Physiotherapy informed by acceptance and commitment therapy for chronic low back pain: A randomized trial

Chronic low back pain (CLBP) is a highly prevalent condition and a leading cause of disability worldwide. Given its complex etiology, there is growing interest in applying the biopsychosocial model to CLBP management in order to address psychological barriers - such as low motivation - that influence pain perception, exercise adherence, and overall treatment outcomes. Physiotherapy-informed Acceptance and Commitment Therapy (PACT) - a third-wave cognitive-behavioral approach - has shown promise in chronic pain management by promoting psychological flexibility and values-based action.

The primary objective of this study is to evaluate patients' exercise motivation of PACT versus usual physiotherapy care (UC). Secondary objectives are to assess and compare the efficacy of PACT versus UC on functioning and disability, adherence to exercise, acceptance of pain and autonomy support from physiotherapists. Both interventions incorporated dynamic neuromuscular stabilization (DNS)-based graded exercise as a core physiotherapy approach.

Fifty patients with CLBP participated in this study. All participants completed paper-and-pencil self-reported questionnaires to assess relevant outcome measures. Data were collected at two time points: baseline (prior to the first therapy session) and at week 6, immediately following the completion of the intervention period (post-intervention). Participants were randomly assigned to one of two groups. The PACT group received ACT-based physiotherapy combined with DNS-based graded exercise. The usual care (UC) group received individualized graded therapeutic exercise based on the DNS concept, complemented by manual therapy.

The PACT group showed significantly higher levels of exercise motivation compared to the UC group, with greater scores in introjected motivation (baseline: $4.15\pm 1.56$ versus $3.19\pm 1.38$ , $p=0.029$ , $r=0.31$ ; post-intervention: $4.49\pm 1.05$ versus $3.27\pm 1.43$ , $p=0.001$ , $d=0.97$ ) and identified motivation (post-intervention: $6.25\pm 0.76$ versus $5.35\pm 1.31$ , $p=0.015$ , $r=0.35$ ). Within-group comparisons revealed no significant changes in the UC group, whereas the PACT group demonstrated a decrease in external motivation ( $\text{diff}=-0.40\pm 0.74$ , $p=0.027$ , $r=0.55$ ) and increases in identified ( $\text{diff}=0.45\pm 0.95$ , $p<0.034$ , $r=0.54$ ) and intrinsic motivation ( $\text{diff}=0.80\pm 1.13$ , $p<0.001$ , $r=0.76$ ). Participants in the PACT group also reported significantly higher perceived autonomy support from the physiotherapist ( $6.52\pm 0.54$ , $p=0.027$ ) than those in the UC group ( $5.86\pm 0.90$ ) ( $p=0.027$ , $d=0.40$ ). Furthermore, adherence to the recommended physical activity was significantly greater in the PACT group ( $18.96\pm 3.17$ , $p<0.001$ ) compared with the UC group ( $13.32\pm 2.58$ ) ( $p<0.001$ , $r=0.71$ ). No statistically significant differences were observed between groups for measures of functioning and pain acceptance, however, both groups demonstrated significant within-group improvements. Disability decreased in UC ( $\text{diff}=-1.04\pm 1.27$ , $p=0.001$ , $r=0.63$ ) and PACT ( $\text{diff}=-1.08\pm 2.10$ , $p=0.018$ , $r=0.63$ ) while pain acceptance increased in UC ( $\text{diff}=1.12\pm 2.42$ , $p=0.047$ , $r=0.72$ ) and PACT ( $\text{diff}=1.24\pm 1.98$ , $p=0.002$ , $d=0.89$ ).

PACT, combined with DNS-based graded exercise, enhanced exercise motivation, perceived autonomy support, and adherence to exercise in patients with CLBP compared to UC. However, no significant improvements were observed in functioning or pain acceptance. These findings suggest that integrating ACT into physiotherapy care may improve motivational outcomes and engagement in physical activity, which are crucial in the management of CLBP. However, further studies with larger samples and longer follow-up periods are necessary to confirm the stability and durability of these positive effects.