Many coaches say the behind-the-neck pulldown is unsafe. It can be, if you don't know what you're doing. The problem is that lifters usually think of this as an exercise for the lats. It's not. It's a mid-back exercise.
How to Do It Right
Contract and squeeze the rhomboids and keep that position during the entire set.
Bring the bar down only to the back of the head, upper ear level. Do not bring it down to the neck.
Keep some bend in the elbows at the top. Don't let the bar pull your arms straight.
This is one case where a shorter range of motion is actually safer and more effective.
The first rule of fixing your bench press is admitting your bench sucks. The second rule is that you must read this article and learn about the set-up, grip, ascent, and descent.
Like everyone else, I've had my role models and mentors who've looked out for me. My mother has taught high school English for over 20 years, so I owe a lot of my writing success to her. My father taught me to tie a tie and to remember to check the oil in my car. My brother, the accountant, is always a phone call away if I need financial advice.