Download De Lisa Lecture Series

PM& R Lecture Series
Therapeutic Physical Agents
Physical Medicine

the application of physical agents such
as:





heat
cold
sound
water
electricity and other mechanical agents
in the treatment of disease.
Therapeutic Heat
Physiologic Effects:


Increase of 3oC increases collagenase
activity



Heating hands to 450C reduces MCPJ stiffness
by 20%
Changes of 5-7oC alter blood flow and
collagen extensibility
Hot paraffin increases local skin temp by
7.5oC and intraarticular temp by 1.7oC
Therapeutic Heat
HEAT
Inc. in temperature
Analgesia
(heat serv es as counterirritant to pain on nerv es)
Sedation
Muscle Relaxation
(dec firing of -spindle
fiber)
inc. in metabolism
(due to heat-produced
metabolites like histamine)
arteriolar dilatation
inc. in capillary flow
clearing of
heat & metabolism
supply of O2,
nutrients,
leukocytes
inc. in capillary pressure
edema
(why heat not applied
immediately after
traumatic injury)
Therapeutic Heat
Indications





relief of pain
relief of spasm
increased exetensibility of collagen tissue (e.g.
fractures/contractures)
decreased joint stiffness (OA, RA)
increased blood flow
* remember, the physiologic effects of heat manifest
themselves only if the heat is applied for at least
twenty minutes at a temperature of 40-45o C.
General Indications







Pain
Muscle spasm
Contracture
Tension myalgia
Production of
hyperemia
Acceleration of
metabolic process
Hematoma resolution







Bursitis
Tenosynovitis
Fibrositis
Fibromyalgia
Superficial
thrombophlebitis
Induction of reflex
vasodilatation
Collagen vascular
disease
General Contraindications






Acute inflammation,
trauma or hemorrhage
Bleeding disorders
Cutaneous insensitivity
Inability to
communicate or
respond to pain
Poor thermal regulation
Malignancy






Edema
Ischemia
Atrophic skin
Scar tissue
Unstable angina or
blood pressure
Decompensated heart
failure within 6 to 8
weeks of an MI
mode of transfer
heating modality
depth of
penetration
1. conduction (by
direct contact)
hot packs
paraffin
superficial
2. convection (via a
medium in motion
such as air, water)
hydrotherapy
fluidotherapy
superficial (reaches
skin and muscle)
3. conversion (actual
conversion of a
different form of
energy to heat)
shortwave diathermy
microwave
ultrasound
reaches area of
ligaments, tendons,
osseous structures
Hot Moist Packs






applied at a temperature of
46oC
stays warm for twenty
minutes or more
inc blood flow by as much
as 68%
sacks filled with silica gel
(expensive)
blood flow doesn’t return to
resting level until 40 mins.
after cessation
for analgesia and muscle
relaxation
Paraffin Wax Bath




applied at a temperature of 4554oC
solution contains 1 part mineral
oil (useful for those whose skin
had undergone trophic changes)
to 7 parts paraffin (can be
tolerated by px with sensory
deficits)
higher temperature is tolerable
without the risk of burns (due to
high specific heat of paraffin)
commonly used on the hand and
wrist and other uneven surfaces
Paraffin Wax Bath

Dipping technique






Immerse part 6-10 times to build
up layers of paraffin
Followed by wrapping extremity
with an insulating cover
Skin temp achieved: 47oC
Subcutaneous temp change of
3oC
Intraarticular temp change of
around 1oC
Continuous immersion



Dipped 6-10 times, then kept
immersed for 20-30 mins
Subcutaneous temp change of
50 C
Intraarticular temp change of 3oC
Infrared Radiation







Uses that portion of the EMS from
7700-150000 A
Maximum penetration of 3mm
(superficial)
Dry heat (less comfortable)
Commonly used to decrease skin
resistance by inc. blood flow (e.g. in
Bell’s palsy)
Wound healing and other
dermatological conditions (dries up
wound but has no other effects
unlike UV light)
Heat inversely proportional to
distance and angle of delivery
Usual distance about 40-50 cm and
perpendicular to surface treated
Hydrotherapy





applied at a temperature of
33-43oC
full body immersion can
increase core temp by 0.3oC
heat and exercise can be
done at the same time
bouyancy effect permits
easier movement of weak or
painful extremities
agitation of medium permits
gentle debridement (e.g. for
burns)
Fluidotherapy


Convection
heating modality
Uses cellulose
particles
suspended in jets
of warm air
Contrast Bath







One bath at 38 to 40oC
The other bath at 13 to 16oC
Produces reflex hyperemia and
neurologic desentisization
Initial soaking in warm bath for 10
mins
Followed by 4 cycles of alternate 1 to
4 minute cold soaks and 4-6 minute
warm soak
Ends with cold soak to minimize
edema
Used in treatment of CRPS type I
(RSD)
Ultrasound Diathermy




involves conversion of sound
waves at a frequency faster
than 17000-20000 cycles/sec
applied to tissues causing
mechanical vibration which
dissipates heat
deepest penetrating agent;
only agent that can
significantly heat the hip jt.
(by 8-10oC)
both thermal and nonthermal
effects
Ultrasound Diathermy

