Definition of Aquatic Exercise
Aquatic exercise refers to the use of water (in multidepth immersion pools or tanks) that facilitates the application of established therapeutic interventions, including stretching, strengthening, joint mobilization, balance and gait training, and endurance training.
Goals and Indications for Aquatic Exercise
The specific purpose of aquatic exercise is to facilitate functional recovery by providing an environment that augments a patient's and/or practitioner's ability to perform various therapeutic interventions. Aquatic exercise can be used to achieve the following specific goals:
Facilitate range of motion (ROM) exercise14,31,43,83
Initiate resistance training14,20,40,43,62,68,82
Facilitate weight-bearing activities2
Enhance delivery of manual techniques3,72
Provide three-dimensional access to the patient,69,72
Facilitate cardiovascular exercise13,59,60,74
Initiate functional activity replication14,58,83
Minimize risk of injury or reinjury during rehabilitation25,83
Enhance patient relaxation31,48
Although research studies support these goals for aquatic exercise, Hall and associates41 cited the need for more research with robust designs that address temperature, depth of immersion, and care settings.
Precautions and Contraindications to Aquatic Exercise
Most patients easily tolerate aquatic exercise. However, the practitioner must consider several physiological and psychological aspects of immersion that affect selection of an aquatic environment.
Fear of water can limit the effectiveness of any immersed activity. Fearful patients often experience increased symptoms during and after immersion because of muscle guarding, stress response, and improper form with exercise. Often patients require an orientation period designed to provide instruction regarding the effects of immersion on balance, control of the immersed body, and proper use of flotation devices.58
Ataxic patients may experience increased difficulty controlling purposeful movements. Patients with heat-intolerant multiple sclerosis may fatigue with immersion in temperatures greater than 33°C.12,59,61 Patients with controlled epilepsy require close monitoring during immersed treatment and must be compliant with medication prior to treatment.49,69
Water immersion may adversely affect the breathing of the patient with a respiratory disorder. Lung expansion tends to be inhibited due to hydrostatic pressure against the chest wall. Additionally, increased circulation in the chest cavity may further inhibit lung expansion due to increased circulation to the center of the body. Maximal oxygen uptake is lower during most forms of water exercise than during land exercise.69
FOCUS ON EVIDENCE
Although the above precautions have been cited, Kurabayashi and associates51 compared nose and mouth immersion to non-immersion. Participants spent 30 minutes/day for five days/week for two months in the pool with water temperature set at 38° C. There was a significant difference in the immersion group with increased %FVC (p=0.058), increased FEV1.0% (p=0.018), increased peak flow (p=0.039), and increased Pao2 (p=0.010). Based on their findings, they recommended the use of subtotal immersion to improve respiratory function for individuals with chronic pulmonary emphysema. Pechter and colleagues60 compared 30 minutes of water-based aerobics to land-base aerobics done twice weekly for 12 weeks. The water-based group demonstrated increases in peak VO2, peak O2 pulse, peak ventilation, and peak load, as well as decreases in serum creatinine, glomerular filtration rate, cystatin-c in serum, protein/creatinine ratio, systolic and diastolic blood pressure, total serum cholersterol, and serum triglycerides. They recommended the use of low-intensity aquatic exercise to improve cardiorespiratory and renal function in individuals with chronic renal failure.
Patients with angina, abnormal blood pressure, heart disease, or compromised pump mechanisms also require close monitoring.19,78,80
FOCUS ON EVIDENCE
Meyer and Leblanc55 provided an algorithm for clinical decision-making when prescribing aquatic therapy for patients with left ventricular dysfunction and/or stable congestive heart failure. In their review of the literature, they suggested the following for rehabilitation and secondary prevention: 1) Temporary abnormal hemodynamic responses may be elicited by immersion to the neck. 2) Water therapy is absolutely contradindicated in patients with decompensated congestive heart failure. 3) Feeling good in water does not equate with left ventricular toleration of increased volume loading caused by immersion. 4) If patients with previous severe myocardial infarctions and/or congestive heart failure can sleep supine, they may be able to tolerate bathing in a half-sitting position provided immersion does not exceed the xiphoid process. 5) Patients with Q-wave myocardial infarctions older than 6 weeks may exercise in a pool for orthopedic reasons provided they do so in an upright position and immersion does not exceed the xiphoid process.
Small, Open Wounds and Lines
Small, open wounds and tracheotomies may be covered by waterproof dressings. Patients with intravenous lines, Hickman lines, and other open lines require proper clamping and fixation.69 Precautions should also be exercised with patients having G-tubes and suprapubic appliances. Observation for adverse reactions to aquatic therapy is essential.15
Contraindications to aquatic therapy include any situation creating the potential for adverse effects to either the patient or the water environment.8 Such factors include:
Incipient cardiac failure and unstable angina.
Respiratory dysfunction, vital capacity of less than 1 liter.
Severe peripheral vascular disease.
Danger of bleeding or hemorrhage.
Severe kidney disease (patients are unable to adjust to fluid loss during immersion).
Open wounds without occlusive dressings, colostomy, and skin infections, such as tinea pedis and ringworm.
Uncontrolled bowel or bladder (bowel accidents require pool evacuation, chemical treatment, and possibly drainage).
Menstruation without internal protection.
Water and airborne infections or diseases (examples include influenza, gastrointestinal infections, typhoid, cholera, and poliomyelitis).
Uncontrolled seizures during the last year (they create a safety issue for both clinician and patient if immediate removal from the pool is necessary).15
The unique properties of water and immersion have profound physiological implications in the delivery of therapeutic exercise. To utilize aquatics efficiently, practitioners must have a basic understanding of the clinical significance of the static and dynamic properties of water as they affect human immersion and exercise.
Physical Properties of Water
The properties provided by buoyancy, hydrostatic pressure, viscosity, and surface tension have a direct effect on the body in the aquatic environment.9,24,32,38,56
Definition. Buoyancy is the upward force that works opposite to gravity (Fig. 9.1).
Percentage of weight bearing at various immersion depths.
Properties. Archimedes' principle states that an immersed body experiences upward thrust equal to the volume of liquid displaced.32
Clinical significance. The effects of buoyancy include the following.
Buoyancy provides the patient with relative weightlessness and joint unloading by reducing the force of gravity on the body. In turn, this allows the patient to perform active motion with increased ease.
Buoyancy provides resistance to movement when an extremity is moved against the force of buoyancy. This technique can be used to strengthen muscles.
The amount of air in the lungs will affect buoyancy of the body. Buoyancy will be increased with fully inflated lungs and decreased with deflated lungs.
Body composition will also affect buoyancy. Obese patients will have increased buoyancy due to fat tissue having a lower specific gravity. Patients with increased bone density will have less buoyancy than those with decreased bone density.
