The anatomical, histological, and ultrasound findings in the cadaver study confirmed the diffusion of the solution in the interfascial space. Study in patients confirms that the interfascial block in the back musculature can be as effective as in the abdominal musculature. The presence of nerve structures in this space, confirmed by the histological study, seems to explain the pain relief reported by the patients with this interfascial technique.

The connective septum of endotenon located between the two main components of the DBBT is responsible for the US image of two separate tendons and functionally enables it to work as two separate entities, thus allowing respective folding and gliding. The paratenon surrounding the lacertus fibrosus and the DBBT plays an important stabilization role, enabling them to change shape and arrangement during joint motion. It is also an important conduit for nerves and blood vessels.

Deep fascia is present from week 21 of human development in the lower back and upper and lower limbs. Blood vessels and nerves develop parallel to it and occasionally cross it from the deep to superficial plane. The presence of Tcf4+ fibroblasts in the deep fascia suggests a crucial role for this structure in muscle morphogenesis.