Instead it has ankles like these:
The ankle pivots around a fixed peg coming out of the leg.
To firm up this pivot joint you can work a bit of thin cotton thread into the horizontal seam between the leg and the ankle (there's no need to open up the leg nor the ankle to do this).
I hope that is the solution you're looking for.
Just for illustration, here are some old pics showing what the insides of this type of ankle look like:
The next pics show how to insert a bit of cotton wire to firm up the ankle joint (to keep the figure form toppling over).
Cheers,
-- Eric.



