic effects

• However • small numbers - 10 patients

• unusually high analgesic effect

Dry needling

Deep or Superficial

Dry Needling

Lewit (1979) - described the “needle

effect” - immediate complete analgesia

Case report - needle effect seen in 271

of 312 structures

All but 43 had some improvement

Dry Needling

Unilateral needle stimulation to active

MTrP resulted in bilateral EMG activity

Audette et al, 2004

Dry Needling

Deep needling to MTrPs more effective in

treatment of LBP than standard acupuncture or

superficial needling

(Itoh et al, 2004)

Trigger point acupuncture greater short term

effects on LBP than sham acupuncture

(Itoh et al, 2006)

DN versus LA Injection

• Hong (1994)

– No significant difference in immediate

response LA vs DN (100% if LTR seen)

(p<0.05)

– LTR’s needed for optimal effect (p<0.05)

– Effect fades over time

– Post injection soreness worse and

prolonged with DN - 100% vs 42%, 1.5 vs

5 days (p<0.05)

Our Research

Common myofascial

syndromes

Headache

Number of studies shown presence of TrPs in headache and

migraine patients

Calandre et al, 2006

Couppe et al, 2007

Fernandez-de-Las-Penas, 2005, 2006

Headache

Upper arm/shoulder pain

Neck-shoulder pain

trapezius TrPs (Ge 2006, Al-Shenqiti 2005, Voerman

2006)

Frozen shoulder

subscapularis (Jancovic, 2006)

Upper arm pain

Low back pain

TrP deep dry needling greater short term effects on LBP than

sham acupuncture or superficial needling

Itoh et al, 2004, 2006

Low back pain

Hamstring pain

REFERENCES

Simons DG, Travell JG, Simons LS. Travell

& Simons' Myofascial pain and dysfunction:

the trigger point manual. 2d ed. Baltimore:

Williams & Wilkins, 1999

Rachlin ES. Trigger points. In: Rachlin ES,

ed. Myofascial pain and fibromyalgia: trigger

point management. St. Louis: Mosby 1994

REFERENCES

Alvarez DJ, Rockwell PG Trigger Points:

Diagnosis and Management Am Fam

Physician. 2002;65(4):653-661

Domerholt J. Dry needling — peripheral and

central considerations J Man Manip Ther

2011;19(4):223–227

REFERENCES

Kietrys DM et al ―Effectiveness

of dry needling for upper-quarter myofascial

pain: A systematic review and meta-analysis,‖

J Orthop Sports Phys Ther 2013;43(9):620-

634.

Furlan A, Tulder M, Cherkin D, et al.

Acupuncture and dry-needling for low back

pain: an updated systematic review within the

framework of the Cochrane collaboration.

Spine 2005;30:944–63