The document discusses pain physiology and assessment. It defines pain and describes the fast and slow pain fiber pathways. It discusses gate control theory and different classifications of pain including nociceptive, inflammatory, and pathological pain. The document also covers parameters for understanding a patient's pain like intensity, duration, frequency, relieving/aggravating factors. It provides guidance on assessing characteristics of pain from different tissues.

1. PAIN PHYSIOLOGY AND
ASSESSMENT

2. • The International Association for the Study of
Pain's widely used definition states: "Pain is an
unpleasant sensory and emotional experience
associated with actual or potential tissue
damage, or described in terms of such
damage.
• In medical diagnosis, pain is a symptom.
• Pain is a subjective entity,and its
manifestaions are unique to each individual.
• Is a complex experience involving several
dimensions.

3. Properties of fast and slow pain fibres
Properties Fast pain Slow pain
RECEPTORS Free nerve endings Free nerve endings
AFFERENTS Grp. 3 fibres Grp.4 fibres
ACTION POTENTIAL 5-30m/s 0.5-2m/s
CONDUCTION VELOCITY Relatively slow Very slow
SUBJECTIVE SENSATION Sharp,pricking Dull burning
ONSET OF SENSATION Short latency,quick onset Long latency, slow onset
LOCALISATION Well localised Poorly localised
DURATION OF SENSATION Short Long
SUBJECTIVE RESPONSE Reflex withdrawal Possible emotional and
automatic response

5. • The 20th-century theory was gate control theory,
introduced by Ronald Melzack and Patrick Wall
in the 1965 Science article "Pain Mechanisms: A
New Theory" The authors proposed that both
thin (pain) and large diameter (touch, pressure,
vibration) nerve fibers carry information from
the site of injury to two destinations in the
dorsal horn of the spinal cord, and that the more
large fiber activity relative to thin fiber activity at
the inhibitory cell, the less pain is felt. Both
peripheral pattern theory and gate control
theory have been superseded by more modern
theories of pain

6. • In 1994, responding to the need for a
more useful system for describing
chronic pain, the International
Association for the Study of Pain (IASP)
classified pain according to specific
characteristics: (1) region of the body
involved (e.g. abdomen, lower limbs), (2)
system whose dysfunction may be
causing the pain (e.g., nervous,
gastrointestinal), (3) duration and
pattern of occurrence, (4) intensity and
time since onset, and (5) etiology.
However,

7. • this system has been criticized by Clifford J. Woolf
and others as inadequate for guiding research
and treatment.Woolf suggests three classes of
pain : (1) nociceptive pain, (2) inflammatory pain
which is associated with tissue damage and the
infiltration of immune cells, and (3) pathological
pain which is a disease state caused by damage to
the nervous system or by its abnormal function
(e.g. fibromyalgia, irritable bowel syndrome,
tension type headache, etc.).

8. PHYSIOLOGY FOR THE PAIN-
SPECIFIC PRESENTATIONS

9. • a | Nociceptive pain is physiological protective
pain involving activation of high-threshold
nociceptor neurons by noxious mechanical,
chemical or thermal stimuli. b | Inflammatory
pain is pain hypersensitivity involving detection of
active peripheral tissue inflammation by
nociceptors and sensitization of the nociceptive
system. c | Pathological pain is not adaptive, has
no protective function and can be divided into
two types: neuropathic and dysfunctional.

10. Neuropathic pain is a maladaptive plasticity due
to a lesion or disease that affects the
somatosensory system and alters nociceptive
signal processing so that responses to noxious
and innocuous stimuli are enhanced and pain is
felt in the absence of stimuli. Conversely,
dysfunctional pain is the result of nociceptive
signalling amplification in the absence of neural
lesions or inflammation.

14. The role of therapist for influencing
the inhibition of pain transmission

15. PAIN ASSESSMENT

16. Acute-often severe, continuous and perhaps
disabling.
Chronic-more aggravating and is not as
intense.

17. SYSTEMIC
Disturbs sleep
arthralgia,
arthralgia,fatigue,weight
loss,low grade
Deep aching or throbbing
Reduced by pressure
Constant or waves of pain and
spasms.
Associated
with:jaundice,migratory
arthralgia,fatigue,weight
loss,low grade fever,tumors
and infection.
MUSCULOSKELETAL
Generally lessens at night
Sharp or superficial ache
Usually decreases with
cessation of activity
continuous and intermittent
Aggravates by mechanical
stress.

18. Pain and its relation to severity of
repetitive stress activity
• Level 1:pain after specific activity
• Level 2:at start of the activity resolving the warm up
• Level 3:during and after specific activity that doesn’t
affects performance
• Level 4:during and after specific activity that does
affects perfomance
• Level 5:with ADLs
• Level6:constant dull aching pain at rest and doesn’t
disturbs sleep.
• Level7:highest level of severity

19. PARAMETERS TO LOOK FOR ,IN
UNDERSTANDING PATIENT`S PAIN
• Intensity
• Duration and
• Frequency
• Relieving aggravating factors
• What Time of the day
• Type or quality of pain

20. • Constant pain:chemical irritation,tumors or
possibly visceral lesions.
• Whether periodic or occasional;ask for what
activity,position or posture .
• Episodic pain:is related to specific activities.
• Morning stiffness with pain improves with
activity,indicating chronic inflammation.
• Pain at rest and pain that is worst at the beginning
of activity than at the end implies acute
inflammation.
• Pain ;not affected by rest/activity usually indicates
bone pain OR could be related to organic/systemic
disorders or diseases of viscera.

21. • pain and cramping with prolonged walking may indicate lumbar
canal stenosis[neurogenic intermittent claudication],vascular
probems[ vascular or circulatory interittent claudication].
• Iv disc pain-aggravates with forward bending and sitting.
• Facet joint pain-gets relieved by the above two and is aggravated
with extension and rotation.
• Type or quality of pain:
nerve pain-sharp[lancinating],bright and burning and tends to run in
the distribution of nerve fibres.
Bone pain-deep,and localised.
Visceral pain-diffuse,aching and poorly localized and may be referred
to other areas .
Muscle pain-hard to localize,dull and aching,aggravates with injury ay
get referred to other areas also.
Inert tisse such as ligaments,capsules,and bursa tends to be
intditinguishable from muscle pain.
Each of these above tissue pains sometimes grouped as neuropathic
pain.
Somatic pain:severe chronic or aching ,inconsistent with injury.
Radiating pain-usually is minimal in bone involvements,and is
increased; `on applying pressure to the nerve roots

22. Each of these above tissue pains sometimes
grouped as neuropathic pain.
Somatic pain:severe chronic or aching ,inconsistent
with injury.
Radiating pain-usually is minimal in bone
involvements,and is increased; `on applying
pressure to the nerve roots rs esults in
radiculopathy or radiating pain .pressure over
nerve trunks produces no pain but
parasthesia(pins and needles).
Autonomic pain-likely to be of a burning type.
Referred pain-nerve itself being a cause, lets brain
recognise pain coming from the periphery.

23. Assessment tools