Justifiable Aquatic Physical Therapy: Patients with Spinal Dysfunctions

Byline: Andrea Salzman, MS, PT

We have all read books and articles extolling (sans references) the virtues of aquatic physical therapy.

This is unfortunate. In order to be taken as credible witnesses regarding the benefits of aquatic intervention, we must first remove ourselves from the role of the cheerleader and begin to play devil's

advocate.

This is particularly important for patients with spinal disorders, as it is often difficult to determine etiology and mechanism of dysfunction. I am a believer in the virtues of aquatic physical therapy, but only for the right patients with the right aquatic interventions. Before selecting this treatment option for any of your patients with spinal dysfunction, ask yourself the following: 1

1. Have I established that the patient has impairments and/or functional limitations which may be positively affected by physical therapy?

2. Have I established that the patient requires skilled intervention in order to diminish these deficits?

3. Have I established that water offers a therapeutic environment for the performance of these interventions which is unachievable on land?

4. Have I established that the evidence (scientific research) has demonstrated benefits with aquatic physical therapy for this type of patient?

Question 1. Does the patient have impairments, functional limitations and/or disabilities which may be positively affected by physical therapy?

First, you must determine if the patient's condition can even be altered by intervention. The American Physical Therapy Association created The Guide to Physical Therapy Practice: Part II: Preferred Practice Patterns which is of singular use in tackling this question. 2  Look for the pattern which best describes your patient to determine if its associated impairments and functional limitations may be positively affected by physical therapy.

If the answer is yes, continue to question 2.

If the answer if no, the patient should not be seen for any intervention, aquatic or land-based. (Note: one exception to this would be a limited number of sessions designed to educate the patient to self-treat his dysfunction).

Question 2. Does the patient require skilled intervention in order to diminish deficits?

Once it has been established that the patient has impairments or functional limitations which may be altered by physical therapy, it then becomes important to ask: Do the patient's problems require a physical therapist? The hallmark of professionalism is the ability to provide the best care with the least depletion of valuable resources. Not all patients require skilled care in order to get better. And not all patients require aquatic physical therapy to get better either; it's critical to know when it's not appropriate. 3

In order to determine if your patient requires skilled intervention to diminish his deficits, ask yourself these questions: 4  

Does the patient require an:

 Individualized examination in order to determine a diagnosis, prognosis and interventions?

 Individualized program of therapeutic interventions to alleviate impairments and functional

limitations?

 Individualized program for prevention of injury, impairment, functional limitation and/or

disability?

It is sometimes helpful to ask yourself: If I was referring this patient for land-based treatment for these same deficits, would I refer the patient to one on one PT or to a health club or group class setting?

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Question 3. Does water offer a therapeutic environment that is unachievable on land?

The water offers a unique therapeutic environment which can be harnessed by a skilled provider to permit activities unachievable on land. In water, weight bearing of the lower extremities and spine can be reduced or eliminated by buoyancy, pain can be reduced by the application of superficial heat, proprioceptive input can be enhanced by viscosity and turbulence, and the pain cycle can be interrupted by offloading the spine and buffeting the body with sensory input. It is both difficult and clinically impractical to achieve these effects on land.

Consider the following four points:

1. Application of weight bearing in graded or progressive manner

Hypothesis: Exercise in water produces less spinal and lower extremity joint compression than the identical exercise performed on land. This reduction in compression creates an environment in which weight bearing and joint compression (of the lower extremities and spine) can be applied in a graded or progressive manner by the therapist.

Argument: Archimedes' principle states: "when a body is wholly or partially immersed in a fluid, it experiences an upthrust equal to the weight of fluid displaced." 5  This upthrust, or buoyancy, counterbalances gravity and supports the body, resulting in an apparent reduction in weight bearing through the spine and lower extremities. 6  Buoyancy can provide either assistance and support or resistance to movement of the body in the water, depending on the position of the individual. 7

Weight bearing may be systematically reduced by increasing the amount of the body submerged. 8,9  A study by Harrison and Bulstrode measured static weight bearing in a pool using a population of healthy adults. 8 Results indicated that weight bearing during immersion was reduced to less than land-based weight. Immersion to C-7 levels reduced weight to 5.9 percent to 10 percent of normal weight. Immersion to the xiphosternum reduced weight to 25 percent to 37 percent of normal. Immersion to the level of the

anterior superior iliac spine (ASIS) reduced weight to 40 percent to 56 percent of normal.

