A recent 60-sec doodle here.
Nice work and job, on your quick attitude of the backside, TommyL. Nice motion and movement of this difficult pose.
Yet, if I was to suggest you a comment on your quick sketch, it would be to say that some of the back muscles and bones are a bit too arthritic in the fluidity. Why don't you please compose yourself with 60 minutes of 30 second sketches of nudes and drapes (draped models)????? (60 poses)
The reason why you could and would, and should do this little critical trick is because, if your current goal is to reduce stiffness in your sketches, plus doodles, and to make them more fluid, dynamic, energetic and vital.
For more inspiration on your quick pose goal, then I suggest you please check out this video, it's about a certain animator named VivziePop (Vivienne Medrano). It's very useful cause she's been able to apply quick sketching and Fred-Moore-type drawing.
Well cheers to you, and good luck on your new goal.