Download hydrotherapy

King Saud University
Collage of Applied Medical Sciences
Rehabilitation Department
Hydrotherapy course
For level six
By
Dr. Afaf Ahmed Shaheen
2007-1428
Contents
Page
Introduction
-
Structure of the skin
Circulatory system of the skin
Types of sensation
Types of sensory receptors
Types of nerve fibers
Definition of hydrotherapy
Advantages of hydrotherapy
Therapeutic properties of water
- Physical properties
- Chemical properties
Physiological effects of hydrotherapy
-
General physiological effects
Physiological effects of heat
Physiological effects of cold
Indications,
Contraindications
hydrotherapy
Immersion Bathes
-
Hot bathes
Cold bathes
Neutral bathes
Contrast bathes
Whirlpool bathes
Hubbard tank
Paraffin bath
Douches
-
Jet douche
Scotch douche
Under water douche
Packs
-
Hot packs
Cold packs
Chemical packs
Cryotherapy
Hydrogymnastics
-
Examples of under water exercises
and
precautions
of
Objectives
Upon completion of this course the students should be able to:
1.
2.
3.
4.
Know what the meaning of hydrotherapy is.
Discuss the physical properties of water.
Identify the physiological effects of hydrotherapy.
Examine how the physical properties and physiological effects of
hydrotherapy can be used for muscloskeletal, support and
resistance, cardiovascular and respiratory training and
psychological benefits.
5. Assess the indications, contraindications and precaution of
hydrotherapy.
6. Choose and use the most appropriate hydrotherapy treatment
technique to have desired treatment goals.
Structure of the Skin
The skin is the largest human organ. It covers between 1.5 and 2
m2, comprising about 16% of total body weight. Distribution of skin
thickness varies for different body parts. It is 10 times as thick on the
palm of the hand as compared with other body areas.
The skin is the organ, which is of main concern in water applications
since it lies between the body and the environment. It shields the body
from the extremes of heat and cold and is able to protect the body from
injury because:
 It is waterproof, elastic, pliable & durable.
 It transmits stimuli to the central nervous system (C.N.S).
 It mirrors the general bodily functions and gives clues to the state
of the person's health.
 Normal skin feels stimuli quickly; it is clear feels elastic warm
and smooth.
 As the individual ages; the skin became atrophic and degenerative
changes occurs.
The skin performs a complex role in human physiology:

Serves as a barrier to the environment, and some glands
(sebaceous) may have weak anti-infective properties.

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Acts as a channel for communication to the outside world.
Protects us from water loss, friction wounds, and impact wounds.
Uses specialized pigment cells to protect us from ultraviolet rays of
the sun.
Produces vitamin D in the epidermal layer, when it is exposed to
the sun's rays.
Helps regulation of body temperature through sweat glands.
Provides sensory reception.
Helps regulation of metabolism.
Composition of the Skin:
The skin is composed of two main layers:
1 - The surface epithelium (the epidermis).
2- The subjacent connective tissue layer (the dermis).
1. The epidermal layers:
As the outermost skin layer, the epidermis forms the actual protective
covering against environmental influences. Its thickness averages 0.1
mm. On the face it is only 0.02 mm, while on the soles of the feet
between 1 and 5 mm. It is non-vascular& consists of epithelium cell.
The epidermis has several strata (layers) that contain four cell types:
 Keratinocytes produce keratin, a protein that gives skin its
strength and flexibility and waterproofs the skin surface.
 Melanocytes produce melanin, the dark pigment that gives skin its
color.
 Merkel's cells are probably involved with touch reception.
 Langerhans' cells help the immune system by processing antigens
(They engulf foreign material that invades the epidermis and
migrate out of the skin to stimulate an immune response).
2. The dermal layers:
The dermis, called "true skin", is the layer beneath the epidermis. It
contains living cells, a great density of blood vessels that are related to
both nutrition of the skin and to its thermoregulation. Its major parts are
collagen (a protein that adds strength), reticular fibers (thin protein
fibers that add support), and elastic fibers (a protein that adds flexibility).
