Hydrotherapy and Land-Based Exercise: Differential Impacts on Pain, Knee Biomechanics and Quadriceps Activation in Osteoarthritis

Abstract

Abstract Purpose Stiffness during walking is a frequent problem among individuals with knee osteoarthritis, primarily resulting from pain. Currently, there is no agreement on the optimal exercise approach to relieve gait-related symptoms in these patients. This study examines the impact of hydrotherapy and land-based exercises on factors contributing to stiff gait during the early stance phase, including pain, knee kinematics, and the co-activity of flexor and extensor muscles in women with knee osteoarthritis. Methods A single-blind randomized controlled trial was conducted with 36 women diagnosed with knee OA of grade 2 or higher. Participants were randomly assigned to three groups: control, hydrotherapy, and land-based exercise. Pain levels were assessed using the Knee Injury and OA Outcome Score (KOOS), while kinematic and electromyographic (EMG) analyses were performed during walking. The interventions consisted of 18 sessions over 8 weeks, focusing on strengthening exercises. Data were analyzed using two-factor mixed-method ANOVA, with significance set at P < 0.05. Results Both exercise modalities significantly reduced pain (P = 0.006) and improved knee range of motion (ROM) (P = 0.001) during early stance of gait. The hydrotherapy group demonstrated a greater reduction in pain compared to the land-based exercise group, indicated by a higher effect size. Kinematic analysis also revealed a significant increase in knee flexion during the early stance phase for both groups, with hydrotherapy showing a larger effect size for this improvement. EMG results indicated that hydrotherapy significantly enhanced rectus femoris activity (P < 0.001), while both interventions reduced biceps femoris and semimembranosus activity. Conclusions The results indicate that hydrotherapy outperforms land-based exercises in reducing pain and improving knee kinematics and muscle activity in women with knee osteoarthritis. The unique properties of water, such as buoyancy and resistance, likely play a significant role in these advantages by reducing the load on the joints, strengthening muscles, and enhancing functional mobility. In general, hydrotherapy proves to be a highly effective approach for treating knee osteoarthritis, resulting in significant improvements in factors influencing stiff gait during the early stance phase, especially when compared to land-based exercise programs. These findings advocate for the inclusion of hydrotherapy in rehabilitation strategies for women suffering from knee osteoarthritis.