Exam 2 Flashcards
specific gravity of water
1
object with specific gravity more than 1 will
sink
object with specific gravity less than 1 will
float
definition of specific gravity
a ration of an objects weight to the weight of an equal volume of water
specific gravity of humans
0.95-0.97
-obese 0.93 (float)
-lean 1.10 (sink)
Archimedes principle of buoyancy
a body partially or fully immersed in a fluid will experience an upward thrust of that fluid that is equal to the weight of the fluid the body displaces
what does a specific gravity of 0.95 mean (% of floating and submerged)
95% body is submerged
5% of the body is floating
center of buoyancy
buoyancy is the upward force
gravity is the downward force
viscosity of water
resistance to movement within a fluid caused by the friction of the fluid molecules
-aka water resists the movement
is the resistance to a body that is moving through it
drag
form drag
resistance that an object encounters in a fluid
-size and shape
-larger has more drag (turbulence)
wave drag
is the waters resistance because of turbulence caused by the speed of an object in the water
-change positions and speed
friction drag
result of waters surface tension
-competitive swimmers
-shaving arms and legs
Pascals law of Hydrostatic pressure
states that pressure from a fluid is exerted equally on all surface of an immersed object at any given depth
-deeper = greater pressure (ears pop)
what can hydrostatic pressure have a positive effect on
-post injury edema
-exercise without risk (better optimal loading)
whose center of gravity is higher
males COG is higher than females
-% of body weight borne at different depth varies between males and females
advantages of aquatic therapy
-restricted weight bearing
-relaxation of muscles
-reduced joint compression = reduced pain
-warmth = overrides sensory system = relaxation and increased ROM
-reduced stress on muscles
precautions of aquatic therapy
-fear of water
-medications (HR, BP, respiration, cardiorespiratory function)
-ear infections (cover the ear)
-specific conditions: diabetes, CV disease, seizures, sensitive to pool chemicals
contraindications to aquatic therapy
-illness
-open wounds
-other medical conditions (DVT)
differences of running gait from walking gait
-shorter stance phase
-lengthened swing phase
-no double support
-nonsupport phase = double float phase
running stride
the time during a running cycle when one foot makes contact with the ground to the time the opposite foot contacts the ground
running cycle
cycle that includes 2 running strides
cycle time
amount of time it takes to perform one step length
stride rate
inverse of stride time