Sensory innervation of the thoracolumbar fascia in rats and humans.
Level 5 - mechanism / opinion, no new human data
Animal and bench histological study
PubMed 21839150 · doi:10.1016/j.neuroscience.2011.07.066
What was done
Investigators conducted a quantitative histological evaluation of calcitonin gene-related peptide (CGRP) and substance P (SP)-positive free nerve endings across different layers of the rat thoracolumbar fascia (TLF). They also performed a preliminary non-quantitative evaluation on human TLF specimens.
What was found
The abstract reports no numerical values. Rat TLF was characterized into three layers: outer (transversely oriented collagen fibers), middle (massive oblique collagen bundles), and inner (loose connective tissue over paraspinal muscles). Dense sensory innervation was concentrated in the subcutaneous tissue and the outer layer. SP-positive free nerve endings, presumed to be nociceptive, were found exclusively within the outer layer and subcutaneous tissue.
Why it matters
The study demonstrates nociceptive sensory nerve endings within specific layers of the thoracolumbar fascia, providing an anatomical mechanism for fascia as a potential source of low back pain.
Limits
No sample sizes for rats or human tissue specimens are reported in the abstract. Quantitative data, counts, and statistical measures are absent from the abstract. The human evaluation was non-quantitative, and structural presence of nerve endings does not establish functional clinical pain.
Cited by
- supports Fascial connective tissue contains a high density of nerve endings.