tendons
During a cruciate ligament surgery, the patellar tendon was used as a ligament graft. Originally, the plan was to take the tendon from the quadriceps muscle. However, this was not possible because the tendon was too weak and not strong enough. The patellar tendon was also not ideal, but more usable.
Now to my question: why do some people have such poor tendons, and is there a way to improve this - through more exercise, targeted nutrition, or vitamin intake?