The Effects of Pedaling-Based Progressive Resistance Training on Range of Motion, Muscle Strength, and Physical Function in Female Patients with Total Knee Arthroplasty: Single-Blind Randomized Controlled Trial

<i>Background and Objectives</i>: Total knee arthroplasty (TKA) is an effective solution for pain relief and functional recovery in patients with end-stage osteoarthritis. However, stiffness of the knee, limited range of motion, and weakened muscle strength are challenges of postoperative rehabilitation. This study investigated the effects of a pedaling-based progressive resistance training (PPRT) program on range of motion, muscle strength, physical function, and gait in patients who had undergone TKA. <i>Materials and Methods</i>: A total of 48 female patients (aged 65-79) who underwent TKA participated in the study and were randomly assigned to either the PPRT group (<i>n</i> = 24) or the control group (<i>n</i> = 24). The PPRT group performed the training for 60 min per session, twice a day, five days a week, for four weeks. The primary outcomes were the muscle strength and range of motion (ROM) of the knee. Secondary outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Timed Up and Go (TUG) test. <i>Results</i>: There was a significant time × group interaction effect in all the quadriceps strength values (<i>p</i> < 0.05), with a moderate to large effect size (<i>η</i>²<i>_p</i> = 0.142-0.390). The PPRT group showed a smaller decrease in knee flexor and extensor strength and a greater improvement in knee flexion range of motion compared with the control group (<i>p</i> < 0.05). The WOMAC index and TUG time were also significantly improved compared with the control group (<i>p</i> < 0.05). In the time × group interaction, a significant effect was shown in WOMAC pain, physical function, and total score (<i>p</i> < 0.05) with a moderate to large effect size (<i>η</i>²<i>_p</i> = 0.099-0.196). TUG time also showed a significant time × group interaction (<i>p</i> < 0.05) with a moderating effect (<i>η</i>²<i>_p</i> = 0.0840). <i>Conclusions</i>: This study suggests that pedaling-based progressive resistance training helps maintain knee flexor and extensor strength as well as improves range of motion and physical function in patients following TKA and can be proposed as effective training for post-TKA rehabilitation.