Background and aims Fascial anatomical structures have been and continue to be difficult to fully understand for more than 100 years. Important questions about fascial connections and movement of fascia predominate current research, particularly in relation to local anaesthetic spread and fascial block reliability. Scientific answers have yet to fully elucidate the intricacies of deep fascial planes and their connections, but some basic fascial understandings may guide future research and explain the potential for variable results from fascial blocks.

Methods Literature review of anatomical and clinical evidence of fascial blocks.

Results The current knowledge about deep fascia, deep fascial planes and fascial blocks suggest four main areas to appreciate:

1. Fascia differs amongst body regions.

2. Fascia is a moveable anatomical structure that responds to muscle movement and body position.

3. Fascia is locally innervated, which, when exposed to local anaesthetic may change its intrinsic behaviours.

4. Variety may or may not be the ‘spice of life’ when it comes to fascial block access points.

Conclusions A regional histological mapping of fascia would aid the prediction of the type of spread to be expected from various access points to deep fascia. An understanding of the propensity of fascial adhesions, and their detection, would also allow anaesthetists to better predict fascial block success. Knowledge of the various fascial blocks and their access points, combined with the understanding that each side of every patient is unique, may allow anaesthetists to be better prepared for variable success of a fascial block.