Had this on T/N a few weeks ago but maybe here is better:
Does anyone know whether there are different training effects from pausing for an isometric contraction during the concentric portion of a rep vs. pausing during the eccentric portion?
Well I don’t see a point of pausing on the way up, since that’s when you want to explode 
It could mimic a sticking point maybe.
well why reinforce something bad?!
That was funny. But I mean, doesn’t it provide the training stimulus of increased tension at a certain point in the movement?