Structure of the skin
The dermis has two layers: the papillary layer, which has loose
connective tissue, and the reticular layer, which has dense connective
tissue. These layers are so closely associated that they are difficult to
differentiate.
 The papillary layer lies directly beneath the epidermis and
connects to it via papillae (finger-like projections). Some papillae
contain capillaries that nourish the epidermis; others contain
Meissner's corpuscles, sensory touch receptors.
 The reticular layer contains criss-crossing collagen fibers that
form a strong elastic network. This network forms a pattern called
cleavage (Langer's) lines. It also contains Pacinian corpuscles,
sensory receptors for deep pressure, sweat glands, blood and lymph
vessels, smooth muscle, and hair follicles.
The hypodermis (subcutaneous layer):
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It lies beneath the dermis. Loose connective tissue which in many
places is transformed into subcutaneous adipose tissue.
It insulates the body, conserving heat.
The hypodermis is loosely connected to underlying deep fascia, or
periosteum.
It also contains blood vessels, lymph vessels, and the bases of hair
follicles and sweat glands.


The fat distribution in this layer gives the female form its
characteristic curves.
The skin is continuous, with several mucous membranes e.g. at the
lips, eyelids & anus
Pigmentation of the skin:
The melanin pigmentary system is composed of functional units
called epidermal melanin units. Each unit consists of a melanocyte that
supplies melanin pigment to a group of keratinocytes (about 36).
Pigmentation is determined primarily by the amount of melanin
transferred to the keratinocytes.
enzyme
Tyrosine (amino acid)
melanin.
Dopoxidase
This reaction is accelerated by ultraviolet.

Melanin keeps excessive ultraviolet rays from burning the
skin.
Glands:
Two main glands are embedded in the dermis
1- Sebaceous glands:
They secrete fatty substances called Sebum, which waterproof the
skin and lubricate it. They are all over the body except on the palms of
hands and soles of feet. The glands empty via ducts into the bases of hair
follicles and secrete sebum (a mixture of fats, waxes, and hydrocarbons).
Sebaceous glands are numerous on the face and scalp.
2- Sweat glands:
They reach the skin surface by way of ducts and openings called
pores. These pores don't open and close. Sweat is able to be act as a
lubricant.
There are two types of sweat glands.
a) The apocrine sweat glands fail to open directly onto the skin
surface, but drain into large hair follicles. They are located near the
armpits and around the genitalia.
b) The eccrine sweat gland, are distributed over the skins entire
surface. The secretion of the apocrine differs to that of the eccrine;
it is thick and creamy in contrast to the watery solution of the
eccrine glands.
These glands aid in the removal of dirt and oil from the pores, help to
regulate body temperature and also maintain the skin's PH balance.
Circulation of the Skin
Circulation through the skin serves two functions:
A- Nutrition of the skin tissue.
B- Regulation of body temperature by conducting heat from the
internal structures of the body to the skin, where it is lost by
exchange with the external environment (by convection,
conduction and radiation).
The cutaneous circulatory apparatus is well-suited to its functions. It
comprises two types of vessels:
1- The usual nutritive vessels (arteries, capillaries and veins).
2- Vascular structures concerned with heat regulation. They include:
C- An extensive subcutaneous venous plexus which can hold large
quantities of blood (to heat the surface of the skin).
D- Arteriovenous anastomoses which are large direct vascular
communication between arterial and venous plexuses.
Arteriovenous anastomoses are only present in some skin
areas which are often exposed to maximal cooling, as the
volar surfaces of hands and feet, the lips, the nose and the ear.
Circulation of the skin
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
The specialized vascular structures just mentioned, bear strong
muscular coats innervated by sympathetic adrenergic
vasoconstrictor nerve fibers. When constricted, blood flow into the
subcutaneous venous plexus is reduced to almost nothing (minimal
heat loss); while, when dilated, extremely rapid flow of warm
blood into the venous plexus is allowed (maximal heat loss).
