Patterns of Muscle Health in Single- and Multi-Site Chronic Pain: A UK Biobank Normative Modeling Study

Area of Science:

• Musculoskeletal health
• Medical imaging
• Pain research

Background:

• Chronic pain is linked to muscle health issues, but the cause (local, systemic, or both) is unknown.
• This study investigates if muscle health markers from MRI show location-specific changes in chronic pain.

Purpose of the Study:

• To determine if muscle health markers from MRI exhibit site-specific patterns in individuals with chronic pain.
• To analyze muscle volume and intramuscular fat (IMF) deviations from normative values.

Main Methods:

• Utilized UK Biobank whole-body MRI data from 2006-2010.
• Employed the MuscleMap Toolbox for quantifying muscle volume and IMF in 42 abdominal, pelvic, and thigh muscles.
• Developed normative models to calculate Z-scores representing deviations from normal muscle health.

Main Results:

• Chronic back pain showed localized changes in abdominal muscles (decreased volume, increased IMF).
• Chronic hip pain exhibited widespread changes across abdominal, pelvic, and thigh muscles.
• Chronic knee pain demonstrated localized changes in thigh muscles.
• Increased chronic pain sites correlated with decreased muscle volume and increased IMF.
• AI-based analysis accurately classified chronic pain groups but not acute pain groups.

Conclusions:

• Whole-body MRI with AI analysis reveals distinct site-specific muscle health patterns in chronic pain.
• Muscle health deviations are localized or widespread depending on the chronic pain site.
• Findings highlight the utility of advanced imaging techniques in understanding pain-related muscle alterations.