Ace the VTCT Sports Massage Level 3 Test 2026 – Stretch Your Limits and Score Big!

Thin filaments are built mainly from actin, which forms the filament backbone that myosin heads pull on during contraction. Actin polymerizes into long, helical filaments that provide the binding sites for myosin to attach and generate force. Tropomyosin sits along actin and, with the troponin complex, regulates access to those binding sites but does not constitute the filament itself. Nebulin helps stabilize and set the length of the thin filament rather than forming the filament. Myosin, in contrast, forms the thick filaments that interact with actin to produce movement.