What is a power stroke in anatomy?

In anatomy, a power stroke refers to the phase of muscle contraction during which myosin heads pull actin filaments toward the center of the sarcomere, leading to muscle shortening and force generation. This process is part of the cross-bridge cycle in skeletal and cardiac muscle contraction, where ATP is utilized to detach myosin from actin, allowing for repeated cycles of binding and pulling. The power stroke is essential for various movements and functions in the body, including locomotion and heartbeats.