Pool Therapy, Aquatic Therapy or Hydrotherapy

Number: 0174

Table Of Contents

Policy
Applicable CPT / HCPCS / ICD-10 Codes
Background
References

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Policy

Scope of Policy

This Clinical Policy Bulletin addresses pool therapy, aquatic therapy or hydrotherapy.

1. Medical Necessity

   Aetna considers aquatic therapy (hydrotherapy, pool therapy) medically necessary for musculoskeletal conditions.

   Aquatic therapy that is carried out to maintain a level of function (maintenance therapy), where the member is neither improving nor regressing, is considered not medically necessary.

2. Experimental and Investigational

   The following indications and modalities are considered experimental and investigational because the effectiveness of these approaches has not been established (not an all-inclusive list):

   1. Treatment of asthma and all other non-musculoskeletal indications (e.g., atopic dermatitis, autism, chronic obstructive pulmonary disease, developmental coordination disorder, end-stage dementia, reducing risk of falls in the elderly, lymphedema, management of individuals with cancer, neonatal brachial plexus palsy, peripheral artery disease, psoriasis, sickle cell anemia, stroke rehabilitation, and traumatic brain injury);
   2. Passive hydrotherapy WATSU (WaterShiatsu) for the treatment of juvenile idiopathic arthritis, Parkinson's disease, and all other indications;
   3. Crenobalneotherapy (spa therapy) for knee osteoarthritis, low back pain and all other indications;
   4. Nano-bubble hydrotherapy for the treatment of palmar plantar keratosis and all other indications.

3. Policy Limitations and Exclusions

   Note: Pool, aquatic, or hydrotherapy is considered to be a physical therapy modality subject to the physical therapy guidelines and any applicable plan benefit limits for physical therapy (see CPB 0325 - Physical Therapy).

   Note: Aetna covers only the professional charges of a physical therapist or other recognized, licensed providers (e.g., doctor of medicine, doctor of osteopathy, podiatrist, and physical therapy assistant), for physical therapy modalities administered in a pool, which require direct, one-on-one, patient contact.  Charges for aquatic exercise programs, or separate charges for use of a pool, are not covered.

   Note: Aquatic therapy must be carried out for restoring the member's level of function that was lost or reduced by injury or illness.  The provider must have direct (one-to-one) patient contact when reporting aquatic therapy.  Supervising multiple patients in a pool at one time and billing for each of these patients per 15 minutes of therapy time is inappropriate.
   

4. Related Policies

   • CPB 0325 - Physical Therapy
   • CPB 0699 - Dry Hydrotherapy (Hydromassage, Aquamassage, Water Massage)

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Table:

CPT Codes / HCPCS / ICD-10 Codes

Code	Code Description
CPT codes covered if selection criteria are met:
97036	Application of a modality to one or more areas; Hubbard tank, each 15 minutes
97113	Therapeutic procedure, one or more areas, each 15 minutes; aquatic therapy with therapeutic exercises
ICD-10 codes covered if selection criteria are met:
M30.3 - M99.9	Diseases of the musculoskeletal system and connective tissue
S00.00 - S99.929	Injury
Z87.81 - Z87.828	Personal history of injury
Z51.89	Encounter for other specified aftercare [physical therapy]
ICD-10 codes not covered for indications listed in the CPB:
C00.0 – D49.9	Neoplasms
D57.0 - D57.819	Sickle cell disorders
F02.A0, F02.B0, F02.C0, F02.C11, F02.C18, F02.C2, F02.C3, F02.C4	Dementia in other diseases classified elsewhere
F03.A0, F03.B0, F03.C0, F03.C11, F03.C18, F03.C2, F03.C3, F03.C4	Unspecified dementia
F82	Specified developmental disorder of motor function
G30.0 - G30.9	Alzheimer's disease
I61.0 – I61.9	Nontraumatic intracerebral hemorrhage
I63.00 – I63.9	Cerebral infarction
I69.10 – I69.198	Sequelae of nontraumatic intracerebral hemorrhage
I69.20 – I69.298	Sequelae of other nontraumatic intracranial hemorrhage
I69.30 – I69.398	Sequelae of cerebral infarction
I73.00 - I73.01	Raynaud's syndrome
I73.1	Thromboangiitis obliterans [Buerger's disease]
I73.9	Peripheral vascular disease, unspecified
I89.0	Lymphedema, not elsewhere classified
J40 - J47	Chronic lower respiratory diseases
L20.0 – L20.9	Atopic dermatitis
L40.0 – L40.9	Psoriasis
P14.0	Erb's paralysis due to birth injury
P14.1	Klumpke's paralysis due to birth injury
P14.3	Other brachial plexus birth injuries
R29.6	Repeated falls [risk of falls in the elderly]
Passive hydrotherapy WATSU:
CPT codes not covered for indications listed in the CPB:
Passive hydrotherapy WATSU: No Specific code
ICD-10 codes not covered for indications listed in the CPB:
G20	Parkinson's disease
G21.0 – G21.9	Secondary parkinsonism
M08.00 - M08.9A	Juvenile arthritis [idiopathic]
Crenobalneotherapy:
CPT codes not covered for indications listed in the CPB:
Crenobalneotherapy -no specific code
ICD-10 codes not covered for indications listed in the CPB:
M17.0 – M17.9	Osteoarthritis of knee
M54.50 – M54.9	Low back pain
Nano-bubble hydrotherapy:
CPT codes not covered for indications listed in the CPB:
Nano-bubble hydrotherapy -no specific code
ICD-10 codes not covered for indications listed in the CPB:
L85.1	Acquired keratosis [keratoderma] palmaris et plantaris
L85.2	Keratosis punctata (palmaris et plantaris)

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Background

Aquatic therapy has been shown to provide relief of symptoms from a variety of arthritides, traumatic injuries, and other musculoskeletal conditions.  This procedure uses the therapeutic properties of water (e.g., buoyancy, resistance).  Aquatic therapy may necessary for a loss or restriction of joint motion, strength, mobility, or function which has resulted from a specific disease or injury.  The medical record should show objective loss of joint motion, strength, or mobility (e.g., degrees of motion, strength grades, levels of assistance).  Standard treatment duration is 3 to 4 times per week for 2 to 4 weeks.  It is not necessary to have more than one form of hydrotherapy during the same visit (NHIC, 2002).  Other forms of exercise therapy may be necessary in addition to aquatic therapy when the member cannot perform land-based exercises effectively to treat his/her condition without first undergoing the aquatic therapy, or when aquatic therapy facilitates progress to land-based exercise or increased function.

Harmer and colleagues (2009) compared outcomes between land-based and water-based exercise programs delivered in the early subacute phase up to 6 months after total knee replacement (TKR).  Two weeks after surgery (baseline), 102 patients were randomized to participate in either land-based (n = 49) or water-based (n = 53) exercise classes.  Treatment parameters were guided by current clinical practice protocols.  Thus, each study arm involved 1-hr sessions twice-weekly for 6 weeks, with patient-determined exercise intensity.  Session attendance was recorded.  Outcomes were measured at baseline and at 8 and 26 weeks post-surgery.  Outcomes included distance on the 6-min walk test, stair climbing power (SCP), the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index (n = 85 English-proficient patients), visual analog scale for joint pain, passive knee range of motion, and knee edema (circumference).  Planned orthogonal contrasts, with an intent-to-treat approach, were used to analyze the effects of time and time-group interactions.  Compliance in both groups was excellent with 81 % attending 8 or more sessions.  Loss to follow-up was 5 %.  Significant improvements were observed across time in all outcomes at 8 weeks, with further improvements evident in all variables (except WOMAC pain) at 26 weeks.  Minor between-group differences were evident for 4 outcomes (SCP, WOMAC stiffness, WOMAC function, and edema) but these appear clinically insignificant.  The authors concluded that a short-term, clinically pragmatic program of either land-based or water-based rehabilitation delivered in the early phase after TKR was associated with comparable outcomes at the end of the program and up to 26 weeks post-surgery.