The rate of cutaneous blood flow required to regulate body
temperature varies in response to changes in the metabolic activity
of the body and/or the temperature of the surroundings. Exposure
to extreme cold reduces the rate of blood flow to very low values,
so that the nutritive function may sometimes suffer. On the other
hand, heating the skin until maximal vasodilatation occurs (as in
hot climate), increases the cutaneous blood flow 7 times the normal
value (2.8L/min.). This diminishes the peripheral resistance and
increases the cardiac output, which may lead to the
decompensation of the heart in borderline-heart-failure subjects
exposed to hot weather.
*The triple response: A firm stroke applied to the skin results in three
local reactions collectively known as the triple response:
(a) At first blanching of the skin occurs for a very brief moment (due to
pressure exerted by the stroke), followed by a red line due to
capillary dilatation (caused by histamine and other mediators of
vasodilatation released from damaged tissues).
(b) A red flare follows the red line by 20-40 seconds and is due to
arteriolar dilatation through a local axon reflex (the axon reflex is
caused by stimulation of the pain nerve fibers with impulses passing
up these fibers and down to their endings where vasodilator
algogenic--i.e, pain-inducing--substances are released).
(c) finally, a wheal may appear after 1 minute, reaching full
development within 5 minutes (the wheal is best seen in people with
hypersensitive skin; it is due to release of histamine which causes
arteriolar dilatation and venular constriction, raising the capillary
blood pressure with transudation of fluid into the tissues).
Types of Sensation
a) Exteroceptive sensations (cutaneous sensations):
Are those from the surface of the body (skin) as touch, temperature
and pain senses. Sensory receptors of the skin include: mechanoreceptor, thermo-receptors and pain receptors. In this course of electro
and hydrotherapy we shall deal chiefly with cunteneous sensations.
b) Proprioceptive sensations (deep sensation):
Include senses of position and movement. It also includes sensations
from deeper tissues, muscles, tendons and joints.
c)Visceral Sensations: Sensations from viscera of the body as visceral
pain, sense of micturation and defecation.
Sensation of the Skin:
 The skin is innervated with around one million afferent nerve fibers.
Most terminate in the face and extremities; relatively few supply the
back. The cutaneous nerves contain axons with cell bodies in the
dorsal root ganglia.
 There are special cutaneous nerve endings or receptors for touch,
pressure, temperature, and pain terminate in the epidermis. The pain
receptors are just free nerve endings.
 These nerves transmit stimuli, to the brain insuring that the body is
made aware of environmental conditions.
 Sympathetic nerves control the sweat glands, hair follicles (goose
flesh) and the wall of blood vessels.
Receptors of the Skin
Specificity versus pattern theory of pain (A), Specific for each type of sensation (B),
Pattern of action potentials resulting in sensation of pain.


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Meissner's corpuscle
These touch receptors are especially effective in detecting light
touch and soft, fleeting movements.
Pacinian corpuscles
These function as receptors for deep pressure and vibration
Free Nerve Endings
These are derived from non-myelinated fibers occur in the
superficial dermis and in the overlying epidermis; they are
sensitive to pain, temperature changes and itchiness.
They detect changes in the external or internal environment and
inform the central nervous system of such changes along afferent
nerves in the form of action potentials (impulses).Receptors act as
detectors for energy changes in the environment and transducers as
they transform this change to electrical impulses.
There is intrinsic feedback system those found directly with in
skeletal muscle tissue or nearby and extrinsic feedback system
located outside skeletal muscle .e.g. ligaments, joint capsules, skin.
Types of Receptors
 Mechanoreceptors: These receptors respond to mechanical form
of energy. They detect mechanical deformation e.g. touch,
pressure.
 Thermoreceptors: Detect temperature changes, some for cold and
warmth.
 Chemoreceptors: These receptors respond to chemical changes in
the environment e.g. small receptors, taste receptors.
 Electromagnetic receptors: These receptors detect light on the
retina of the eye.
 Nociceptors: These are pain receptor which respond to any form of
energy destroys the tissues, e.g. deep pain, superficial pain
(cutaneous pain) and visceral pain.
*Points to be remembered about receptors:
-Most of the activity of the nervous system is produced as a result of
stimulation of the receptors.
-Impulses from the receptors may lead to immediate reaction or ascend to
the brain leading to perception of particular stimulation.
