I've started training about 3 months ago. I had neglected my lower back training for a while before starting to train it again.
Now, my body fat percentage is about 10% and my spine is very visible in the middle of my back .
Is this due to the lack of muscle mass in the lower back ? if not,what muscle do I have to train to get rid of that skinny look ?
Note: I do pullups, bodyweight rows and arch ups to train the entire back.