Terminology is a good thing. It helps define what we’re doing. It gives you somewhere to aim. But sometimes it doesn’t communicate, except by example. That’s what I found when I was learning about “pinch points.”
The other day I’m at lunch and someone asks me what I’ve been up to. An innocent and frequent question that leaves me cold. I freeze, like always, but this time I blurt out “pinch points.” I get a few looks. No, this has nothing to do with fifty shades of kink, but it is probably a technique used in Fifty Shades of Grey, though I’d be hard pressed to identify where it’s used. Pinch points are new to my vernacular as a writer. Although I studied screenwriting back in the day, and even wrote a couple of screen plays, that should stay hanging with the dust bunnies under the bed, this was new terminology to me. Maybe that’s why my screen plays never quite worked. They’re that moment in the story that takes you right to the emotional crux of the situation, not through the point of view of one of the principal characters, but by direct action. A pinch point reignites the emotional quest and reminds the reader of what’s at stake. Pinch points are found in the middle of the story – in act two. They show the conflict in a quick snapshot.

Here Are Some Examples of Pinch Points:
From: Romance University on Pinch Points

Here’s an example from the movie Raiders of the Lost Ark. Its second act looks like:

25% Turning Point #1, Call to Action = Army Intelligence sending Indy after Ark (Outer Goal clear)
*Pinch Point #1: Indy thinks Marion is dead, confronts Balloq and threatens to kill him, even though Balloq’s men would then kill Indy.
50% Midpoint: Indy finds both the Ark’s whereabouts and that Marion is alive (reversal) but instead of freeing her, leaves her with Nazi’s so that he can go after Ark. Reaffirms Outer Goal (obtaining Ark), while denying Inner Goal (need for a partner).
*Pinch Point #2: Marion and Indy “reunited” along with the snakes in the Well of Souls (reversal of first pinch point and midpoint where they were separated)
75% End of Act 2: Indy saves Marion by conquering physical manifestation of his Inner Conflict (fear of failure) Everything seems lost, the Nazis have the Ark, they have no transportation, no weapons, no plan…
Notice how the pinch points are more focused on setting up the emotional change in the character rather than action.

Or from Wikipedia on Screenwriting

Here’s an example using Star Wars:

Pinch 1: A reminder scene at about 3/8 the way through the script (halfway through Act 2a) that brings up the central conflict of the drama, reminding us of the overall conflict. For example, in Star Wars, Pinch 1 is the Stormtroopers attacking the Millennium Falcon in Mos Eisley, reminding us the Empire is after the stolen plans to the Death Star R2-D2 is carrying and Luke and Ben Kenobi are trying to get to the Rebel Alliance (the main conflict).

Pinch 2: Another reminder scene about 5/8 through the script (halfway through Act 2b) that is somehow linked to Pinch 1 in reminding the audience about the central conflict. In Star Wars, Pinch 2 is the Stormtroopers attacking them as they rescue the Princess in the Death Star. Both scenes remind us of the Empire’s opposition, and using the Stormtrooper attack motif unifies both Pinches.

Or from my Favorite:
Larry Brooks on Pinch Points

Pinch Points can be very simple and quick. It can be one character reminding the other of what’s going on. A glimpse of an approaching storm – take that literally or metaphorically, one will apply to your story – and the havoc it is capable of bestowing on all in its path.
It can be a kidnapper beating the captive just for the fun of it. Or to play the screams over the phone to pressure the person paying the ransom.
The simpler and more direct it is, the more effective it is.