python, keymap: Jump to Marker

There is no python command nor keymap possible for the Marker operations "Jump to Previous Marker", "Jump to Next Marker". I tend to do a lot of animating by setting markers on other objects for a start/end sequence and then want to update animations on other objects/armatures to synchronize movements. An example would be a couple dancing or gesturing. I then need to Jump Back to create a starting pose keyframe, and then jump Forward again to set destination pose -- and repeat for other bones. Being able to set markers and then 'b'/'f' (jump-back/forward) would eliminate constant mouse clicking on menus.