The chain is just as strong as it weakest link. This becomes very clear in the mythology of Achilles, who was invincible after being immersed in the river Styx by his mother ... who held his heel: the place that would eventually be his death.
I have recently been looking into the issues in the Achilles' heel from an energetic point of view and made some interesting discoveries.
Oftentimes the stories of these myths run very deep into human consciousness, and the myth of Achilles makes no exception.
What I saw was quite a lot of survival issues held in this tendon (as well as in the rest of the heel by the way). It won't surprise you that clearing these out, will have an effect on the overall energy system of the person.
The amount of tension in this tendon also affects the overall tension in the body.
Maybe truly a matter of strengthening the weakest link and increasing the overall strength for the entire body?
I am currently running a series of experiments to see how this works out ...