Introduction to Hydrotherapy

Hydrotherapy Introduction

• Hydrotherapy is the application of water for treating physical or psychological issues.
• It's derived from Greek words meaning "water" and "healing."
• Hydrotherapy can be applied through immersion (full-body or partial) or non-immersion techniques (spraying, bathing).

Physical Properties of Water

• I- Specific Heat and Thermal Conductivity:

  • Specific heat is the amount of heat needed to raise the temperature of a unit mass by one degree Celsius. Water takes a long time to heat up or cool down, meaning it retains temperature.
  • Thermal conductivity is the rate at which heat transmits through a material. Water's thermal conductivity is much higher than air, meaning, it transfers heat much faster.

• II- Buoyancy (Upward Thrust Force):

  • Buoyancy is an upward force opposing gravity.
  • According to Archimedes' principle, the buoyant force is equal to the weight of the fluid displaced by the body.
  • Increasing the body's surface area immersed increases buoyancy effect.

• III- Density:

  • Density is the relationship between mass and volume (kg/m³).
  • Water's highest density is at 4°C.
  • Dissolved substances increase water's density (seawater is denser than pure water).
  • Relative density (specific gravity) compares a substance's density with water as a standard. Water's specific gravity is 1.0.

• IV- Resistance:

  • Water resistance opposes body movement.
  • Resistance increases with speed and frontal area of the body in contact with water.
  • Using paddles or fins will also increase resistance.
  • Resistance is lower when body parts are moving parallel to the direction of movement, and the speed is slower.

• V- Viscosity:

  • Viscosity is the internal friction within a fluid.
  • Water's viscosity is greater than air's; hence, movement in water is more challenging.
  • Viscosity decreases with increasing temperature, aiding easier movement in warmer water.

• VI- Surface Tension:

  • Surface tension is a force between surface molecules of a liquid, pulling them together.
  • Water's surface tension is higher than in other fluids; it enables insects to walk on water.

• VII- Hydrostatic Pressure:

  • Hydrostatic pressure is the pressure a fluid exerts on a body immersed in it.
  • Pressure increases with depth.
  • Pressure on distal extremities (further from the body's centre) of an upright body immersed in water is greater than the pressure on proximal parts.

Hydrostatic Pressure benefits during Exercise

• Increased venous return due to hydrostatic pressure on the limbs can boost cardiovascular function.
• Hydrostatic pressure may improve blood circulation and alleviate edema (swelling).
• The pressure may also provide support for unstable joints or weak muscles.

Hydrostatic Pressure Influence on Position in Water

• Hydrostatic pressure increases with depth.
• Greatest benefits occur with vertical positioning (feet immersed).
• Horizontal positioning has less effect as limbs are at shallower depths.

Non-Immersion Hydrotherapy

• Non-immersion techniques do not utilize hydrostatic pressure effects.
• Results from non-immersion techniques are less than those from immersion techniques.