Abstract
Background: Asymmetrical joint space narrowing occurs in many cases of knee osteoarthritis (OA). The objective of the present study is to elucidate the biomechanics of lateral wedges in shoes used to widen the medial joint space in predominantly medial OA, and the biomechanics of medial wedges in shoes used to widen the lateral joint space in predominantly lateral OA. Methods: Medial or lateral shift of the center of weight bearing of the foot is largely offset by movement of the flexible hip joint, which changes the tilt angle of the femoral head in the frontal plane. The altered tilt can widen asymmetrical joint space narrowing in a beneficial way to a degree that is easily calculated from anatomic measurements. Results: Initial calculations suggest that with proper technique 1 to 2 mm of extra joint space widening can be created to individualize beneficial effects. A concept is presented for real time monitoring of the degree of widening during fitting of wedges, using bioimpedance sensed by skin surface electrodes at the joint line. Conclusions: Low-cost mechanical correction for excessive asymmetrical articular cartilage wear in the knee joint during standing and walking using simple orthotics in shoes is theoretically possible. Opportunities for follow-on research are straightforward.
Keywords
Alignment, Biomechanics, Deformity, Exercise, Gait, Impedance, Insole, Knee, Lateral wedge, Orthotic, Osteoarthritis, Stabilizer, Valgus, Varus.
Date of this Version
1-21-2026
Recommended Citation
Babbs, Charles F., "Design concept for low-cost management of early medial or lateral osteoarthritis" (2026). Weldon School of Biomedical Engineering Faculty Working Papers. Paper 41.
https://docs.lib.purdue.edu/bmewp/41