The force of a twitch is less than that in a tetanus, BECAUSE:
One action potential does not release sufficient Ca++ to saturate the troponin binding sites Ca++ reuptake into the sarcoplasmic reticulum is so rapid that there is insufficient time for all the troponin Ca++ -binding sites to be occupied Crossbridge cycling is not fast enough to allow expression of the maximum possible force before Ca++ dissociates from troponin All of the above