Why the kneecap feels less force
The kneecap sits in a groove at the end of the thighbone and acts like a pulley for the quadriceps, the muscles at the front of the thigh. When those muscles tighten to steady or straighten the knee, they also press the kneecap against the thighbone. That contact force is one source of pressure at the front of the knee.
In ordinary forward walking, the quadriceps help control the knee as the leg accepts body weight and moves forward. Walking backward changes the timing and direction of that work: the quadriceps may not need to brake the body in the same way. With less force transmitted through the kneecap during parts of the step, pressure on that joint can be lower.
A different gait, not a reversed one
Backward walking changes more than which way the feet point. People tend to use shorter steps and alter how the foot meets the ground, shifting the demands among muscles and joints. Those changes can reduce the knee-bending and muscle forces that contribute to kneecap compression, though the effect depends on a person’s pace, technique, and knee condition.
That makes backward walking a possible way to vary the load during exercise—not a guarantee that every knee will feel better. Its practical tradeoff is visibility: because the walker cannot see where the next step lands, a clear, level path matters as much as the change in knee mechanics.
