When running, with every step, the knees bear seven times your body weight in pressure, the quadriceps bear four times, and the soles of your feet bear three times. Medical experts point out that when running with proper form, the knees move forward normally, maximizing the contact area between the patella and femur, which allows force to be evenly distributed. However, if your posture is incorrect—especially when you take long strides in an attempt to run faster—it increases joint pressure and may even cause the patella to tilt outward or rotate inward, accelerating cartilage wear on the contact surfaces. This not only affects future running performance but can also make walking and climbing stairs difficult.

Incorrect posture: 1. Leaning backward makes forward strides more strenuous; 2. Landing on the heel with the leg straight both increases the impact force on the knees and prevents the thigh muscles from helping to distribute the load, thereby indirectly increasing knee pressure; 3. Taking large strides causes the body’s center of gravity to be farther from the supporting foot, forcing the quadriceps to work harder to maintain balance and increasing strain on the patellofemoral joint.

Correct posture: 1. Leaning slightly forward helps propel you forward with less effort; 2. Bending the knees makes it easier to engage the thigh muscles to share the load and cushion the impact, while also increasing the contact area between the patella and femur for more even pressure distribution and reduced friction; 3. Taking quicker, shorter strides keeps the body’s center of gravity closer to the supporting foot, reducing the amount of effort needed from the quadriceps to maintain balance and lessening the strain on the patellofemoral joint.