Comparison of Aquatic vs Land-Based Exercise in Knee Osteoarthritis: Quasi-Experimental Study

Abstract

Background:
Knee osteoarthritis is a common degenerative musculoskeletal condition associated with chronic pain, functional limitation, and reduced quality of life. Exercise-based rehabilitation remains a cornerstone of conservative management; however, pain and reduced weight-bearing tolerance often limit participation in land-based exercise programs. Aquatic exercise has gained attention as an alternative modality due to its reduced joint loading and supportive environment, yet comparative evidence within local clinical settings remains limited.

Objective:
To compare the effectiveness of aquatic exercise and land-based exercise in reducing pain and improving functional outcomes among individuals with knee osteoarthritis.

Methods:
A quasi-experimental study was conducted in selected rehabilitation centers in Karachi, Sindh, from February to September 2022. Sixty participants with clinically and radiographically confirmed knee osteoarthritis were allocated to either an aquatic exercise group or a land-based exercise group. Both groups underwent supervised exercise sessions three times per week for eight weeks. Pain intensity was assessed using the Visual Analog Scale, while functional status was evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index. Data were analyzed using paired and independent sample t-tests, assuming normal distribution, with statistical significance set at p < 0.05.

Results:
Both groups demonstrated significant post-intervention improvements in pain and function. The aquatic exercise group showed a greater reduction in pain scores (mean decrease: 3.7 points) compared with the land-based group (mean decrease: 2.4 points; p = 0.004). Functional outcomes also improved more substantially in the aquatic group, with a greater reduction in WOMAC total scores (19.2 vs 12.0 points; p = 0.006).

Conclusion:
Aquatic exercise was more effective than land-based exercise in reducing pain and improving functional performance in individuals with knee osteoarthritis. These findings support the clinical use of aquatic therapy as a valuable rehabilitation option, particularly for patients with limited tolerance to weight-bearing exercise.

Keywords:
Aquatic Therapy, Exercise Therapy, Knee Osteoarthritis, Pain Management, Physical Function, Rehabilitation, Water-Based Exercise