Effects of lower body positive pressure treadmill on functional improvement in knee osteoarthritis: A randomized clinical trial study

BACKGROUND: Knee joint pain and stiffness are the two main symptoms of knee osteoarthritis (OA) and thus restrict a patient’s activities, such as walking and walking up and downstairs. The lower body positive pressure (LBPP) treadmill as one of the emerging body weight support system devices brings new hope for exercise-related rehabilitation for knee OA patients. AIM: To investigate the biomechanical effects and the subjective clinical assessment of LBPP treadmill walking exercise when compared with conventional therapy in mild to moderate knee OA patients. METHODS: Eighteen patients with mild-to-moderate knee OA were recruited in this randomized controlled trial (RCT) study. The eligible knee OA patients were randomly assigned to two groups: LBPP and control groups. The patients in the LBPP group performed an LBPP walking training program for 30 min/session per day, 6 d per week for 2 wk whereas the patients in the control group performed walking on the ground for the same amount. All patients underwent clinical assessments and three-dimensional gait analysis at pre- and 2-wk post-treatment. RESULTS: The Western Ontario and McMaster Universities Arthritis Index and visual analog scale scores in both the LBPP group and control group were found to decrease significantly at the post-treatment point than the pre-treatment point (LBPP: 70.25 ± 13.93 vs 40.50 ± 11.86; 3.88 ± 0.99 vs 1.63 ± 0.52; control: 69.20 ± 8.88 vs 48.10 ± 8.67; 3.80 ± 0.79 vs 2.60 ± 0.70, P < 0.001). Moreover, compared with the control group, the LBPP group showed more improvements in walking speed (P = 0.007), stride length (P = 0.037), and knee range of motion (P = 0.048) during walking, which represented more improvement in walking ability. CONCLUSION: The results of our RCT study showed that the LBPP group has a greater effect on improving gait parameters than the conventional group, although there was no significant advantage in clinical assessment. This finding indicates that LBPP treadmill walking training might be an effective approach for alleviating pain symptoms and improving lower extremity locomotion in mild to moderate knee OA patients.