This is a variation of the Shadow Imitation Technique, designed for offensive purposes. The user extends their shadow along a target's body, which, because the shadow has physical properties, the target can feel. There, the shadow can be used for restraint, replacing or adding to the binding of the Shadow Imitation; the closer the user is to their target, the stronger this binding becomes. Like the Shadow Imitation, the Shadow–Neck Binding requires a great deal of chakra to maintain, making it weaker over extended periods of time. For this reason, it is most effective when immediately used to strangle a target, hence the name.
The Shadow–Neck Binding's ability to apply pressure to a body gives the user some additional options. If the user falls victim to a genjutsu, they can use their shadow to break their own finger, freeing themselves from the genjutsu's influence. In The Last: Naruto the Movie, Shikamaru Nara uses the Shadow–Neck Binding to control the Ōtsutsuki clan's puppet, forcing them to fight among themselves.
Its full name is "Leaf Secret: Shadow–Neck Binding Technique" (木ノ葉秘伝・影首縛りの術, Konoha Hiden: Kage–Kubishibari no Jutsu, Literally meaning: Tree Leaf Secret: Shadow–Neck Binding Technique).
The technique appears in Naruto: Ultimate Ninja Storm as Shikamaru's ultimate technique. However, rather than strangling the opponent, it binds them to a nearby rock and then tightly squeezes them, destroying the rock and crushing the opponent.