Introduction to Physical Agents Flashcards
A method of applying energy, force, and
equipment or material to a patient’s body.
Physical Agents
Categories of Physical Agents
Thermal
Mechanical
Electromagnetic
An equipment/ material that could either increase or
decrease tissue temperature.
Thermal
A type of agent that can increase or decrease pressure on the body. It could either put pressure or reduce the pressure
MECHANICAL
A form of treatment that uses water as a form of
providing therapeutic effects or benefits to a
patient.
Hydrotherapy
Helps patients with ADHD vis treatment
with warm water, which helps the patient relax.
The cold water helps in reducing inflammation.
Thermal Conductivity
An upward thrust allowing the body to float in
water. We could maximize this force as
a form of treatment in rehabilitation. It
relieves pressure by decreasing the force of
our collective/body as it hits the ground. It produces
low-impact forces on certain joints in our
body. It facilitates weight-bearing activities.
Buoyant Force
The amount of weight an object/person; whether
it floats in water. (Density of water is 1, if greater than 1 it will sink, if less than 1 it will float)
Density
Form of pressure that is exerted all throughout
the body as it is immersed underwater.
The deeper the water, the greater the pressure being exerted on distal parts of the body. According to
Pascal’s Law. Decreased edema because HP can help
regulate blood circulation. Also helps in decreasing blood pooling in the lower extremities.
Hydrostatic Pressure
A force that separates certain joints or body
structure. Spinal decompression unit.
Traction
Approximates a particular joint or body structure.
Compression
An agent that uses radiation/rays or electric
current. Emits heat/energy.
Electromagnetic
● disease or injury
● Refers to the medical condition; alteration on the
anatomy or the function of the body leading to a
medical condition.
Pathology
Abnormality of structure or function
● Primary level of which physical agents have
direct effects
● Anatomical/Physiological loss.
Impairment
Restrictions in the ability to perform components
of daily life
Functional Limitation
Inability to perform typical activities of daily living.
Disability
A form of energy generated because of the two different temperatures; one is higher than the other, causing an energy.
Heat
Boiling point
Fahrenheit: 212 F
Celsius: 100 C
Kelvin: 373 K
Freezing point
Fahrenheit: 32 F
Celsius: 0 C
Kelvin: 273 K
The amount of heat an object can hold.
Heat Capacity
A principle that helps us understand the amount of
the heat that is being gained or lost in an object.
Heat Capacity
Amount of energy required to increase the
the temperature of a given material by a given number
of degrees
Specific Heat
Specific Heat of Various Materials
➔ Specific Heat of Various Materials
◆ Water 4.19 J/g/C
◆ Air 1.01 J/g/C
◆ Average Human Body 3.56 J/g/C
◆ Skin 3.77 J/g/C
◆ Muscle 3.75 J/g/C
◆ Fat 2.30 J/g/C
◆ Bone 1.59 J/g/C
True or False:
Heat energy always moves from HOT object →
COOLER object.
True
Sources of Heat
Chemical
Mechanical
Electrical Current
Thermal
Referring to something related to food metabolism.
- Fuel burning
Chemical
In relation to friction.
- Rub or shear forces to another object, it may
produce heat. Examples: Rubbing your hands
together
Mechanical
Through the use of electricity.
Electrical Current
The sun is a primary source of ________
Thermal heat
How heat is transferred from one object to another.
Energy Transfer:
a. Heat is transferred through a material by being
passed from one particle to the next.
Conduction
a. Takes place in a material where particles can
move around inside the material, i.e. liquid or gas
Convection
Heat transfer by movements of air or fluid from a
warmer area to a cooler area or moving past a
cooler body part
Convection
e. Heat transfers from a warmer object to a cooler
object through direct molecular interaction of
objects in physical contact.
Conduction
The rate of heat transfer depends on the
temperature difference between the two objects
Conduction
A transfer of heat directly from the source to the
object by a wave or by a ray or radiation.
Radiation
transfer of heat from a warmer object
to a cooler object through the transmission of
electromagnetic energy without heating an
intervening medium.
Radiation
It’s an absorption of energy as the result of the
conversion of a material from a liquid to a vapor.
b. Example: Vapocoolant sprays used in acute
injuries.