Buoyancy allows the practitioner three-dimensional access to the patient.
Rotator cuff pathology. A patient recovering from rotator cuff repair can use the buoyancy force to increase range of motion in shoulder abduction and/or flexion while performing the motion in neck-deep water.11 When performing shoulder extension from a 90° flexed position, the force of buoyancy becomes a resistance as the patient pulls the arm downward through the water.
Definition. Hydrostatic pressure is the pressure exerted by the water on immersed objects.
Properties. Pascal's law states that the pressure exerted by fluid on an immersed object is equal on all surfaces of the object. As the density of water and depth of immersion increase, so does hydrostatic pressure.
Clinical significance. The effects of hydrostatic pressure include the following.
Increased pressure reduces or limits effusion, assists venous return, induces bradycardia, and centralizes peripheral blood flow.
The proportionality of depth and pressure allows patients to perform exercise more easily when closer to the surface.
Regulation of performance. Barbosa and colleagues4 compared the physiological adaptations of aquatic exercise with different levels of immersion to land exercise. Participants performed the same exercise on land, immersed to the hip, and immersed to the breast for 6 minutes. Physiological responses were higher when exercising immersed to the hip than when immersed to the breast and when exercising on land than immersed to either depth. The clinician should consider a progression from immersion to breast to immersion to hip to exercises on land to increase the physiological demands on the patient.
Definition. Viscosity is friction occurring between molecules of liquid resulting in resistance to flow.
Properties. Resistance from viscosity is proportional to the velocity of movement through liquid.
Clinical significance. Water's viscosity creates resistance with all active movements.
Lymphedema. Jamison46,47 cited the effectiveness of hydrostatic pressure and viscosity for increasing lymph flow and reducing edema in patients with lymphedema. However, caution is needed as the dependent position of the extremity may cancel this effect. Recommended aquatic activities include Watsu® (a form of water Zen Shiatsu incorporating stretches that release blockages and produce relaxation), Jahara, Ai Chi (a form of water Tai Chi), water aerobics, Halliwick Method® (a technique that increases balance, strength, coordination, and flexibility), and aquatic proprioceptive neuromuscular facilitation (PNF). The reader is referred to the following list of references for further information on these interventions:
Watsu®: Dull, H: WATSU® Freeing the Body in Water, ed. 4. Victoria, BC: Trafford Publishing, 2008.
Jahara: Jahara Journal 10th Anniversary Edition, 2007–2008. Available at: http://www.jahara.com Accessed 13 June 2010.
Ai Chi: Sova, R: Ai Chi—Balance, Harmony and Healing. Port Washington, WI: DSL, Ltd., 1999.
Water aerobics: Sova, R: Aquatics—The Complete Reference Guide for Aquatic Fitness Professionals. Port Washington, WI: DSL, Ltd., 2000.
Halliwick Method: Duffield, MH, Skinner, AT, and Thompson, AM: Duffield's Exercise in Water. Philadelphia: W.B. Saunders, 1983.
Aquatic PNF: Jamison, L, and Ogden, D: Aquatic Therapy Using PNF Patterns. Tuscon, AZ: Therapy Skills Builders, 1994.
Definition. The surface of a fluid acts as a membrane under tension. Surface tension is measured as force per unit length.
Properties. The attraction of surface molecules is parallel to the surface. The resistive force of surface tension changes proportionally to the size of the object moving through the fluid surface.
Clinical significance. The effect of surface tension includes the following.
Definition. Hydromechanics comprise the physical properties and characteristics of fluid in motion.38
Components of flow motion. Three factors affect flow; they are laminar flow, turbulent flow, and drag.
Laminar flow. Movement in which all molecules move parallel to each other, typically slow movement.
Turbulent flow. Movement in which molecules do not move parallel to each other, typically faster movements.
Drag. The cumulative effects of turbulence and fluid viscosity acting on an object in motion.
Clinical significance of drag. As the speed of movement through water increases, resistance to motion increases.5,42
Moving water past the patient requires the patient to work harder to maintain his or her position in pool.
Application of equipment (glove/paddle/boot) increases drag and resistance as the patient moves the extremity through water.62
Increasing resistance to motion. If the goal is to increase muscular force production during the early part of knee extension, the clinician should consider the use of a hydro-boot or similar device to increase the drag force on the leg/foot. Barbosa and associates5 measured hydrodynamic drag in barefoot and hydro-boot conditions to determine the coefficients of drag on a human leg/foot model during simulated knee extension-flexion exercise. The influence of water resistance created higher drag force when using the hydro-boot during the early part of extension.
Water temperature has an effect on the body and, therefore, on performance in an aquatic environment.42
Definition. Specific heat is the amount of heat (calories) required to raise the temperature of 1 gram of substance by 1°C.38
Properties. The rate of temperature change is dependent on the mass and the specific heat of the object.
Clinical significance. Water retains heat 1000 times more than air. Differences in temperature between an immersed object and water equilibrate with minimal change in the temperature of the water.
Center of buoyancy, rather than center of gravity, affects the body in an aquatic environment (Fig. 9.2).31,37,56
Definition. The center of buoyancy is the reference point of an immersed object on which buoyant (vertical) forces of fluid predictably act.
Properties. Vertical forces that do not intersect the center of buoyancy create rotational motion.
Clinical significance. In the vertical position, the human center is located at the sternum.
In the vertical position, posteriorly placed buoyancy devices cause the patient to lean forward; anterior buoyancy causes the patient to lean back.
During unilateral manual resistance exercises, the patient revolves around the practitioner in a circular motion.
A patient with a unilateral lower extremity amputation leans toward the residual limb side when in a vertical position.
Patients bearing weight on the floor of the pool (i.e., sitting, kneeling, standing) experience aspects of both the center of buoyancy and center of gravity.
Aquatic Temperature and Therapeutic Exercise
A patient's impairments and the intervention goals determine the water temperature selection. In general, utilize cooler temperatures for higher-intensity exercise and utilize warmer temperatures for mobility and flexibility exercise and for muscle relaxation.15,26,50,69 The ambient air temperature should be 3°C higher than the water temperature for patient comfort. Incorrect water or ambient air temperature selection may adversely affect a patient's ability to tolerate or maintain immersed exercise.
Temperature regulation during immersed exercise differs from that during land exercise because of alterations in temperature conduction and the body's ability to dissipate heat.15,26,69 With immersion there is less skin exposed to air, resulting in less opportunity to dissipate heat through normal sweating mechanisms.
Water conducts temperature 25 times faster than air9 — more if the patient is moving through the water and molecules are forced past the patient.
Patients perceive small changes in water temperature more profoundly than small changes in air temperature.
