The morphological and microscopical characteristics of posterior layer of human thoracolumbar fascia; A potential source of low back pain.

Background: Posterior layer of thoracolumbar fascia (PTLF) is the deep fascia of back of the trunk, which connects the trunk, upper limb and lower limb muscles. Very few cadaveric studies of posterior layer of thoracolumbar fascia (PTLF) are found in the literature, which mention the presence of nerve receptors in it but, quantification of the nerve receptors where not found. Providing the morphological and morphometrical data of PTLF may help the exercise physiologists, sports physicians, occupational health assistants and, physiotherapists to modify or invent new protocol of treatment to help the society.

Methods: In this study, twenty formalin embalmed human cadavers were used and we have documented the orientation of the PTLF and quantified the number of peripheral nerve endings at the different vertebral levels.

Results: Mean distance of PTLF from vertebral spines to the musculofascial junction was at thoracic region 3.38cm and 3.34cm; at lumbar region, it was 7.4cm and 7.36cm and at sacral region it was 2.98cm and 2.96cm on right and left side, respectively. The angulation of PTLF varies from 18-110 degrees at different vertebral levels. The microscopic data shows the thickness of PTLF and number of nerve endings in the sacral level is increased compared to that of thoracic vertebral levels.

Conclusions: We have contributed the novel morphological and microscopical details to the limited existing data on PTLF. We also have provided the quantitative data of nerve fibers, which are possible nociceptors of PTLF.