Integrating center
Afferent
Efferent
Receptor
Effector
Stimulus
Response
Feed back
Stimulus is a detectable change in the environment. Each type of
receptor is most sensitive to a particular from of energy ( specificity
of receptors ) i.e. there a specific adequate stimulus for each
receptor .
-As the intensity of
increased.
the stimulus increase the receptor potential
Types of nerve fibers
Definition of hydrotherapy
Hydrotherapy, derived from the Greek wards hydro and therapeia
meaning water and healing, is the application of water, either internally or
externally, for the treatment of physical or psychological dysfunction.
Or
It is the use of water at different temperature in any of its forms (solid,
liquid or vapor) and in different ways (internally or externally) in the
treatment of disease or trauma.
The healthy human body maintains a normal uniform physiological
stability within and among its parts, known as homeostasis. To preserve
this homeostasis, the body must continually make physiological
adjustments to many environmental influences.
Factors that can affect the physiological process within the human
body:
1. Seasonal changes
2. Temperature
3. Atmospheric pressures
4. Rainfall
5. Sunlight
6. Various radiation
7. Clothing
8. Food and water
The ease with which heat could be lost from the body has a definite effect
on various bodily functions such as growth and reproduction, the
production of antibodies, resistance to infection, metabolism and even the
mental activity.
In hydrotherapy, the environment of the body is changed by means of
water, which may be at varying temperature and could be applied by
various mechanical means. In general, the physiological responses are in
direct proportion to the extent of the environmental changes.
Benefits of hydrotherapy
The goal of hydrotherapy is to improve the circulation and quality of
blood.
 This is important, since blood deliveries nutrient to and remove the
waste products from the tissues and organs.
 If circulation is poor or slow, healing nutrients could not be
delivered and toxins could not be removed, which causes
degeneration of tissues and organs.
 By improving the quality of blood, more nutrients are available for
cells to use and toxins are managed more efficiently.
Basics of heat transfer
Heat transfer is concerned with two things; temperature (the amount of
thermal energy available) and the heat flow (the movement of thermal
energy from place to place).
Mechanism of heat transfer
There are many methods of heat loss or heat transfer; conduction,
convection, conversion, radiation and evaporation.
1. Conduction: Heat transfer by direct contact such as hot packs
and cold packs
2. Convection: Heat transfer by circulation of a medium of a
different temperature such as Fluidotherapy, Whirlpool, Blood
Circulation
3. Conversion: Conversion from one type of energy to another
such as Ultrasound Diathermy, and metabolism
4. Radiation: Exchange of energy directly without an intervening
medium such as Infrared Lamp
5. Evaporation: Absorption of energy as the result of conversion of
a material from a liquid to a vapor state such as vapocoolant
sprays.
Regulation of body temperature
 The rate of heat production usually balances the rate of heat loss.
 The thermostatic control of temperature occurs in neural centers in
the spinal cord and in the hypothalamic region.
 Reflex and semi-reflex thermoregulatory centers include
autonomic, somatic, endocrine and behavioral patterns.
 Reflex responses activated by the cold are controlled from the
posterior hypothalamus, while those activated by warmth are
controlled from anterior hypothalamus.
*Some terms related to sensations:
 Heat …………..……...is a form of energy that could be
transferred from a body of high temperature to a body or
environment of lower temperature.
 Hyperemia………………. is an increased content of blood
 Anesthesia: ........................ is complete loss of sensation.
 Hypoalgesia: ..................... is diminished pain sensibility.
 Hyperalgesia: .................... is increased pain sensibility.
 Analgesia:...........................is loss of temperature sensation.
 Hypothermaesthesia: ........ is diminished temperature sensation.
Therapeutic properties of water
Water has unique therapeutic properties, which include physical and
chemical prosperities that make it well –suited to a variety of
rehabilitation application.
A) Physical properties:
These properties include: 1) high specific heat and thermal conductivity
2) Bouncy 3) resistance 4) and hydrostatic pressure
1) Specific heat and thermal conductivity
 Water can transfer heat by conduction (stationary water) and
convection (moving water) and can therefore be used as a
superficial heating or cooling agents.
