By Rich Harris, MSc, CSCS, PTA, CES, CSAC, and Jose Dominguez, PT, MS, ATC

The therapy staff at Fyzical Therapy and Balance Center, Mechanicsburg, Pa, has successfully utilized the many benefits of water therapy to help rehabilitate members of its patient population, which is composed of individuals affected by a variety of physical ailments and diagnoses. At this clinic, patients of all ages with a variety of conditions, including postsurgery rehabilitation, impaired balance, joint replacements, and chronic pain, have been treated successfully with aquatic therapy. The physical therapy market in south-central Pennsylvania is fiercely competitive with many other privately owned clinics, corporate practices, and multiple large health systems. However, having a heated therapy pool equipped with multiple underwater treadmills helps Fyzical remain very competitive. It does so because water provides physical properties that can help ease the rehabilitation process where land-based programs have proven inadequate for conditions such as osteoarthritis, fibromyalgia, joint replacements, anterior cruciate ligament (ACL) reconstruction, muscle weakness, gait disturbances, as well as neurological disorders.

Bouyancy for Unweighting

Aquatic therapy has tremendous rehabilitative potential, which ranges from the treatment of acute injuries as well as overall health maintenance of many chronic diseases.1 There is also considerable research which has demonstrated the efficacy of aquatic therapy, both within the basic science literature and clinical literature.1 Exercising in water provides benefits that land-based programs cannot offer due to the principles of hydrodynamics. The physical properties of water, such as viscosity, hydrostatic pressure, thermodynamics, as well as buoyancy, create tremendous biological changes as the result of water immersion. The buoyancy of water is created by submerging the body, which causes water displacement and the resultant force of buoyancy.

To understand the benefits of buoyancy, consider that when the body is immersed in waist-high water to the umbilicus, approximately 50% of the weight of the body is reduced. Furthermore, when submerged to the chest, about 75% of the body’s weight is reduced. The result of this buoyancy, especially for individuals affected by arthritis or joint-related pain symptoms, is the ability to move more freely in the water. This creates an environment where clients can perform movement and activities with considerably less pain than on dry land. Likewise, it allows the participant to move with greater ease due to the sensation of feeling lighter in the water.

Patients who suffer from osteoarthritis are able to walk and even jog in water, thus improving their range of motion, strength, fitness, and overall function. To illustrate this point, one study demonstrated that participants significantly improved knee and hip flexibility, strength, and aerobic fitness while performing aquatic exercise while rehabilitating from arthritis.2

[sidebar float=”right” width=”250″]Product Resources

The following companies provide products for aquatic therapy:

Aquatic Access Inc

Endless Pools

Hudson Aquatic Systems LLC


Nespa Tiled Spas

NZ Manufacturing

Sprint Aquatics

Sure Hands Lift and Care Systems

SPRI Products


Gentle Resistance

Another attribute of water that creates an additional benefit to the therapeutic environment is hydrostatic pressure. Water exerts a pressure of 22.4 mm Hg/ft of water depth, which equates to 1mm Hg/1.36 cm (0.54 inches) of water depth.1 It is this pressure that improves circulation and provides more oxygen and nutrients to injured tissues as well as reduces edema from injured extremities. When moving or exercising in water, viscosity or the opposition of the water creates a sensation of drag or friction to the body that provides a gentle resistance that can be used to improve muscle strength. The greater the force the body applies to the water, the greater the resultant viscous force and therapeutic resistance provided.

The thermodynamics of water include both a heat capacity that is 1,000 times greater than an equivalent volume of air, and the quality of being an efficient conductor which transfers heat 25 times faster than air.1 These properties also make the use of water in rehabilitation very effective. At the Fyzical clinic location in Mechanicsburg, the pool water temperature is maintained at 89 degrees, which creates a warm and comfortable therapeutic environment for exercising.

