This is an ill-posed question. When you refer to infinity ("an infinite number of causes or effects"), you are implying accountability, and that's not a physical fact, but a fact related with our human subjectivity.
If you touch a rock pebble with your finger, the pebble moves. But the pebble is not moving due to a single physical action (for example, one atom in your brain would be the simple final cause). There is an unaccountable portion of the universe that could be subjectively related to the action, and it only depends on a subjective definition of thresholds (for example, the number of "related" neurons that "apply more than X micro amperes" to produce the movement).
If you assume that the universe can be divided into a precise quantity of objects and a precise number of events, perhaps you can count the objects and events involved in the action, evidently, implying subjective thresholds. But that's not a physical reality.
The question is equivalent to asking how many arcs a circle has (a friend at the university failed a test when he answered "a hundred" to our calculus teacher).