Parkinson's Disease (PD) is a progressive neurodegenerative disorder characterized by motor symptoms such as bradykinesia, tremors, and postural instability, as well as various non-motor symptoms. Conventional land-based rehabilitation is standard; however, aquatherapy-utilizing water's buoyancy, hydrostatic pressure, and viscosity-offers a promising alternative to improve balance and mobility while reducing fall risks. This study aims to evaluate the effects of aquatherapy on gait, balance, posture, freezing of gait, activities of daily living (ADL), pain, and depression in Turkish PD patients.

This is a prospective, single-blind, randomized controlled trial involving 42 patients at Ankara City Hospital. Participants will be divided into two groups:

• Group 1 (Control): Home-based exercise program (5 days/week for 6 weeks).
• Group 2 (Intervention): Home-based exercises plus supervised aquatherapy (3 sessions/week, 45 minutes each, in a 30-32°C pool).

The study utilizes high-tech objective measurements and validated scales:

• Gait & Posture: Zebris Gait Analysis (spatiotemporal parameters) and Diers Formetric 4D (topographical posture analysis).
• Balance: HUR-Smart Balance device and the Berg Balance Scale.
• Clinical Scales: PDQ-39 (quality of life), Freezing of Gait Questionnaire, Falls Efficacy Scale, MMSE (cognitive), Beck Depression Inventory, and VAS (pain).

This research is noteworthy as the first aquatherapy study among Turkish PD patients to utilize a large sample size and standardized aquatic exercise protocols. It seeks to provide a comprehensive analysis of both motor and non-motor improvements, potentially establishing aquatherapy as a superior adjunctive treatment for enhancing functional independence in Parkinson's patients.

Primary hypothesis or outcome measure : Parkinson's Disease Questionnaire-39 . PDQ-39 is a patient-reported outcome measure designed to evaluate the health-related quality of life in Parkinson's patients across eight specific domains, including mobility, activities of daily living, and emotional well-being.

Abstract / Project Description Parkinson's Disease (PD) is a progressive neurodegenerative disorder characterized by the degeneration of dopamine-producing cells in the substantia nigra, ranking as the second most common neurodegenerative disease after Alzheimer's. The prevalence of the disease in Turkey is approximately 2/1000. The primary symptoms of Parkinson's disease include bradykinesia, resting tremor, rigidity, and postural instability. Posture, balance, and gait disturbances are significant findings that emerge during the course of the disease, causing severe disability. The gait pattern in PD varies across different stages and affects patients to varying degrees. Typically, a shortening of step length, patients walk slowly with small steps. In advanced stages, difficulty in initiating gait, freezing of gait, and postural instability are frequently developing symptoms. In addition to classic motor findings, non-motor symptoms such as urinary incontinence, sexual dysfunction, orthostatic hypotension, sleep disorders, depression, anxiety, and pain may also be observed.

The Modified Hoehn & Yahr Staging is a scale used to stage Parkinson's disease, with proven validity and reliability in Turkish. Developed by Hoehn and Yahr in 1967, this system allows both the patient and the clinician to easily define the severity of the disease and evaluate its progression across five stages. In the literature, Stages 1 and 2 are classified as "mild," Stage 3 as "moderate," and Stages 4 and 5 as "severe".

As conventional rehabilitation therapy, Parkinson's patients are frequently prescribed land-based gait and mobilization, posture, relaxation exercises, occupational therapy, and respiratory and swallowing exercises. Whether combined with other therapies or not, aquatherapy improves balance and functional mobility in PD patients compared to conventional rehabilitation. Aquatherapy, developed to improve balance, make walking more functional, and minimize strength imbalances between muscles, is considered a viable method for PD .

Aquatherapy is a rehabilitation method based on exercises performed in water using the physical properties of water . It is beneficial in the treatment of musculoskeletal, neurological, and cardiopulmonary diseases, among other conditions. The therapeutic safety margin of aquatherapy is quite broad . During treatment, the physical properties of water are utilized: hydrostatic pressure increases lymphatic and venous return in the extremities, contributing to the reduction of edema. Due to the buoyancy of water, patients move more comfortably; body weight is reduced by 90% with immersion up to the cervical region and by 60% up to the xiphoid process . Because of water's viscosity, resistance to movement is higher than in air, allowing movements to be performed at a constant speed. This resistance makes water an effective environment for strengthening. Additionally, heat can be retained or transferred through the thermodynamic effect of water . Aquatherapy is recognized as an effective adjunctive treatment in PD, particularly for improving motor symptoms . It reduces pressure on the joints, alleviates pain, provides support during movement, and reduces the risk of falling, thereby helping patients improve their balance skills .

