Wow or Ow?

I am taking some action to track my sadhana.  Part of that is I have started, just today, to email my favorite friend about what happened in my practice.  Let me share what I wrote:

Alignment seems to have more ease in it.  I usually have to make a number of adjustments from chaturanga dandasana to urdhva mukha svanasana, moving hands or feet, but not so today.  Body just flowed forward almost effortlessly.

Continued on through the postures and I noticed that I was not shaking quite as much as I have been.  Also really engaged every muscle I could in every posture.  I definitely had more energy and no lethargy moving out of each pose.  One noticeable exception was natarajasana with the right leg raised.  There was absolutely no life in that right leg, almost painfully so.

As I continued through the sequence, I came to ardha shalabasana and had a very unexpected experience:  I pressed my hips down and both legs came off the floor high enough my hips started lifting off my arms.  Went into ardha shalabasana and each leg came up only a portion of what happened in the full posture.  No ego reaction to it though.

Moved into ardha navasana, paripurna navasana with less shaking and more ease in the breath.  As I came down into dandasana, my tail bone was already behind me and the sits bones were well place.  That never happens and was a nice thing to experience.  As I folded into paschimottanasana, I could feel my back opening and exhaled forward slightly more and heard and felt a very sloppy sounding pop in my low back just above the sacrum.  Minor sense of electricity but no real pain.  I felt slight discomfort in setu bandhasana but gentle movement helped relieve that.

Sitting, as I do most of the day, is stiffening up my back though, very uncomfortable; so, I have been squirming and walking to keep the area from seizing up.  No real pain though.