A hammer curl done on the incline – that is with the bench dropped back from vertical – is surprisingly hard since as we lean back, the biceps get a bit stretched, so have to work harder to lift the weight. To get the benefit, we need to let the arms hang straight under the shoulders and not creep forwards. Incline hammer curls are both an excellent variation to the standard seated hammer curl and can also be used as part of a bi- or tri-set for building up the biceps.
So a simple way of bulking up the biceps is to do a set of, say, 6 – 8 reps with the bench set back about 45°, then re-set the bench to about 70º and do another set of 6 – 8 reps, then finally lift the bench to upright and do a 3rd set. Between sets, there will be about a 10 second rest. Keep the speed you move the dumbbells at absolutely constant, so lift for, say 1 second and lower for 4 seconds.
If new to training the arms, it is sensible to start by alternating biceps and triceps exercises to get the muscles used to be worked out. If we jump straight into heavy training, such as outlined in the previous paragraph, the chances of injury are extremely high and we won’t be training again for months. So in this case, dropping the bench back adds variety to the workouts.
Head position when leaning back is argued about. Personally, I recommend resting the head on a folded towel to avoid straining the muscles in the front of the neck and aggravating forward head posture. Also, to train muscles for maximum effect, be for strength or increase in size, we want the tension in those muscles only. So the neck is relaxed and so are the shoulders. We want our biceps screaming for mercy and not our shoulders or jaw. I went into more detail about this in the blog, How to do a dumbbell bicep curl.
A point argued about with head position is what is happening in the spine at the neck. If we lift the chin, some say the biceps get stronger and others say the opposite is true. Doing either too much will compromise the spine, but as long as the move is small, then it is a matter of experimentation.
Familiarise yourself with this simple variation of the bicep curl and find new levels of pain. Lovely.