Over time, water temperature may penetrate to deeper tissues. Internal temperature changes are known to be inversely proportional to subcutaneous fat thickness.9
Patients are unable to maintain adequate core warmth during immersed exercise at temperatures less than 25°C.9,22
Conversely, exercise at temperatures greater than 37°C may be harmful if prolonged or maintained at high intensities. Hot water immersion may increase the cardiovascular demands at rest and with exercise.70
In waist-deep water exercise at 37°C, the thermal stimulus to increase the heart rate overcomes the centralization of peripheral blood flow due to hydrostatic pressure.
At temperatures greater than or equal to 37°C, cardiac output increases significantly at rest alone.15,18
Mobility and Functional Control Exercise
Aquatic exercises, including flexibility, strengthening, gait training, and relaxation, may be performed in temperatures between 26°C and 35°C.9,15,69
Therapeutic exercise performed in warm water (33°C) may be beneficial for patients with acute painful musculoskeletal injuries because of the effects of relaxation, elevated pain threshold, and decreased muscle spasm.9,15,69
Cardiovascular training and aerobic exercise should be performed in water temperatures between 26°C and 28°C. This range maximizes exercise efficiency, increases stroke volume, and decreases heart rate.18,69,76
There are several considerations for immersion times and pool temperatures.12,26,66,80
Because of the increased demands placed on the patient's temperature regulating systems when exercising in a pool the following are recommended.
Generally use a maximum immersion time of 20 minutes for patients with non-compromised cardiopulmonary systems. Begin with 10-minute sessions and increase the time as tolerated.
Always monitor vital signs to ensure patient safety.
Generally water temperatures between 36°C and 37°C are considered high and between 26°C and 35°C are considered low. In addition to the following guidelines, the patient's fatigue factor needs to be considered.
Higher temperatures are recommended for patients with rheumatoid arthritis except in the acute stage.
Lower temperatures are recommended for patients with spasticity or for those whose immersion time lasts 20 to 45 minutes.
For general flexibility, strengthening, gait training and relaxation, the range may be between 26°C and 35°C.9,15,69
Cardiovascular training and aerobic exercise should be performed in water temperatures between 26°C and 28°C.
Pools for Aquatic Exercise
Pools used for aquatic therapy vary in shape and size. The rooms in which pools are housed need to be adequately ventilated to avoid the accumulation of condensation on walls, windows, and floors. A dressing room should be provided for changing clothes and showering.
Traditional Therapeutic Pools
Traditional therapeutic pools measure at least 100 feet in length and 25 feet in width (Fig. 9.3). Depth usually begins at 3 to 4 feet with a sloping bottom, progressing to 9 or 10 feet.
Traditional therapeutic pool. (Courtesy of F.A. Davis Co., Philadelphia, PA.)
This larger type pool may be used for groups of patients and the therapists conducting the session while in the pool.
Entrance to larger therapeutic pools includes ramps, stairs, ladders, or mechanical overhead lifts.
These pools have built-in chlorination and filtration systems.
Pools designed for individual patient use are usually smaller, self-contained units (Fig. 9.4).
Hydro Track©, self-contained underwater treadmill system. (Courtesey of Ferno-Washington Inc., Wilmington, OH.)
These self-contained pools are entered via a door or one to two steps on the side of the unit.
The therapist provides instructions or cueing from outside the unit.
In addition to built-in filtration systems, these units may include treadmills, adjustable currents, and varying water depths.
Special Equipment for Aquatic Exercise
A large variety of equipment exists for use with aquatic exercise. Aquatic equipment is used to provide buoyant support to the body or an extremity, challenge or assist balance, and generate resistance to movement. Resistive paddles, floats, paddle boards, and weighted stools and chairs are just a few of the many types of available equipment. By adding or removing equipment, the practitioner can progress exercise intensity. Type of equipment used is determined by the current functional level of the patient and the specific goals for the therapy session.
Collars, Rings, Belts, and Vests
Equipment designed to assist with patient positioning by providing buoyancy assistance can be applied to the neck, extremities, or trunk. Inflatable cervical collars are used for the supine patient to support the neck and maintain the head out of the water (Fig. 9.5). Flotation rings come in various sizes and are used to support the extremities in any immersed position (Fig. 9.6). Often the rings are used at the wrists and ankles during manual techniques to assist with patient positioning and relaxation. Several types of belts exist that may be used to assist with buoyancy of an extremity or the entire body (Fig. 9.7). Belts and vests are used to position patients supine, prone, or vertically for shallow and deep water activities.
Cervical collar. (Courtesy of Rothhammer International Inc., San Luis Obispo, CA.)
Flotation rings. (Courtesy of Rothhammer International Inc., San Luis Obispo, CA.)
Buoyancy belts. (Courtesy of Rothhammer International Inc., San Luis Obispo, CA.)
Buoyant dumbbells (swim bars) are available in short and long lengths. They are useful for supporting the upper body or trunk in upright positions and the lower extremities in the supine or prone positions (Fig. 9.8). Patients can balance (seated or standing) on long swim bars in deep water to challenge balance, proprioception, and trunk strength.
Swim bars. (Courtesy of Rothhammer International Inc., San Luis Obispo, CA.)
Gloves, Hand Paddles, and Hydro-tone® Balls
Resistance to upper extremity movements is achieved by applying webbed gloves or progressively larger paddles to the hands (Fig. 9.9). These devices are not buoyant and, therefore, only resist motion in the direction of movement. Hydro-tone® bells are large, slotted plastic devices that increase drag during upper extremity motions. The bells generate substantially more resistance than gloves or hand paddles.
Hand paddles. (Courtesy of Rothhammer International Inc., San Luis Obispo, CA.)
Fins and Hydro-tone® Boots
The application of fins or boots to the feet during lower extremity motions generates resistance by increasing the surface area moving through the water. Fins are especially useful for challenging hip, knee, and ankle strength. Hydro-tone® boots are most effective during deep water walking and running (Fig. 9.10).
Hydro-tone® boots and bells. (Courtesy of Rothhammer International Inc., San Luis Obispo, CA.)
The shapes and styles of kickboards (Fig. 9.11) vary extensively among manufacturers. Nevertheless, kickboards remain a versatile and effective aquatic tool for augmenting any exercise program. Kickboards may be used to provide buoyancy in the prone or supine positions, create resistance to walking patterns in shallow water when held vertically, or used to challenge seated, kneeling, or standing balance in the deep water.
Kickboards. (Courtesy of Rothhammer International Inc., San Luis Obispo, CA.)
Therapeutic pools require regular care and cleaning to avoid Pseudomonas aeruginosa (an infection causing folliculitis).30,44,45 Frequent use increases the total organic carbon as well as ammonia and organic nitrogen found in the pool.
Cleaning should occur at least twice weekly, and chlorine and pH level tests should be done twice daily.
All walking surfaces near and around the pool should be slip-resistant and free of barriers. Water splashses should be dried immediately to prevent slips and falls.
