Thermoforming of the two hemi-valves on the positive polurethane. The two pieces
must exceed the trim lines drawn on the positive plaster cast.
2 - First assembly
The thermoformed hemi-valves are positioned on the positive polyurethane.
The metal bars are curved and a first provisional assembly is carried out.
The final trim lines and the final adjusting of the two pieces will be carried
out at the time of the initial fitting.
3. Whithout fitting
When precise measurements of height and circumference have been made during the
digital cast, it is possible to carry out the final construction directly.
4. Used material
The rigid asymmetrical lateral pieces of polycarbonate are connected posteriorly
at the midline by a duraluminium bar like the historical Lyon brace. The
posterior metal bar is curved in the sagittal plane by following the positive
polyurethane. All metal parts are similar to those of the old Lyon brace. Both
anterior and lower ratcheting buckles are rigid, the upper third is Velcro