The design process of 3D printed orthopedic insoles combines biomechanical analysis, digital modeling and personalized customization technology. The specific process is as follows:
I. Preliminary evaluation and diagnosis
Medical history and demand collection
Record the patient’s age, weight, medical history (such as diabetic foot, flat feet), daily activity intensity and symptom description to clarify the orthopedic goal.
Foot morphology examination
Identify structural abnormalities (such as high arches and inversion of the foot) through palpation, arch height measurement and foot symmetry analysis.
Gait and pressure analysis
Combined with the plantar pressure gait analysis system, quantify the dynamic pressure distribution, step length, step frequency and center of gravity offset trajectory, and locate the abnormal force area.
Three-dimensional foot scanner
II. Data acquisition and processing
Use a non-contact 3D laser scanner to obtain more than 20 three-dimensional data such as foot length, foot width, arch height, etc. within 20 seconds with an accuracy of 0.5mm.
Dynamic capture of pressure distribution
Through the pressure sensing array or gait analysis system, the changes in plantar pressure at each stage of the walking cycle are recorded to generate a thermal map and a mechanical axis report.
3. Biomechanical analysis and program formulation
Location of mechanical abnormalities
Combining three-dimensional data with pressure distribution, pathological characteristics such as arch collapse, metatarsal high-pressure area, and calcaneal tilt are identified.
Correction strategy design
Support optimization : Adjust the height and range of the arch support point to improve the alignment of the lower limb force line (such as correcting the axis deviation of the ankle joint).
Pressure redistribution : Through the design of grooves or buffer structures, the load of high-pressure areas such as metatarsal heads and heels is transferred.
4. 3D modeling and insole design
Parametric modeling
Import the scanned data into CAD/CAM software, and construct structures such as arch support surfaces and decompression grooves according to the biomechanical scheme.
Functional zoning design
Forefoot area : Add elastic materials to relieve impact;
Arch area : Use rigid materials to provide stable support;
Heel area : Design a cup-shaped structure to limit abnormal inward/outward rotation of the calcaneus.
V. Simulation test and optimization adjustment
Virtual mechanical simulation
Use finite element analysis software to simulate the stress distribution of the insole during walking and standing to verify the support effect and durability.
Parameter iteration adjustment
Optimize the support angle, thickness and material hardness according to the simulation results to ensure the balance between mechanical correction and comfort.
VI. Material selection and printing parameter setting
Multi-material composite application
Combined with materials such as TPU (flexible buffer) and PA12 (rigid support), zone printing achieves differentiated mechanical properties.
Printing accuracy control
Set the layer thickness to 0.1-0.2mm and the filling density to 20-80%, taking into account both structural strength and surface smoothness.
7. Trial verification and fine-tuning
Dynamic fit test
After the patient tries on the shoes, the pressure sensor insole is used to monitor the adjusted plantar load distribution in real time to confirm the correction effect.
Personalized fine-tuning
For local pressure or insufficient support areas, fine-tuning such as polishing and attaching buffer layers is performed.
8. Final delivery and follow-up
Usage guidance
Provide wearing time recommendations, cleaning methods and contraindications (such as open wounds).
Effect tracking
Gait data is collected through regular follow-up to evaluate long-term correction effects and optimize iterative solutions.
This process deeply combines digital technology with biomechanics to achieve a fully closed-loop design from precise evaluation to dynamic optimization, significantly improving the individual fit and efficacy of orthopedic interventions.
