Fabrication

Scenario: The AFO is “fishmouthing”/buckling during mid- to late-stance phase of gait.

1) Nylon corregation: To avoid “fishmouthing” or buckling of the anterior trimlines, you may add parachute cord at the ankle during fabrication to increase the dimension of the plastic in the ML plane. The parachute cord is often removed as it is not the reinforcing structure. Rather, it is the change in geometry of the plastic that increases the rigidity. Flexural rigidity = material stiffness (E) x geometry (I)

2) Trimline variables: If the reliefs at the malleoli are large, you may need to modify the trimlines to allow more effective vertical loading through the anterior trimline. The image below illustrates the highest stress (red) is located on the AFO with wider reliefs.

After Fabrication

Welding Thermoplastic: Plastic Welder Instructions

Tools

• Kamweld Technologies – Model 46-RW Welder
• Kamweld Technologies – Model 47-RW Welder
• Kamweld Technologies – Model 44-AW Welder
• Kamweld Technologies – KS-2C Tip