A follow-up study by Harrison, Hillma, and Bulstrode compared weight bearing during immersed standing, slow and fast walking. 9  During slow walking, subjects had to be immersed to the ASIS before weight bearing was reduced to 75 percent of normal. Immersion to the clavicle during slow walking reduced weight bearing up to 50 percent of normal values, and immersion above the clavicle resulted in weight bearing 25 percent of normal or less.

During fast walking, mid-trunk immersion produced weight-bearing up to 75 percent of actual weight. Subjects had to be immersed deeper than the xiphosternum in order for weight bearing to be less than 50 percent and deeper than C-7 for weight bearing to be less than 25 percent of normal values.

2. Decrease in subjective complaints

Assumptions: Patients with spinal disorders suffer from subjective complaints, including muscle spasm, pain and stiffness. Individuals with these symptoms seek relief from them.

Hypothesis: Aquatic therapy performed in a therapeutic pool provides a palliative effect and may reduce these complaints.

Argument: Although dependent on the population using the facility, therapeutic pools are generally heated to between 92 degrees and 97 degrees Fahrenheit. 10  At temperatures above "thermoneutral" (approximately 93 degrees to 95 degrees F at rest and 91 degrees to 92 degrees F during mild exercise), 11,12  body temperature increases due to the reduced ability of the body to dissipate heat through the skin. 13,14  Thermal energy (heat) is exchanged between water and the body and between air and the body. Energy exchange between a submerged body and the water occurs through both convection and conduction. Thermal energy is also exchanged between the body and the air through radiation and

evaporation—methods which become more critical if the total body is immersed and the water temperature prevents heat dissipation from occurring during aquatic exercise. 13

Immersion in water warmer than the skin will result in a rise in superficial tissue temperature which creates a palliative effect like that experienced during the therapeutic use of paraffin, Fluido therapy® and moist heat. 14 The mechanism of pain relief may come from one of several phenomena discussed in great detail in the July 1997 issue of the Journal of Aquatic Physical Therapy. 15

3. Movement-induced enhancement of somatosensory input (improved proprioceptive input)

Hypothesis: Movement of a body part through water results in greater somatosensory input to receptors than movement of that body part through air.

Argument: Movement through water is affected by turbulence and viscosity. 5  Water is more viscous than air, and resistance to flow through water is greater than resistance to flow through air. Thus, it takes more force to push through water molecules than to push through air molecules.

Additionally, the faster an object is pushed through the water, the more turbulence is created and this creates additional resistance to movement. Richley Geigle and colleagues argue that somatosensory input is increased more by moving an object through a viscous liquid than by moving through a less viscous gas (air). They postulate that resistance to movement may "cause distention or stretch of the skin resulting in stimulation of rapidly adapting mechanoreceptors, perhaps contributing to better proprioception." 16

4. Interruption of pain cycle

Hypothesis: Standing in water results in less spinal and lower extremity weight bearing than standing on land. This reduction in weight bearing results in a reduction in motor activity required from postural muscles. This reduction in motor activity allows patients to maintain an upright, stable position with less muscle spasm.

Argument: Archimedes' principle states: "when a body is wholly or partially immersed in a fluid, it experiences an upthrust equal to the weight of fluid displaced." 5  Water has a relative density (specific gravity) equal to 1. It serves as the reference point for all objects. Objects with specific gravity less than water float, and those with specific gravity greater than water sink. Objects with specific gravity near the value of water hover just below the surface. The human body has elements which tend to sink (dense

muscle) and elements which tend to float (fatty tissue and air-filled lungs). This tendency to float counterbalances gravity and supports the body, resulting in an apparent reduction in weight. 7  This reduction in weight can provide relief from compressive forces on painful joints. It is therefore possible for a person to stand, even walk, with reduced pain without external support or abnormal protective mechanisms in the water. Thus, the patient can initiate "normal" weight bearing tasks such as gait, transfers, and balance drills in the water and offset any deconditioning effects of immobility or reduced movement.

