Although some people can afford to buy leg-braces, they are VERY expensive. Some are fortunate enough to find secondhand braces. For many, the only option is to make them yourself. The end result will rarely be as good as the real thing, but what is fabricated may help.
The link is to a couple of documents which show how one wannabe (Fred) made leg-braces for his own use. These first appeared in the Legbraces-Devotees Yahoo Group in 2007. See https://www.dropbox.com/sh/wrjhn1kmru2fwbr/AACJuBP29g592AygtHMcP40ra?dl=0 .