Aquatic exercise (water-based exercises)
Exercises that are performed in water in multidepth immersion pools or tanks.
Why aquatics?
-Alternate therapeutic environment
-Start rehab sooner
-Good env. to dissipate body heat during exercise
-Easily progress activities or modify
-Can work harder with less load
Goals and indications
● Decrease joint stiffness and ↑ ROM
● Perform resistance training to improve strength
● Facilitate cardiovascular function
● Address balance
● Edema control and ↑ venous return
● May decrease pain and spasm
● Muscle relaxation
● Improves endurance
● Progression of WB status
● ↓ joint loading & compression
Buoyancy
the upward force that works opposite to gravity
Archimedes’ principle
an immersed body experiences upward thrust equal to the volume of liquid displaced
Benefits of buoyancy
-Offloads body weight
-Postural support
-Joint unloading
-Provides resistance
How will buoyancy be affected?
-Increase with fully inflated lungs
-Decrease with deflated lungs
-Body composition
Buoyancy and Body Weight
● Iliac crests 40-50% WB
● Xiphoid 33% WB
● Nipple line 25-30% WB
● C7 10% WB
Buoyancy Assisted
● Movement toward the surface of the water
○ AAROM, PROM of standing GH abduction
○ Lumbar flexion in standing with single knee to chest
Buoyancy Supported
Movements perpendicular to the upward force of the
water; parallel to the bottom of the pool; similar to gravity minimized
○ Horizontal abd and add
○ Lumbar sidebending in supine
Buoyancy Resisted
Movements that oppose buoyancy; towards the bottom of the pool; similar to resistance exercise
○ Shoulder extension from a flexed position
○ Lumbar flexion in standing
Hydrostatic Pressure
the pressure exerted by the water on immersed objects
Pascal’s Law
the pressure exerted by fluid on an immersed object is equal on all surfaces of the object (any depth);
this increases with increasing depth and density
of fluid
Deeper immersion results in what?
Centralization of blood flow, increasing CO without increasing HR (CO= HR x SV)
Hydrostatic Pressure Clinical Implications
● Deeper immersion results in ↑ CO
● Monitor patients with limited chest expansion
● Deeper immersion controls edema, esp. in extremities
● May support lumbar spine
Viscosity
Magnitude of internal friction of a fluid during motion;
results from the cohesive or attractive forces between water molecules
What does viscosity cause?
Resistance to flow
Surface Tension
the attractive force exerted upon the surface molecules of a liquid by the molecules beneath that tends to draw the surface molecules into the bulk of the liquid
An extremity that moves through the surface performs more work than if kept under water
What causes surface tension?
the cohesiveness and attraction between liquid molecules
Hydromechanics
movement through water
Flow
Water movement that includes:
turbulence flow,
laminar flow, and
drag flow
Laminar flow
(streamline flow)
steady continuous flow of water in one direction in which all molecules are travelling parallel to each other with less lateral movement
smooth and streamlined flow - slow movements
Turbulent flow
chaotic changes in pressure and flow velocity; interrupted flow of water molecules; creates pressure in front of object and drag behind
faster movements
Drag flow
cumulative effects of turbulence and fluid viscosity acting on an object in motion