In a controlled trial with blinded 6-month follow-up, Rahmann and colleagues (2009) assessed the effect of inpatient aquatic physiotherapy in addition to usual ward physiotherapy on the recovery of strength, function, and gait speed after total hip or knee replacement surgery.  Participants (n = 65) were individuals undergoing primary hip or knee arthroplasty (average age of 69.6 +/- 8.2 yrs; 30 men).  Subjects were randomly assigned to receive supplementary inpatient physiotherapy, beginning on day 4: aquatic physiotherapy, non-specific water exercise, or additional ward physiotherapy.  Main outcome measures were strength, gait speed, and functional ability at day 14.  At day 14, hip abductor strength was significantly greater after aquatic physiotherapy intervention than additional ward treatment (p = 0.001) or water exercise (p = 0.011).  No other outcome measures were significantly different at any time point in the trial, but relative differences favored the aquatic physiotherapy intervention at day 14.  No adverse events occurred with early aquatic intervention.  The authors concluded that a specific inpatient aquatic physiotherapy program has a positive effect on early recovery of hip strength after joint replacement surgery.  Moreover, they stated that further studies are needed to confirm these findings.

Hillier and colleagues (2010) stated that aquatic therapy is an intervention for children with developmental coordination disorder (DCD) that has not been investigated formally.  In a pilot randomized controlled trial, these researchers investigated the feasibility and preliminary effectiveness of an aquatic therapy program to improve motor skills of children with DCD.  A total of 13 children (mean age of 7 years 1 month; 10 males) with DCD were randomly allocated to receive either 6 sessions of aquatic therapy (once-weekly session of 30 mins for 6 to 8 weeks) or to a wait-list (control group).  The intervention and measures were demonstrated to be feasible, but barriers, such as limited appointment times and accessibility, were encountered.  Analysis of co-variance indicated that at post-test, mean scores on the Movement Assessment Battery were higher for children who received aquatic therapy compared to those on the wait-list (p = 0.057).  Similar trends were noted on the physical competence portion of the Pictorial Scale of Perceived Competence and Social Acceptance (p = 0.058).  However, these differences were not significant.  These preliminary findings need to be validated by well-designed studies.

Tinti et al (2010) noted that the process of hemoglobin polymerization and the consequent sickling of red blood cells that occurs in patients with sickle cell disease shortens the half-life of red blood cells.  It causes vaso-occlusive complications as well as pain and pulmonary and cardiovascular dysfunction.  In a case study, these researchers evaluated an aquatic rehabilitation program used for patients with sickle cell anemia and examined the possible benefits that exercise in warm water has for the circulatory system for relieving pain as well as for increasing lung capacity.  The patient was a 32-year-old female.  The parameters that were used in this study included respiratory muscle strength (which was calculated by measuring maximum inspiratory pressures and maximum expiratory pressures), the McGill and Wisconsin pain questionnaires (in order to evaluate the patients' characterizations and descriptions of their pain), and the SF-36 Health Survey.  The treatment included warm water exercises, stretching, aerobic exercise, and relaxation, during 2 sessions of 45 mins per week for 5 weeks.  The patient experienced a significant decrease in pain, a significant increase in the strength of respiratory muscles, and improved quality of life.  The authors concluded aquatic rehabilitation can be used to improve the clinical condition of sickle cell anemia patients, and they stated that more research on this new treatment regime, in comparison with other types of therapies, should be encouraged.

Fibromyalgia (FM) is a debilitating condition characterized by the presence of widespread musculoskeletal pain.  Moreover, there is inconsistent evidence regarding the effectiveness of various therapies developed so far, making FM a chronic disease that is difficult to treat.

The University of Texas, School of Nursing, Family Nurse Practitioner Program’s clinical guideline on “Management of fibromyalgia syndrome in adults” (2009) did not mention the use of aquatic therapy/hydrotherapy/pool therapy as a therapeutic option.

Thomas and Blotman (2010) examined the current evidence to support guidelines for aerobic exercise (AE) and FM in practice, and outlined specific research needs in these areas.  Data sources consisted of a PubMed search, 2007 Cochrane Data Base Systematic review, 2008 Ottawa panel evidence-based clinical practice guidelines, as well as additional references found from the initial search.  Study selection included randomized clinical trials that compared an aerobic-only exercise intervention (land- or pool-based) with an untreated control, a non-exercise intervention or other exercise programs in patients responding to the 1990 American College of Rheumatology criteria for FM.  The following outcome data were obtained: pain, tender points, perceived improvement in FM symptoms such as the Fibromyalgia Impact Questionnaire (FIQ) total score, physical function, depression (e.g., Beck Depression Inventory, FIQ subscale for depression), fatigue and sleep were extracted from 19 clinical trials that considered the effects of aerobic-only exercise in FM patients.  Data synthesis showed that there is moderate evidence of important benefit of aerobic-only exercise in FM on physical function and possibly on tender points and pain.  It appears to be sufficient evidence to support the practice of AE as a part of the multi-disciplinary management of FM.  However, the authors stated that future studies must be more adequately sized, homogeneously assessed, and monitored for adherence, to draw definitive conclusions.

Winkelmann et al (2012) noted that the scheduled update to the German S3 guidelines on fibromyalgia syndrome (FMS) by the Association of the Scientific Medical Societies ("Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften", AWMF; registration number 041/004) was planned starting in March 2011.  The development of the guidelines was coordinated by the German Interdisciplinary Association for Pain Therapy ("Deutsche Interdisziplinären Vereinigung für Schmerztherapie", DIVS), 9 scientific medical societies and 2 patient self-help organizations.  Eight working groups with a total of 50 members were evenly balanced in terms of gender, medical field, potential conflicts of interest and hierarchical position in the medical and scientific fields.  Literature searches were performed using the MedLine, PsycInfo, Scopus and Cochrane Library databases (until December 2010).  The grading of the strength of the evidence followed the scheme of the Oxford Center for Evidence-Based Medicine.  The formulation and grading of recommendations was accomplished using a multi-step, formal consensus process.  The guidelines were reviewed by the boards of the participating scientific medical societies.  The authors concluded that low-to-moderate intensity aerobic exercise and strength training are strongly recommended.  Chiropractic, laser therapy, magnetic field therapy, massage therapy, as well as transcranial current stimulation are not recommended.  Aquatic therapy/hydrotherapy/pool therapy was not mentioned as a therapeutic option.

Lima et al (2013) evaluated the effectiveness of aquatic physical therapy in the treatment of FM.  The search strategy was undertaken using the following databases, from 1950 to December 2012: MEDLINE, EMBASE, CINAHL, LILACS, SCIELO, WEB OF SCIENCE, SCOPUS, SPORTDiscus, Cochrane Library Controlled Trials Register, Cochrane Disease Group Trials Register, PEDro and DARE.  The studies were separated into groups: Group I -- aquatic physical therapy × no treatment, Group II -- aquatic physical therapy × land-based exercises and Group III -- aquatic physical therapy × other treatments.  A total of 72 abstracts were found, 27 of which met the inclusion criteria.  For the functional ability (FIQ), 3 studies were considered with a treatment time of more than 20 weeks and a mean difference (MD) of -1.35 [-2.04; -0.67], p = 0.0001 was found in favor of the aquatic physical therapy group versus no treatment.  The same results were identified for stiffness and the 6-min walk test where 2 studies were pooled with an MD of -1.58 [-2.58; -0.58], p = 0.002 and 43.5 (meters) [3.8; 83.2], p = 0.03, respectively.  The authors concluded that 3 meta-analyses showed statistically significant results in favor of the aquatic physical therapy (FIQ, stiffness and the 6-min walk test) during a period of longer than 20 weeks.  Moreover, they stated that due to the low methodological rigor, the results were insufficient to demonstrate statistical and clinical differences in most of the outcomes.

