Assessment of the Effects of Tai Chi Exercises on Balance and Functional Status in Patients With Knee Osteoarthritis
Phase: NA
Conditions: OA Knee
Sponsor: Grzegorz Mańko

STUDY PROTOCOL AND STATISTICAL ANALYSIS PLAN 
Effectiveness of Tai Chi Compared With Standard Physiotherapy and 
Virtual Reality Training on Balance and Functional Outcomes in Patients 
With Knee Osteoarthritis 
10.12.2025

STUDY PROTOCOL AND STATISTICAL ANALYSIS PLAN 
Effectiveness of Tai Chi Compared With Standard Physiotherapy and Virtual Reality Training 
on Balance and Functional Outcomes in Patients With Knee Osteoarthritis 
Study Design: Randomized controlled parallel-group trial (3 arms) 
Study Type: Interventional (Non-Drug) 
Primary Purpose: Treatment 
Masking: Single-blind (Outcome assessor blinded) 
Estimated Enrollment: 96 participants 
Study Duration: 4 weeks intervention 
Ethics Approval: Approved by Ethics Committee of Jagiellonian University Medical College 
(No. 118.0043.1.208.2025) 
Background and Rationale 
Knee osteoarthritis (KOA) is a leading cause of disability in older adults. Exercise-based 
rehabilitation is recommended as first-line treatment. Tai Chi integrates balance control, closed 
kinetic chain movement, and neuromuscular coordination, which may provide superior functional 
improvements compared with standard physiotherapy or virtual reality-based training. 
Objectives 
Primary Objective: 
To compare the effectiveness of Tai Chi versus standard physiotherapy and VR training on 
functional status (WOMAC total score) and balance (Berg Balance Scale). 
Secondary Objectives: 
- To evaluate changes in pain intensity (VAS).
- To assess dynamic balance (Timed Up and Go test).
- To assess knee joint range of motion (flexion and extension).
Study Design 
Participants will be randomly assigned (1:1:1) to one of three groups: 1) Standard Physiotherapy, 
2) Standard Physiotherapy + VR Training, 3) Standard Physiotherapy + Tai Chi. All interventions
last 4 weeks. Assessments will be performed at baseline and at Week 4.
10.12.2025

Participants 
Inclusion criteria 
Exclusion criteria 
Diagnosed knee osteoarthritis 
Patients with significant knee joint effusion and 
excessive valgus or varus deformity of the knee 
joint 
Age between 60 and 80 years 
Post-surgical status 
Patients with a body mass index (BMI) ≥ 34 
Patients after knee joint surgery 
Patients with severe clinically significant 
comorbidities that could interfere with study 
outcomes 
Lack of patient consent to participate in the 
study, as well as non-compliance or diagnosed 
psychiatric disorders 
History of stroke and other neurological 
disorders 
Interventions 
Arm 1: Standard Physiotherapy – manual therapy and physical modalities. 
Arm 2: Standard Physiotherapy + 30 min/day VR training (Kinect). 
Arm 3: Standard Physiotherapy + 30 min/day supervised Tai Chi 
Outcome Measures 
Primary Outcomes: 
- Change in WOMAC total score (0–96).
- Change in Berg Balance Scale (0–56).
- Change in Timed Up and Go (seconds).
The interventions are low-risk behavioral therapies. Adverse events (e.g., musculoskeletal pain 
exacerbation, falls) will be recorded and monitored. No Data Monitoring Committee was 
established due to minimal risk. 
Statistical Analysis Plan 
Statistical analyses will be conducted using R Studio (v4.5.1). Two-sided significance level α = 
0.05. Primary analyses will follow the intention-to-treat (ITT) principle. Per-protocol analyses 
will be conducted as sensitivity analyses. Continuous variables will be summarized using mean ± 
SD or median (IQR). Categorical variables will be summarized using frequencies and 
percentages.  
Within-group comparisons: Wilcoxon signed-rank test. Between-group comparisons: Kruskal–
Wallis test with Dunn post-hoc (BH correction). Effect size will be reported using epsilon-
squared (ε²). 
Secondary Analysis 
10.12.2025

Same analytical framework will be applied to secondary outcomes. Effect sizes will be reported. 
Missing Data 
Missing data will be assessed for pattern and mechanism. If <5%, complete case analysis will be 
performed. If >5%, multiple imputation methods will be considered. 
Software 
R Studio version 4.5.1. 
10.12.2025