KNEE osteoarthritis treatment may advance with 3D printed soles that passively modify gait biomechanics and reduce medial knee loading.
3D Printed Shoes for Knee Osteoarthritis
A prototype 3D printed shoe sole passively replicated key biomechanical effects of toe out gait retraining, reducing measures linked to medial knee loading in healthy adults. The findings suggest a potential low effort conservative intervention for knee osteoarthritis, where sustained gait retraining can be difficult to maintain outside supervised settings.
Knee osteoarthritis is strongly influenced by mechanical loading across the joint. In this study, investigators focused on the knee adduction moment, a surrogate measure of medial knee loading associated with disease severity, cumulative loading, and cartilage loss. The team designed rotational and variable stiffness shoe soles, known as RVS soles, to induce a toe out gait pattern without real time biofeedback or active retraining.
Passive Gait Modification Reduced Knee Loading
The study enrolled 21 healthy adults who completed baseline overground walking trials in control shoes, followed by randomized biofeedback based gait retraining at toe out angles of 5°, 10°, and 15°. Participants then completed walking trials wearing the RVS shoes, with motion capture and ground reaction force data used to analyze gait biomechanics.
Compared with baseline, the second peak knee adduction moment fell significantly after toe out retraining by 13.6% at 5°, 20.2% at 10°, and 31.7% at 15°. RVS shoes alone reduced the second peak knee adduction moment by 16.3%, placing the passive effect between the 5° and 10° retraining conditions. The shoes also reduced knee adduction angular impulse by 8.6%, a reduction not achieved by the retraining strategies.
Why the Findings Matter
The biomechanical effect appeared to be driven largely by changes in knee center of pressure offset and mediolateral ground reaction force, which together explained more than 95% of the variation in second peak knee adduction moment. This supports the concept that shoe sole geometry and stiffness may help shift load during walking without relying on patient adherence to a learned gait pattern.
The findings remain preliminary. Testing was performed in healthy adults, and only immediate biomechanical responses were assessed. Future studies in patients with knee osteoarthritis are needed to determine comfort, adherence, long term effects, and whether personalized sole designs can optimize clinical benefit.
Reference
Jiang Z et al. Advancing Conservative Treatment of Knee Osteoarthritis: 3D-Printed Shoe Soles for Passive Toe-Out Gait Modification. J Foot Ankle Res. 2026;19(2).
Featured Image: Songsak C on Adobe Stock.
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