 It is effective for this application because of its high specific heat
and thermal conductivity
 Specific heat of water means that it takes one calorie of heat to
raise the temperature of one gram of the material one ◦C.
 The specific heat of water is approximately four times that of air
and its thermal conductivity is approximately 25 times that of air.
Thus it transfers the thermal energy 25 times more rapidly than air
at the same temperature.
Clinical benefits:
 Clinically, during hydrotherapy, heat is generally transferred from
warm water to a patient by placing the patient's limb in warm
water.
 Heat may also be transferred from the patient to cooler water by
immersion of a limb or part of it in cold or ice water.
2) Bouncy
o Bouncy is a force experienced as an upward thrust on the body in
the opposite direction of the force of the gravity.
o According to Archimeds' principle, when a body is entirely or
partially immersed in a fluid at rest, it experiences an upward thrust
equal to the weight of the fluid it displaces.
o The amount of the fluid it displaces depends on the density of the
immersed body relative to the density of the fluid.
o If the density of the immersed body is less than the density of the
fluid then it displaces smaller volume of fluid and will float and
vise versa.
o Men have a higher density than women because of a higher muscle
–to-fat ratio (muscle density >fat density). Therefore, women have
more bouncy than men.
Clinical benefits
Bouncy of the body in water can be used clinically to:
o Decrease stress and compression on weight –bearing joints,
muscles, and connective tissues
o Raise weakened body parts against gravity.
o Assist the therapist in supporting the weight of patient's body
during therapeutic activities.
3) Resistance
o Viscosity (internal friction between the molecules) and cohesion
(attractive force exerted by each molecule on those surrounding) of
the water provide resistance to the motion of a body in water.
o Resistance occurs in the against direction of the motion of the body
and increase in proportional to the relative speed of the body's
motion and the frontal area of the body part(s) in contact with
water.
Clinical benefits
o The velocity-dependant resistance provided by water makes it a
safe and effective strengthening medium for many patients.
o Variable resistance and pressure provided by moving water can be
beneficial for debriding and cleansing wounds.
4) Hydrostatic pressure
o Hydrostatic pressure is the pressure exerted by a fluid on the body
immersed in the fluid.
o According to Pascal's law, a fluid exerts equal pressure on all
surfaces of the body at rest at a given depth, and this pressure
increase in proportion to the depth of the fluid.
Clinical benefits
o Immersion in water can assist in promoting circulation or
alleviating peripheral edema due to venous or lymphatic
insufficiency.
o Facilitate cardiovascular function
o Support provided by hydrostatic pressure may help to brace
unstable joints or weak muscles.
o The greatest effect will occur with vertical positioning.
o The effect will be less pronounced if the patient is swimming in
more horizontal position close to the water surface.
o There are also no hydrostatic pressure effects when non-immersion
hydrotherapy techniques are used.
N.B" Bouncy, resistance and hydrostatic pressure can be also called
mechanical properties of water
B) Chemical properties:
This is not a property of water itself but of the gases or solids which it
may contain.
N.B:
Conversion from centigrade (C) to Fahrenheit (F) & vise versa:
C to F: Multiply by 9/5 and add 32
e.g ; (9/5x 37ºC)+32= 98.6 ºF
F to C: subs tract 32 and multiply 5/9
e.g ; (98.6ºF- 32) x 9/5= 37ºC
Physiological effects of hydrotherapy
I. General physiological effects
The physiological effects of water are the results of its physical
(thermal and mechanical) properties and include:
System
1) Musculoskeletal system
2) Cardiovascular system
3) Respiratory system
4) Renal system
5) Psychological aspects
Physiological effects
o
o
o
o
Decrease weight bearing
Strengthening
Slowed bone density
Less fat loss than other forms of
exercise
Increase venous circulation
o Increase cardiac volume
o Increase cardiac out put
o Decrease heart rate, systolic blood
pressure, and Vo2 response to
exercise.
o Decrease vital capacity
o Increased work of breathing
o Decreased exercise induced asthma
o Diuresis
o Increased sodium and potassium
excretion
o Relaxing or invigorating depending
on temperature.
