BackgroundDry hydrotherapy (also known as hydromassage, aquamassage, water massage) is a self-contained massage device consisting of a table or chair. The individual sits or lies back completely clothed on top of a waterproof barrier that contains interior jets, which rotate and pulsate while releasing streams of pressurized heated water along the body. The pressure of the water against the body provides the massage. It is intended to relieve pain, increase blood circulation, range of motion (ROM), and decrease the need for other therapies by combining the effects of hydrotherapy, massage therapy, acupressure, thermotherapy, soft tissue manipulation, and trigger point therapy. There is no peer-reviewed published literature on dry hydrotherapy.
Aquasoothe/AquaMED (JTL Enterprises, Clearwater, FL) and Massage Time Pro (Sidmar Manufacturing, Inc., Princeton, MN) are dry hydrotherapy systems classified by the FDA as class I therapeutic massage devices. They are exempt from the FDA premarket notification requirement. This means the manufacturer was not required to provide valid scientific evidence from human clinical trials showing the device to be safe and effective for its intended use. According to the FDA Physical Medicine Therapeutic Devices Sec. 890.5660, a therapeutic massager is an electrically powered device intended for medical purposes, such as to relieve minor muscle aches and pains.
According to a report on manipulative and body-based practices by the National Institute of Health’s National Center for Complementary and Alternative Medicine (NCCAM) (2004), there are numerous published reports of clinical trials evaluating the effects of various types of massage for a variety of medical conditions (most with positive results). However, these trials are almost all small, poorly designed, inadequately controlled, or lacking adequate statistical analyses. Many trials include co-interventions that make it impossible to evaluate the specific effects of massage, while others evaluate massage delivered by individuals who are not fully trained massage therapists or follow treatment protocols that do not reflect common (or adequate) massage practice.
There have been very few well-designed controlled clinical trials evaluating the effectiveness of massage for any condition. Only three randomized controlled trials have specifically evaluated massage for the condition most frequently treated with massage – back pain. All three trials found massage to be effective, but two of these trials were very small (NCCAM, 2004). None of these published trials reported using dry hydrotherapy devices.
According to information posted on the AquaMED website, the physical and psychological benefits of AquaMED include: increased blood circulation in the treated area and accelerated healing, relief of pain and ache, relief of stress and increased ROM in joints. Information on their website includes an EMG scan report of 15 individuals pre and post therapy, the testimony of a physician who used ultrasound on 20 individuals with soft tissue injury pre and post therapy, and the testimony from another physician who used thermographic imaging on 4 individuals pre and post therapy. This information does not meet the criteria of well-designed clinical trials, thus, no conclusion on the use of AquaMED based on this information can be made. An unpublished study posted on AquaMED’s website reports the results of using AquaMED therapy on 16 men and women age 23 – 80 years old. The study objective was to determine its effectiveness as a treatment modality in reducing pain and stress. The group was divided into healthy individuals (n = 8) and individuals with chronic pain syndrome (CPS) (n = 8). Six cardiovascular indices (systolic and diastolic blood pressures, heart rate, stroke volume, cardiac output and oxygen saturation) were used as indicators of stress. After treatment, the only statistically significant changes were diastolic blood pressure and mean heart rate. Indices for the individuals with CPS indicate diastolic blood pressure decreased from 66 to 61 and mean heart rate increased from 76 to 79. Subjective evaluations of perceived pain and relaxation levels before and after therapy were also reported. The level of pain was reduced from a mean of 5.25 to 2.5 according to the Visual Analog Scale (VAS) in the individuals with CPS. All subjects with CPS and 4 of the 6 healthy individuals expressed marked relaxation. However, the study did not report its methodology, patient selection criteria for the CPS group or treatment protocol, thus, no definite conclusions can be made regarding the benefit, if any, of AquaMED. In addition, rates of healing and ROM were not studied; therefore, any claims that AquaMED increases blood circulation, accelerates healing, increases ROM and promotes wellness remain unproven.
According to information posted on the Sidmar Manufacturing, Inc. website, dry hydrotherapy improves functioning of the circulatory, lymphatic, muscular and nervous systems. Hydromassage is an unattended modality that provides relief from pain by using jets of warm water to massage the soft tissues of the body. The heat and massaging action of the water work together to help improve circulation, relieve muscle tension and stiffness, release trigger points, increase ROM, release pressure on nerves and promotes general relaxation. The physiological effects of heat and massage are very complementary in the treatment of many types of soft tissue injuries and other conditions such as orthopedic, rheumatic, and neurological disorders. The benefits include: reduces muscle spasms, increases circulation, increases flexibility, increases joint mobility and ROM, has an analgesic effect, promotes tissue healing, helps break down aberrant adhesions, relaxes the nervous system and reduces stress, increases endorphin production, stimulates the lymphatic system to remove metabolic toxins, and sooths and relaxes. Information on the website includes a poster presentation from the 1996 APTA Combined Sections Meeting, Atlanta, GA (Graetzer DG, et al) that reports the results of using two back modalities (the Sidmar Hydromassage Table and the Back Machine) on cervical, thoracic, and lumbosacral ROM in 12 healthy, active females (average age 28 years). Trunk ROM measurements were taken immediately before and after 20 minutes of supine treatment and compared with that of a control group (supine rest). The Dynatron 360 computerized ROM tester and goniometer were used. The authors report increases in post-treatment ROM compared with pre-treatment degrees of ROM during both modality treatment trials. No significant changes in ROM were noted during the control trial. The increases in ROM following a single treatment with either modality were similar. No significant changes were noted in heart rate or systolic or diastolic blood pressure. Whether the Sidmar Hydromassage Table would improve physical functions lost as a result of disease or injury remains unproven. Graetzer et al measured the ROM in healthy, active females only. The authors conclude, “Further research assessing the influence of single and multiple treatments using these increasingly popular modalities as non-surgical rehabilitation options for patients with acute pain or chronic back pain due to traumatic or overuse injuries or congenital abnormalities is warranted.”
An assessment by the Washington State Department of Labor and Industries found that, although dry hydrotherapy has been promoted as an alternative to modalities of heat packs, wet hydrotherapy, massage and soft tissue manipulation, “[t]here is no published research that support claims that this modality can take the place of multiple modalities or that this modality has any long-term benefit.”
Well designed randomized controlled studies published in the peer-reviewed medical literature are needed to demonstrate the benefits of dry hydrotherapy devices, if any, to relieve symptoms, improve, develop or restore physical functions lost or impaired as a result of a disease, injury or surgical procedure.