In a Cochrane review, McNamara et al (2013) evaluated the effects of water-based exercise training in people with chronic obstructive pulmonary disease (COPD).  A search of the Cochrane Airways Group Specialised Register of trials, which is derived from systematic searches of bibliographic databases, including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, AMED and PsycINFO, was conducted (from inception to August 2013).  Hand-searching was done to identify further qualifying studies from reference lists of relevant studies.  Review authors included randomized or quasi-randomized controlled trials in which water-based exercise training of at least 4 weeks' duration was compared with no exercise training or any other form of exercise training in people with COPD.  Swimming was excluded.  These researchers used standard methodological procedures expected by The Cochrane Collaboration.  A total of 5 studies were included with a total of 176 participants (71 people participated in water-based exercise training and 54 in land-based exercise training; 51 completed no exercise training).  All studies compared supervised water-based exercise training versus land-based exercise training and/or no exercise training in people with COPD (with average forced expiratory volume in one second (FEV1) %predicted ranging from 39 % to 62 %).  Sample sizes ranged from 11 to 53 participants.  The exercise training programs lasted from 4 to 12 weeks, and the mean age of participants ranged from 57 to 73 years.  A moderate risk of bias was due to lack of reporting of randomization, allocation and blinding procedures in some studies, as well as small sample sizes.  Compared with no exercise, water-based exercise training improved the 6-minute walk distance (mean difference (MD) 62 meters; 95 % confidence interval (CI): 44 to 80 meters; 3 studies; 99 participants; moderate quality evidence), the incremental shuttle walk distance (MD 50 meters; 95 % CI: 20 to 80 meters; 1 study; 30 participants; high quality evidence) and the endurance shuttle walk distance (MD 371 meters; 95 % CI: 121 to 621 meters; 1 study; 30 participants; high quality evidence).  Quality of life was also improved after water-based exercise training compared with no exercise (standardized mean difference (SMD) -0.97, 95 % CI: -0.37 to -1.57; 2 studies; 49 participants; low quality evidence).  Compared with land-based exercise training, water-based exercise training did not significantly change the 6-minute walk distance (MD 11 meters; 95 % CI: -11 to 33 meters; 3 studies; 62 participants; moderate quality evidence) or the incremental shuttle walk distance (MD 9 meters; 95 % CI: -15 to 34 meters; 2 studies; 59 participants; low quality evidence).  However, the endurance shuttle walk distance improved following water-based exercise training compared with land-based exercise training (MD 313 meters; 95 % CI: 232 to 394 meters; 2 studies; 59 participants; moderate quality evidence).  No significant differences were found between water-based exercise training and land-based exercise training for quality of life, as measured by the St George's Respiratory Questionnaire or by 3 of 4 domains of the Chronic Respiratory Disease Questionnaire (CRDQ); however, the fatigue domain of the CRDQ showed a statistically significant difference in favor of water-based exercise (MD -3.00; 95 % CI: -5.26 to -0.74; 1 study; 30 participants).  Only 1 study reported long-term outcomes after water-based exercise training for quality of life and body composition, and no significant change was observed between baseline results and 6-month follow-up results.  One minor adverse event was reported for water-based exercise training (based on reporting from 2 studies; 20 participants).  Impact of disease severity could not be examined because data were insufficient.  The authors concluded that there is limited quality evidence that water-based exercise training is safe and improves exercise capacity and quality of life in people with COPD immediately after training.  There is limited quality evidence that water-based exercise training offers advantages over land-based exercise training in improving endurance exercise capacity, but these investigators remained uncertain as to whether it leads to better quality of life.  They noted that little evidence exists examining the long-term effect of water-based exercise training

Mortimer et al (2014) examined the effectiveness of hydrotherapy on social interactions and behaviors in the treatment of children with autism spectrum disorders (ASDs).  A systematic search of Cochrane, CINAHL, PsycINFO, Embase, MEDLINE®, and Academic Search Premier was conducted.  Studies of participants, aged 3 to 18 years, with ASDs at a high-functioning level were included if they utilized outcome measures assessing social interactions and behaviors through questionnaire or observation.  A critical appraisal, using the McMaster Critical Review Form for Quantitative Studies, was performed to assess methodological quality.  A total of 4 studies of varying research design and quality met the inclusion criteria.  The participants in these studies were aged between 3 to 12 years of age.  The duration of the intervention ranged from 10 to 14 weeks, and each study used varied measures of outcome.  Overall, all the studies showed some improvements in social interactions or behaviors following a Halliwick-based hydrotherapy intervention.  The authors concluded that few studies have investigated the effect of hydrotherapy on the social interactions and behaviors of children with ASDs.  While there is an increasing body of evidence for hydrotherapy for children with ASDs, this is constrained by small sample size, lack of comparator, crude sampling methods, and the lack of standardized outcome measures.  They stated that hydrotherapy shows potential as a treatment method for social interactions and behaviors in children with ASDs.

Marinho-Buzelli et al (2015) summarized evidence on the effects of aquatic therapy on mobility in individuals with neurological diseases.  MEDLINE, EMBASE, PsycInfo, CENTRAL, CINAHL, SPORTDiscus, PEDro, PsycBITE and OT Seeker were searched from inception to September 15, 2014.  Hand-searching of reference lists was performed in the selected studies.  The search included randomized controlled trials (RCTs) and quasi-experimental studies that investigated the use of aquatic therapy and its effect on mobility of adults with neurological diseases.  One reviewer screened titles and abstracts of retrieved studies from the search strategy.  Two reviewers independently examined the full texts and conducted the study selection, data extraction and quality assessment.  A narrative synthesis of data was applied to summarize information from included studies.  The Downs and Black Scale was used to assess methodological quality.  A total of 116 articles were obtained for full text eligibility; 20 studies met the specified inclusion criteria: 4 RCTs, 4 non-randomized studies and 12 before-and-after tests.  Two RCTs (30 patients with stroke in the aquatic therapy groups), 3 non-randomized studies and 3 before-and-after studies showed "fair" evidence that aquatic therapy increased dynamic balance in participants with some neurological disorders.  One RCT (7 patients with stroke in the aquatic therapy group) and 2 before-and-after tests (20 patients with multiple sclerosis) demonstrated "fair" evidence on improvement of gait speed after aquatic therapy.  The authors concluded that their synthesis showed "fair" evidence supporting the use of aquatic therapy to improve dynamic balance and gait speed in adults with certain neurological conditions.

End-Stage Dementia

Becker and Lynch (2018) reported on the case of a 54-year old woman who retired due to progressive cognitive decline, and was diagnosed with early-onset Alzheimer dementia (AD).  Conventional medication therapy for dementia had proven futile.  Initial evaluation revealed a non-verbal female seated in a wheelchair, dependent on 2-person assist for all transfers and activities of daily living (ADL).  She had been either non-responsive or actively resistive for both ADL and transfers in the 6 months before assessment.  After a total of 17 1-hour aquatic therapy sessions over 19 weeks in a warm water therapy pool, she achieved the ability to tread water for 15 minutes, transfers improved to moderate-to-maximum assist from seated, and ambulation improved to 1,000 feet with minimum-to-moderate assist of 2 persons.  Communication increased to appropriate "yes", "no", and "okay" appropriate responses, and an occasional "thank you" and "very nice".  The authors proposed that her clinical progress may be related to her aquatic therapy intervention. Level of evidence: To be determined.  These preliminary findings need to be further investigated.

