Ultrasound evaluation of deep fascia thickness: Reliability and association with clinically evaluated changes

Background: There is growing evidence of fascial involvement in musculoskeletal pathologies; thus, measuring the fascia's properties is clinically essential. Objectives: 1) to evaluate intra- and inter-tester reliability of sonographic measurements of deep fascia thickness in healthy individuals; 2) to assess whether fascial thickness in areas of fascial movement restriction (fascial densification in Stecco's Fascial Manipulation method), differs from contralateral areas with normal fascia. Methods: Part 1 (reliability study): Fascial thickness was sonographically measured in 10 sites (5 on each side), twice by a single examiner to assess intra-rater reliability and once by a second examiner to evaluate inter-rater reliability. Part 2 (cross-sectional study): Unilateral fascial movement restrictions were detected in 5 bilateral sites by palpation. The fascial thickness on the ultrasound image was measured at the restriction site and its normal contralateral side by a blinded assessor. Results: 21 healthy individuals were evaluated in part 1, 15 healthy individuals in part 2. Intra-tester reliability (Interclass correlation – ICC) values ranged from 0.677 to 0.975; inter-tester ICC values ranged from 0.473 to 0.966. No significant differences in fascia thickness between the right and left body sides were observed in most sites. Significant differences were found between the fascial thickness of the site of fascial movement restrictions vs. normal counterpart. Conclusions: Intra- and inter-rater reliability of sonographic measuring fascial thickness was high, and fascial thickness of the site of fascial movement restrictions was greater than in the normal counterpart. Ultrasonography may be used as a reliable method to evaluate fascial alterations.