Impact Force

Running Impact Force as Measured by an Accelerometer

Running impact force is the amount of force that is exerted on your body when your foot strikes the ground. It is measured in units of body weight (BW). A typical running impact force is 2-3 times body weight for midfoot strikers to over 4-5 times body weight for heel strikers.

Impact force can vary depending on a number of factors, including your running form, the surface you are running on, and your speed. For example, heel strikers tend to have higher impact forces than midfoot or forefoot strikers, and running on a hard surface, such as concrete, will produce higher impact forces than running on a soft surface, such as grass.

Too much impact force can lead to injuries, such as shin splints, stress fractures, and runner's knee. However, some impact force is necessary for good running performance.


Once you have collected data from your accelerometer, you can use it to analyze your running impact force and identify areas where you can improve your running form to reduce impact force. For example, if you have high impact forces, you may want to try landing on your midfoot or forefoot instead of your heel. You may also want to try running on softer surfaces, such as grass or dirt.

Tips to reduce impact force during running:

  • Improve your running form. Focus on landing on your midfoot or forefoot, and keep your stride short and quick. Landing on your heels creates a jarring impact on your joints.
  • Run on softer surfaces whenever possible. Softer surfaces, such as grass or dirt, absorb more impact than hard surfaces, such as concrete.
  • Wear properly fitting running shoes. Running shoes should provide adequate cushioning and support for your foot type.
  • Start slowly and gradually increase your speed and distance. This will help your body to adjust to the demands of running and reduce the risk of injury.

It is important to note that there is no one-size-fits-all answer to the question of what is the optimal level of impact force. The best way to find the level that is right for you is to listen to your body and adjust your running form accordingly.

If you have any concerns about your running impact force, or if you are experiencing pain while running, be sure to talk to your doctor or a physical therapist.