If you were a heel strike runner like me at one time, you were probably all too familiar with sore knee joints. After I switched to forefoot running, the first thing I noticed was how less stiff and sore my knees were.
Unlike heel strike running, forefoot running reduces patellofemoral pain by lowering or eliminating vertical peak impact forces underneath the heel as well as underneath the second metatarsal head.
Another Way Forefoot Running Reduces Patellofemoral Pain
At the mechanical level, forefoot running reduces and prevents patellofemoral pain (knee pain) better than heel strike running. But, forefoot running also reduces the impact-related forces that cause patellofemoral pain in heel strike runners.
High vertical peak force underneath the lateral heel and the second metatarsal head were found to be intrinsic risk factors for patellofemoral pain in running.
A study by Thijs et al., (2014) found that heel strikers who suffered patellofemoral pain generated a higher vertical peak force underneath the lateral heel.
The study also found that near the end of the propulsion phase, heel strikers who had higher vertical peak forces underneath the second metatarsal head were predisposed for patellofemoral pain.
In summary, heel strike running is associated with 2 intrinsic risk factors that cause patellofemoral pain: higher vertical peak forces under the heel and second metatarsal head, both of which are significantly reduced or eliminated in forefoot running. How?
In forefoot running, initial ground-contact is on the forefoot and the heel is the last part of the foot to contact the ground. This landing pattern greatly reduces vertical peak forces under the heel because of the small distance separation between the center of mass (torso/head) and the center of pressure on the foot. This means that at touchdown, the center of mass is positioned above, or near foot strike position in which the center of pressure is concentrated in the forefoot, not the heel.
During stance in forefoot running, heel pressures are significantly reduced because the center of mass is held in a constant position over the forefoot -this is how forefoot running spares the heel of the brute forces associated with heel strike running.
The other way forefoot running reduces patellofemoral pain is by lowering vertical peak forces underneath the second metatarsal head via foot-rollover phase elimination.
In contrast, heel strike running utilizes the foot-rollover phase to transfer the center of mass from heel to toe in preparation for forefoot push-off which in turn, causes maximal peak pressures on the second metatarsal head to be the highest. As a consequence, higher vertical forces are transferred to more proximal joints such as the knee. The researchers suggested that the high impact shock could cause an excessive load on the patellofemoral joint, leading to joint overload and pain.
The foot-rollover phase in heel strike running is the best explanation for the difference in peak plantar pressure distribution when compared to that of forefoot running. The foot-rollover phase is not needed to transfer the center of mass heel-to-toe in forefoot running because the center of mass is always positioned above the forefoot.
Thijs et al. Gait-related intrinsic risk factors for patellofemoral pain in novice recreational runners. Br J Sports Med, 2014; 42:466-71.
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.