Lymphedema

Yeung and colleagues (2018) stated that aquatic therapy has several proposed benefits for people with lymphedema.  These researchers performed a systematic review of the evidence for aquatic therapy in lymphedema management.  Five electronic databases were searched to identify RCTs of people with lymphedema, which compared aquatic therapy with other lymphedema interventions.  Qualitative analysis was undertaken where quantitative analysis was not possible.  Study quality was assessed using physiotherapy evidence database (PEDro) scores.  The strength of evidence was evaluated using the Grades of Recommendations Assessment, Development and Evaluation (GRADE) approach; 4 RCTs of moderate quality (average PEDro score of 6.5/10) were included in the review; 2 studies provided results for inclusion in meta-analysis.  There was moderate-level evidence of no significant short-term differences in lymphedema status (as measured by lymphedema relative volume) between patients who completed aqua lymphatic therapy (ALT) compared to land-based standard care (standardized mean difference [SMD]: 0.14; 95 % CI: -0.37 to 0.64, I2 = 0 %, p = 0.59); and low-quality evidence of no significant difference between ALT and standard care for improving upper limb (UL) physical function (SMD -0.27, 95 % CI: -0.78 to 0.23, I2 = 0 %, p = 0.29).  No adverse events  (AEs) were reported.  The authors concluded that current evidence indicated no significant benefit of ALT over standard land-based care for improving lymphedema status or physical function in people with UL lymphedema.  Moreover, they stated that further research is needed to strengthen the evidence from 4 studies in people with UL lymphedema, and to establish the effectiveness of this intervention in people with lower limb lymphedema.

Stroke Rehabilitation

In a pilot study, Morer and colleagues (2017) examined the effect of an intensive program of thalassotherapy and aquatic therapy in stroke patients.  This quasi-experimental prospective study consisted of a specific program assessed pre- and post- 3 weeks treatment to 26 stroke patients with a mild-moderate disability.  The outcomes measured were: Berg Balance scale (BBS), Timed Up and Go test, the Comfortable 10-meter walking test (CWT), 6-minute walking test and pain visual analog scale (VAS).  After intervention, participants had a significant improvement in all outcomes measured.  The authors concluded that these findings suggested that an intensive program of thalassotherapy and aquatic therapy could be useful during stroke rehabilitation to improve balance, gait and pain.  These preliminary findings need to be validated by well-designed studies.

Lee and associates (2017) determined the efficacy of aquatic treadmill training (ATT) as a new modality for stroke rehabilitation, by assessing changes in gait symmetry, balance function, and subjective balance confidence for the paretic and non-paretic leg in stroke patients.  A total of 21 subacute stroke patients participated in 15 intervention sessions of ATT.  Spatiotemporal gait parameters, BBS, CWT, and Activities-specific Balance Confidence scale (ABC) were assessed pre- and post-interventions.  From pre- to post-intervention, statistically significant improvements were observed in the CWT (0.471 ± 0.21 to 0.558 ± 0.23, p < 0.001), BBS (39.66 ± 8.63 to 43.80 ± 5.21, p < 0.001), and ABC (38.39 ± 13.46 to 46.93 ± 12.32, p < 0.001).  The step-length symmetry (1.017 ± 0.25 to 0.990 ± 0.19, p = 0.720) and overall temporal symmetry (1.404 ±0 .36 to 1.314 ± 0.34, p = 0.218) showed improvement without statistical significance.  The authors concluded that ATT improved the functional aspects of gait, including CWT, BBS and ABC, and spatiotemporal gait symmetry, though without statistical significance.  They stated that further studies are needed to examine and compare the potential benefits of ATT as a new modality for stroke therapy, with other modalities.

In a systematic review and meta-analysis, Iliescu and colleagues (2020) examined the effectiveness of aquatic therapy in improving mobility, balance, and functional independence following stroke.  Data sources included articles published in Medline, Embase, CINAHL, PsycINFO, and Scopus up to August 20, 2019.  Studies met the following inclusion criteria: English, adult stroke population, RCT or non-randomized prospectively controlled trial (PCT) study design, the experimental group received greater than 1 session of aquatic therapy, and included a clinical outcome measure of mobility, balance, or functional independence.  Subject characteristics, treatment protocols, between-group outcomes, point measures, and measures of variability were extracted.  Methodological quality was assessed using Physiotherapy Evidence Database (PEDro) tool, and pooled MD ± standard error (SE) and 95 % CI were calculated for Functional Reach Test (FRT), Timed Up and Go Test (TUG), gait speed, and Berg Balance Scale (BBS).  A total of 19 studies (17 RCTs and 2 PCTs) with a mean sample size of 36 subjects and mean PEDro score of 5.6 (range of 4 to 8) were included.  Aquatic therapy demonstrated statistically significant improvements over land therapy on FRT (MD = 3.511 ± 1.597; 95 % CI: 0.381 to 6.642; p = 0.028), TUG (MD = 2.229 ± 0.513; 95 % CI: 1.224 to 3.234; p < 0.001), gait speed (MD = 0.049 ± 0.023; 95 % CI: 0.005 to 0.094; p = 0.030), and BBS (MD = 2.252 ± 0.552; 95 % CI: 1.171 to 3.334; p < 0.001).  The authors concluded that while the effect of aquatic therapy on mobility and balance was statistically significant compared to land-based therapy, the clinical significance was less clear, highly variable, and outcome measure dependent.

In a systematic review, Moritz and co-workers (2020) examined if the combination of aquatic therapy (AT) with usual care would result in greater improvements in activity limitations and neurological-related impairments in individuals with neurological conditions than usual care physiotherapy alone.  These researchers carried out a systematic review of controlled trials to compare usual care physiotherapy with usual care physiotherapy combined with AT for adults with any neurological condition; SMDs and 95 % CIs were calculated from post-intervention means and standard deviations (SDs).  A total of 10 studies with 490 subjects met the inclusion criteria.  Of the included trials, combined aquatic and usual care physiotherapy was evaluated in individuals with stroke in 8 trials and in patients with Parkinson's disease (PD) in 2 trials.  Trial and outcome heterogeneity prevented the completion of meta-analyses.  Data from 5 trials (n = 259) in individuals with stroke suggested that AT improved measures of balance, walking, mobility, and ADL.  No significant differences were detected in measures of activity limitation for patients with PD nor measures of impairment for patients with stroke or PD.  The authors concluded that this review provided preliminary evidence that the combination of AT with usual care physiotherapy may improve activity limitations in individuals with stroke.  This review found no evidence to support the combination of AT with usual care physiotherapy to improve activity limitations in PD or other neurological populations.  These investigators stated that these findings should be interpreted with caution due to the mixed quality of the included trials.

Nayak and associates (2020) stated that the evidence on aquatic therapy (AT) for improving balance and gait deficits post-stroke is unclear.  These researchers examined the effect of AT on balance and gait in stroke survivors.  They searched CINAHL, PubMed, Web of Science, Aqua4balance, Ewac, Cochrane, and Embase data-bases from inception to November 1, 2019.  A total of 11 studies with 455 subjects were included for the review.  Meta-analysis showed that AT was effective for improving balance (MD 3.23, 95 % CI: 1.06, to5.39; p = 0.004; I2 = 61 %) and gait speed (MD 0.77, 95 % CI: 0.25 to 1.29; p = 0.004; I2 = 0 %) when delivered alone.  AT was effective in improving cadence (MD 4.41, 95 % CI: 0.82 to 8.00; p = 0.02; I2 = 68 %) when delivered as an adjunct to land-based therapy.  The authors concluded that AT may be used to improve balance and gait after stroke; however, the evidence to support its use is still low.

Perez-de la Cruz (2020) noted that stroke survivors face severe problems affecting their mobility, such as balance impairments and an increased risk of falls.  In a pilot study, these researchers examined the effects of 12 sessions of Halliwick AT for the treatment of balance in patients with chronic stroke.  A total of 29 individuals with stroke participated in this single-group, experimental trial.  Sessions were carried out thrice-weekly for a total of 12 sessions.  A stabile-metric assessment was performed using a computerized platform.  The evaluations were carried out at baseline, at 4 weeks, and 1 month after completing the aquatic program.  The results obtained revealed significant differences for postural stability values (p < 0.001) and single-leg stabile-metric assessment.  However, in the case of values within the limits of stability, such as forward (F = 0.339, p = 0.676), backward (F = 0.449, p = 0.644), forward right oscillations (F = 1.637, p = 0.21), and the anterior/posterior instability index (F = 0.614, p = 0.55), no significant differences were observed.  The author concluded that these findings suggested that Halliwick AT may potentially improve stroke balance impairments.

