13 Aquatic Therapeutic Exercise

Benefits and Purpose of Aquatic Therex Exercise sometimes possible sooner in water than on dry land Non weight bearing Offers total exercise program: cardiovascular conditioning, flexibility, strength, muscular endurance

Specific Gravity Also called relative density Ratio of an object’s weight to the weight of an equal volume of water Specific gravity of water = 1 For human body, depends on lean and fat mass and distribution of body fat Average specific gravity for body = 0.95-0.97

Archimedes principle: 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.

Buoyancy Archimedes principle A body with a specific gravity of less than 1 will float because weight of water displaced is less than weight of body If body has specific gravity of 0.95, 95% of body will be submerged and 5% will float

Center of Buoyancy The center of gravity of the displaced fluid and the point at which the buoyant force acts on the body When in equilibrium, the center of buoyancy and the center of gravity are in vertical alignment with each other and the body is balanced

Hydrodynamics Viscosity The resistance to movement within a fluid that is caused by the friction of the fluid’s molecules Influenced by cohesion, adhesion, surface tension (continued)

Hydrodynamics Drag: the water’s resistance to a body that is moving through it Form drag Wave drag Frictional drag

Hydrostatic Pressure Pascal’s law: Pressure from a fluid is exerted equally on all surfaces of an immersed object at any given depth The more deeply the object is immersed, the greater the pressure For every foot of submersion, water pressure increases by 0.43 psi Positive impact on edema

Pascal’s Law Reprinted from Bates and Hanson 1996.

Weight Bearing in Water The more deeply the body is submerged, the less weight is borne by the lower extremities. Females’ center of gravity is lower than males’: affects percentage of body weight borne at different depths. The faster a person walks in the water, the higher the weight-bearing percentages.

Weight Bearing in Water Reprinted from Harrison, Hillman, and Bulstrode 1992.

Aquatic Equipment Safety equipment Assistive devices: help stabilize body, maintain buoyancy, assist in motion Resistive devices: used to increase muscle strength/endurance; increase surface area, require speed, add buoyancy or weight Cardiovascular devices

Indications for Aquatic Therex Pain, edema, muscle spasm, loss of motion, weakness, limited endurance Restricted weight-bearing status Maintaining cardiovascular conditioning or normal status of uninvolved extremities

Advantages Can be performed even if weight bearing is restricted Warmth of water can relax muscles, relieve pain Buoyancy reduces joint compressive forces Reduces weight bearing while allowing muscles to continue to function properly in the gait sequence

Advantages Can promote body awareness and balance Can relieve or reduce pain due to immobilization or edema Can be used early in rehabilitation program, helping to prevent deconditioning

Precautions for Aquatic Therex Fear of the water Medications Ear infections Conditions such as diabetes, cardiovascular disease, seizure disorders Never allow patient in pool unattended

Contraindications for Aquatic Therex Contagious infection Severe cold or flu Urinary tract infection Temperature of 100° F or more Open wounds

Application of Aquatic Principles Hydrostatic pressure: more advantageous to exercise swollen extremity in deep water Greater resistance achieved through longer lever arm, straighter extremity increased speed moving object at surface of water or with increased surface area

Aquatic Exercise Progression Early Use buoyancy equipment for increased range of motion. Do gait training in deep water. Use resistance exercises without equipment. (continued)

Aquatic Exercise Progression Mid Emphasize restoration of muscle strength and endurance. Use drag to increase resistance. Add resistive equipment. Increase reps and sets. (continued)

Aquatic Exercise Progression Advanced Focus on restoration of ABCs of proprioception Gait training more intense and varied Hopping, jumping, etc. Eyes open, closed. Increased intensity for strength (continued)

Aquatic Exercise Progression End phase Mimicking skills and demands of sport Aggressive coordination, agility, speed activities Plyometrics

Benefits of Deep-Water Exercise No weight bearing and no impact forces Can help maintain cardiovascular fitness and strength Forces of gravity on a submersed body are minimal Exercises essentially concentric

Correct Vertical Alignment

Correct Position for Deep-Water Running

Refraction of Light

Determining Depth of Water Patient’s confidence in the water Patient’s weight-bearing status Goals of the exercise