This study was performed to develop a self-efficacy theory-based exercise program for total knee arthroplasty (TKA) and to test the program’s efficacy in ameliorating knee pain and restoring function as measured by lower extremity muscle strength, 3 meter walking time, Korean Western Ontario McMaster Index (WOMAC), exercise self-efficacy, and length of hospital stay for TKA patients.

This quasi-experimental study incorporating a non-equivalent control group and pretest-posttest non-synchronized design non-synchronous design was applied to assess self-efficacy reinforcement strategies based on self-efficacy theory. The exercise program consisted of the following steps: TKA, education to prevent postoperative complications, and muscle strength exercises. Respective exercise and control groups included 29 and 27 participants. The experimental group received eight sessions of the program from three weeks before TKA to four weeks after TKA. Collected data were analyzed using the chi-square test, Mann–Whitney U test, and ranked ANCOVA and t-tests using IBM SPSS Statistics 23.

Experimental group showed significant improvement in lower extremity muscle strength (F = 8.63, p = .005), 3 meter walking time (z = - 5.02, p < .001), WOMAC index (z = - 2.22, p = .027), self-efficacy for exercise (z = - 3.29, p = .001), and length of hospital stay (t = - 2.11, p = .040) compared to the control group. No significant differences in knee pain and range of motion were observed.

These findings indicate that a self-efficacy theory-based exercise program can be an effective exercise strategy that patients undergoing TKA can easily follow at home without assistance. It is thus recommended as an exercise intervention for TKA patients.