Transcript This Session by Simon Strauss

This Session by Simon Strauss
• Myofascial Pain. Part A
• Myofascial Pain. Part B
• Pain Assessment Tools. Part C
Definitions and Language
of Pain
Allodynia- 1. A lower than normal pain threshold.
2. A clinical situation where pain results from a
stimulus which should normally be painless.
3. Pain upon palpation at less than 4kg/cm2 or
less at a site, which does not cause pain at the
same anatomic site in normal individuals.
Dysesthesia- Unpleasant sensations ranging from numbness
to ‘pins and needles’.
Definitions and Language
of Pain
Hyperalgesia: A greater than normal response to a
stimulus expected to cause pain in a
normal individual.
Fibromyalgia: Chronic widespread Allodynia.
Nociception: The neurochemical process by which pain
signals are transmitted from the periphery
to the CNS and perceived by the individual
Definitions and Language
of Myofascial Pain
Myofascial Trigger Points (MTrPs) :
May be active or latent
An active Myofascial trigger point
is a focus of hyper-irritability
in a muscle or its fascia
that causes the patient pain.
Definitions and Language
of Myofascial Pain
An active Myofascial trigger point
causes pain and tenderness at rest or with motion that
stretches or loads the muscle.
It prevents full lengthening of the muscle, as well as
fatigue and decreased strength.
Pressure on an active MTrP induces / reproduces some
of the patient’s pain complaint and is recognised by the
patient as being some or all of his or her pain.
Definitions and Language
of Myofascial Pain
A Latent Myofascial Trigger Point: does not cause
pain during normal activities.
It is locally tender, but causes pain only when palpated.
It also refers pain on pressure.
It can be associated with a weakened shortened more easily
fatigued muscle.
A Palpable / Taut Band: is a group of muscle fibres that
is associated with MTrPs and is identifiable by its rope-like
consistency.
Definitions and Language
of Myofascial Pain
Twitch response: a transient contraction of part of the
involved muscle in response to needling or ‘snapping
palpation’
Jump Sign: A general pain response of the patient, who
may wince, vocalise or ‘jump’ in response to pressure on a
MTrP.
Involved muscle: A muscle that contains one or more
MTrPs
Myofascial Pain Syndromes
Can be thought of
as Pain Syndromes
that are caused by and are
maintained by one or more active
Trigger Points and their associated
reflexes
Myofascial Pain Syndromes
The
Trigger Point
is the
Pain Generator
Myofascial Pain Syndromes Prevalence
Unselected and Control Groups
Danish study of 1504 people, aged 30 - 60, 37% of males
and 65% of females had localised myofascial pain.
100 male and 100 female airforce personnel (Av. Age 19)
45% of males and 54% females had focal neck muscle
tenderness ( latent trigger points).
269 female student nurses. 45% had TrPs in masseter,
35% had TrPs in trapezious.
28% had myofascial pain at the time of examination.
Myofascial Pain Syndromes Prevalence
Unselected and Control Groups
Lumbogluteal muscles: Assessment of
100 asymptomatic control subjects.
Revealed latent TrPs in
45% of Quadratus Lumborum,
41% of Gluteous Medius,
11% of Gluteous Minimus,
5% of Piriformis.
Myofascial Pain Syndromes Prevalence
Anecdotal evidence suggests that
Ballerinas, Swimmers, Runners and
indeed any group of athletes that uses a
group of muscles in a prolonged or
repeatedly forceful manner are likely to have
latent trigger points and therefore can be
“toppled” into a Myofascial pain state.
Myofascial Pain Syndromes Prevalence
Patient Groups
Community pain medical center.
96 Patients studied by a neurologist:
93% had at least part of their pain
caused by myofascial TrPs
and in
74% of the patients myofascial TrPs were considered to
be the primary source of Pain.
Myofascial Pain Syndromes Prevalence
Patient Groups
Comprehensive pain center
283 consecutive admissions to a comprehensive pain center:
The diagnosis made independently by a Neurosurgeon and a
Physiatrist based on physical examination as described by
Travell and Simons assigned a primary organic diagnosis of
myofascial pain in 85% of the cases.