The author stated that one of the limitations of this study was the relatively small sample size (n = 29).  This was a non-randomized, single group trial; thus, one could not draw any conclusions on the effectiveness of the intervention.  The intervention (Halliwick method) is difficult to standardize between subjects.  Future studies should increase the number of subjects to more safely extrapolate the results obtained in this pilot study.  Furthermore, this study also lacked a control group to which to compare findings and examine possible differences between treatments.  It would also have been interesting to be able to re-evaluate the subjects over a longer period of time after completion of therapy to verify the duration of the changes that occurred.  Furthermore, this study was not blinded.

In a systematic review and meta-analysis, Veldema and Jansen (2020) evaluated the available evidence of AT in stroke rehabilitation and examined the effect of this intervention in supporting stroke recovery.  The PubMed, the Cochrane Central Register of Controlled Trials and the PEDro data-bases were searched from their inception through to May 31, 2020 on RCTs examining the effect of AT on stroke recovery.  Subjects´ characteristics, methodological aspects, intervention description, and outcomes were extracted.  Effect sizes were calculated for each study and outcome.  Overall, a total of 28 appropriate studies (n = 961) were identified.  A comparison with no intervention indicated that AT was effective in supporting walking, balance, emotional status and health-related quality of life (HR-QOL), spasticity, and physiological indicators.  In comparison with land-based interventions, AT showed superior effectiveness on balance, walking, muscular strength, proprioception, HR-QOL, physiological indicators, and cardio-respiratory fitness.  Only on independence in ADL the land- and water-based exercise induced similar effects.  Established concepts of water-based therapy (such as the Halliwick, Ai Chi, Watsu, or Bad Ragaz Ring methods) were the most effective, aquatic treadmill walking was the least effective.  The current evidence on balance and walking ability is good.  In contrast, the evidence on emotional status and spasticity is very limited.  No evidence exists on cognitive abilities; future studies should fill this gap.  These investigators stated that these findings suggested that the effectiveness of AT depends on technique used.  Standardized concepts were more effective than both aquatic treadmill walking, as well as water‐based walking, balance training, strengthening, and stretching.  Future research should further examine these technique‐induced differences.  The authors concluded that the available evidence is insufficient to support AT within evidence-based rehabilitation; however, the available data indicate that AT can significantly improve a wide range of stroke-induced disabilities.  These researchers stated that future research should devote more attention to this highly potent intervention.

The authors stated that this was the 1st meta‐analysis that examined the potential of water‐based therapy on reducing cognitive and emotional decline as well as spasticity following a stroke.  This was also the 1st meta‐analysis that compared the effectiveness of different water‐based therapy methods.  A limitation of this meta‐analysis was the inconsistency of studies regarding their methodological design (parallel, cross-over), interventions (different AT methods, different control interventions, and different intervention durations), and outcomes (more than 50 outcomes were pooled in 8 areas).  This all may be the reasons for the high inconsistency of effect sizes detected.  Another limitation of this study was the high inconsistency of the methodological quality of the studies analyzed.  The 3 most frequent methodological deficiencies were: First, the absence of subjects, therapist and/or assessor blinding.  Second, the absence of statement regarding the number of subjects from whom key outcomes were obtained.  Third, the absence of intention-to-treat (ITT) analysis.  This all may impede the interpretation of the data.  Furthermore, no data exist regarding the long‐term effects of AT in this cohort; therefore, these investigators could not render any explicit statements on the persistence of the positive effects of this form of therapy.

In a systematic review with meta-analysis, Najafabadi and colleagues (2022) examined the evidence of the effects of aquatic therapy on lower limb disability compared to land-based exercises in post-stroke patients.  Medline, PsycInfo, CENTRAL, SPORTDiscus, PEDro, PsycBITE, and OT Seeker were searched from inception to January 2019.  The search included only randomized clinical trials.  Two reviewers independently examined the full text and conducted study selection, data extraction, and quality assessment.  Data synthesis was applied to summarize information from the included studies.  The quantitative analysis incorporated fixed-effect models.  Of the 150 studies identified in the initial search, 17 trials (629 subjects) satisfied the eligibility criteria.  Aquatic therapy improved balance based on the Berg Balance Scale (BBS) (SMD, 0.72; 95 % CI: 0.50 to 0.94; I2 = 67 %) compared with land-based exercises (control).  Furthermore, aquatic therapy had a small positive effect on walking speed (SMD, -0.45; 95 % CI: -0.71 to -0.19; I2 = 57 %), based on the results of the 10-m walking test, compared to controls.  Aquatic therapy had a small positive effect on mobility (based on Timed Up and Go), (SMD, -0.43; 95 % CI: -0.7 to - 0.17; I2 = 71 %) compared to land-based exercise (control).  The authors concluded that aquatic therapy had a more positive effect on walking speed, balance, and mobility than land-based exercises.  Moreover, these researchers stated that further research is needed to confirm the clinical utility of aquatic therapy for patients following stroke in the long-term.

Cerebral Palsy

Ballington and Naidoo (2018) stated that cerebral palsy (CP) is the most common motor disability in childhood.  Children with CP are more likely to have lower levels of physical activity than their peers, which has negative implications for their health.  However, aquatic exercise can be used to improve levels of fitness among children with CP.  These researchers determined the carry-over effect of an aquatic-based program (postural control and balance) on land (walking, running and jumping) in children with CP, post-aquatic intervention.  The study used a pretest-post-test, randomized group, cross-over design.  Children aged 8 to 12 years (n = 10) were divided into intervention (n = 5) and control (n = 5) groups.  The intervention group participated in two 30-min sessions a week, while the control group continued with normal activities.  Pre- and post-intervention testing was conducted using gross motor function measurement.  The 10-point program of the Halliwick Concept was used.  Results demonstrated that the aquatic therapy had a significant effect on gross motor function scores.  The aquatic program-based group showed increased motor function following the intervention, compared to the control group (z = -2.803, p = 0.005).  Furthermore, the aquatic-based therapy improved the average score for gross motor function measurement, post-intervention.  The authors concluded that an 8-week aquatic-based intervention had the potential to produce greater gains in gross motor function in children with CP, also producing a significant carry-over effect onto land.  However, this study has shown that after a month of no aquatic activity, gains in gross motor function were reversible.  Thus, it suggested that aquatic-based programs should be integrated and considered as an essential continuous mode of treatment for children with CP, to ensure long-term improvements in gross motor function.  Moreover, aquatic therapy is an innovative therapy for children with marked motor impairments, as movements in land-based exercises are restricted for this population.

The authors stated that this study had several drawbacks.  First, it had a small number of participants (n = 5 for the treatment group), and therefore, the possibility of extrapolating to other populations was limited.  Second, the participants did not have a broad range of severity levels: no participants had gross motor function classified at Gross Motor Function Classification System (GMFCS) levels IV and V.  Third, the study was designed as aquatic-based exercise only and determined the carry-over from water to land, but did not determine the effect of land-based exercise only.  Fourth, the study was conducted over 8 weekly sessions for each participant, which put a time restraint on some participants as they did not finish the whole 10-point program.  And lastly, a questionnaire to assess the enjoyment and or psychological status of the participants, which would have strengthened the overall study design, is needed in future studies.

