283 Gait: a biomarker for pain and function in chronic low back pain

OBJECTIVES/GOALS: Chronic low back pain (cLBP) is associated with gait impairments. Gait may serve as an important biomarker for improvement following therapy interventions; however, gait has not been sufficiently studied in relationship to pain and function in cLBP. METHODS/STUDY POPULATION: Adults with cLBP completed a two-minute-walk-test around a 37.5 m oval track while wearing an inertial measurement unit (IMU—Lifeware LLC, Pittsburgh, PA) over the L5 spinous process. Step time average, step time variability, step length, and symmetry (harmonic ratio) were calculated based on linear trunk accelerations, and gait speed was calculated based on distance walked. Participants completed the PEG tool (Pain, Enjoyment, General activity; scores closer to 10 indicate worse pain) to quantify pain intensity/interference and the PROMIS Physical Function SF-6b tool (mean t-scores=50 +/- 10; higher scores indicate better function) to quantify physical function. Pearson correlation coefficient (r) was used to determine strength of associations between gait and pain/physical function. RESULTS/ANTICIPATED RESULTS: Eleven adults (8 female, age 40 +/- 17, pain duration≥3 months) with cLPB participated in this study after completing an informed consent process approved by the University of Pittsburgh Institutional Review Board. Participants with a history of cancer, spinal cord compression, discitis, or activity restrictions prohibiting them from protocol completion were excluded. The mean PEG scores and PROMIS Physical Function t-scores were 2.8 +/- 1.8 and 47.8 +/- 8.2 respectively. There was a moderate-strong correlation between step time average and PEG (r=0.67, p=0.02), and a moderate-strong correlation between gait speed and PROMIS Physical Function (r=0.62, p=0.04). There were no other significant associations. DISCUSSION/SIGNIFICANCE: Gait speed and step time may be important movement biomarkers to consider when evaluating patients with cLBP. Generalizability of results are limited by the small study cohort and this cohort's relatively low pain burden and high level of physical function.