Muscle activity may be systematically reduced by increasing the amount of the body submerged. Mano et al examined the effects of graded immersion on skin and muscle receptors during quiet standing. 17  Mano and his team examined the effects of immersion in warm water on muscle sympathetic activity (MSA) and electromyography (EMG) of the soleus muscle, and skin sympathetic activity (SSA) of the sole of the foot. As the level of immersion increased, both MSA and EMG activity decreased proportionally as weight bearing diminished. With immersion to the cervical spine, both MSA and EMG became almost absent. In other words, the subjects' calf muscles became less active in a buoyant environment. In effect, the calf muscle responsible for maintaining upright posture in a gravity-based environment had diminished responsibilities. Additionally, as the level of immersion was increased, the sympathetic activity of the skin on the sole of the foot decreased. With immersion to the cervical spine, the SSA showed a marked and proportional decrease in activity. Translated, this means that although immersion

results in less motor activity for postural muscles such as the calf, it also results in less sensory input to the skin (and probably joint) receptors which record weight bearing.

Question 4. Has the evidence (scientific research) demonstrated benefits with aquatic physical therapy for this type of patient?

The short answer is yes, barely. Although there exist several studies on the beneficial effects of aquatic physical therapy for patients with spinal dysfunction, this area of research lags far behind work done on other populations, such as rheumatology.

As a detailed discussion of the scientific literature is beyond the space constraints of this article, readers are directed to the primary research (free abstracts available on PubMed at

www4.ncbi.nlm.nih.gov/PubMed/) and to the text Evidence-based Aquatic Therapy for more detailed discussions on this topic.

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References

1. Poteat Salzman, A. (1998). Prove it! Justifiable aquatic therapy. East Hampstead, NH: Northeast

Seminars lecture series.

2. American Physical Therapy Association. (1997). The Guide to Physical Therapy Practice: Part II:

Preferred Practice Patterns. Physical Therapy, 77(11), 1227-1619.

3. American Physical Therapy Association Aquatic Physical Therapy Section. (1992). Statement of

Purposes, Rationale, and Goals. Alexandria, VA: Author.

4. American Physical Therapy Association. (1997). The Guide to Physical Therapy Practice: Part I:

Description of Patient/Cleint Management. Physical Therapy, 77(11), 1178.

5. Edlich, R.F., Towler, M.A., Goitz, R.J., Wilder, R.P., Buschbacher, L.P., Morgan, R.F., &

Thacker, J.G. (1987). Bioengineering principles of hydrotherapy. Journal of Burn Care

Rehabilitation, 8(6), 580-584.

6. Cirullo, J.A. (1994). Aquatic physical therapy approaches for the spine. Orthopedic Physical

Therapy Clinics of North America, 3(2), 179-208.

7. Styer-Acevedo, J., & Cirullo, J.A. (1994). Integrating land and aquatic approaches with a

functional emphasis. Orthopedic Physical Therapy Clinics of North America, 3(2), 165-178.

8. Harrison, R.A., & Bulstrode, S. (1987). Percentage weight bearing during partial immersion in

the hydrotherapy pool. Physiotherapy Practice, 3, 60-63.

9. Harrison, R.A., Hillman, M., & Bulstrode, S. (1992). Loading of the lower limb when walking

partially immersed: Implications for clinical practice. Physiotherapy, 78(3), 164-166.

10. Whitney, S.L. (1989). Physical agents: Heat and cold modalities. In: R.M. Scully & M.R.

Barnes.Physical therapy. Philadelphia: J.B. Lippincott Company.

11. Christie, J.L., Sheldahl, L.M., Tristani, F.E., Wann, L.S., Sagar, K.B., Vevandoski, S.G., Ptacin,

M.J., Sobocinski, K.A., & Morris, R.D. (1990). Cardiovascular regulation during head-out water

immersion exercise. Journal of Applied Physiology, 69(2), 657-664.

