Associations Between Dynamic Quantitative Sensory Testing and Physical Therapy Outcomes in Chronic Low Back Pain: An Exploratory, Prospective Longitudinal Cohort Study

ABSTRACT Background The primary objective of this study was to determine whether baseline conditioned pain modulation (CPM) is associated with pain and disability outcomes following a 6‐week course of physical therapy intervention. Secondary objectives included investigating whether baseline temporal summation scores are associated with pain and disability outcomes and whether changes in CPM and temporal summation are correlated with clinical improvement. Methods In this prospective cohort study, 34 individuals with cLBP completed baseline CPM and temporal summation testing, followed by a 6‐week course of individualized physical therapy. Pain (Numeric Pain Rating Scale [NPRS]) and disability (Oswestry Disability Index [ODI]) were assessed at baseline and discharge. Post‐intervention CPM and temporal summation were reassessed. Baseline‐adjusted linear regression was used to analyze associations between baseline CPM and temporal summation and final NPRS and ODI scores. Pearson correlation coefficients were used to assess associations between changes in CPM and temporal summation and clinical outcome scores. Results Baseline CPM was not significantly associated with final ODI ( β = 0.020, p = 0.273) or NPRS ( β = 0.002, p = 0.561). Higher baseline temporal summation values were significantly associated with higher final NPRS ( β = 0.036, p = 0.026). A moderate, statistically significant correlation was observed between CPM change scores and NPRS change scores ( r = 0.375, p = 0.038). Conclusions CPM demonstrated limited prognostic value in this cLBP cohort. Although baseline temporal summation was associated with final pain outcomes, the magnitude was small and limits clinical utility. Significance Statement This study examined whether baseline conditioned pain modulation (CPM) and temporal summation were associated with clinical outcomes after physical therapy in individuals with chronic low back pain (cLBP). Baseline CPM was not associated with pain or disability, while higher baseline temporal summation was associated with greater pain intensity at discharge, although the magnitude of this association was small. These findings suggest limited clinical utility of dynamic quantitative sensory testing (QST) as standalone prognostic tools for cLBP in physical therapy settings.