Safety rules and regulations are a must, as are emergency procedures, and should be posted and observed by all involved in therapeutic pool use.84
Life preservers should be readily available and at least one staff member who is CPR certified should be present at all times.
Prior to the first therapeutic session, the treatment schedule, procedures to be used, and proper pool attire should be discussed with the patient. This is a good time to review their previous pool experiences and their expectations for the sessions, any bowel or bladder problems, use of any assistive or adaptive equipment, and medications.
Exercise Interventions Using an Aquatic Environment
Patients may tolerate immersed stretching exercises better than land stretching because of the effects of relaxation, soft tissue warming, and ease of positioning.14,17,31,43,83 However, buoyancy creates an inherently less stable environment than the land. Therefore, careful consideration is warranted when recommending aquatic stretching.
Manual Stretching Techniques
Manual stretching is typically performed with the patient supine in waist depth water with buoyancy devices at the neck, waist, and feet. Alternatively, the patient may be seated on steps. The buoyancy-supported supine position improves (versus land techniques) both access to the patient and control by the practitioner, as well as the position of the patient.
However, turbulence from wave activity can adversely affect both the patient's and the practitioner's ability to perform manual stretching. Difficulties may be experienced maintaining and perceiving the subtleties of end-range stretching and scapular stabilization in the supine buoyancy supported position. Anecdotal evidence indicates that careful consideration of all factors is warranted prior to initiating manual stretching in an aquatic environment.3,72
The manual stretching techniques described in this section are considered passive techniques but may be adapted to utilize muscle inhibition techniques. The principles of stretching are the same as those discussed in Chapter 4.
The following terms are used to describe the stretching techniques.
Practitioner position. Describes the orientation of the practitioner to the patient.
Patient position. Includes buoyancy-assisted (BA) seated or upright positioning and buoyancy-supported (BS) supine positioning.
Hand placement. The fixed hand, which stabilizes the patient, is typically the same (ipsilateral) hand as the patient's affected extremity, and it is positioned proximally on the affected extremity. The movement hand, which guides the patient's extremity through the desired motion and applies the stretch force, is typically the opposite (contralateral) hand as the patient's affected extremity and is positioned distally.
Direction of movement. Describes the motion of the movement hand.
Spine Stretching Techniques
Stand at the patient's head facing caudalward.
BS supine without cervical collar.
Cup the patient's head with your hands, the forearms supinated and thumbs placed laterally. Alternatively, place your hands in a pronated position with the thumbs at the occiput. This results in a more neutral wrist position at end-range stretch.
As you flex the cervical spine, the patient has a tendency to drift away from you if care is not taken to perform the motion slowly.
Cervical Spine: Lateral Flexion
Stand at the side facing the patient (Fig. 9.12).
Hand placement and stabilization for stretching to increase cervical lateral flexion.
BS supine without a cervical collar.
Reach the fixed hand dorsally under the patient and grasp the contralateral arm; support the head with the movement hand.
Move the patient into lateral flexion and apply stretch force at desired intensity. This position prevents patient drift as the fixed hand stabilizes the patient against the practitioner.
Thoracic and Lumbar Spine: Lateral Flexion/Side Bending
Stand on the side opposite that to be stretched, facing cephalad with ipsilateral hips in contact (e.g., if stretching the left side of the trunk, the therapist's right hip is against patient's right hip) (Fig. 9.13).
Hand placement and stabilization for stretching to increase lateral trunk flexion.
BS supine, if tolerated. The patient's stretch side arm is abducted to end-range to facilitate stretch.
Grasp the patient's abducted arm with the fixed hand; alternately, grasp at the deltoid if patient's arm is not abducted. The movement hand is at the lateral aspect of the lower extremity of the side to be stretched (more distal placement improves leverage with stretch).
With the patient stabilized by your hip, pull the patient into lateral flexion. This technique allows variability in positioning and hand placement to isolate distinct segments of the spine.
Shoulder Stretching Techniques
Stand on the side to be stretched facing cephalad (Fig. 9.14).
Hand placement and stabilization for stretching to increase shoulder flexion.
BS supine with the affected shoulder positioned in slight abduction.
Grasp the buoyancy belt with the fixed hand; the movement hand is at the elbow of the affected extremity.
After positioning the arm in the desired degree of abduction, direct the arm into flexion and apply the stretch force with the movement hand.
Stand on the affected side facing cephalad with your hip in contact with the patient's hip.
Stabilize the scapula with the fixed hand; the movement hand grasps medially on the affected elbow joint.
Guide the arm into abduction and apply the stretch force. The hip contact provides additional stabilization as the stretch force is applied.
Shoulder External Rotation
Stand lateral to the affected extremity facing cephalad.
BS supine; position arm in desired degree of abduction with elbow flexed to 90°.
Grasp the medial side of the patient's elbow with the palmar aspect of the fixed hand while fingers hold laterally; grasp the midforearm with the movement hand.
Movement hand guides forearm dorsally to externally rotate the shoulder and apply stretch force.
Shoulder Internal Rotation
Stand lateral to the patient's affected extremity facing caudalward.
BS supine; position arm in desired degree of abduction with elbow flexed to 90°.
Stabilize the scapula with the dorsal aspect of the fixed hand entering from the axilla; the movement hand is at the distal forearm.
Direct the forearm palmarward and apply the stretch force. Use care to observe the glenohumeral joint to avoid a forward thrust and substitution.
Hip Stretching Techniques
Kneel on one knee at the patient's affected side.
BS supine with the hip extended and the knee slightly flexed.
Stabilize the patient's affected extremity by hooking the top of the foot with your ipsilateral thigh. Grasp the buoyancy belt with the movement hand and guide the motion with the fixed hand on the knee.
Direct the patient caudally with the movement hand. To increase the stretch on the rectus femoris, lower the patient's knee in the water. Motion is performed slowly to limit spinal and pelvic substitution.
Face the lateral aspect of the patient's thigh with your ipsilateral arm under the patient's flexed knee.
BS supine; hip flexed 70° and knee flexed 90°.
Grasp the buoyancy belt with the contralateral (fixed) hand while the ipsilateral (movement) hand grasps the thigh.
Externally rotate hip with the movement hand as the patient's body lags through water to create stretch force.
Face the lateral aspect of the involved thigh with the ipsilateral arm under the flexed knee.
BS supine, hip flexed 70° and knee flexed 90°.
Stabilize the buoyancy belt with the contralateral (fixed) hand while grasping the thigh with the ipsilateral (movement) hand.
Internally rotate the hip as the patient's body lags through water to create the stretch force.
Knee Stretching Techniques
Knee Extension with Patient on Steps
Half-kneel lateral to the affected knee with the ankle of the affected extremity resting on your thigh.
Semi-reclined on pool steps.
Place one hand just proximal and one just distal to the knee joint.