12. Sagawa, S., Shiraki, K., Yousef, M.K., & Konda, N. (1988). Water temperature and intensity of

exercise in maintenance of thermal equilibrium. Journal of Applied Physiology, 65(6), 2413-

2419.

13. Walsh, M. (1986). Hydrotherapy: The use of water as a therapeutic agent. In: S.L. Michlovits &

S. Wolf (Eds.). Thermal agents in rehabilitation. Philadelphia: F.A. Davis Company.

14. Michlovitz, S.L. (1986). Biophysical principles of heating and superficial heat agents. In: S.L.

Michlovits & S. Wolf (Eds.). Thermal agents in rehabilitation. Philadelphia: F.A. Davis

Company.

15. Poteat, A.L., Bjerke, M.D., Johnston, T.D., & Mairs, J.P. (1997). Evidence-based aquatic therapy:

Building a case for use of aquatic physical therapy for fibromyalgia patient populations. Journal

of Aquatic Physical Therapy, 5(2), 8-16.

16. Richley Geigle, P., Cheek, W.L., Gould, M.L., Hunt, H.C. III, & Shafiq, B. (1997). Aquatic

physical therapy for balance: the interaction of somatosensory and hydrodynamic

principles. Journal of Aquatic Physical Therapy, 5(1), 4-10.

17. Mano, T., Iwase, S., Yamazaki, Y., & Saito, M. (1985). Sympathetic nervous adjustments in man

to simulated weightlessness induced by water immersion. Sangyo Ika Diagaku Zasshi. 7(Suppl):

215-227.

Further studies on the beneficial effects of aquatic physical therapy for patients with spinal

dysfunction

 Guillemin, F., Constant, F., Collin, J.F., & Boulange, M. (1994). Short and long-term effects of spa

therapy in chronic low back pain. British Journal of Rheumatology, 33(2), 148-151.

 Konrad, K., Tatrai, T., Hunka, A., Vereckei, E., & Korondi, I. (1992). Controlled trial of

balneotherapy in treatment of low back pain. Annals of Rheumatology Dis, 51(6), 820-822.

 Langridge, J.C., & Phillips, D. (1988). Group hydrotherapy exercises for chronic back pain sufferers:

Introduction and monitoring. Physiotherapy, 74, 269-273.

 Lefort, S.M., & Hannah, T.E. (1994). Return to work following an aquafitness and muscle

strengthening program for the low back injured. Archives of Physical and Medical Rehabilitation, 75(11),

1247-1255.

 Cunha, M.C., Oliveira, A.S., Labronici, R.H., & Gabbai, A.A. (1996). Spinal muscular atrophy type II

(intermediary) and III (Kugelberg-Welander): Evolution of 50 patients with physiotherapy and

hydrotherapy in a swimming pool. Arq Neuropsiquiatr, 54(3), 402-406.

 McIlveen, B., & Robertson, V.J. (1998). A randomised controlled study of the outcome of

hydrotherapy for subjects with low back or back and leg pain. Physiotherapy, 84(1), 17-26.

 Roberts, J., & Freeman, J. (1995). Hydrotherapy management of low back pain: A quality

improvement project. Austrailian Journal of Physiotherapy, 41(3), 205-208.

 Sjogren, T., Long, N., Storay, I., & Smith, J. (1997). Group hydrotherapy versus group land-based

treatment for chronic low back pain. Physiotherapy Research Int, 2(4), 212-222.

 Smit, T.E., & Harrison, R. (1991). Hydrotherapy and chronic lower back pain: A pilot

study. Austrailian Journal of Physiotherapy, 37(4), 229-234.

 Woods, D. (1989). Rehabilitation aquatics for low back injury: Functional gains or pain

reduction? Clinical Kinesiology, 43(4), 96-103.

 Poteat Salzman, A.L. (2001). Evidence-based aquatic therapy. Philadelphia: W.B. Saunders (pending

release). To receive notice upon publication, fax a request to (715) 248-7258 and request to be placed

on waiting list for release.