I see two possible cases when you reach anchor, which one seems more correct? Thanks.
1. You squeeze your back muscles all the way together, you can tense them only a bit more as you release, say about a 1/4" at most. This means the increased tension makes you release.
2. You do not squeeze your muscles completely together and leave a bit of room between your shoulder blades (maybe an inch) so you can squeeze them together more. This means the increased movement makes you release.