Definition of hydrotherapy
It consists of treatment techniques using water and its properties. It is a form of aquatic exercise.
The therapeutic interventions in hydrotherapy are stretching, strengthening, joint mobilization,
balance and gait training and endurance training.
Goals and indications
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Facilitate ROM exercise
Initiate resistance training
Facilitate weight bearing activities
Provide three dimensional access to patients
Facilitate cardiovascular exercise
Minimise risk of injury during rehabilitation
Enhance patient relaxation
Properties of Water
1. Buoyancy
 It is the upward force that works opposite to gravity.
 Archimedes’ principle states that an immersed body experiences upward thrust
equal to the weight of the liquid displaced.
Clinical significance of buoyancy
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Buoyancy provides the patient with relative weightlessness by reducing the force of
gravity on the body. This allows the patient to perform active motion with increased
ease.
 Buoyancy provides resistance to movement when an extremity is moved against the
force of buoyancy. This technique can be used to strengthen muscles.
 Buoyancy allows the practitioner three-dimensional access to the patient
2. Hydrostatic pressure
 It is the pressure exerted by water on immersed objects.
 According to Pascal’s law, the pressure exerted by a fluid on an immersed object is
equal on all surfaces.
 Hydrostatic pressure increases with density of water and depth of immersion.
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Clinical significance of hydrostatic pressure
Increased pressure reduces effusion, assists venous return, decreases heart rate,
centralizes peripheral blood flow.
Since pressure and depth are directly proportional, it allows patients to perform
exercises more easily when closer to the surface.
3. Viscosity
 Viscosity is friction occurring between molecules of liquid resulting in resistance to
flow.
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Resistance from viscosity is proportional to the velocity of movement through liquid.
Clinical significance of viscosity
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Viscosity creates resistance with all active movements.
Increasing the velocity of movement increases the resistance.
Increasing the surface area moving through water increases resistance.
4. Surface tension
 Surface tension is the property of the surface of a liquid that allows it to resist an
external force.
 Surface tension is measured as force per unit length.
 Surface tension is proportional to the size of the object.
Clinical significance of surface tension
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An extremity that moves through the surface performs more work than if kept
under water.
Using equipment at the surface of the water increases the resistance.
Hydromechanics
Hydromechanics comprises the physical properties and characteristics of fluid in motion.
Components of flow motion
Three factors affect flow; they are laminar flow, turbulent flow, and drag.
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Laminar flow - Movement in which all molecules move parallel to each other, typically slow
movement.
Turbulent flow - Movement in which molecules do not move parallel to each other, typically
faster movements.
Drag - The cumulative effects of turbulence and fluid viscosity acting on an object in motion.
Clinical significance of drag
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As the speed of movement through water increases, resistance to motion increases.
Application of equipment (glove/paddle/boot) increases drag and resistance.
Centre of buoyancy
The centre of buoyancy is the point on an immersed object on which buoyant (vertical) forces of
fluid act.
Clinical significance of centre of buoyancy
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In the vertical position, the human centre of buoyancy is located at the sternum. In the
vertical position, posteriorly placed buoyancy devices cause the patient to lean forward;
anterior buoyancy causes the patient to lean back.
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Patients bearing weight on the floor of the pool (i.e., sitting, kneeling, standing) experience
aspects of both the centre of buoyancy and centre of gravity.
Aquatic temperature
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26-33 deg C is used for flexibility, strengthening, gait training, relaxation
33 deg C used for painful musculoskeletal conditions
26-28 deg C is used for cardiovascular training
22-26 deg C is used for high intensity exercises
Precautions
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Fear of water = This can limit effectiveness of any immersed activity.
Neurological disorders = Patients with neurological disorders like epilepsy must be closely
monitored during treatment.
Cardiac dysfunctions = Patients with angina, abnormal bp, heart disease must be closely
monitored during treatment.
Open wounds = open wounds and tracheostomies must be covered with waterproof
dressings before treatment.
Respiratory disorders = Water immersion may adversely affect breathing of patients with
respiratory disorders. Lung expansion may be inhibited by hydrostatic pressure against chest
wall.
Contraindications
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Cardiac failure and unstable angina
Respiratory dysfunction, vital capacity less than 1 litre
Severe peripheral vascular disease
Danger of bleeding or hemorrhage
Severe kidney disease
Open wounds, skin infections
Uncontrolled bowel or bladder
Water and airborne infections or diseases like typhoid, cholera, GIT infection
Uncontrolled seizures
Equipments used for hydrotherapy
The rooms in which pools are housed need to be adequately ventilated to avoid the accumulation of
condensation on walls, windows, and floors. A dressing room should be provided for changing
clothes and showering.
1. Whirlpool
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A whirlpool may be used to improve circulation, mobility, and comfort after an injury or
after surgery
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Used only for extremities.
Useful to treat painful conditions, assisted exercises, mobilization.
2. Hubbard tank
 Stainless steel tank that has the shape of a key hole.
 Tank designed for full immersion of the body
 A narrow section at the middle of the tank allows the therapist to reach the patient,
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and wider sections at each end permit full abduction of the patient's legs and arms.
The Hubbard tank is useful in the treatment of patients with extensive
burns and those with chronic multiple joint disorders.
3. Outdoor pools
 Suitable for all types of aquatic exercise
 Dressing cubicles, waiting rooms, heated cupboards or drying area provided
 Doorways are wide enough for wheelchairs and stretchers to pass
 Entrance to larger therapeutic pools includes ramps, stairs, ladders, or mechanical
overhead lifts.
 These pools have built-in chlorination and filtration systems
 They have parallel bars of adjustable height and width
 Submerged bench or seat
Special equipment for aquatic exercise
Aquatic equipment is used to provide buoyancy and resistance to movement.
Cervical collars
Floatation rings
Belts, vests
Dumbbells
Gloves, paddles
Fins, boots
Kickboards
Support neck in supine position and keep
head out of water
Support extremities in immersed position
For buoyancy and support patients in
supine, prone or vertically
Support upper body or trunk in upright
positions
Support lower extremities in supine or
prone positions
Provide resistance to upper extremity
movements
Provide resistance to lower extremity
movements
Provide buoyancy in supine or prone
positions
Create resistance to walking in shallow
water when held vertically
For balance training in water