Fascia is the continuous web of connective tissue surrounding every muscle, organ, and bone. Treats the body as a tensile system, not a stack of independent muscles.
Mechanism: Fascia transmits force between non-adjacent muscle groups, stores elastic energy in dynamic movement, and contains a dense supply of mechanoreceptors. Hydration and movement quality keep it pliable.
Use case: Foam rolling, soft-tissue work, dynamic mobility, sufficient water intake. The 'tightness' that doesn't release with stretching often releases with fascial work.
Caveats: The fascia literature has more hype than data. Mechanism is real, magnitude of intervention effect is modest.