Off night & getting musings, questions off my chest.

Many of you advanced BB'ers tout flexing, posing ....was thinking, even noobs or above could do the following:

Can't do a dip? Get in the top position anyway (arms straight) and hold as long as you can for 5-10 'timed' reps.

Can't do a pushup? Same as above, get in the top position & hold as long as you can.

Can't do a chin/pullup? - start with dead hangs

Tried doing a pushup with arms locked at the top and close handspacing and hold til gave out....no, didn't time. Whole chest, arms get to feeling taxed real soon.

There's got to be something to these 'non moving' weighted isometric, flexed exercises.