Improvement of Predisposing Risk Factors to Falls in the Elderly

Martínez-Carbonell Guillamon and associates (2019) stated that according to the World Health Organization (WHO), the elderly are at the highest risk of injury or death from a fall.  Age-related changes in strength, balance and flexibility are degenerative factors that may increase the risk of falling, and an aquatic training may offer a favorable environment to improve these modifiable risk factors.  These investigators carried out a systematic review to evaluate the potential preventative role of aquatic exercise for reducing the risk of falls in the elderly by improving predisposing risk factors.  Electronic databases and reference lists of pertinent articles published between 2005 and 2018 were searched; RCTs that directly or indirectly examined the effect of aquatic exercise for the prevention of falls in healthy subjects were included within the synthesis.  Studies were included if they were reported between January 2005 and May 2018 within a population aged between 60 and 90 years old who were without exercise-effecting co-morbidities.  Data related to subject demographics, study design, methodology, interventions and outcomes was extracted by 1 reviewer.  Methodological quality assessment was independently performed by 2 reviewers using the PEDro (Physiotherapy Evidence Database) scale.  A total of 14 trials met the inclusion criteria.  Exercise intervention duration and frequency varied from 2 to 24 weeks, from 2 to 3 times per week, from 40 to 90 mins per session.  Fall rate was not reported in any of the studies analyzed.  However, aquatic exercise improved key predisposing physical fitness components that were modifiable and internal risk factors for falling.  The authors concluded that there is limited, low-quality evidence to support the use of aquatic exercise for improving physiological components that are risk factors for falling.  These researchers stated that although the evidence is limited, and many interventions were not well-described, these findings should be considered by health and exercise professionals when making evidence-based, clinical decisions regarding training programs to reduce the risk of falling.  They stated that further research is needed to create an evidence-based, replicable protocol for aquatic training with a specific aim of improving the commonly reported predisposing risk factors of falls.

The authors stated that there is some evidence to support using aquatic exercise for improving predisposing, modifiable risk factors of falls.  However, the quality of this evidence was low, and many interventions were poorly described.  The lack of consistency between study methodologies made intervention comparison difficult.  Furthermore, these findings did not find a statistically significant relationship between training variables and falls.  Resistance equipment was not included to increase exercise intensity, and few studies highlighted the importance of execution speed during the aquatic exercises.  Regarding the types of exercise, most of them referred to general exercises of upper and lower limbs; however, the exercises should be described in detail so that professionals could achieve the desired results.  Regarding the flexibility variable, it was included during the programs directed to older adults but it was not discussed as a relevant variable.  Flexibility was not treated in a specific way, obviating the importance of the pelvic musculature in the disturbance of the gait and thus of the risk of falling.  Researchers should avoid describing a superficial and uncritical methodology in order to design specific and valid aquatic programs for reducing the most modifiable predisposing risk factors of falls in the elderly.

Neonatal Brachial Plexus Palsy

In an integrative literature review, Frade and colleagues (2019) analyzed the scientific literature aimed at identifying and describing existing rehabilitation treatments/therapies for neonatal brachial plexus palsy (NBPP).  The data collection was carried out in January 2019, in the EBSCOhost and BVS (Biblioteca Virtual em Saúde) platforms, in the CINAHL Complete, Medline Complete, LILACS and PubMed databases.  A total of 13 articles were included in this integrative literature review, based on a literature search spanning title, abstract and full text, and considering the inclusion criteria.  Two main treatments/therapies for NBPP rehabilitation were identified: conservative treatment and surgical treatment.  Conservative treatment includes teamwork done by physiatrists, physiotherapists and occupational therapists.  These professionals use rehabilitation techniques and resources in a complementary way, such as electro-stimulation, botulinum toxin (BTX)  injection, immobilizing splints, and constraint induced movement therapy (CIMT) of the non-injured limb.  Professionals and family members work jointly.  Surgical treatment includes primary surgeries, indicated for children who do not present any type of spontaneous rehabilitation in the first 3 months of life; and secondary surgeries, recommended in children who after primary surgery have some limitation of injured limb function, or in children who have had some spontaneous recovery, yet still have significant functional deficits.  Treatment options for NBPP are defined by clinical evaluation/type of injury, but regardless of the type of injury, it is unanimous that conservative treatment is always started as early as possible.  The authors stated that it should be noted that there was no evidence in the literature of other types of rehabilitation and techniques used in clinical practice, such as preventive positioning of contractures and deformities, hydrotherapy/aquatic therapy (from the age of 6 months), among others, thus, these researchers considered there is a need for further studies at this level in this area.

Peripheral Artery Disease

Park and colleagues (2019) noted that peripheral artery disease (PAD) is an atherosclerotic disease that is associated with attenuated vascular function, cardiorespiratory capacity, physical function, and muscular strength.  It is essential to combat these negative effects on health by incorporating lifestyle interventions to slow disease progression, such as exercise.  In a randomized clinical trial, these researchers examined the effects of aquatic walking exercise on cardiovascular function, cardiorespiratory capacity [maximal volume of oxygen consumption (V̇o2max)], exercise tolerance [6-min walking distance (6MWD)], physical function, muscular strength, and body composition in patients with PAD.  Patients with PAD (n = 72) were randomly assigned to a 12-week aquatic walking training group (AQ, n = 35) or a control group (CON, n = 37).  The AQ group performed walking and leg exercises in waist-to-chest-deep water.  Leg arterial stiffness [femoral-to-ankle pulse wave velocity (legPWV)], heart rate (HR), blood pressure (BP), ankle-to-brachial index (ABI), V̇o2max, 6MWD, physical function, muscular strength, body composition, resting metabolic rate (RMR), and flexibility were measured before and after 12 weeks.  There were significant group × time interactions (p < 0.05) after 12 weeks for legPWV and HR, which significantly decreased (p < 0.05) in AQ, and V̇o2max, 6MWD, physical function, and muscular strength, which significantly increased (p < 0.05) in AQ, compared with no changes in CON.  There were no significant differences (p > 0.05) for BP, ABI, RMR, or flexibility after 12 weeks.  Interestingly, there was relatively high adherence (84 %) to the aquatic walking exercise program in this population.  These findings suggested that aquatic walking exercise was an effective therapy to reduce arterial stiffness and resting HR and improve cardiorespiratory capacity, exercise tolerance, physical function, and muscular strength in patients with PAD.  The authors concluded that the findings of this study revealed for the first time that aquatic walking exercise could decrease arterial stiffness and improve exercise tolerance, cardiorespiratory capacity, and muscular strength in patients with PAD.  These researchers stated that aquatic walking exercise training demonstrated relatively high exercise adherence in this population; it may be a useful therapeutic intervention for improving physical function in patients with PAD.  These preliminary findings need to be validated by well-designed studies.

Traumatic Brain Injury

In a 2-arm RCT, Curcio and colleagues (2020) examined the effectiveness of an AT in patients with severe traumatic brain injury (sTBI) on balance.  The secondary objectives were to examine the effects on gait, ADL, and QOL, comparing to a land-based conventional protocol.  A total of 20 inpatients with sTBI, Glasgow Coma Scale score of less than or equal to 8, and Level of Cognitive Functioning of greater than or equal to 7 were recruited and randomly assigned to the AT group (ATG) or to the conventional training group (CTG).  Patients underwent 12 individual rehabilitation sessions (3 days/week, 4 weeks), in a rehabilitation pool during the post-acute intensive neuro-rehabilitation.  The primary outcome measure was the Berg Balance Scale (BBS); secondary outcome measures were the Modified Barthel Index (MBI), Disability Rating Scale (DRS), Tinetti Gait Balance Scale (TBG) and QOL After Brain Injury (QOLIBRI).  All the evaluations were carried out at baseline and after 4 weeks of training.  The within-subjects analysis showed a significant improvement both in ATG and CTG in MBI, BBS, TBG, and QOLIBRI.  The authors concluded that these findings may support the use of AT during post-acute phase to improve motor functions and QOL in patients with sTBI.  These preliminary findings need to be validated by well-designed studies.

