[thewizardofaus]

This is extremely common in the triphasic training approach.

"Each block focuses on a particular portion of the main lifts—the eccentric (down) phase, the isometric (static) phase, and the concentric (up) phase."

Another common technique for force production in elite sport is to use weight releasers that overload the eccentric phase of a movement.

For example; squat eccentric 200kg, weight releases, concentric with 100kg.

[ehnto]

I am enjoying seeing so many different training styles in the comments, and the commonality in some of them. We train using pause sets which sounds like what you mean by the static portion of a lift? Unless you mean the squeeze at the top of a lift?

Squat down, pause for a few seconds, then up.