Excessive counter-tension would slow movement, yes. But muscles are usually maintaining some small level of tension. There’s not really a fully untensed state.
That said, I’m not actually sure that more counter-tension does speed up reaction times within normal ranges. There is such a thing as anticipatory muscle tension when an action is prepared, but that may be a by-product, not a functional way of speeding up reaction times. And I’m not sure it happens when no specific action is being prepared.
So I don’t know. If I’d thought a little harder about this, I’d have framed it as a hypothesis. Sorry!
Excessive counter-tension would slow movement, yes. But muscles are usually maintaining some small level of tension. There’s not really a fully untensed state.
That said, I’m not actually sure that more counter-tension does speed up reaction times within normal ranges. There is such a thing as anticipatory muscle tension when an action is prepared, but that may be a by-product, not a functional way of speeding up reaction times. And I’m not sure it happens when no specific action is being prepared.
So I don’t know. If I’d thought a little harder about this, I’d have framed it as a hypothesis. Sorry!