So now that you know the doing part.
Q: Were you able to move as far on each side?
Q: Or did you have the same range of motion or a little different with each side?
Q: Were you able to keep your hands together or did the arms bend at a certain point?
Q: Were you able to comfortably get one arm (or both sides) to the floor?
Q: Did your head move?
Q: Were you breathing or holding your breath?
What were you noticing in the feeling part?
Q: Did it feel easy or did you feel a lot of effort or strain?
Q: Did it feel easier on one side more than the other?
Q: Did you feel your head move or was it glued in the middle? How did your neck feel as you were moving from side to side?
Q: If you were able to get your arm on the floor. Was that easy or did you "try" to do it?
See, when people first try this. Many are tuned into the doing part and focus just on that.
How do I know? People will tell me that they can't really feel or tune in as well. Or haven't done so for awhile.
That is OK and normal even if you haven't been delving into your proprioceptive sense.
Doing and Feeling
If you focus both on doing and feeling, then you can engage the motor-sensory (doing-feeling) loop.