1) Musculoskeletal effects
 The bouncy of water unloads the weight-bearing anatomical
structures allow patients with load –sensitive joints to perform
exercises with less trauma and pain. This effect can help patients
with arthritis, ligamentous instability, and other degenerative or
traumatic conditions.
 Bouncy can also be helpful for obese patients for whom land based
exercise places extreme stress on the weight bearing joints.
 Velocity –dependant resistance provided by water can be used to
provide a force against the working muscle in order to gain or
maintain strength. For example , water based exercises increase
upper and lower extremity strength in patient with neuromuscular
diseases and maintain strength in healthy individuals.
 The hydrostatic pressure exerted by water increase resting muscle
blood flow by 100% to 225% during immersion of the body up to
neck
improve muscular performance by increasing oxygen
availability removal of waste product
effective muscle
training
2) Cardiovascular effects
The cardiovascular benefits of hydrotherapy are due to the effects
of hydrostatic pressure.
 The hydrostatic pressure
displaces the venous blood
proximally from the extremities
enhances venous return
by shifting blood from the periphery to the trunk vessels and then
to the thorax and the heart.
 With immersion to the neck, central blood volume increase by
about 60% and cardiac volume increase by nearly 30%.
The velocity-dependant resistance to motion provided by water also
 Increase the metabolic rate and energy expenditure, as measured by
Vo2, approximately a factor of 3 when an activity is performed at
the same speed in water as on dry land.
3) Respiratory system
 Immersion of the whole body in water increases the work of
breathing because of the shift of venous blood from the peripheral
to the central circulation
increase the circulation in the
chest cavity.
 The hydrostatic pressure on the chest wall
increase to the
resistance lung expansion.
 Immersion in water up to the neck
decrease expiratory
reserve volume by about 50% and decrease the vital capacity by
6% to 12%. These effects, combined, increase the total work of
So
breathing by about 60%.
exercise in water can improve the
efficiency and strength of the respiratory system.
 Water based exercise is also recommended for patients with
exercise induced asthma because of various properties of water:
Absence of pollen over of the water
Hydrostatic pressure on the chest
Hypoventilation
Peripheral vasoconstriction
And high humidity of the inspired air in the pool environment.
4) Renal effects
Immersion of an individual up to the neck in water
increase
urine production and urine, sodium , and potassium excretion. These
effects are the results of:
Increased renal blood flow and decreased antidiuretic hormone
(ADH) and aldosterone production.
5) Psychological Effects
Psychological effects depend on the temperature of the water
 Soaking in warm water is generally relaxing
 Cold water immersion is found to be invigorating and energizing.
6) Central and peripheral nervous system
 Pain modulation.
 Relaxation effect.
II. Physiological effects of heat application
(Thermo therapy)
Therapeutic application of heat is known as thermotherapy
 Therapeutic heat………40ºC to 45ºC
 More than45ºC………..tissue damage.
 Less than 40ºC………..mild heating.
1. Hemodynamic effect (effect on vascular bed)
Dilatation of the blood vessels (vasodilatation) leads to hyperemia and
sweating.
Mechanism of vasodilatation
a) Direct reflex activation of smooth muscles of blood vessels by
cutaneous thermoreceptors.
b) Indirect activation of spinal cord reflexes by cutaneous
thermoreceptors or by increasing the local release of chemical
mediators of inflammation.
Temperature
Inflammation
Vasodilators
(histamine+ prostaglandin)
release
cutaneous thermoreceptors
spinal cord dorsal
root ganglion
smooth muscle relaxation
Sympathetic adrenergic activation
Vasodilatation
How heat cause vasodilatation
With maximal vasodilatation there are:
 Rise in pulse rates.
 Drop in blood pressure
 Profuse sweating with chloride loss
 Increase fluid transfer across the capillary wall with increased
removal of tissue metabolites.
2.Neuromuscular effects (on muscles and nerve)
1) On muscles:
a) Relaxation:
 This occurs when the warm blood reaches deeper and deeper
into the muscles causing the vessels to expand.
 Relaxation
relieve of pain by easing any pinching of
nerves or blood vessels and by helping the muscles to
remove lactic acids and other metabolic wastes.