Nonthermal effects

Cavitation


Streaming


US travelling through liquid
produces bubbles which
oscillate in size
Produces shear forces in
tissue that may accelerate
metabolic processes
Standing waves

Produces areas of
alternating high and low
pressure
Ultrasound Diathermy

Penetration
dependent upon:



Type of tissue
Frequency (usually 1
or 3 MHz)
Angle of orientation
Ultrasound Half Value Depth in
Millimeters
Medium
1MHz
3MHz
Adipose tissue
50.0
16.5
Skeletal muscle (fibers
parallel to sound beam)
24.6
8.0
6.2
2.0
11.1
4.0
Skeletal muscle (fibers
perpendicular to sound
beam)
9.0
3.0
Cartilage
6.0
2.0
Compact bone
2.1
_
Tendon
Skin
Kitchen and Bazin(1996) Clayton’s Electrotherapy 10th ed.
Ultrasound Diathermy

Indications





Musculoskeletal conditions
(tendinitis, arthritis,
patellofemoral pain)
Contractures
Wounds and inflammation
Trauma (subacute phase)
Fractures
Ultrasound Diathermy

Contraindications







Fluid filled cavities (eyes,
gravid uterus)
Spinal cord, esp laminectomy
sites
Immature bone (e.g. children)
Heart, brain, cervical ganglia
Metal implants
Methylmethacrylate implants
(plastics, bone cement)
Acute inflammation
Injury
General Musculoskeletal
Disorders:
Muscle spasm
Joint stiffness
Pain
Tissue Repair:
Soft tissue repair
Stimulation of blood flow
Bone fracture repair
Tendon repair
THERMAL EFFECT
NON-THERMAL
EFFECT
CONTINUOUS WAVE
PULSED WAVE
Shortwave diathermy





involves conversion of
radiofrequency EM current into
heat energy
commonly uses 27.12 Mhz
uses condenser pads, plates and
internal metal electrodes for heat
transfer (not very convenient)
penetration between skin and
subcutaneous tissue
Can heat larger areas than
ultrasound
Shortwave diathermy

Inductive applicators



Capacitively coupled applicators



Generate magnetic eddy currents in
tissue
Highest temperature in water rich,
highly conductive tissue (e.g.
muscle)
Generate electrical fields
Highest temperature in water poor
tissue like fat, ligament, tendon or
joint capsules
May be pulsed or continuous
Microwave diathermy



Uses 915 and 2456
MHz
Does not penetrate as
deeply as SWD or US
Highest temperatures
are achieved at the fatmuscle interface
Therapeutic Cold

Decreases collagenase activity


Cooling hands to 180C increases MCPJ
stiffness by 20%
Icing an acutely inflamed knee


Decreases skin temp by 160 C
Decreases intraarticular temp by 5-60 C
Therapeutic Cold
COLD
anaesthesia
decrease in metabolism
relaxation
(dec firing of -spindle
fibers)
vasoconstriction
(first 5-15 mins)
reflex vasodilatation
(after 30 mins)
* cold can also stimulate a-motor neurons and cause muscles to contract
rather than relax
General Indications

Acute musculoskeletal trauma







Edema
Hemorrhage
Analgesia
Pain
Spasticity
Adjunct in muscle reeducation
Reduction of local and systemic metabolic
activity
General Contraindications








Ischemia
Cold intolerance
Raynaud’s phenomenon or disease
Severe cold pressor responses
Cold allergy
Inability to communicate or respond
to pain
Poor thermal regulation
Cutaneous insensitivity
Therapeutic Cold

Modalities





ice packs
cryogel packs
ice immersion
ice cube
ethyl chloride spray
Electrotherapy
Transcutaneous Electrical Nerve
Stimulation (TENS)
 two theories:

gate control theory:



electrical stimulus carried through large a-fibers
which arrive at the substantia gelatinosa before
the pain impulses traveling through the c-fibers.
treatment is effective only during application.
endorphin stimulation:


TENS stimulates production of natural analgesics.
Treatment is effective even after cessation.
Electrotherapy

high frequency, low
intensity


stimulates large diameter
afferent fibers
Low frequency, high
intensity

endorphin stimulation
Other Modalities

Low power laser



Not a heating modality
Stimulates collagen
production, alters DNA
synthesis, improves
function of damaged
nerves
FDA approved for CTS,
neck, and shoulder pain
Other Modalities

UV light







no heating function
uses part of EMS between 18002900 angstroms
dose is determined by testing called
Minimum Erythemal Dose (MED);
erythema should appear w/in 30
mins- 1 hr and disappear after 24
hrs.
penetration does not exceed 0.1 mm
bactericidal (helps wound healing)
anti-rachitic (vit. D formation
Anti-psoriatic
Thank you!