Psychological inflexibility and physical disability in older patients with chronic low back pain and knee pain

Aim: This study examined the associations between psychological inflexibility (PI) and physical disability (PD) among older patients with chronic low back and knee pain. Methods: Pain avoidance and cognitive fusion were assessed in outpatients as components of PI and PD, and sociodemographic and pain-related variables were used as covariates. Hierarchical multiple linear regression was used. The covariates were first entered, followed by PI. Results: Age and pain intensity had significant positive associations with PD. After adding PI, only pain avoidance was significantly and positively associated with PD. Conclusion: Focusing on pain avoidance may be effective for physical disability when acceptance and commitment therapy is administered to older patients with chronic low back and knee pain. Plain language summary Recently, psychological inflexibility (PI) as a psychological process of acceptance and commitment therapy (ACT) has attracted attention in the treatment of chronic pain. However, previous studies have not found a relationship between PI and physical disability (PD) in older patients with chronic lower limb pain. This study investigated whether PI is associated with PD in older patients with chronic low back and knee pain. PI, PD and sociodemographic and pain-related variables were measured using a questionnaire. The results showed that pain avoidance in PI was associated with PD, whereas cognitive fusion was not. Focusing on pain avoidance may be effective for physical disability when ACT is administered to older patients with chronic low back and knee pain.