Thermodynamics in Aquatic Therapy

1. ThermodynamicsThermodynamics

2. Water temperature has an effect on theWater temperature has an effect on the
body and, therefore, performance in anbody and, therefore, performance in an
aquatic environmentaquatic environment

3. Specific heat is the amount of heat (calories)Specific heat is the amount of heat (calories)
required to raise the temperature of 1 gramrequired to raise the temperature of 1 gram
of substance by 1 Cof substance by 1 C

4. The rate of temperature change is dependentThe rate of temperature change is dependent
on the mass and the specific heat of theon the mass and the specific heat of the
object.object.

5. Water retains heat 1000 times more thanWater retains heat 1000 times more than
air. Differences in temperature between anair. Differences in temperature between an
immersed object and water equilibrate withimmersed object and water equilibrate with
minimal change in the temperatureminimal change in the temperature
of the water.of the water.

6. Water conducts temperature 25 times fasterWater conducts temperature 25 times faster
than air. Heat transfer increases withthan air. Heat transfer increases with
velocity. A patient moving through thevelocity. A patient moving through the
water loses body temperature faster than anwater loses body temperature faster than an
immersed patient at rest.immersed patient at rest.

7. A person’s impairments and the intervention goalsA person’s impairments and the intervention goals
determine the water temperature selection. Indetermine the water temperature selection. In
general, utilize cooler temperatures for higher-general, utilize cooler temperatures for higher-
intensity exercise and utilize warmer temperaturesintensity exercise and utilize warmer temperatures
for mobility and flexibility exercise and for musclefor mobility and flexibility exercise and for muscle
relaxationrelaxation

8. The ambient air temperature should be 3 C higherThe ambient air temperature should be 3 C higher
than the water temperature for patient comfort.than the water temperature for patient comfort.
Incorrect water or ambient air temperatureIncorrect water or ambient air temperature
selection may adversely affect a patient’s ability toselection may adversely affect a patient’s ability to
tolerate or maintain immersed exercise.tolerate or maintain immersed exercise.

9. Temperature regulation during immersed exerciseTemperature regulation during immersed exercise
differs from that during land exercise because ofdiffers from that during land exercise because of
alterations in temperature conduction and thealterations in temperature conduction and the
body’s ability to dissipate heatbody’s ability to dissipate heat

10. With immersion there is less skin exposed to air,With immersion there is less skin exposed to air,
resulting in less opportunity to dissipate heatresulting in less opportunity to dissipate heat
through normal sweating mechanisms.through normal sweating mechanisms.

11. Water conducts temperature 25 times fasterWater conducts temperature 25 times faster
than air more if the patient is movingthan air more if the patient is moving
through the water and molecules are forcedthrough the water and molecules are forced
past the personpast the person

12. A person perceive small changes in waterA person perceive small changes in water
temperature more profoundly than smalltemperature more profoundly than small
changes in air temperaturechanges in air temperature

13. Over time, water temperature may penetrateOver time, water temperature may penetrate
to deeper tissues. Internal temperatureto deeper tissues. Internal temperature
changes are known to be inverselychanges are known to be inversely
proportional to subcutaneous fat thicknessproportional to subcutaneous fat thickness

14. A person are unable to maintain adequateA person are unable to maintain adequate
core warmth during immersed exercise atcore warmth during immersed exercise at
temperatures less than 25 C.temperatures less than 25 C.

15. Conversely, exercise at temperatures greater thanConversely, exercise at temperatures greater than
37 C may be harmful if prolonged or maintained37 C may be harmful if prolonged or maintained
at high intensities. Hot water immersion mayat high intensities. Hot water immersion may
increase the cardiovascular demands at rest andincrease the cardiovascular demands at rest and
with exercisewith exercise..

16. In waist-deep water exercise at 37 C, theIn waist-deep water exercise at 37 C, the
thermal stimulus to increase the heart ratethermal stimulus to increase the heart rate
overcomes the centralization of peripheralovercomes the centralization of peripheral
blood flow due to hydrostatic pressureblood flow due to hydrostatic pressure

17. At temperatures greater than or equal to 37At temperatures greater than or equal to 37
C, cardiacoutput increases significantly atC, cardiacoutput increases significantly at
rest alonerest alone