How High Peak Breaking Forces can Increase Running Injuries


A new study looked at the relationship between running-related injury and increased peak braking forces (PBFs), then explored the effectiveness of gait retraining to decrease those forces.

First, what are PBFs?

Peak braking force is the amount of energy that is transferred into your leg when your foot hits the ground while running or walking. When you stop suddenly after running at full speed, RBF measures the strength of that energy. When that force is more than 0.27 times your body weight, you are eight-times more likely to be injured.

Our bodies are designed to absorb energy that is directed up or down, but not front to back, which is why a high PBF can be so problematic.

RBF and Gait Retraining

A 2018 study investigated how gait retraining could decrease PBF. They took a group of 12 female recreational runners and put them in an 9-session gait retraining program, then measured their progress with an advanced treadmill. The treadmill provided real-time biofeedback of braking forces.

The Results

The retraining program helped the runners to reduce their PBF by an average of 15%, as well as a 7% increase in step frequency and a 6% decrease in step length. The increase in frequency and decrease in length helped even out the gait, so runners weren’t causing undo stress on their legs.

These small changes were able to decrease the risk of injury for these runners.

What Does it Mean For You?

While you may not have access to this type of treadmill in your home, you may be able to tell that you pound the pavement harder than is comfortable. A gait analysis in our office can help determine your best plan of action. But in the meantime, think about increasing your step frequency and decreasing the length, and see how that makes you feel.