If I understand your question correctly, you’re asking about locked short and locked long muscles. I will be releasing extensive material about this topic soon so please keep an eye on your email inbox but here’s a short overview:

A locked short muscle responds positively to deep and regular stretching. Flexibility is progressively improved and the sensation of tightness is lessened. Also a locked short muscle tends to have less range of motion when compared with the same muscle on the other side of the body.

A locked long muscle, on the other hand, tends to NOT respond positively to deep and regular stretching. While stretching a locked long muscle can sometimes feel like, “yes, this muscle sort of wants this,” the stretching doesn’t have the effect of reducing the feeling of tightness in a lasting way. In fact, stretching locked long muscles can sometimes aggravate them.

So the questions to ask when stretching a particular muscle:

Does this truly feel relieving? Does this improve the flexibility of the muscle? Is the range of motion less than on the other side of the body which is then improved by stretching? If so, it’s more likely to be a locked short muscle.

OR

Does stretching aggravate the muscle and make no improvements in reducing the feeling of tightness? If so, it may be a locked long muscle.

I hope that helps!