Evaporation
a. Temperature changes result when energy is
transformed from one form to another.
b. Example: Mech energy → Thermal energy
c. Modality: Therapeutic ultrasound
Conversion
Refers to the vessels; the arteries, veins, and capillaries.
Hemodynamic effects
When we apply heat to the patient locally, on
certain areas of the body, it could cause ____________.
Vasodilation
a. stimulated cutaneous thermoreceptors; causes
vasodilation of local/adjacent blood vessels
b. Increase local release of chemical mediators of inflammation
Reflex Vasodilation
True or False:
Vasodilation is the narrowing of the blood vessels
False: Widening
True or False:
Vasodilation causes an increase in blood flow to
the heated area.
True
Heating and increase in blood flow will increase
the capillary pressure and permeability of the
cells.
Increased fluid dynamics
Hemodynamic Effects includes
- Vasodilation
- Increased fluid dynamics
Elevation of muscle temperature by 42C has
been shown to result in:
○ Decreased firing rate of type II muscle
spindle and gamma efferent fibers
which reducing afferent firing from the
spindles
○ increased firing rate of type lb fibers
from GTO (Golgi Tendon Organ) that
leads to reflex inhibitory effect of the
respective muscle.
● Stimulation of Alpha motor neurons that allow muscular spasm and relaxation of muscle.
NCV increase by how much?
2m/sec for every 1 deg C (1.8deg F) increase in temperature
Neuromuscular effects include
A. Changes in nerve conduction velocity and firing
rate
B. Increased pain threshold
Refers to the free nerve ending pacinian corpuscles merkel’s disc, and meissners
Sensory Receptors
A-beta, C-fibers, and A-delta fibers.
Sensory fibers
Fibers responsible for pain
C and A Delta fibers
● responsible for pain;
● myelinated; allows saltatory
conduction which causes speeding up
of transmission (Hoping of impulses
because of nodes of ranvier).
● Transmission of pain is faster
● Referred to as acute pain. (Sharp type
of pain
A-delta fibers
● Also pain receptor.
● Unmyelinated; no saltatory conduction
kaya mas mabagal ang transmission of
impulses
● Referred to as chronic pain.
Manifestation of pain occurs at a later
time
C-fibers
● Medium-sized fiber that is myelinated.
● Not a pain receptor;
● Signals/Sensation: tapping, rubbing,
scratching, deep touch, temperature, or
pressure
A-beta fibers
Activation of ______ fibers leads to inhibition
of pain receptors. (Application of heat)
A-beta fibers
Activation of spinal gating mechanism through stimulation of free nerve ending (A-beta/Free nerve ending) leads to blocking the transmission of pain at the level of the spinal cord.
Direct Mechanism
Heat leads to vasodilation and increased blood flow resulting in reducing pain through which what mechanism?
Indirect mechanism
Change in the firing rate of type II fibers,
gamma efferent and Ib fibers from Golgi’s tendon
organ.
Change in muscle strength
Metabolic effects includes:
Increase Metabolic rate
True or False:
The older the patient, the longer the heating
time. The younger the patient is, the shorter the
heating time.
True
True or False:
10 - 15 mins is already sufficient to produce
tissue extensibility to younger individuals, but to
older patients, it must reach 30 mins.
True
SYSTEMIC EFFECTS includes:
Generalized skin vasodilatation
Generalized sweating
Increase pulse rate
Increase respiratory rate
Decrease blood pressure
Therapeutic effects of heat
A. Pain control
B. Increase range of motion and decrease joint
stiffness
C. Accelerate healing
General indications of thermal agents
➔ Subacute and chronic pain
➔ Subacute and chronic inflammation
➔ Subacute and chronic infection
➔ Tissue healing
➔ Muscle spasm
➔ Reduction of edema
➔ Prior to range of motion exercise
General contraindications of thermal agents
➔ Acute injuries ( sprain & strain)
➔ Acute inflammation
➔ Impaired circulation
➔ Impaired sensation
➔ Neoplasm
Factors Affecting These Physiological Effects
➔ Size of the heated area
➔ Depth of absorption of specific radiation
➔ Duration of heating
➔ Frequency of treatment
➔ Intensity of radiation
➔ Method of application