Passive Hydrotherapy WATSU (WaterShiatsu)

Ramirez and associates (2019) stated that juvenile idiopathic arthritis (JIA) is a rheumatologic disease in children under 16 years of age, which causes early physical disability.  The use a form of passive hydrotherapy in chest-deep thermo-neutral water (WATSU [WaterShiatsu]; 35° C = 95° F = 308.15 K) in these patients was proposed.  WATSU combines elements of myofascial stretching, joint mobilization, massage, and shiatsu.  These researchers examined the effectiveness of WATSU compared with conventional hydrotherapy on HR-QOL, functional health status, pain, and ranges of joint motion in patients with acute or subacute JIA.  In a single-blind, parallel controlled clinical trial, 46 patients with acute and subacute JIA between 8 to 18 years of age were randomized in a 1:1 manner to the WATSU group (n = 24) and to the conventional hydrotherapy group (n = 22).   Subjects participated in 10 sessions of 45 minutes once-weekly.  Pediatric Quality of Life Inventory 4.0 (PedsQL4.0), Childhood Health Assessment Questionnaire (CHAQ), and 10-joints Global range of motion score (GROMS) assessments were measured in the beginning, post-treatment, and at 3-month follow-up.  WATSU therapy showed statistically significant improvements in physical functioning – HR-QOL (p = 0.041), disability index (p = 0.015), distress index (p = 0.015), and functional health status -- CHAQ (p = 0.013) after treatment compared to conventional hydrotherapy.  The authors concluded that  WATSU therapy improved HR-QOL, pain sensation, and functional health status compared to conventional hydrotherapy.  Moreover, these researchers stated that methodological adaptations are needed in future studies to improve the external validity of these findings.

The authors stated that the limited number of subjects (n = 24 in the WATSU group)and the heterogeneity of their baseline clinical condition hindered the external validity of these findings.  For future studies, it is proposed to increase the intervention period with WATSU therapy, to perform randomized sampling stratified by type of JIA and sex, along with adding instruments that measure the barriers to adherence to treatment perceived by children and their families, in order to improve the methodological level of the studies, promote adherence to treatment, and favor long-term remission status.

In a systematic review and meta-analyses, Schitter and colleagues (2020) examined the applications, indications, and the effects of WATSU to form a basis for future studies.  They carried out a search for "WATSU OR watershiatsu OR (water AND shiatsu)" without any restrictions in 32 data-bases.  Peer reviewed original studies addressing WATSU as a stand-alone hydrotherapy were examined for risk of bias.  Quantitative data of effects on pain, physical function, and mental issues were processed in random model meta-analyses with subgroup analyses by study design.  Effect sizes were expressed as Hedges's g (± 95 % CIs).  Of 1,906 unique citations, 27 articles regardless of study design were evaluated for risk of bias.  WATSU has been applied to individuals of all ages.  Indications covered acute (e.g., pregnancy-related low back pain [LBP]) and chronic conditions (e.g., CP) with beneficial effects of WATSU regarding relaxation or sleep quality.  Meta-analyses suggested beneficial effect sizes of WATSU on pain (overall Hedges's g = -0.71, 95 % CI: -0.91 to -0.51), physical function (overall Hedges's g = -0.76, 95 % CI: -1.08 to -0.44), and mental issues (overall Hedges's g = -0.68, 95 % CI: -1.02 to -0.35).  The authors concluded that various applications, indications and beneficial effects of WATSU were identified.  The grade of this evidence is estimated to be low-to-moderate at best.  These researchers stated that high-quality RCTs are needed to strengthen the findings of this study.  They noted that the presented meta-analyses are suited to serve future researchers for designing trials and sample size calculations to further examine the effect of WATSU on pain, physical function, and mental issues.

The authors stated that this systematic review was limited by the quality of findings, as only 7 of the studies evaluated for risk of bias had control groups.  The assessment revealed that not only the studies’ designs, but also poor reporting hampered accurate judgement in several studies.  In subgroup analyses, however, the effect sizes of the meta-analyses were confirmed consistently with minimal heterogeneity, indicating that the inclusion of trials with lower methodological rigor led to an increase of noise without major over- or under-estimation of the effect size as observed in RCTs.  The weighted effect sizes provided in the current article warrant attempts to reproduce the reported results and may support future researchers in designing adequately powered RCTs regarding the effectiveness of WATSU.

Loureiro and colleagues (2022) noted that sleep disorders are one of the most frequent non-motor symptoms of Parkinson's disease (PD).  In a RCT, these researchers examined if adding WATSU to land-based therapy would result in additional beneficial therapeutic effects regarding quality of sleep and quality of life (QOL) in individuals with PD.  Participants completed 9-week interventions.  The control group (CG) received land-based therapy, while the intervention group (IG) received the same land-based therapy and additionally WATSU.  Sleep quality and QOL were measured at baseline and post-interventions by Pittsburgh Sleep Quality Index and Nottingham Health Profile, respectively.  A total of 28 subjects completed the study.  In contrast to CG, the IG presented with significant improvements in both, quality of sleep and QOL (p < 0.001).  The authors concluded that WATSU has the potential to be an attractive adjunctive therapy for producing positive health impacts regarding sleep quality, which may translate to an overall improvement in QOL of individuals with PD.  These preliminary findings need to be validated by well-designed studies.

Schitter and associates (2022) examined if and how frequently scientifically studied application areas and effects of WATSU occur in practice, whether similar effectiveness of WATSU is observed in trials and practice, and whether practitioners could contribute additional application areas and effects of WATSU.  Application areas and effects of WATSU reported in a recent systematic review were extracted verbatim to be evaluated in a worldwide multi-lingual cross-section online survey, generating quantitative and qualitative data.  A pre-test and re-test were carried out to ensure quality and evaluate the questionnaire's psychometric properties; answers of 191 respondents were processed.  All proposed 26 application areas and 20 effects were confirmed, each with relatively high ratings of observed effectiveness of WATSU.  WATSU was frequently used in healthy individuals (including during pregnancy), and individuals in various pain-related (e.g., LBP, neck pain, myofascial pain, fibromyalgia) and stress-related (e.g., stress, depression, sleep disorders, fatigue, anxiety disorders) conditions.  Frequently confirmed effects were physical relaxation, relief of physical tension, pain relief, increased mobility and flexibility, improved QOL, spiritual experiences, and increased psychological health.  Respondents contributed 73 additional application areas and effects (both, mental and physical) of WATSU.  The authors concluded that application areas and effects of WATSU are consistently employed practically and scientifically.  Respondents' ratings of effectiveness of WATSU matched tentative research efforts.  These researchers stated that WATSU is cautiously recommended for the use in pain-related as well as stress-related conditions; moreover, short-term and long-term effectiveness of WATSU need to be examined in high level intervention studies.

Improvement of Balance in the Elderly

Shariat and colleagues (2022) stated that balance is a key component of movement for daily activities, especially in the elderly.  Previous studies examining aquatic therapy as an effective way for improving balance have yielded inconsistent findings.  In a systematic review and meta-analysis, these investigators examined the effectiveness of aquatic therapy on balance among the elderly.  Sources include Cochrane Central Register of Controlled Trials, Medline, ISI Web of Science, EBSCO, Embase, Cumulative Index to Nursing and Allied Health Literature, and Scopus.  Randomized controlled or cross-over trials published by February 2020 were included following pre-determined search and selection criteria.  Data extraction was carried out by 2 researchers independently using a pre-determined data extraction form.  Methodological quality was evaluated by 2 reviewers using the PEDro scale that was used to rate trials according to criteria such as concealed allocation, blinding, and ITT analysis.  Furthermore, meta-analysis was conducted where possible.  A total of 15 trials with 385 healthy subjects aged 50 or over were included.  Results showed that aquatic therapy had a significant effect on dynamic balance (SMD, - 1.13; 95 % CI: - 1.45 to - 0.82]; I2 = 77 %).  The analysis indicated that aquatic therapy improved balance ability compared to controls.  The authors concluded that aquatic therapy had a positive impact on dynamic balance in the elderly; however, further high-quality and appropriately powered studies are needed to confirm this conclusion.

