Magicians want to pride themselves on knowing 'all' of Houdini's secrets. Frankly, that's a delusional approach. Houdini had so many secrets and methods to his various effects, it's impossible to nail them all down. I love however, when a secret comes along that wasn't known or at least wasn't well known. And normally, I would never reveal a secret, but in this case, it is NOT a secret that has anything to do with methods.
This secret involved his upside down straitjacket escape. The device in question, two ankle/leg straps, which were hidden underneath the pant legs which protected his legs and ankles. In early photos Houdini might have cloth around his ankles to protect them, but this leather brace device was far more safe and secure.
On first glance, they look to be in great condition. But upon closer inspection you can see the corrosion on all the metal buckle parts. And the leather straps look quite brittle. The ends of the straps look to be dry rotted, so I wouldn't unbuckle them just out of precaution.
I first saw these in 2011, when I visited Ken Klosterman. I was beyond thrilled to see such a thing. And now, this unique piece of Houdini's life can be yours, because they are listed next Potter and Potter Auction. This is lot #176 and has a starting bid of $1000. If the Houdini Trunk from the last Potter Auction is any indication, these leather leg braces could go quite high.
Here is a link to the actual item. https://auctions.potterauctions.com/__HOUDINI___Houdini_s_Leather_Upside_Down_Straitja-LOT94103.aspx