 Relaxation
in ROM allowing for gentle
exercises and stretching.
b) Increase blood flow
 Heat
increase blood flow in the muscles
this
is beneficial in muscle spasm or sustained contractions where
ischemia may contribute to the pain.
2) On nerve
 Analgesia on the peripheral and central nervous system.
 Sedative action: as the body tries to register a temperature
change, the central nervous system becomes depressed,
contributing to muscle relaxation and temporarily relieve of
pain.
 The thermal stimulus that affects the pain sensation is
explained by the gait control theory of pain.
3.Effect on connective tissues
Heat and stretch could alter the viscoelastic properties of the connective
tissues. Heating decreases joint stiffness and increase tissue extensibility.
4. On the whole body
 Rise body temperature.
 Increased pulmonary ventilation.
 Increased metabolism: 10 ºC increase in the temperature will twice
or triple the metabolic rate leading to an increase of oxygen uptake,
an increase of nutrients and promotion of healing.
Reflex effect of prolonged heat
 Prolonged heat to one extremity causes vasodilatation of the
contra-lateral extremity.
 Prolonged heat to the abdominal wall causes a decreased in the
intestinal blood flow, diminish in the intestinal motility and
decrease in the secretion of acid in the stomach.
 Prolonged heat to the pelvis relaxes the musculature of the pelvic
organs, dilates the blood vessels and increases menstrual flow.
 Prolonged moist heat to the chest promotes ease of respiration and
expiration.
 Prolonged heat to the trunk, such as a hot trunk pack, relaxes the
ureters or bile ducts and relieves renal or gallbladder colic.
 Prolonged moist heat to the area over the kidneys in the back and
over the lower abdomen in front increases the production of urine.
III. Physiological effects of cold application (Cryo
therapy)
1.Hemodynamic effect (effect on vascular bed)
Cold application causes an immediate constriction of the cutaneous
blood vessels and a reduction in blood flow.
a) Initial decrease in blood flow
If cold is applied to the skin, it causes an immediate constriction of the
cutaneous vessels and a reduction in blood flow. This vasoconstriction
persists as long as the duration of the cold application is limited to less
than 15 to 20 minutes.
Mechanism of vasoconstriction
 Direct reflex activation of smooth muscles of blood vessels by
cutaneous cold receptors.
 Indirect : by decreasing the production and release of vasodilator
mediator, such as histamine and prostaglandins, resulting in
reduced vasodilatation. Decreased the tissue temperature also cause
reflex activation of sympathetic adrenergic neurons
vasoconstriction
Cold
reduce the circulatory rate by increasing blood viscosity
Increasing the resistance to flow.
b) Later increase in blood flow
When cold is applied for longer period of time or when tissue
temperature reaches less than 10ºC (50ºF) vasodilatation may occur. This
phenomenon is known as cold-induced vasodilatation (CIVD).
Hunting response:
Following the application of intense cold to the body there was
vasoconstriction with liberation of histamine- like (H) substance
produced by the intense cold and noxious stimuli. When there were
sufficient H substances vasodilatation occurred for about 4 to 6 minutes
remove all H substance vasoconstriction was established again, with
vasodilatation occurring at further intervals of 15 to 30 minutes. The
sudden vasodilation due to intense cold application is termed the (hunting
response). The initial vasoconstrication lasts about 9 to 16 minutes.
lewis also stated that the after- effect following removed of intense cold
for a prolonged period was vasodilation which increased for 20 minutes
then subsided slowly.
Temperature
blood
viscosity
Vasodilator
(histamine +prostaglandin)
release
cutaneous thermoreceptors
smooth muscle
contraction
vasoconstriction
spinal cord dorsal root
ganglion
sympathetic adrenergic
activation
blood flow
How cold (cryotherapy ) decrease blood flow
2.Neuromuscular effects (on muscles and nerve)
1)On muscle:
a) Altered muscle stretching: depending on the duration of the treatment
and the time of measurements, of cryotherapy has been associated with
both decrease and increase in muscle strength.
 Isometric muscle strength increase directly after the application of
ice massage for 5 minutes or less due to facilitation of motor nerve
excitability and an increased psychological motivation to perform.

