When I'm starting to flex my arm, the myosin and actin slide over each other in a ratchet like mechanism. When I've totally flexed my arm, are the actinomyosin left in this contracted state? Since there is a visible decrease in length of the muscle, muscle fibres should have contracted.
So do they remain in this contracted state? Does the myosin head attach to the actin all this time? If it leave the actin, does the myosin snap back to its original position and relieve the tension/comeback to original length? Does it require any energy expenditure? Because I can keep my arm flexed throughout the day without getting fatigued. Also, What is the state of the actinomyosin if left in a half flexed state?
By state, I mean, the stage of the cross-bridge cycle