How is whole muscle force achieved in vivo?

Answer 1

Whole muscle force in vivo is achieved through the coordinated activation of muscle fibers by motor neurons, which stimulate muscle contraction through the release of calcium ions and the interaction of actin and myosin filaments. The force generated is influenced by the number of motor units recruited, the frequency of stimulation (rate coding), and the initial length of the muscle fibers. Additionally, factors such as muscle architecture and the type of muscle fibers (e.g., slow-twitch vs. fast-twitch) also play crucial roles in determining the overall force output during contraction.