Hydro

Question 1

Therapeutic effects

Answer 1

• Freedom of movement = more ROM
• Body weight support = unloads joints and less force needed to elicit muscle activity (due to buoyancy)
• Reduced need for manual guidance (safety - less falls risk)
• Psychological - fun and motivating. Adherence.
• Hydrostatic pressure reduces swelling and increases venous return
• Viscosity provides resistance for strength and control

Possible physiological effects
- Muscle relaxation due to heat and thermal conductivity of water
- Vasodilation = increased blood flow = removing waste products such as lactate = pain reduction
- Increased collagen extensibility

Question 2

Properties of water: heat and thermal conductivity
- Degrees
- Thermal conductivity

Answer 2

32-34 degrees
25 x greater than air = heat provides relaxation!

Question 3

Properties of water: Buoyancy
- What does it allow?
- Define
- Dependent on?

Answer 3

• Flotation
• Upward forward applied by the fluid on the body when immersed in water
• Density eg stroke spasticity = sink

Question 4

Archimedes Principle: Buoyancy

Answer 4

When a body is immersed in fluid, it experiences an upward force equivalent to the weight of the fluid it displaces.

Question 5

Two forces affecting buoyancy?

Answer 5

Centre of gravity (S2)
Centre of buoyancy (S1)

Question 6

Properties of water: viscosity
- What is it
- How much more compared to air?

Answer 6

• Viscosity = friction between molecules
• x 12 resistance to the movement compared with air

Question 7

Properties of water- Viscosity: Drag - what are the two types?

Answer 7

• Drag = resistance an object/body encounters when moving through a fluid
• Frontal Drag: Resistance from water pushing against the front of your body.
• Propulsive Drag: Resistance created by your limbs or body as you try to push the water backward (e.g., during swimming) to move forward.

Question 8

Drag: Newton’s Law

Answer 8

1: Swimmer will stay in motion unless stopped by another force
2: Speed is a constant battle between these two forces (propulsive/frontal drag)
3: For every action there is an equal and opposite reaction (Main one that is relevant)

Question 9

Properties of water: Hydrostatic pressure

Answer 9

Decreased swelling, increased venous return and central blood volume

Pascal’s law

Question 10

Physiological effects

Answer 10

• Decrease weight bearing (only 10% of BW in neck deep water)
• Strengthening
• Improve joint ROM/stiffness

Question 11

Physiological effects

Answer 11

MSK effects
- Decrease weight bearing (only 10% in deep water)
- Strengthening
- Improve joint ROM/stiffness

Cardiovascular effects
- Increased central blood volume
- Increased cardiac output

Respiratory
- Increased respiratory workload (hydro pressure)
- More compression to the chest wall = more load
- Decreased vital VC & end expiratory volume
- Decrease exercise induced asthma
- May increase resp muscle strength

Renal effects
- Increased blood flow to kidneys = more urine production = hydrate!