The muscles of a recently deceased human can remain in a contracted state, termed rigor mortis, for several hours, due to the lack of _____. the muscles of a recently deceased human can remain in a contracted state, termed rigor mortis, for several hours, due to the lack of _____. calcium ions needed to bind to troponin atp needed to break actin-myosin bonds sodium ions needed to fire action potentials oxygen supplies needed for myoglobin