Yuka is a secular Afro-Cuban tradition of drumming, singing and dancing, developed in western Cuba in colonial times by enslaved people from the Kongo region. It predates rumba and gave rise to the yambú.
Yuka originated in Matanzas and Pinar del Río. It has survived in Kongo communities in Pinar del Río, especially in El Guayabo and Barbacoa (San Luis).
Yuka drums are hollowed avocado trunks, with a skin nailed to one end. There are three sizes:
The drummer wears two rattles (nkembí) on the wrists. Staves may sound on a guagua, and strokes on a piece of iron, a muela, or a hoe blade (guataca).
A couple performs a stylised contest: the man chases, the woman avoids. Wikipedia mentions steps such as the ronquido (side steps) and the campanero (a figure eight), which are not found in rumba.
Yuka predates other Afro-Cuban dance genres such as rumba, and rumba draws on it among other things. Yuka gave rise to the yambú, the oldest and slowest rumba style. The chase between man and woman also returns in rumba for couples. According to Wikipedia, the vacunao of guaguancó, the pelvic thrust with which the man tries to "catch" the woman, derives from the yuka and makuta dances; EcuRed calls the erotic couple dances "of makuta or yuka" the possible basis of yambú and guaguancó.