Aquatic Therapy for Atopic Dermatitis and Psoriasis

Jazani et al (2022) stated that atopic dermatitis (AD) and psoriasis are chronic inflammatory diseases that have significant skin complications.  In a systematic study, these investigators examined the evidence obtained from human studies on the effectiveness of hydrotherapy, spa therapy, and balneotherapy in patients with atopic dermatitis and psoriasis.  This systematic review was carried out according to the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statements.  Furthermore, for this study databases such as Embase, PubMed, Scopus ProQuest, and sciences direct database were searched from the beginning to April 2021.  All human studies that examined the effectiveness of balneotherapy, spa therapy, and hydrotherapy on atopic dermatitis and psoriasis were published in the form of a full article in English.  A total of 22 (out of the 424) articles met the inclusion criteria for analysis.  Most studies have shown that balneotherapy, spa therapy, and hydrotherapy may reduce the effects of the disease by reducing inflammation and improving living conditions.  Furthermore, the results of the Downs and Black score showed that 7 studies received very good scores, 3 studies received good scores, 9 studies received fair scores, and 3 studies received poor scores.  The authors concluded that the findings these studies showed that hydrotherapy resulted in an improvement in the PASI score index.  Moreover, these researchers stated that more clinical trials are needed to determine the mechanism of action of hydrotherapy on these diseases.

Aquatic Therapy for Management of Individuals with Cancer

Reger et al (2022) noted that water therapy such as hydrotherapy, balneotherapy or aqua therapy are often used in the relief of disease- and treatment-associated symptoms of cancer patients.  However, a systematic review for the evidence of water therapy including all cancer entities has not been conducted to-date.  These investigators stated that cancer patients often suffer from symptoms which in patients with other diseases are successfully treated with water therapy; they gathered more information regarding the risks and benefits of water therapy for cancer patients.  In May 2020, a systematic search was conducted searching 5 electronic databases (Embase, Cochrane, PsychInfo, CINAHL and PubMed) to find studies concerning the use, effectiveness and potential harm of water therapy on cancer patients.  Of 3,165 search results, 10 publications concerning 12 studies with 430 patients were included in this systematic review.  The patients treated with water therapy were mainly diagnosed with breast cancer.  The therapy concepts included aqua lymphatic therapy, aquatic exercises, foot bathes and whole-body bathes.  Outcomes were state of lymphedema, QOL, fatigue, body mass index (BMI), vital parameters, anxiety and pain.  The quality of the studies was assessed with the AMSTAR2-instrument, the SIGN-checklist and the IHE-Instruments.  The studies had moderate quality and reported heterogeneous results.  Some studies reported significantly improved QOL, extent of lymphedema, neck and shoulder pain, fatigue and BMI while other studies did not find any changes concerning these endpoints.  The authors concluded that due to the very heterogeneous results and methodical limitations of the included studies, a clear statement regarding the effectiveness of water therapy on cancer patients is not possible.

The authors stated that this systematic review had several drawbacks.  First, these researchers excluded studies concerning children or teenagers.  Second, only studies in English or German language were included.  Third, studies published before 1995 were excluded.

Crenobalneotherapy

In a systematic review, Forestier and Francon (2008) examined the effectiveness of crenobalneotherapy for the treatment of limb osteoarthritis and discussed the study methods used to evaluate this treatment modality.  These investigators searched Medline using the following keywords: "spa therapy", "mud", "radon", "balneotherapy", and "hydrotherapy" in combination with "osteoarthritis", "arthrosis", and "gonarthrosis".  They also reviewed the reference lists of articles retrieved by the Medline search.  Studies that compared crenobalneotherapy to any other intervention or to no intervention were selected, and a checklist was used to examine their internal validity.  Furthermore, external validity and the quality of the statistical analysis were evaluated.  Crenobalneotherapy was associated with improvements in the evaluation criteria (pain, function, and QOL) compared to baseline; however, inadequate internal validity precluded the establishment of a causal link between these improvements and crenobalneotherapy.  External validity was often poorly defined.  Some studies found no significant differences with the control group but failed to include a sample-size calculation, suggesting inadequate statistical power as a possible explanation for the result.  In several studies, the use of multiple evaluation criteria and measurements led to a high risk of Type I error.  The authors concluded that although the consistency of the results suggested a therapeutic effect of crenobalneotherapy in limb osteoarthritis, available studies were methodologically inadequate and sample sizes too small to allow definitive conclusions.  These researchers suggested a number of solutions to these shortcomings.  They stated that carefully designed studies in larger patient populations are needed to determine the role crenobalneotherapy in knee osteoarthritis.

Forestier et al (2022) stated that crenobalneotherapy is a treatment commonly used in Europe and the Middle East.  It employs mineral water sometimes combined with different hydrotherapy techniques.  Most patients treated in spa centers suffer from low back pain (LBP).  These investigators identified clinical trials on crenobalneotherapy for LBP.  Publication research was carried out by means of Medline, Cochrane, and PEDRO databases.  Clinical trials were analyzed for internal validity, external validity, quality of statistical analysis, and quality of collection of adverse events.  These investigators presented the best level of evidence.  Bibliographic research identified 21 clinical trials and the co-authors added 5 references.  The 26 studies represented 2,695 patients.  Some exhibited good methodological quality and allowed considering crenobalneotherapy as a potential treatment for LBP, even if the role of mineral water remains uncertain.  The authors concluded that the methodological quality of therapeutic trials should be improved; and these trials should be analyzed in the future guidelines on LBP.

Nano-Bubble Hydrotherapy

Nanobubble hydrotherapy entails infusion of compressed air into water to form a cloud of tiny bubbles, which allows for a form of hydrotherapy.  Some manufactures purport that nanobubble hydrotherapy enhances growth of skin cells, improves functioning of blood vessels and stimulates the body's immune system.

Paknahad et al (2021) stated that the use of bulk nano-bubbles in biomedicine is increasing in recent years, which is attributable to the array of therapeutic and diagnostic tools promised by developing bulk nanobubble technologies.  From cancer drug delivery and ultrasound (US) contrast enhancement to malaria detection and the diagnosis of acute donor tissue rejection, the potential applications of bulk nano-bubbles are broad and diverse.  Developing these technologies to the point of clinical use may significantly impact the quality of patient care.  These researchers summarized a representative collection of the current applications, fabrication techniques, and characterization methods of bulk nano-bubbles in biomedicine.  Current state-of-the-art generation methods are not designed to create nano-bubbles of high concentration and low polydispersity, both characteristics of which are important for several bulk nano-bubble applications.  Currently, microfluidics has not been widely considered as a tool for generating nano-bubbles, although the small-scale precision and real-time control offered by microfluidics may overcome the afore-mentioned challenges.  The authors suggested possible uses of microfluidics for improving the quality of bulk nano-bubble populations and proposed ways of leveraging existing microfluidic technologies, such as organ-on-a-chip platforms, to expand the experimental toolbox of researchers working to develop biomedical nano-bubbles.

Lu et al (2022) noted that low-frequency (20 to 100 kHz) US-assisted drug delivery has been widely examined as a non-invasive method to enhance the permeability and retention effect of drugs.  The functional micro-/nano-bubble loaded with drugs could provide an unprecedented opportunity for targeted delivery.  Then, US with higher intensity would locally burst bubbles and release agents; thus, avoiding side effects associated with systemic administration.  In addition, US-mediated destruction of micro/nano-bubbles could effectively increase the permeability of vascular membranes and cell membranes; thereby, not only increasing the distribution concentration of drugs in the interstitial space of target tissues but also promoting the penetration of drugs through cell membranes into the cytoplasm.  These advancements have transformed US from a purely diagnostic utility into a promising theragnostic tool.  The authors discussed the structure and generation of micro-/nano-bubbles; US parameters and mechanisms of therapeutic delivery; and potential biomedical applications of micro-/nano-bubble-assisted US.  Finally, these investigators discussed the challenges and future directions of US combined with micro-/nano-bubbles.

Furthermore, an UpToDate on “Palmoplantar keratoderma” (Kubo, 2022) does not mention nano-bubble hydrotherapy management.  The authors state that palmoplantar keratoderma (PPK) is a heterogeneous group of inherited or acquired disorders characterized by excessive epidermal thickening of the palms and soles.  Patients with certain types of PPK will benefit from daily to weekly bath soaks followed by gentle mechanical scale removal with tools that are chosen according to patient preference.  Examples of useful tools include a pumice stone, a synthetic polyurethane pumice bar (which is softer), or a callus file.  Professional foot and hand care may be appropriate for some patients.  Frequent and liberal use of emollients is advisable.

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