It's often used in the context of food preparation, like crushing spices, grinding grains, or making sauces. You might hear "machucando el ajo" ("crushing the garlic") in a recipe.
However, it can also have a more metaphorical meaning, implying something is causing harm or distress. For example, you might hear "Me está machucando la cabeza" ("My head is pounding") or "El trabajo me está machucando" ("Work is wearing me down").