Extend the patient's knee.
Knee Flexion with Patient on Steps
Half-kneel lateral to the affected knee.
Semi-reclined on pool steps.
Grasp the distal tibia with the ipsilateral hand; the contralateral hand stabilizes the lateral aspect of affected knee.
The stretch force into flexion.
Knee Flexion with Patient Supine
Half-kneel lateral to the affected knee with the dorsal aspect of the patient's foot hooked under the ipsilateral thigh (Fig. 9.15).
Hand placement and stabilization for stretching to increase knee flexion.
BS supine, affected knee flexed.
Place the ipsilateral (fixed) hand on distal tibia and the contralateral (movement) hand on buoyancy belt to pull the body over the fixed foot.
Pull the patient's body over the fixed foot, creating the stretch to increase knee flexion. Lower the patient's knee into the water to extend the hip and increase the stretch on the rectus femoris. Perform the motion slowly to limit spinal and pelvic substitution.
Face the patient and rest the patient's affected extremity on your ipsilateral shoulder.
BS supine, knee extended.
Place both hands at distal thigh.
Start in the squatting position and gradually stand to flex the hip and apply the stretch force. Maintain knee extension by pulling the patient closer and increasing the stretch.
Self-Stretching with Aquatic Equipment
Often the intervention plan is to instruct the patient to perform independent stretching.26,39,64,67 Self-stretching can be performed in either waist-deep or deep water. The patient frequently utilizes the edge of the pool for stabilization in both waist-depth and deep water.
Applying buoyancy devices may assist with stretching and increase the intensity of the aquatic stretch.76,83 However, buoyancy devices are not required to achieve buoyancy-assisted stretching—that is, as buoyancy acts on any submersed extremity, correct patient positioning adequately produces a gentle stretch. The following guidelines describe the use of equipment for mechanical stretching; the descriptions apply similarly for use without buoyancy equipment. Providing verbal cueing and visual demonstration for patient positioning and form aids in achieving the desired stretching effects.
Positioning for self-stretching of every body part is not described in this section. Typically, positioning for immersed self-stretches reflects traditional land positioning.
The following terms are used to describe the self-stretching techniques.
Patient position. Includes buoyancy-assisted (seated/upright), buoyancy-supported (supine), or vertical.
Buoyancy-assisted. Using the natural buoyancy of water to "float" the extremity toward the surface.
Equipment-assisted. Includes use of buoyancy devices attached or held distally on an extremity.
The following are some examples of self-stretching.
Shoulder Flexion and Abduction
Upright, neck level immersion.
Small or large buoyant dumbbell or wrist strap.
Grasping the buoyant device with the affected extremity allows the extremity to float to the surface as the buoyancy device provides a gentle stretch.
Upright, immersed to waist, or seated at edge of pool/on steps with hips immersed (Fig. 9.16).
Self-stretching technique to increase hip flexion (stretch the hamstrings) using aquatic equipment.
Small buoyant dumbbell or ankle strap. For hip flexion with knee flexion, place strap/dumbbell proximal to the knee. For hip flexion with knee extension (to stretch the hamstrings), place strap/dumbbell at the ankle.
Allow buoyancy device to float hip into flexion, applying stretch to hip extensors or hamstrings.
Seated on steps/edge of pool with knee in a position of comfort.
Small dumbbell or ankle strap.
Allow buoyancy device to extend knee toward the surface applying stretch to increase knee extension.
Stand immersed to waist with hip and knee in neutral position; increasing the amount of hip extension increases the stretch on the two joint knee extensors.
Small dumbbell or ankle strap.
Allow buoyancy device to flex the knee toward the surface, applying stretch to knee extensors.
By reducing joint compression, providing three-dimensional resistance, and dampening perceived pain, immersed strengthening exercises may be safely initiated earlier in the rehabilitation program than traditional land strengthening exercises.83 Both manual and mechanical immersed strengthening exercises typically are done in waist-depth water. However, some mechanical strengthening exercises may also be performed in deep water. Frequently, immersion alters the mechanics of active motion. For example, the vertical forces of buoyancy support the immersed upper extremity and alter the muscular demands on the shoulder girdle.76 Furthermore, studies have demonstrated that lower extremity demand is inversely related to the level of immersion during closed-chain strengthening.4,5,36
Manual Resistance Exercises
Application of aquatic manual resistance exercises for the extremities typically occurs in a concentric, closed-chain fashion.3,72 Manual aquatic resistance exercises are designed to fixate the distal segment of the extremity as the patient contracts the designated muscle group(s). The practitioner's hands provide primary fixation and guidance during contraction. As the patient contracts his or her muscles, the body moves over or away from the fixed distal segment (generally over the fixed segment for the lower extremity and away from the fixed segment for the upper extremity). The patient's movement through the viscous water generates resistance, and the patient's body produces the drag forces. Verbal cueing by the practitioner is essential to direct the patient when to contract and when to relax, thereby synchronizing practitioner and patient.
Stabilization of the distal extremity segment is essential for maintaining proper form and isolating desired muscles. However, appropriate stabilization is not possible in the buoyancy-supported supine position for eccentric exercises or rhythmic stabilization of the extremities. The patient's body will have a tendency to tip and rotate in the water. In addition, the practitioner will have difficulty generating adequate resistance force, and the patient's body will move easily across the surface of the water with minimal drag producing inadequate counterforce to the practitioner's resistance. When supine, some motions, including horizontal shoulder adduction and abduction, should be avoided because of the difficulty the patient may have isolating proper muscle groups. Nevertheless, for many motions, the aquatic environment allows closed-chain resistive training through virtually limitless planes of motion.
The following terms refer to manual resistance exercise in water.
Practitioner position. Describes the orientation of the practitioner to the patient.
Patient position. Buoyancy-supported in the supine position.
Hand placement. The guide hand is generally the ipsilateral hand as the patient's affected extremity and typically is positioned more proximally. It directs the patient's body as muscles contract to move the body through the water. The resistance hand is generally the contralateral hand and typically is placed at the distal end of the contracting segment. More distal placement increases overall resistance.
Direction of movement. Describes the motion of the patient.
Upper Extremity Manual Resistance Techniques
Face caudal, lateral to the patient's affected shoulder (Fig. 9.17 A & B).
Manual resistance exercise for strengthening shoulder flexion. (A) start position and (B) end position.
BS supine; affected extremity flexed to 30°.
Place the palmar aspect of the guide hand at the patient's acromioclavicular joint. The resistance hand grasps the distal forearm. An alternative placement for the resistance hand may be the distal humerus; this placement alters muscle recruitment.
Active shoulder flexion against the resistance hand causes the body to move away from the practitioner. Active shoulder extension from a flexed position causes the body to glide toward the practitioner.
