BACKGROUND CONTEXT Accurate assessment of pain and function are crucial to the effective management of patients with spinal disorders. The most frequently-utilized measure of function is the Oswestry Disability Index (ODI), a self-report measure designed for low back pain patients, which assesses potential deficiencies in 10 different domains. The ODI has several limitations. Due to its subjective nature, ODI is inherently limited by factors such as recall error, social desirability, misinterpretation of terminology, and failure to quantify the totality of physical activity dimensions and contexts. Thus, the relationship between patients’ self-reported ODI scores and their actual functional limitations is likely quite suspect. Gait analysis is an alternative objective tool that can both provide a clearer picture of the impact of pain on patients’ functional ability and can allow for more accurate assessment of the effectiveness of spinal interventions. PURPOSE To investigate the relationship of self-reported function to objectively-measured gait pattern alterations in patients with spinal disorder. STUDY DESIGN/SETTING A prospective cohort study. PATIENT SAMPLE A total of 235 spinal disorder patients (85 adult degenerative scoliosis, 66 cervical spondylotic myelopathy, 64 spondylolisthesis, and 20 sacroiliac). OUTCOME MEASURES The main measures were ODI scores along with gait spatiotemporal parameters: cadence, walking speed, stride time, step time, opposite foot off, opposite foot contact, foot off, single support, double support, stride length, step length, and gait width. METHODS Patients completed the ODI questionnaire one week before their surgery. Each patient also performed a series of over-ground gait trials at a self-selected comfortable speed. Correlation analysis was used to determine the relationship between the self-reported function measures and the objective gait biomechanical data. RESULTS The ODI overall score was not correlated with any of the spatiotemporal variables (p>0.050). Detailed analysis shows correlation between the ODI walking question score to stride length (r=-0.132, p=0.048) and gait width (r=0.133, p=0.046). CONCLUSIONS For patients with spinal disorders, the ODI may not adequately reflect functional deficits due to its subjectivity. Function is objective and quantifiable, whereas pain in and of itself is subjective and unquantifiable. There was a minimal correlation between the ODI walking domain score and objective gait parameters. The multidimensional, complex, and subjective nature of pain makes it very challenging to assess both in terms of intensity and in terms of relief as a response to treatment. It is important for pain and function assessments to have scientifically valid tools in order to determine quality and intensity of pain and function, aid diagnosis, direct treatment, and evaluate effectiveness after discrete interventions. The data presented from this preoperative patient population validates that gait parameters provide an objectively accurate analysis of gait. Objective gait analysis could significantly affect surgical decision-making and allow for better understanding of the effects of spinal surgery on patients’ function, and, ultimately, quality of life. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.