"Theory & Concept – Physical Assistive Modalities - Indications - Contraindications" for Bachelor of Occupational Therapy Students

1. Theory &
Concept – PAM
Indications - Contraindications
Dr. Asir John Samuel, PhD (Physiotherapy), MPT (Neurosciences and Paediatric
Neurology), BPT, BSc (Psychology), DYScEd, MAcu,
Additional Professor,
Yenepoya Physiotherapy College
Yenepoya (Deemed to be University),
Mangalore, Karnataka

2. Pain modification
• Date back to era of Hippocrates
• Sarlandiere, described the use of electrical
stimulation of acupuncture points in 19th century
• Serendipitously reports reduced pain

3. Classification of nerve fibres
Type
of
fibre
Function Diameter
(μm)
Velocity
(m/sec)
A Somatic motor & sensory 2-20 12-120
Aα GTO, ms afferent with
annulospiral endings
12-20 80-120
Aβ ms with flower spray
endings, touch, pressure
5-12 30-80
Aγ Motor neuron to muscle
spindle
3-6 15-30
Aδ Pain, temp (cold), touch 2-5 12-30
B Autonomic fibres 1-3 3-15
C Unmyelinated pain fibres 0.3-1.1 0.5-2

4. Pre-synaptic inhibition
• Afferent stimulation
• Simple blocking of afferent impulses of
nociceptors
• Stimulation produced analgesia (SPA)
• Production and utilization of endogenous
opiates, such as endorphins and enkephalins

6. Descending pain suppression
• 1978, Basbaum and Fields, low rate, high
amplitude stimulation results in analgesia
• Activated ascending pathways leading to
awareness of pain
• Axons synapses within medullary reticular
formation nuclei then to periaqueductal gray
(PAG) region of midbrain and to thalamus

7. Descending pain supression

8. Descending pain suppression
• These regions possess high concentrations of
endogenous opiates
• When activated, facillate cells in nuceli raphe
magnus (NRM) in rostral ventromedial
medulla and reticularis gigantocellularis (RCG)
generates encephalin in substantia gelatinosa

9. Descending pain supression

10. Descending pain suppression
• Encephalin is a neurotransmitter, inhibits
transmission of C activity
• Short term sensory stimulation transiently
reduce the corticospinal excitability

12. Dangers and contraindications
• Damaged skin – lower impedance
• Cross-infection
• Pregnancy
• Tumours – not all
• Indwelling metal
• Transthoracic or neck or carotid sinus
- Arrhythmia and fibrillation

13. Dangers and contraindications
• Pacemaker
• Allergic response to the electrodes, gel or tape
• Over dermatological lesions
• Mental confusion
• Caffeine intake (3 cups/day or 200 mg/day)

14. Precautions
• Abnormal skin sensation
• Avoid active epiphyseal regions in children
• Electrodes should not be placed over the eyes
• LBA in pregnant women

15. Indications
• Rheumatoid arthritis
• Osteoarthritis
• Dysmenorrhea
• Labor and post labor pain
• Post-abdominal/thoracic surgery
• Low back pain

16. Indications
• Chronic pain syndromes resulting from various
disorders
• Various gynecological procedures
• Poststroke painful shoulder
• Poststroke spasticity
• Trigeminal neuralgia
• Myofascial pain
• Unstable angina pectoris

17. Superficial heat
• Superficial heat is the use of a thermogenic
agent which induces a temperature increase
• Subsequent physiologic changes to the
superficial layer(s) of the skin, fat, tissues,
blood vessels, muscles, nerves, tendons,
ligaments, and joints
• < 1 cm

18. Superficial heat modalities
• Hot packs
• Heating pads
• Paraffin bath
• Infrared
• Fluidotherapy
• Ultrasound

19. Hot packs

20. Hydrocollator packs with unit

21. Hydrocollator packs - application

22. Wax bath

24. Infra-red lamb

25. Whirlpool bath

26. Transfer method
• Conduction - transfer of heat between two
objects at different temperature (hot packs,
paraffin bath)
• Convection - transfer of heat by fluid
circulation (fluidotherapy)
• Conversion - changing of one energy form into
another (ultrasound)

27. Physiologic effects
• Thermal energy - provides pain relief, increase
in local blood flow, metabolism, and elasticity
of connective tissues
• Heat increases blood flow and subsequently
may induce edema and exacerbate acute
inflammation

28. Blow flow increase?
• Stimulates - cutaneous thermoreceptors that
are connected to the cutaneous blood vessels
• Releases of bradykinin which relaxes the
smooth muscle walls resulting in vasodilation

29. Indications
• Subacute to chronic conditions
• To reduce pain and muscle spasm
• To relax skeletal muscles
• Decrease joint stiffness

30. Contraindications
• Patients with peripheral vascular disease
• Bleeding disorders
• Local malignancy
• Acute inflammation or trauma
• Oedema
• Infection

31. Contraindications
• Open wounds
• Over large scars
• Patients with impaired sensation (neuropathy)
• Impaired ability to communicate (dysphasia)
• Cognitive impairments
• Dementia