1. Ca2+ binds to troponin (TnC), causes a conformation change which pulls tropomyosin away from the binding site
2. ATP binds to myosin, releasing it from the actin (head is in low energy configuration, bent)
3. ATP gets broken down to ADP + Pi, which causes the myosin head to fall forwards, after which it springs back to high energy configuration, upright
4. As it does so, it hits the actin binding site, ADP + Pi is released which strengthens the attachment
5. Myosin twists a bit to ensure its facing the binding site on the next-adjacent actin filament, this continues in a spiral as cross bridges are formed and contract
6. Myosin head bends down towards the M-line, pulling actin along, allowing the filaments to move ~10nm inwards --> power stroke
7. Z lines move inwards, sarcomere contracts and becomes shorter