Hydrotherapy Flashcards
Hydrostatic pressure
Increases with depth due to the weight of water pressing down. When standing in water= more pressure in the ankles than the chest.
Relative density
Relative density is defined as the density of an object or substance relative to the same volume of pure water. The average density of water is 1Kg/m3, the average body with air in the lungs= 0.975, and without air =1.2. The body’s density increases with increased muscle and bone mass.
Buoyancy
Is the result of the pressure gradient creating an upward force (upthrust) exerted on an object in water.
Depth of water
Water depth= ASIS= 50% WB
Xiphisternum or T11- 25-30%
C6/7 or sternal notch- 8-10%
Stability in water
A body immersed in water is subject to 2 opposing forces. Gravity acts downwards and Buoyancy acts upwards. The shape, distribution of mass and density of a body determine stability. 2 forces acting= COG and COB.
Metacentric effect
the restoring or stabilising rotation on an immersed body when forces of gravity and buoyancy are not acting in the same vertical plane.
Resistance to movement- drag
3 elements that contribute to 90% of drag= negative pressure of the turbulence behind a moving object, skin friction, size of th ecolumn of fluid adhering to each other. Other 10%= bow waves (positive pressure from weight of water in front of moving object), viscositiy, cohesion and surface tension
drag resistance is increased by
increased speed, decreased streamline, increased lever length, changed direction quickly
refraction
its what happens when light rays pass through a material of different densities. Meaning light can bend as they pass through water.
use of buoyancy
to strengthen muscle action
assist joint movement
assist prolonged muscle stretches
to provide weight relief
to assit relaxation
use of drag
to assist movement, to resist isometric and isotonic muscle action, to maintain/displace/restore balance, to assist/resistance walking
use of meacentric effect
to assist/ initiate movement o.e rolling
recruit trunk stability muscles
promote balance/stability
Muscle actions during immersion- concentric
BA-movement towards the surface of the water (grade I muscle power), BC- movement parallel to waters surface, DA- a movement created by either moving the body part to create a drag effect in the direction of movement to assist, DR- patient initiated movement in any direction at a speed that creates negative pressure from turbulent water- increased speed= increased resistance
Muscle actions during immersion- eccentric
Moving towards the water surface slower than the speed of buoyancy progressed with additional floats,
Muscle actions during immersion- Isometric
hold a position against the buoyancy force, increased by using a float. Metacentre- hold a posture against the metacentric rotational force, turbulence- hold posture against applied turbulence, drag effect- hold a posture against the drag effect created by the therapist moving the patient through the water or patient moving themselves through water
Physiological effects of immersion- CV changes
30% increase in cardiac volume improves the myocardial efficiency by the stretch enhancing actin-myosin filament relationship. Increase in CO, SV, HR, PR, BP
Physiological effects of immersion- pulmonary
hydro affects pulmonary function due to direct hydrostatic pressure on the thorax, venous engorgement from increased CBV reducing the diffusion capacity. Immersion increases WOB by 60% due to pressure on rib cage
Physiological effects of immersion- pulmonary changes
TV remains unchanged or slightly diminshed, Reduced- expiratory reserve volume, VC, TLC, FRC,
increased= airway resistance
Physiological effects of immersion- central and peripheral NS changes
skin sensory nerve endings including temp, touch and pressure receptors are affected by immersion. the sympathetic nervous system can develop and sustain neurogenic pain with the release of noradrenaline. Warm water suppresses SNS. Increased CBV stimulates baroreceptors- causing vasomotor centre to inhibit noradrenaline release
Physiological effects of immersion- suppression of SNS and release of noradrenaline may….
Reduce ischaemic pain by reducing arterial tone= increased vasodilation and blood flow, interrupts pain cycle, reduce inflammatory response
Physiological effects of immersion- MSK changes
increase in cardiac output, decrease in joint pain
Benefit of aquatic physiotherapy- Pain
pain relief and reduction of muscle spasms. Due to the warmth of the water, suppression of the SNS, stimulation of skin sensory nerve endings, reduced effect of gravity
Benefit of aquatic physiotherapy- joints
ease of movement, joint range and flexibility. Due to: support of buoyancy, reduced effect of gravity
Benefit of aquatic physiotherapy- reduction of oedema and improved circulation
hydrostatic pressure, ability to move freely
Benefit of aquatic physiotherapy- strength
viscosity of water, drag effect, negative pressure from turbulence, weight and density of water, force of buoyancy
Benefit of aquatic physiotherapy- Re-education of functional activities
metacentric effect, support of buoyancy and variation in weight-bearing, assistance or resistance to movement
Benefit of aquatic physiotherapy- improved CV fitness
hydrostatic pressure, resistance to movement, opportunity for exercise
Benefit of aquatic physiotherapy- enhanced relaxation
reduced effect of gravity, support buoyancy, reduction in pain, hypnotic effect of water
Benefit of aquatic physiotherapy- enhanced feeling of well being
ability vs disability, social interaction, enjoyment, independence
progression of buoyancy resisted exercise
Increase the size of the flotation aid, slower movement, longer lever if possible, starting position
to progress a drag resisted exercise
increase speed of movement, increase in SA, longer lever