Myofascial Pain Syndromes Prevalence
Percentage of Patients with another diagnosis who also
had Myofascial TrPs contributing to their pain problems
Diagnosis
Number
Myofascial
TrPs % with
Source
Cervicogenic
Headache
80
100%
Lin et al
Reflex
sympathetic
Dystrophy
84
82%
Lin et al
Fibromyalgia
19
100%
Finestone et al
Myofascial Trigger Points
Clinical Features
History of spontaneous pain associated
with acute overload or chronic overuse of
the muscle.
The mildest symptoms are caused by latent TrPs which
cause no pain but cause some degree of functional
disability.
More severe involvement results in pain related to the
position or movement of the muscle.
The most severe level involves pain at rest.
Myofascial Trigger Points
Clinical Features
Palpable Band.
A cord like band of fibres is present in the involved
muscle.
INJURY
This can be difficult to identify when there are overlying
muscles or thick subcutaneous tissue.
Myofascial Trigger Points
Clinical Features
Spot Tenderness
A very tender small spot which is found in a Taut
Band.
The sensitivity of this spot (TrPs) can be increased by
increasing the tension on the muscle fibres of the taut
band.
Myofascial Trigger Points
Clinical Features
Jump Sign
Pressure on the tender spot causes the patient to
physically react to the precipitated pain by exclaiming or
moving.
Ah-Shi - Oh yes!
This reaction indicates the level of tenderness but is
also dependent on the pressure exerted by the examiner.
Myofascial Trigger Points
Clinical Features
Pain Recognition
Digital pressure on or needling of the tender spot
induces / reproduces some of the patient’s pain
complaint and is recognised by the patient as being
some or all of his or her pain.
Ah-Shi - Oh yes!
This finding by definition identifies an active trigger point.
This replication of the patient’s pain may require
sustained pressure (5 - 60 seconds) on the TrP.
Myofascial Trigger Points
Clinical Features
Twitch Response
Is a transient contraction of the muscle fibres of the
taut band containing the trigger point.
The twitch response can be elicited by “snapping”
palpation of the trigger point.
Or more commonly by precise needling of the trigger
point.
Myofascial Trigger Points
Clinical Features
Elicited referred pain and or tenderness
An active MTrP refers pain in a pattern characteristic of
that muscle -Usually to a site distant to the TrP.
85% of TrPs project distally.
[The area of the referred pain is often tender and may
contain satellite trigger points.]
Latent TrPs also refer pain on pressure but usually require
more pressure to do so.
Myofascial Trigger Points
Clinical Features
Restricted Range of Movement.
Full stretching of the affected muscle is often involuntarily
restricted by pain.
Inactivation of the associated MTrP releases the taut band
that is (? reflexly) restricting the muscle.
Myofascial Trigger Points
Clinical Features
Muscle Weakness
The patient is unable to demonstrate normal muscle
strength on static testing of the affected side as compared to
the contra-lateral non-affected side.
The involved muscle is also more easily fatigued.
Myofascial Trigger Points
Postulated Explanations of Clinical Features
Clinical Feature
Possible Explanation
Palpable Band
Continuos abnormal release of Calcium
from sarcoplasmic reticulum
Spot Tenderness
Sensitisation of nociceptors in vicinity of
motor endplate
Jump Sign
Severity of Trigger Point tenderness
Pain Recognition
Aggravation of the Trigger point
Twitch Response
Spinal reflex activation of motor units
Referred Pain and Tenderness
Excitation of ‘sleeping nociceptors’
Restricted Range of Movement
Increase release of acetylcholine in
neuromuscular junctions due to
mechanical stress with related increase of
sensitising substances
Muscle Weakness
Reflex inhibition of involved muscle
Myofascial Trigger Points
Pathogenic Factors
Acute overload
Overwork - Fatigue (Including postural stress)
Chilling
Gross Trauma
Other Trigger Points
Emotional distress
Joint or nerve damage
Visceral disturbance
Chart outlining the natural course of
Myofascial pain caused by Trigger Points
Pathogenic
Factors
Taut Band
Latent TrPs
STRESS
Active TrPs
Spontaneous
Recovery
Persistence
without
progression
Perpetuating
Factors
Additional TrPs
& Chronicity