Ultrasound Imaging Measurements of the Thoracolumbar Fascia

In this prospective proof of concept study, eligible subjects with chronic non specific low back pain and asymptomatic volunteers will undergo a research dynamic ultrasound (US) exam of the thoracolumbar fascia (TLF) of the lower back. A musculoskeletal radiologist will perform the US exams consisting of a series of 5 dynamic scans of both the right and left paraspinal muscles, obtained during 15 degrees of passive flexion of the lower body using a motorized table.

Following the US exam, the group of patients and the group of volunteers will be respectively randomized to receive either a standardized massage technique intervention or a sham technique. The US exam will be repeated after the intervention.

Ultrasound image segmentation will be performed by two independent observers and inter-rater variability will be assessed. Post-processing of the US recordings will include assessment of geometrical (thickness), mechanical (percent shear strain between the TLF and the epimysium-muscle complex) and tissue ultrastructure features (the mean intensity μ, the scatterer clustering parameter α and the structure parameter κ of the echo envelope). These features will be compared between patients and volunteers and between the intervention groups.

Inclusion criteria

Patient group:

• Presenting with chronic low back and/or referred pain (non specific pattern) above or just below the gluteal fold of at least 3/10 on a numerical pain rating scale (NRS), for at least 6 months;
• Pain is present at least 50% of the time during the day;

Asymptomatic group:

• No history of low back pain or any other chronic pain limiting activities of daily living or work.

Exclusion criteria

• History of back surgery;
• History of severe back or low extremity injury;
• Back pain attributable to a specific, recognizable, known pathology (i.e.: infection, tumor, fracture, spinal stenosis, sciatica etc.);
• Corticosteroid medication intake or corticosteroid injection in the lumbar spine in the previous 3 months;
• Pregnancy.