Slightly longer poses seemed to produce better results.
I'm still foreshortening the dimensions a little too much, I wonder if it's my height ratio to the model? - I'm 6'4", whereas the model is perhaps 5'3 / 5'4?
A very basic full - on drawing was made to test the theory that my sighting (being above the model) is causing too much foreshortening in the legs...
This drawing was conducted whilst seated on a drawing stool, lowering my eye level to that of the model. It appears to have corrected the proportion issues....
Some of the exercises in "Drawing Projects; An exploration of the language of Drawing", (2011), Maslin, M. and Southern, J., London, Black Dog Publishing, were considered suitable themes to investigate in future drawing sessions. I have purchased this excellent book for myself and will work through the exemplars through the coming months in my own time...
http://blackdogonline.com/art/drawing-projects.html