In contrast after cooling for 30 minutes isometric muscle strength
decreased and then increased an hour later, to reach greater than
pre-cooling strength for the following 3 hours or longer. The
proposed mechanism: prolonged cooling
reduction of
blood flow to the muscles, slowed motor nerve conduction,
increased muscle viscosity and increased joint or soft tissue
stiffness.
b) Decreased spasticity: cold can temporarily decrease spasticity
Two mechanisms are involved: first, a decrease in gamma motor neuron
activity and later a decrease in afferent spindle and Golgi tendon organ
activity.
c) Facilitation of muscle contraction: brief application of cryotherapy
facilitate alpha motor neuron activity to produce a contraction in a muscle
that is flaccid due to upper neuron dysfunction
2) On nerve
 Analgesia due to de-sensitivity of nerves: local cold application has
numbing, analgesic or anesthetic effect. This has been used for the
relief of certain types of acute pain, such as acute joint pain, pain of
acute bursitis, sprains and other acute trauma and burn pain.
 Prolonged exposure
damage to the nerve may be result.
3.Metabolic effects
Cold decrease the rate of all metabolic reactions, including those
involved in inflammation and healing. Thus Cryotherapy can be used to
control acute inflammation.
Segmental relations of skin and viscera
Organs
Heart and Aorta
Lungs
Stomach
Intestines
Liver and Gallbladder
Kidneys
Segments
Dorsal 1-4
Dorsal 1-7(2-5 most)
Dorsal 7-9
Dorsal 9-11
Dorsal 3, 6-9
Dorsal 10 to lumber 1
Bladder Mucosa
Testis
Bladder muscles
Uterus; Upper portion
Uterus; Lower Portion
Sacral 3-4
Dorsal 10
Dorsal 11 to lumber 1
Dorsal 11,12
Sacral 3-4
Factors affecting the physiological effects of heat and cold
1. Water temperature
2. Difference between the temperature of water and the skin, i.e
if one hand is placed in hot water and the other in cold water,
then both in luke warm water, there will be a sensation of hot to
the hand that was first in cold water.
3. Mechanical impact of water, i.e. showers, sprays.
4. Suddenness of application (rapid or slow)
5. Surface area to be treated (the larger the area the more
receptors stimulated and the greater the physiological effects).
6. Age and general heath of the patients
7. Duration and frequency of the treatment
Indications, contraindication and
precautions of hydrotherapy
Main indications or clinical uses of hydrotherapy
1.
2.
3.
4.
5.
6.
Relief of pain
Relief of muscle spasm
Improve circulation
Mobilization and under water exercises
General sedation reducing nervous excitability
Treatment of spacticity either through reciprocal inhibition
(brief icing on the antispastic muscles) or direct inhibition
(long icing over the spastic muscles or warm application
over the spastic muscles.
7. Local anesthesia (icing)
Hydrogymnastics (Under water exercises)
Definition:
Hydrogymnastics or pool therapy or underwater exercises are exercises in
water.
Thy differ from apparently similar exercises in air because of the
difference in physical properties of two mediums.
Types of water exercises
1.
2.
3.
4.
5.
Swimming
Running with or without a vest or belt
Walking
Cycle ergometry
And other forms of upright exercise can be performed in water
Uses of water exercises
A) General uses
B) Specific uses
A) General uses: To increase
 Circulation
 Muscle strength
 Joint viscoelasticity
 Flexibility
 Range of motion (ROM)
To improve
 Ambulation
 Coordination
 Cardiovascular and respiratory conditioning
 Psychological conditioning
B) Specific uses
Problems
Effects
Orthopedic problems
 Decrease weight bearing on
joints
 Velocity dependant resistance
 Closed or open chain exercises
Neurological problems
Cardiac fitness
Exercise in water during pregnancy
Exercise induced asthma
 Slowed bone density loss
 Proprioceptive input
Increased safety
Improved balace
 Cardiac conditioning in
patients with poor tolerance
for land-based exercises
 Decrease weight bearing
Less elevation of heart rate with
exercise
Decreased risk of maternal
hyperthermia
Less exercise-induced asthma than
with other forms of exercise