Long ground contact time during running is not always a good thing because it allows more time for abnormal stresses and movements of the foot/ankle complex to occur. The problem? The more time your feet spend on the ground, the greater the potential for more force production on the body. This is what you don’t want.
Is Long Ground Contact Time Bad When Running?
Ground contact time is the length of time of which the foot interacts with the ground and it begins at touchdown and ends at toe-off to initiate flight.
More Time for Bad Stuff to Happen
Long ground contact time exacerbates or prolongs abnormal foot mechanics such as excessive pronation.
- excessive pronation is the biomechanical problem often cited as being associated with most lower leg running injuries!
The problem with long ground contact time in heel strike running is that it triggers abnormal stresses further up the kinetic chain.
For instance, as ground contact time increases, excessive pronation increases, leading to excessive internal rotation of the tibia which places abnormal rotational stress on the knee-joint.
Long ground contact time may also prolong the braking effect associated with heel strike running. In this case, the posterior tibialis works harder to restrain the forward movement of the tibia over the foot. As a result, angular velocities increase causing the muscles to work harder to control the foot and knee and may result in injuries such as tendinitis.
The Simple Fix = Forefoot Running
One of the best interventions to reduce excessive pronation is to run with a forefoot strike. This way, the feet have minimal interactions with the ground which cuts down on cumulative stresses to the body because there is less time for abnormal foot postures and movements to take place.
More on Forefoot Running:
Bates et al. Lower extremity function during the support phase of running. Biomechanics VI-B, Baltimore, University Park, 1970, pp. 30–39.
Brody, DM. Running injuries.Clin Symp, 1982; 32(4):2-36.
Hamill et al. Timing of lower extremity joint actions during treadmill running. Med Sci Sports Exerc, 1992; 24(7):807-13.
James, SL and Jones, DC. Biomechanical aspects of distance running injuries. Biomechanics of distance running. Human kinetics books, Champaign, 1999, PP. 249–69.
McClay, I and Manal, K. A comparison of three-dimensional lower extremity kinematics during running between excessive pronators and normals. Clin Biomech, 1998; 13(3):195-203.
Messier,SP and Pittala, KA. Etiological factors associated with selected running injuries. Med Sci Sports Exerc, 1998; 20(5);501-505.
BSc Neurobiology; MSc Biomechanics candidate, ultra minimalist runner & founder of RunForefoot. I was a heel striker, always injured. I was inspired by the great Tirunesh Dibaba to try forefoot running. Now, I'm injury free. This is why I launched Run Forefoot, to advocate the health & performance benefits of forefoot running and to raise awareness on the dangers of heel striking, because the world needs to know.
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