To provide the benefits of aquatic therapy to its clientele, Fyzical has installed three AquaGaiter underwater treadmills submerged in a 5-foot section of our pool. These underwater treadmills from Hudson Aquatic Systems LLC, Angola, Ind, help speed the recovery process for patients by utilizing all of the aforementioned attributes that water provides. The Hudson AquaGaiter provides the clinic’s patients with the option to walk or move in multiple directions or even jog in water while taking advantage of the many benefits water creates. Many patients are able to walk greater distances and speeds than they could by walking on land-based treadmills or outdoors on sidewalks or roads. Even older adult patients that have compromised balance or gait disturbances are able to walk safely and confidently without the fear of falling, as the AquaGaiter has side rails that the patient can hold onto and use to help maintain their balance.

From a sports-related perspective, the clinic can begin to have its athlete clientele begin a more aggressive but safe rehabilitation process by having them run much sooner on the Hudson AquaGaiter than would be possible on land; providing them a head start toward returning to their sport. To illustrate this point, Vinit Patel (pictured) is one of the clinic’s recent patients who suffered an ACL injury while playing college football. He had ACL reconstructive surgery and was referred to the Mechanicsburg clinic for physical therapy. After being approved by his surgeon, Patel began a running program at the facility on the Hudson AquaGaiter much sooner than a land treadmill would allow due to the many benefits of the aquatic environment; particularly in his case the benefit of buoyancy, which removed the stress of gravity from his newly constructed graft.

Moving Forward with Aquatics

Physical therapy clinics considering whether an aquatics program could be the next step in enhancing its services or expanding its client base have certain considerations to address, including the task of researching and identifying a full-size pool or modular unit that provides the needed features and at an acceptable cost. Budgets and target clientele vary. For example, one clinic may need only a modular unit equipped with an underwater treadmill that accommodates a single user and fits within an existing gym area; while another clinic may have the resources to build out a new space with a below-ground pool equipped with a movable floor, underwater cameras, underwater treadmills, or resistance jets.

Hudson’s AquaGaiter met the needs of Fyzical’s aquatic program, but several manufacturers offer pool products tailored for the PT market. Among them is HydroWorx, Middletown, Pa, which offers an above-ground and in-ground pools in a range of sizes and feature sets. Another source is SwimEx, Fall River, Mass, which offers a line of fiberglass hydrotherapy pools designed to accommodate one-to-one therapy or group sessions.

Ins and Outs of Pool Access

Clinics that install aquatic facilities will also need to address questions associated with how individuals will enter and exit the pool. This is especially important for clients who have limited mobility, motion-limiting pain, or who use wheelchairs or assistive devices. One solution is to install an ADA-approved pool lift. These are available from several manufacturers, including Aquatic Access, Louisville, Ky, which offers watered-powered lifts designed for use with above-ground or in-ground pools, and equipped with features such as headrests, seatbelts, and flip-up arms.

The literature strongly supports participation in regular physical activity as a prevention strategy for improving health and preventing chronic disease. The Centers for Disease Control and Prevention (CDC) has recommended a minimum of 150 minutes of physical activity to prevent the development of chronic diseases such as diabetes, hypertension, obesity, osteoarthritis, and cardiovascular disease. Many people affected by these conditions may find that the benefits of the aquatic environment allow them to be physically active and exercise more comfortably than land-based activity or exercise. With this consideration in mind, Fyzical has developed aquatic wellness programs available for those who would like to continue to pursue a healthy lifestyle and remain active despite having conditions that make it difficult to utilize land-based activities. PTP

Rich Harris, MSc, CSCS, PTA, CES, CSAC, is the general manager of Fyzical Therapy & Balance Center, and has 19 years of experience working with physical therapy professionals and patients, as well as 27 years of experience in the fitness and wellness industry.

Jose Dominguez, PT, MS ATC, is the owner of Fyzical Therapy & Balance Center and has 26 years of experience in the physical therapy industry. For more information, contact [email protected].


1. Becker BE. Aquatic therapy: scientific foundations and clinical rehabilitation applications. PM R. 2009:1(9); 859-872.

2. Wang TJ, Belza B, Elaine Thompson F, Whitney JD, Bennett K. Effects of aquatic exercise on flexibility, strength and aerobic fitness in adults with osteoarthritis of the hip or knee. J Adv Nurs. 2007:57(2);141-152.