HOME / RESEARCH / ELBOW BRACE
Custom made, heavy duty elbow brace for sport use
The technical solution presented here is the second version of my prototype. The first one, designed and produced using the same methodology- 3D scanning, X-ray imaging, CAD design and 3D printing-was used extensively over the last 4 years, and has proven extremely efficient, strong and comfortable.
After assembly the adjoining panels contacting the skin are equipped with orthopedics comfort foam. Both lower and upper arm adjoining panels are fastened using polyamide straps. Finally, the upper arm part of the brace is secured in position to the arm in order to prevent any sliding during use via an elastic link joined to a dedicated shoulder sleeve.
Identification of anatomical features to be protected
The X-ray below shows the extensive damages of the radial head several months after a second failed bone graft. It is clearly apparent that such a weakened joint should be properly supported in order to carry on doing sports where high speed crashes occur.
Design’s objectives
Ensure perfect alignment with anatomical features
Made using 3D scanning and X-rays imaging only
Provide optimum rigidity and support of a weakened joint
Provide optimum comfort upon wearing and fastening
Protect the weakened articulation and stabilize it for future crashes
Be impact and wear resistant
Ramain in position at all times
Be well ventilated
Be modular
Be light
Sleek and elegantly designed
Ensure perfect alignment with anatomical features
Design approach
The X-ray of the injured limb was integrated into a CAD software, scaled and aligned with a 3D scan of the arm taken in a similar position to that of the X-ray.
The anatomical features properly in place, the brace could be designed.
The main features of the brace
A stiff carbon fiber reinforced frame produced in 2 parts providing stiffness, impact protection and anchoring features for the pivot joint and the adjoining anatomical panels
4 adjoining flexible anatomical panels providing ease of insertion, protection and comfort.
2 ball bearings inserted into the frame providing smoothness of action and rigidity to the frame.
The pictures below illustrate the perfect alignment of the brace and the elbow articulation while providing protection from further injury
Manufacturing
3D printing material:
- PA6 20% carbon charged
- Continuous carbon fiber reinforcement deposited inside the 3D printed matrix.
The blue areas in the following pictures depict the distribution of the reinforcement material within the frame in order to achieve the desired stiffness while keeping the weight to minimum.Selective fiber placement in the frame attached to the upper arm
Selective fiber placement in the frame attached to the upper arm
Complete filling in the frame attached to the lower arm
Furthermore, each layer of carbon fiber can be fully customized before printing.
This approach allows a perfect control of the orientation of the fibers from one layer to the next in order to ensure both flexural and torsional stiffness of the frame.
Below is an example of a possible different orientation of the fibers (0°-45°) between 2 consecutive layers of the upper arm frame combined with concentric fibers along the outer and inner surfaces.
