The rock climbing foot does look like a solid candidate for 3d printing. Do you happen to know what its made out of? It would have to be durable to support weight on something so abrasive. The bartlet looks incredibly stout, but its all metal, and that's a hydraulic piston for the main movement, rather complex but not impossible. Likely made on a CNC w/billet aluminum.
On the tendon subject, I was reminded of a few projects for leg augmentation/rehab for injured non-amputees, as seen here:

http://www.npr.org/blogs/health/2014...ing-to-leaping
http://www.popularmechanics.com/tech...-war-9#slide-9