Offset Mechanisms in Evaluation of Lumbar Medial Branch Blocks

Pain intensity difference during heat stimuli measured on a 0-100 sliding scale (0 is no pain, 100 is the most intense pain imaginable) at baseline

Patients respond to the question "How would you rate your back pain right now?" from 0 (no pain) to 10 (worst imaginable pain) to see how intense their back pain is each hour after the lumbar medial branch block.

Participant self-reports the number of years they have experienced low back pain. The number of years for each participant will be reported.

Assessment for self-reported average pain and pain interference within past 7 days. Responses range from 0 (no pain) to 10 (pain as bad as you can imagine). Total scores range from 0-30, and higher scores indicate more pain interference.

Assessment for determining how much a person hurts with a question ranked on a 11-point scale, from "0 = no pain" to "10 = worst imaginable pain." The minimum raw summed score is 0 and the maximum score is 10. Lower raw response scores suggest lower pain intensity and better outcomes.

Assessment for self-reported consequences of pain with 4 questions ranked on a 5-point scale, from "not at all" to "very much". The minimum raw summed score is 4 and the maximum score is 20. Lower scores suggest better outcomes.

Assessment for self-reported capability with 6 qualitatively scaled questions ranked on a 5-point scale, from "without any difficulty" to "unable to do" or "not at all" to "cannot do." The minimum raw summed score is 6 and the maximum score is 30.

Assessment for self-reported perceptions of sleep quality and sleep depth with 6 questions ranked on a 5-point scale. The minimum raw summed score is 6 and the maximum score is 30. Lower scores suggest better outcomes.

Standardized survey score assessing pain perception before the study procedures begin. Rumination subscale score ranges from 0-16. Magnification subscale score ranges 0-12. Helplessness subscale score ranges from 0-24. Total score can be calculated by summing subscales. Total score ranges from 0-52, with higher scores indicating more pain catastrophizing.

The PHQ-2 inquires about the frequency of depressed mood and anhedonia over the past two weeks. The PHQ-2 includes the first two items of the PHQ-9. A PHQ-2 score ranges from 0-6. The authors identified a score of 3 as the optimal cutpoint when using the PHQ-2 to screen for depression.

If the score is 3 or greater, major depressive disorder is likely.

Assessment for self-reported negative mood and views of self with 4 questions ranked on a 5-point scale, from "never" to "always". The minimum raw summed score is 4 and the maximum score is 20. Lower t-scores suggest better outcomes.

Assessment for self-reported fear, anxious misery, hyperarousal, and somatic symptoms with 4 questions ranked on a 5-point scale, from "never" to "always". The minimum raw summed score is 4 and the maximum score is 20. Lower scores suggest better outcomes.

The digital body figure contains 36 anterior regions and 38 posterior regions on which participants can mark areas in which they experience chronic pain. The number of pain areas each participant recorded will be reported, with a possibility of 74 total regions.

Assessment for the subject's expectations of treatment effec prior to lumbar medial branch block. Scores range from 0 (not at all) to 4 (very much), with total scores ranging from 0-24. Higher scores indicate higher expectations of the low back pain treatement.

The subject's impression of the impact of the lumbar medial branch block on their pain and function will be measured with a 7-item scale (1 = very much worse, 2 = much worse, 3 = minimally worse, 4 = no change, 5 = minimally improved, 6 = much improved, 7 = very much improved).

Standardized survey score assessing pain perception immediately following the lumbar medial branch block. Scores range from 0-24, with higher scores representing more pain catastrophizing.

Changes in pain intensity during quantitative sensory tests measured on a 0-100 sliding scale (0 is no pain, 100 is the most intense pain imaginable)

Patients respond to the question "How would you rate your back pain on average?" from 0 (no pain) to 10 (worst imaginable pain) to see how intense their back pain is before the lumbar medial branch block.

Patients respond to the question "How would you rate your back pain right now?" from 0 (no pain) to 10 (worst imaginable pain) to see how intense their back pain is each hour after the lumbar medial branch block.