Influence of patients’ health beliefs on rehabilitation exercise adherence after knee replacement: the mediating role of exercise psychological needs satisfaction

To analyze the influence of patients' health beliefs on adherence to rehabilitation exercise after knee replacement and to verify the mediating role of exercise psychological needs satisfaction. From January 2023 to December 2025, patients who underwent knee replacement at the First Affiliated Hospital of Henan Medical University were selected by convenience sampling as the research subjects. According to the inclusion and exclusion criteria and patients' voluntary participation in screening, 316 cases were finally included. This study was a cross-sectional study. Patients' adherence to rehabilitation exercise was evaluated using the Exercise Adherence Questionnaire (EAQ). The Chinese version of the Champion Health Belief Model Scale (SF-HBMS) was used to evaluate the health beliefs of the participants. The Psychological Need Satisfaction in Exercise Scale (PNSES) was used to evaluate the satisfaction of exercise psychological needs. The current status of patients' health beliefs, rehabilitation exercise adherence, and exercise psychological needs was summarized. Pearson correlation analysis and mediation analysis were conducted to examine the relationships among the three variables. The total EAQ score of the 316 patients was (32.02 ± 5.22), and the adherence index was (57.17 ± 13.57)%. Among them, 68 cases were in a low adherence state, accounting for 21.52%; 227 cases were in a moderate adherence state, accounting for 71.84%; and 21 cases were in a high adherence state, accounting for 6.65%. The total SF-HBMS score was (59.85 ± 9.88), and the total PNSES score was (83.47 ± 13.08). Pearson correlation analysis revealed positive correlations between EAQ and SF-HBMS (r = 0.665), EAQ and PNSES (r = 0.581), as well as SF-HBMS and PNSES (r = 0.525) (all P < 0.001). Mediation effect analysis involved three models, namely: rehabilitation exercise adherence = 10.689 + 0.351 × total health belief score; exercise psychological needs satisfaction = 41.887 + 0.695 × health beliefs; rehabilitation exercise adherence = 5.347 + 0.263 × health beliefs + 0.128 × exercise psychological needs satisfaction. The indirect effect of exercise psychological needs satisfaction on the relationship between rehabilitation exercise adherence and health beliefs was significant [b = 0.089, P < 0.001, 95% CI (0.064, 0.115)]. Exercise psychological needs satisfaction played a partial mediating role between rehabilitation exercise adherence and health beliefs, with an effect value of 0.089, accounting for 25.23%. Health beliefs had a significant positive predictive effect on exercise psychological needs satisfaction [a = 0.695, P < 0.001, 95% CI (0.570, 0.820)], and exercise psychological needs satisfaction had a significant positive predictive effect on rehabilitation exercise adherence [a = 0.128, P < 0.001, 95% CI (0.091, 0.164)]. At the same time, the direct effect of health beliefs on rehabilitation exercise adherence was significant [b = 0.263, P < 0.001, 95% CI (0.215, 0.311)], and the total effect was also significant [c' = 0.351, P < 0.001, 95% CI (0.307, 0.395)]. Rehabilitation exercise adherence among patients following knee arthroplasty was moderate. Health beliefs were positively correlated with both exercise adherence and exercise psychological needs satisfaction. Mediation effect analysis indicated that exercise psychological needs satisfaction partially mediated the relationship between health beliefs and rehabilitation exercise adherence. The direct correlation between health beliefs and rehabilitation exercise adherence was also statistically significant.