NOTE: The patient must be able to actively flex through 120° for proper resistance to be provided.
Face medially, lateral to the patient's affected extremity.
BS supine; affected extremity in neutral.
Place the palmar aspect of guide hand at the proximal humerus as the thumb wraps anteriorly and the fingers wrap posteriorly. Place the resistance hand at the lateral aspect of distal humerus.
The practitioner determines the amount of external rotation and elbow flexion. Active abduction against the resistance hand causes the body to glide away from the affected extremity and the practitioner.
Shoulder Internal/External Rotation
Face medially on the lateral side of the patient's affected extremity (Fig. 9.18 A & B).
Manual resistance exercise for strengthening shoulder external rotation. (A) start position and (B) end position.
BS supine; affected extremity's elbow flexed to 90° with the shoulder in the desired amount of abduction and initial rotation.
Place the palmar aspect of the guide hand at the lateral aspect of the elbow. The resistance hand grasps the palmar aspect of the distal forearm. An alternative method requires the practitioner to "switch" hands. The practitioner's ipsilateral hand becomes the guide hand and grasps the buoyancy belt laterally. The practitioner's contralateral hand becomes the resistance hand. This approach allows improved stabilization; however, the practitioner loses contact with the patient's elbow and must cue the patient to maintain the desired degree of shoulder abduction during the exercise.
Active internal rotation by the patient against the resistance hand causes the body to glide toward the affected extremity; active external rotation causes the body to glide away from the affected extremity.
Unilateral Diagonal Pattern: D1 Flexion/Extension of the Upper Extremity
Stand lateral to the patient's unaffected extremity and face medially and caudally.
BS supine; affected extremity internally rotated and pronated with slight forward flexion.
Secure the medial and lateral epicondyles of the distal humerus with the guide hand. Place the resistance hand on the dorsal surface of the distal forearm.
Prior to contraction, cue the patient to execute the specific joint motions expected in the diagonal patterns. Active contraction through the D1 flexion pattern causes the body to glide away from the practitioner. At the end position of D1, secure the medial and lateral epicondyles of the distal humerus with the guide hand. The resistance hand will be on the palmar aspect of the distal forearm. From the flexed position, the practitioner cues the patient to contract through the D1 extension pattern.
Unilateral Diagonal Pattern: D2 Flexion/Extension of the Upper Extremity
Stand lateral to the patient's affected shoulder; face medially and caudally (Fig. 9.19 A & B).
Manual resistance exercise for upper extremity unilateral diagonal D2 flexion pattern. (A) start position and (B) end position.
BS supine; affected extremity adducted and internally rotated.
Secure the medial and lateral epicondyles of the distal humerus with the guide hand. Wrap the palmar aspect of the resistance hand on the dorsal wrist medial to the palmar surface.
Active movement through the D2 flexion pattern causes the body to glide away from the practitioner. From the fully flexed position, cue the patient to then move into the D2 extension pattern. This causes the body to glide toward the practitioner.
Bilateral Diagonal Pattern: D2 Flexion/ Extension of the Upper Extremities
Stand cephalad to patient, facing caudally (Fig. 9.20 A & B).
Manual resistance exercise for upper extremity bilateral diagonal D2 pattern. (A) start position and (B) end position.
BS supine; upper extremities adducted and internally rotated.
Use both hands to provide resistance. Grasp the dorsal aspect of each of the patient's wrists, wrapping medially to the palmar surface.
Active contraction through the D2 flexion pattern causes the body to glide away from the practitioner. From the fully flexed position, cue the patient to contract through D2 extension, causing the patient to move toward the practitioner.
Lower Extremity Manual Resistance Techniques
Stand lateral to the patient's affected extremity and face medially.
Place the guide hand on the buoyancy belt and the resistance hand on the patient's medial thigh.
Active contraction of the hip adductors causes the affected leg to adduct as the contralateral leg and body glides toward the affected leg and the practitioner.
Stand lateral to patient's affected extremity, facing medially (Fig. 9.21).
Manual resistance exercise for strengthening hip abduction with resistance applied to lateral aspect of the leg.
Place the guide hand on the buoyancy belt or lateral thigh and the thumb and base of the resistance hand on the patient's lateral leg.
Active contraction of the hip abductors causes the affected leg to abduct as the contralateral leg and body glide away from the affected leg and the practitioner.
Hip Flexion with Knee Flexion
Stand at the side of the patient's affected extremity, facing cephalad (Fig. 9.22).
Manual resistance exercise for strengthening hip and knee flexion.
Place the guide hand on the buoyancy belt or lateral hip. The resistance hand grasps proximal to the distal tibiofibular joint.
Active contraction of the hip and knee flexors causes the patient's body to glide toward the practitioner and fixed distal extremity.
Hip Internal/External Rotation
Stand lateral to the patient's affected extremity, facing medially.
BS supine; hip in neutral at 0° extension with knee flexed to 90°.
Contact the distal thigh medially with the guide hand for resisted internal rotation and laterally for resisted external rotation. Place the resistance hand at the distal leg.
Active contraction of hip rotators (alternating between internal and external rotation) causes the patient's body to glide away from the distal fixed segment.
PRECAUTION: Avoid this exercise for patients with possible medial or lateral knee joint instability.
Stand at the patient's feet, facing cephalad.
Place the guide hand at the patient's lateral thigh and the resistance hand on the dorsal aspect of the distal tibiofibular joint.
Active contraction of the quadriceps against the practitioner's resistance hand directs the body away from the practitioner as the knee extends.
Stand lateral to the affected leg, facing caudally.
The hand placement creates a short lever arm at the patient's ankle. As the patient moves through the resisted ankle motions, the patient's entire body moves through the water, producing a significant amount of drag and demand on the ankle complex.
PRECAUTION: For patients with ligamentous laxity and unstable ankles or compromised ankle musculature, the practitioner should cue the patient to avoid maximum effort during contraction to avoid potential injury.
Ankle Dorsiflexion and Plantarflexion
Place the guide hand on the lateral aspect of the leg and the resistance hand over the dorsal aspect of the foot to resist dorsiflexion and on the plantar aspect to resist plantarflexion.
The body moves toward the practitioner during dorsiflexion and away from the practitioner during plantarflexion.
Ankle Inversion and Eversion
Place the guide hand on the lateral aspect of the lower leg during inversion and on the medial aspect of tibia during eversion. To resist inversion, grasp the dorsal medial aspect of the foot and to resist eversion grasp the lateral foot.
During inversion, the body glides toward the practitioner, and during eversion, the body glide aways from the practitioner.
Dynamic Trunk Stabilization
By applying concepts utilized for spinal stabilization exercises on land (see Chapters 15 and 16), the practitioner can challenge the dynamic control and strength of the trunk muscles in the aquatic environment. The BS supine position creates a unique perceptual environment for the patient.
