A Prospective, Single-Arm, Observational Case Series Evaluation of the Impact of Robotic Spinal Mobilization on Functional Mobility, Axial Rigidity, Chronic Back Pain, and Sleep Quality in Community-Dwelling Adults With Parkinson's Disease

Study Rationale and Background: Axial rigidity is a cardinal motor feature of Parkinson's Disease (PD) that contributes significantly to gait impairment, balance dysfunction, and chronic pain. Unlike appendicular symptoms, axial symptoms often show limited response to standard dopaminergic medication. This study investigated the utility of the BackHug robotic device to mechanically mobilize the thoracic and lumbar spine, evaluating the hypothesis that reducing axial stiffness improves systemic mobility.

Technical Description of the Intervention: The BackHug device is an automated spinal mobilization system featuring 26 independent robotic therapeutic heads. The mechanism employs real-time load sensing to adapt pressure to the user's spinal curvature. Participants received a standardized 40-minute protocol targeting the neck, shoulders, thoracic, and lumbar spine. Treatment intensity was personalized to user tolerance via the device's control app.

Quality Assurance and Data Validation Plan: To ensure data integrity and minimize bias in this observational setting, the following quality assurance procedures were implemented:

• Administrator Qualifications: All functional assessments were administered by HCPC-registered physiotherapists trained in standard PD assessment protocols (e.g., TUG, STS) to ensure inter-rater reliability.
• Source Data Verification: Primary functional data was recorded on standardized paper Assessment Forms (source documents) at the point of care. These were subsequently verified against the electronic study database.
• Video Verification: Where participant consent was granted, video recordings of functional tests were utilized as source data to cross-verify the accuracy of timed metrics (e.g., confirming gait speed to the nearest millisecond).
• Data Consistency Checks: The data management system employed logic checks during entry to flag out-of-range values (e.g., age outside 18-75, VAS scores outside 0-10) for immediate review against clinician notes.

Data Management and Missing Data

Data Dictionary: All variables were defined according to standard clinical scales (e.g., Visual Analog Scale 0-10 cm; Likert Scale 1-5).

Handling of Missing Data: The study adhered to a Per-Protocol analysis. Missing data points resulting from missed sessions or incomplete assessments were documented in the study log but excluded from the final efficacy calculation for that specific endpoint. No data imputation methods were used.

Statistical Analysis Plan

Sample Size Assessment: As a pilot observational case series, the sample size (N=16) was determined based on feasibility and the capacity of the single-center clinical facility. The objective was to generate effect size estimates and standard deviation data sufficient to power a future randomized controlled trial (RCT).

Descriptive Statistics: Baseline demographics (Age, Gender, Disease Duration) were summarized using means and standard deviations.

Efficacy Analysis: The primary analytical method compared Pre-Intervention vs. Post-Intervention scores to determine the percentage change in performance. Paired t-tests were employed to assess the statistical significance of acute and longitudinal changes in functional mobility and strength.