The basic backbeat already has your hands and one foot doing different things. Basic coordination generalizes that — the same hi-hat pattern in your hands, with the kick drum landing on every possible position underneath. Each variation is its own coordination puzzle.
Order matters. Easy first (kick on every beat), harder later (kick on the offbeats only). Don't skip ahead — the muscle memory you build on the easy ones is what lets you play the hard ones.
When the Foot Breaks the Hands
Watch for the stutter: hands running smoothly until the exact beat the foot enters, then a tiny hesitation. That beat is your practice target. Isolate it by playing just that one beat of the pattern (hand stroke plus kick together), freeze, reset, and repeat ten times before rejoining the full bar. Ten clean repetitions of the hard beat teach more than fifty loops that limp through it.
It also helps to sing the kick pattern before playing it: "boom, rest, boom, rest" against the click. A pattern your voice can place, your foot can usually find. If the leg burns on Ex 4, your heel is doing all the work — let the whole leg rock and the pedal rebound help you.