Introduction to Hydrotherapy

Introduction to Hydrotherapy

• Hydrotherapy combines the Greek words "hydro" (water) and "therapeia" (healing).
• It's a therapeutic modality using water (hot, cold, steam, liquid, ice) for physical or psychological issues.

Hydrotherapy's Purpose

• Aims to improve neuromuscular and skeletal function, and proprioception in patients with acute, subacute, and chronic disabilities.

Physiological Effects of Hydrotherapy

Cardiovascular System

• Hydrostatic pressure displaces blood centrally, increasing central venous pressure.
• The extent of blood displacement correlates with submersion depth.
• Immersion to the neck displaces 700 cm³ of blood from the periphery to the thorax and heart, increasing right atrial pressure, stroke volume, cardiac output, and muscle circulation, while lowering systemic vascular resistance.
• Stroke volume: the amount of blood pumped by the left ventricle during each heart contraction.
• Cardiac output: the amount of blood pumped by the heart per minute.
• VO2 max: the greatest amount of oxygen consumed during intense exercise, a key indicator of cardiovascular fitness and aerobic endurance.
• Cardiac output, with a normal heart rate of 86 beats per minute, increases to 8.6 liters per minute when immersed.
• Velocity-dependent water resistance increases metabolic rate and energy expenditure by approximately 3 times, compared to on land.

Pulmonary System

• Vital capacity (the total air expelled after maximum inhalation) decreases by 6-9% due to hydrostatic pressure on the chest wall.
• Work of breathing increases by 60% with water up to neck level.
• Pulmonary blood flow increases, pulmonary wedge pressure rises to 22 mm Hg, and chest circumference slightly decreases (around 10%) along with reduced chest wall compliance.

Renal System

• Renal blood flow increases.
• Creatinine clearance, sodium excretion, and potassium excretion elevate.
• Reduced renin, aldosterone, and ADH levels increase diuresis (urine production).
• Full-body immersion hydrotherapy is used to treat resistant edema in nephrotic syndrome and cirrhosis patients.

Musculoskeletal System

• Water buoyancy reduces the weight-bearing load on anatomical structures.
• Water's velocity resistance increases.
• Hydrostatic pressure leads to a 100-225% increase in resting blood flow when submerged (up to the neck).

Additional Effects

• Immersion helps eliminate edema, lactate, and other metabolic byproducts.
• Water temperature causes peripheral vasodilation.