Dynamic Trunk Stabilization: Frontal Plane
Hold the patient at the shoulders or feet (Fig. 9.23).
Isometric trunk stabilization exercise using side-to-side motions of the trunk.
Typically, the patient is placed in a supine position with buoyancy devices at the neck, waist, and legs.
Have the patient identify his or her neutral spine position, perform a "drawing-in maneuver" (see Chapter 16), and maintain the spinal position (isometric abdominal contraction). Move the patient from side to side through the water; monitor and cue the patient to avoid lateral trunk flexion, an indication that the patient is no longer stabilizing the spine.
Moving the patient through the water faster increases drag and exercise intensity. Holding the patient more distally increases exercise intensity.
Dynamic Trunk Stabilization: Multidirectional
Stand at the shoulders or feet of the patient and grasp the patient's extremity to provide fixation as the patient contracts.
Typically, the patient is placed in a supine position with buoyancy devices at the neck, waist, and legs.
Instruct the patient to assume a neutral spine, perform the drawing-in maneuver, and "hold" the spine stable. Instruct the patient to perform either unilateral or bilateral resisted extremity patterns while maintaining a neutral spine and abdominal control. Monitor and cue the patient to avoid motion at the trunk, an indication that the patient is no longer stabilizing with the deep abdominal and global muscles. Upper extremity motions include shoulder flexion, abduction, and diagonal patterns. Lower extremity motions include hip and knee flexion and hip abduction and adduction.
Unilateral patterns are more demanding than bilateral patterns. Increasing speed or duration increases exercise intensity.
Independent Strengthening Exercises
Often patients perform immersed strengthening exercises independently. Because the resistance created during movement through water is speed-dependent, patients are able to control the amount of work performed and the demands imposed on contractile elements.35,42,69 Typically, positioning and performance of equipment-assisted strengthening activities in water reflect that of traditional land exercise. However, the aquatic environment allows patients to assume many positions (supine, prone, side-lying, seated, vertical). Attention to specific patient positioning allows the practitioner to utilize the buoyant properties of water and/or the buoyant and resistive properties of equipment that can either assist or resist patient movement.11,26,50,62 Before initiating immersed strengthening activities, patients should be oriented to the effects of speed and surface area on resistance. Specific exercises for mechanical strengthening of every body part are not described. Only selected exercises are discussed and illustrated to reinforce major concepts and principles of application.
The following terms are used for equipment-assisted exercise.
Buoyancy-assisted (BA): Vertical movement directed parallel to vertical forces of buoyancy that assist motion (patient may use buoyant equipment to assist with motion).
Buoyancy-supported (BS): Horizontal movement with vertical forces of buoyancy eliminating or minimizing the need to support an extremity against gravity (patient may use buoyant equipment to assist with motion).
Buoyancy-resisted (BR): Movement directed against or perpendicular to vertical forces of buoyancy, creating drag (performed without equipment).
Buoyancy-superresisted (BSR): Use of equipment generates resistance by increasing the total surface area moving through water by creating greater drag. Increasing the speed of motion through water generates further drag.
Extremity Strengthening Exercises
The most common aquatic upper and lower extremity strengthening exercises are outlined in Table 9.1.26,50 Typically, patients are positioned standing immersed to shoulder level for upper extremity strengthening and to mid-trunk level for lower extremity strengthening (Fig. 9.24 A, B, C, D, and E). However, many exercises may be performed with the patient positioned vertically in deep water. The prone or supine position is useful when practitioners wish to progress patients or when patients require position-specific or sports-specific strengthening. Some exercises, most notably bilateral lower extremity diagonals, require the patient to be positioned supine, prone, or vertical in deep water.
Mechanical resistance for strengthening (A) shoulder internal and external rotation, (B) elbow flexion and extension, (C) hip flexion and extension, (D) functional squatting, and (E) ankle plantarflexion.
TABLE 9.1Summary of Motions Used for Upper and Lower Strengthening Exercises ||Download (.pdf) TABLE 9.1 Summary of Motions Used for Upper and Lower Strengthening Exercises
|Shoulder ||Flexion/extension |
| ||Abduction/adduction |
| ||Horizontal abduction/adduction |
| ||Internal/external rotation |
| ||Unilateral diagonals |
| ||Bilateral diagonals |
|Elbow ||Flexion/extension |
| ||Diagonals |
| ||Push/pull |
|Hip ||Flexion/extension |
| ||Abduction/adduction |
| ||Internal/external rotation |
| ||Unilateral diagonals |
| ||Bilateral diagonals |
|Knee ||Flexion/extension |
| ||Diagonals |
Lumbar Spine Strengthening
Spinal stabilization may be performed in shallow, mid-depth, or deep water levels. Typically, patients are instructed to maintain a neutral spine with the drawing-in maneuver (see Chapter 16) while performing functional activities or moving the extremities. The patient's ability to stabilize the spine can be challenged by increasing the duration of the activity, the speed or surface area moving through water, and by the addition of buoyant devices in the deep water. The exercises are summarized in Table 9.2.
TABLE 9.2Summary of Lumbar Spine-Strengthening Exercises ||Download (.pdf) TABLE 9.2 Summary of Lumbar Spine-Strengthening Exercises
|Standing ||Walking patterns: forward, backward, lateral, lunge walk, high stepping |
| ||Unilateral/bilateral stance with upper extremity motions |
|Semi-reclined ||Bicycling |
| ||Hip abduction/adduction |
| ||Flutter kick |
| ||Bilateral lower extremity PNF patterns |
| ||Unilateral/bilateral hip and knee flexion/extension |
|Supine ||Bridging with long dumbbell placed at knees |
| ||Swimming kicks |
|Prone ||Swimming kicks |
|Deep water ||Vertical stabilization exercises; abdominal bracing with arm and leg motions in the pike and iron-cross positions |
| ||Seated on dumbbell; abdominal bracing and balance while performing unilateral or bilateral arm motions |
| ||Standing on a kickboard or dumbbell; abdominal bracing and balance while performing bicycling motions and/or arm motions |
Trunk-Strengthening Exercises: Standing
Have the patient hold a kickboard vertically in the water to increase resistance while walking in various patterns.
Have the patient use unilateral or bilateral stance while performing upper extremity motions. The buoyant and turbulent forces of the water require co-contraction of the trunk muscles to stabilize the immersed body. Use equipment (Hydro-tone® bells, paddles, resistive tubing) to increase resistance and the need for co-contraction of the trunk muscles.
Trunk-Strengthening Exercises: Semi-Reclined
Patients may use noodles, dumbbells, or kickboards for support. The practitioner can further challenge the patient by having him or her hold buoyant equipment, such as paddles, and then stabilize the trunk against the movement. A variety of lower extremity movements are suggested in Table 9.2.
