Increasing normalized walking speed from Fr=0.10 to Fr=0.40 in healthy young adults increases tibial cartilage compressive strain from approximately 1% to 6%, with greater strain observed at the medial tibial plateau compared to the lateral tibial plateau, demonstrating that walking intensity directly influences localized cartilage loading.

When a person walks faster, the force pushing down on the knee joint increases, squeezing the cartilage and pushing fluid out of it. This causes the cartilage to compress and thin more, especially on the inner side of the knee where the force is concentrated. The cartilage keeps getting squished until it reaches a point where no more fluid can move out, and the compression stops increasing.