That is a terible solar view. Not enough of the lunar surface has been trimmed away and only the solar corona is visible.
Tom thanks! The image makes this case easy to discuss. I have marked it up with my thoughts. What I would do is bring the heels back to the Red Line, take breakover to the blue line and remove some of the bars in the yellow areas!
Tendons have but two lengths, resting and working. They are basically inelastic and as such, lack the ability to contract(shorten) or stretch(lengthen) beyond those two lengths. And, those two lengths are very close together. However, if we are referring to the Deep Flexor Muscle, that it a different story as muscle tissue does indeed have the capability to contract and stretch. Very true. By its ambiguity, it leads the reader to decide for him/herself which structure is being discussed. I chose to read it as thought it was the DDFT under review because so often, writers use terms like 'contracted tendons" and 'stretched tendons'. In my corner of the sandbox, the former doesn't exist and the latter is referred to as 'bowed'.
In the beginning of that article, which I hadnt pasted he states what you have above about tendon lengths and the muscle and says a better description of it is contraction of deep flexor unit. I see why you would read it as you did without having read the entire article, for me out here trying to explain this to fifty year old vets who believe it can be stretched has been a huge problem but thankfully now results are speaking for themselves