Trunk-Strengthening Exercises: Supine
Various swimming kicks are used in the supine position. Instruct the patient to concentrate on the drawing-in maneuver and on maintaining the neutral spine position while moving the legs. Bridging while maintaining a neutral spine can be done with a long dumbbell placed at the knees.
Trunk-Strengthening Exercises: Prone
In the prone position, various swimming kicks, such as the flutter kick, are used while the patient performs the drawing-in maneuver and maintains a neutral spine.
Trunk-Strengthening Exercises in Deep Water
Stabilization exercises performed in deep water with the patient positioned vertically typically require the patient to brace with the abdominal muscles.21,71,81 Emphasize identifying the neutral spine, activating the drawing-in maneuver, and holding the spine in the stable position while performing the various activities. Utilize any combination of unilateral or bilateral upper and/or lower extremity motions to further challenge the stabilization effort. Add equipment devices to the hands or legs for additional resistance and increased challenge when the patient can maintain good stabilization control. Variations include:
Altering trunk positions such as the pike position or the iron-cross position.
Sitting on a dumbbell and bicycling forward or backward or moving the upper extremities through any combination of motions.
Standing on a kickboard or dumbbell and moving the upper extremities through various combinations of motions, first without then with equipment. Such standing activities typically induce obligatory abdominal bracing and challenges to balance.
Aquatic exercise that emphasizes aerobic/cardiovascular conditioning can be an integral component of many rehabilitation programs.59,82 Aerobic/cardiovascular exercise typically takes place with the patient suspended vertically in deep water pools without the feet touching the pool bottom. Alternative activities that may be performed in mid-level water, 4 to 6 feet in depth, include jogging, swimming strokes, immersed cycling, and immersed treadmill. Understanding the various treatment options, physiological responses, monitoring methods, proper form, and equipment selection allows the clinician to use this form of exercise effectively and safely in a rehabilitation program.
Deep-water walking/running (Fig. 9.25). Deep water walking and running are the most common vertical deep-water cardiovascular endurance exercises. Alternatives include cross-country motions and high-knee marching. Deep-water cardiovascular training, which may be used as a precursor to mid-water or land-based cardiovascular training, eliminates the effects of impact on the lower extremities and spine.
Deep water walking/jogging. (Courtesy of Rothhammer International Inc. San Luis Obispo, CA.)
The patient can be tethered to the edge of the pool to perform deep-water running in those pools with limited space. Some small tanks provide resistance jets for the patient to move against.
Mid-water jogging/running (immersed treadmill running). Mid-water aerobic exercise, which may be used as a precursor to land training, lessens the effects of impact on the spine and lower extremities. As a patient's tolerance to impact improves, mid-water jogging may be performed in progressively shallower depths to provide increased weight bearing and functional replication. In pools with limited space, tethering with resistive tubing can provide resistance.
Immersed equipment. Immersed equipment includes an immersed cycle, treadmill, or upper body ergometer.
Swimming strokes. For patients able to tolerate the positions necessary to perform various swim strokes (neck and shoulder ROM and prone, supine, or side-lying positions), swimming can be an excellent tool to train and improve cardiovascular fitness. Swimming may elicit significantly higher elevations of heart rate, blood pressure, and VO2max than other aquatic activities. Swimming contributes the added benefit of hip and trunk strengthening for some patients with spinal conditions.
PRECAUTION: Recommending swimming for poorly skilled swimmers with cardiac compromise may adversely challenge the patient's cardiovascular system.
Physiological Response to Deep-Water Walking/Running
Various physiological responses to deep-water walking and running have been reported.1,13,23,33,34,65
Cardiovascular response. Patients without cardiovascular compromise may experience dampened elevation of heart rate, ventilation, and VO2max compared to similar land-based exercise. During low-intensity exercise, cardiac patients may experience lower cardiovascular stresses.54 As exercise intensity increases, cardiovascular stresses approach those of related exercise on land.4,78
Training effect. Patients experience carryover gains in VO2max from aquatic to land conditions.45 Additionally, aquatic cardiovascular training maintains leg strength and maximum oxygen consumption in healthy runners.33,34,49,76
Proper Form for Deep-Water Running
Instruction for beginners. Proper instruction is important to ensure correct form because many beginners experience a significant learning curve.9 Once immersed, the patient should maintain a neutral cervical spine and slightly forward flexed trunk with the arms at the sides. During running the hips should alternately flex to approximately 80° with the knee extended and then extend to neutral as the knee flexes.
Accommodating specific patient populations. For patients with positional pain associated with spinal conditions, a posterior buoyancy belt helps maintain a slightly forward flexed position, and a flotation vest helps maintain more erect posture and a relatively extended spine. Patients with unilateral lower extremity amputations may have difficulty maintaining a vertical position. Placing the buoyancy belt laterally (on the contralateral side of the amputation) allows the patient to remain vertical more easily.
Monitoring intensity of exercise. Monitor the rate of perceived exertion and heart rate.
Rate of perceived exertion. Because skill may affect technique, subjective numerical scales depicting perceived effort may inadequately identify the level of intensity for novice deep-water runners. However, at both submaximal and maximal levels of exertion, subjective numerical rating of effort appears to correlate adequately with the heart rate during immersed exercise.33
Heart rate. Because of the physiological changes that occur with neck level immersion, various adjustments have been suggested in the literature to lower the immersed maximum heart rate during near-maximum cardiovascular exercise.1,13,23,65,76 The suggested decreases range from 7 to 20 beats per minute.1,13,23,65,76 The immersed heart rate can be reliably monitored manually or with water-resistant electronic monitoring devices.
Monitoring beginners. Care should be taken to monitor regularly the cardiovascular response of novice deep-water runners or patients with known cardiac, pulmonary, or peripheral vascular disease.55 Novice deep-water runners may experience higher levels of perceived exertion and VO2max than they would during similar land exercise.23
Deep water equipment. Selection of buoyancy devices should reflect the desired patient posture, comfort, and projected intensity level. The most common buoyant device for deep-water running is the flotation belt positioned posteriorly (see Fig. 9.7). Patients presenting with injuries or sensitivity of the trunk may require an alternative buoyant device, such as vests, flotation dumbbells, or noodles. Providing the patient with smaller buoyant equipment (i.e., smaller belts, fewer noodles) requires the patient to work harder to maintain adequate buoyancy, thereby increasing the intensity of the activity. Fins and specially designed boots can be applied to the legs and feet to add resistance. Also, bells or buoyant dumbbells can be held in the hands to increase resistance (see Fig. 9.10).
Midwater equipment. Specially designed socks can help eliminate the potential problem of skin breakdown on the feet during impact activities, such as running. Patients can run against a forced current or tethered with elastic tubing for resistance. Using noodles around the waist or running while holding a kickboard increases the amount of drag and resistance against which the patient must move.