Nothing else is needed....for a mediocre, at best, stroke with low cue power and poor speed control.
Good news is, that even if you are working around an oversimplified model of your stroke, your subconscious mind will save you from yourself and you will still utilize more than just that one muscle...which isn't even the biceps as Bob pointed out earlier, it's the brachialis, unless you want to turn your wrist over, then it's the biceps.