In this study, the aquatherapy exercise program will be conducted in a therapy pool with a depth of 120 cm. Patients will be recommended to wear aquatic shoes to prevent slipping. Access to the pool will be provided via a lift. The water temperature will be maintained at 30-32°C. The aim of this study is to investigate the effects of aquatherapy on gait, balance, posture, freezing, activities of daily living (ADL), pain, and depression in Parkinson's patients.

3. Expected Benefits and Risks of the Research In this study investigating the efficacy of aquatherapy in PD, patients will be divided into two groups: the first group will receive only home-based exercises, while the second group will receive aquatherapy for 45 minutes three days a week in addition to the home exercise program. The objective is to evaluate the efficacy of aquatherapy on ADLs, gait, balance, posture, pain, and depression.

Expected contributions to the literature include:

• Being the first aquatherapy study conducted among Turkish patients diagnosed with Parkinson's.

• Evaluating balance, gait, posture, depression, and pain within the same study.

• Utilizing a larger sample size compared to existing studies in the literature.

• Standardizing aquatherapy exercises for Parkinson's patients. Potential risks include patient non-compliance with the treatment, sensitivity to pool chemicals, and the development of exercise intolerance.

  4. Type, Scope, and Design of the Planned Research This study is designed as a prospective, single-blind, randomized controlled trial. Patients diagnosed with Parkinson's who apply to the Ankara City Hospital Physical Medicine and Rehabilitation Hospital outpatient clinic and meet the inclusion criteria will be included. Informed consent will be obtained from participants. Clinical and demographic data will be recorded. The 42 patients included in the study will be divided into two groups using the single-blinded sealed envelope technique.

• Group 1: Will perform home exercises at least 5 days a week for 6 weeks.

• Group 2: Will perform the home exercise program 5 days a week, plus aquatherapy exercises 3 days a week for 6 weeks under the supervision of a physiotherapist.

Patients will be evaluated before and after treatment. Home exercises for Group 1 include posture, flexibility and stretching, balance-coordination, strengthening, and gait exercises. For Group 2, in addition to home exercises, a pool prescription including water walking, side-stepping, forward and lateral lunges, single-leg stance/balance, hip kicks at the pool wall, deep-water cycling, arm raises, and standing knee raises will be implemented.

The following scales, which have proven Turkish validity and reliability, will be utilized in the study: Parkinson's Disease Questionnaire-39 (PDQ-39), Berg Balance Scale, Freezing of Gait Questionnaire, Falls Efficacy Scale, Mini-Mental State Examination (MMSE), Beck Depression Inventory, and the Visual Analog Scale (VAS), MDS-Unified Parkinson's Disease Rating Scale .

• Gait Analysis: Patients' gait patterns will be evaluated using the Zebris gait analysis system. Parameters to be measured include step length (distance between two consecutive footprints), step time (duration to complete a gait cycle), step width (mediolateral distance between ankle joint centers), walking speed, and cadence.
• Posture Analysis: Postural assessments will be conducted using the Diers Formetric 4D system, allowing for a comprehensive topographical analysis of the spine and pelvis.
• Balance Testing: Balance assessments will be performed using the HUR-Smart Balance device to provide objective data on stability and weight distribution.

Inclusion Criteria:

• Having a diagnosis of Idiopathic Parkinson's Disease between the ages of 40-80 and consenting to the treatment.
• Being regularly followed by a neurologist and having a stable medical treatment regimen for at least 3 months.
• Having a disease stage between 1-3 according to the Modified Hoehn-Yahr Staging Scale (MHY).
• A score of 24 or higher on the Mini-Mental State Examination (MMSE).
• Being able to verticalize independently and ambulate with or without assistance.

Exclusion Criteria:

• Having orthopedic, rheumatological, or non-Parkinson's neurological disorders that affect functional status.
• Having a medical treatment regimen that has been modified within the last 3 months.
• Presence of Atypical Parkinson's Disease.
• Visual impairment.
• Presence of dementia.
• Decompensated cardiac or respiratory failure.
• Diabetes insipidus.
• Presence of systemic infection.
• Impaired skin integrity or the presence of skin infections.
• Increased sensitivity to inhaled steam or water chemicals.
• History of epilepsy or asthma.
• Urinary or fecal incontinence.
• Refusal to participate in or consent to the treatment.

Individual participant data will not be shared publicly to protect patient confidentiality and ensure strict adherence to personal data protection laws. The raw data contains sensitive health information that could potentially lead to the de-identification of participants, which would violate the ethical terms outlined in the informed consent forms

The study was designed as a single-blind trial, where participants were kept unaware of their group assignments.