The document discusses the unique properties of water and their physiological implications for aquatic therapy. It describes how buoyancy provides weightlessness and joint unloading, allowing for easier movement. Hydrostatic pressure from water acts equally on all surfaces and increases with depth, assisting venous return. Viscosity creates resistance proportional to speed of movement. These properties allow aquatic therapy to be a beneficial exercise medium.

1. Hydrostatic pressureHydrostatic pressure
HydromechanicsHydromechanics

2. The unique properties of water and
immersion have profound physiological
implications in the delivery of
therapeutic exercise
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

3. The properties provided by buoyancy,
hydrostatic pressure, viscosity, and
surface tension have a direct effect on
the body in the aquatic environment
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

4. Buoyancy is the upward force that works
opposite to gravity
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

5. Properties. Archimedes’ principle states
that an immersed body experiences
upward thrust equal to the volume of
liquid displaced
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

6. Clinical Significance Buoyancy provides
the person with relative weightlessness
and joint unloading, allowing
performance of active motion with
increased ease. Buoyancy allows the
practitioner three-dimensional access to
the person.
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

7. Hydrostatic pressure is the pressure
exerted on immersed objects.
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

8. Pascal’s law states that the pressure
exerted by fluid on an immersed object
is equal on all surfaces of the object. As
the density of water and depth of
immersion increase, so does hydrostatic
pressure
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

9. Increased pressure reduces or limits
effusion, assists venous return, induces
bradycardia, and centralizes peripheral
blood flow. The proportionality of depth
and pressure allows you to perform
exercise more easily when closer to the
surface.
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

10. Viscosity is friction occurring between
molecules
of liquid resulting in resistance to flow
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

11. Resistance from viscosity is proportional
to the
velocity of movement through liquid
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

12. Water’s viscosity creates resistance with
all active movements. A shorter lever
arm results in increased resistance.
During manual resistance exercises
stabilizing an extremity proximally
require you to perform more work.
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

13. Stabilizing an extremity distally requires
you to perform less work.
Increasing the surface area moving
through water increases resistance
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

14. The surface of a fluid acts as a
membrane
under tension. Surface tension is
measured as force per unit length.
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

15. The attraction of surface molecules is
parallel to the surface.
The resistive force of surface tension
changes proportionally to the size of the
object moving through the fluid surface
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

16. 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
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

17. Hydromechanics comprise the physical
properties and characteristics of fluid in
motion
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

18. Laminar flow. Movement where all
molecules move parallel to each other,
typically slow movement.
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

19. Turbulent flow. Movement where
molecules do not move parallel to each
other, typically faster movements.
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

20. Drag. The cumulative effects of
turbulence and fluid viscosity acting on
an object in motion
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

21. As the speed of movement through water
increases, resistance to motion increases.
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

22. Moving water past you requires you to
work harder to maintain his/her position
in pool.
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training

23. Application of equipment
(glove/paddle/boot) increases drag and
resistance as you moves the extremity
through water.
Stephan BetterBodyz van Breenen
Aquatic Fitness Therapy Training