Watch the Behind the Nut Bends online guitar lesson by Chris Buono from 60 Electric Guitar Techniques You MUST Know
Pushing a string down behind the nut is exactly what a behind the nut bend is. More often than not, this is an attempt by country and Americana players at a faux lap steel vibe by way of this technique. In the hands of a master, it does the job right. Unlike most techniques in the course, your guitar may limit this one. You need a headstock with some room below the strings coming off the nut to the tuning machines so you can push the string down. A Telecaster or Tele-style axe is the go-to axe for behind the nut bends, but they're plenty of other possibilities such as the Vigier Excalibur you see me playing in the video.
Looking for inspiration? Tele players are by the most prevalent purveyors of behind the nut bends. Players such as Danny Gatton, Roy Buchanan, and our own Jim Campilongo
are very good guys to start with.