Knee pain after jogging may be due to a high mileage of jogging with a heel strike landing as landing this way on the foot during jogging increases the risk of knee lesions.
Jogging and Knee Pain
A study by Weidekamm at el. reported that heel striking joggers who ran more than 32-km per week had more knee lesions compared with heel striking joggers with a lower running frequency (i.e. less mileage per week).
Below are illustrations taken from the study showing the heel strike induced-changes in the knee-ligament architecture.
- The nature of the knee lesions included subtle intrameniscal mucoid changes, indicating chronic degeneration of the meniscus.
How did this happen?
- Arendse et al. found that ankle dorsiflexion in heel strike running is associated with a higher magnitude of the ground reaction force.
Sustaining the high ground reaction force during heel strike running results in a repetitive increase in external loading on the knee-joint which in turn produces transient intrameniscal lesions immediately after running.
Based on the data, the researchers came up with a twist: osteoarthritis is linked to low to moderate levels of physical activity, yet the joggers with high running mileage had a higher percentage of slight chronic cartilage lesions in the knee!
Heel Striking Increase Fluid Build-Up in Knee
Often the external impact on the knee from heel strike running is accompanied by mild joint effusion (fluid production). The images below, taken from the study, show the relative fluid buildup influenced by heel strike running.
The researchers reasoned that joint effusion at the knee is likely a by-product to a better adaptation by the knee joint to manage the repetitive external loads induced by heel strike running.
Arguably, the knee joint is a closed musculoskeletal unit where unceasingly fluid production is never a good thing. In the same study, mild joint effusion at the knee was present in more than half of the joggers!
On the other hand, a forefoot running style is more than enough to prevent the formation of knee lesions as well as fluid buildup in the knee-joint.
Traditionally we think of running as an activity that is bad for the knees. That is clearly true if the runner heel strikes. However, in forefoot running, knee flexion is higher and the ankle is plantarflexed at initial contact, preventing impact from pervading the knee. Instead, the mechanical work is redistributed away from the knees to the ankles where it should be.
Another benefit of forefoot running is that increased speed is not accompanied by increased work at the ankle. Mechanical work at the ankle minimizes when speed increases during forefoot running.
More from Run Forefoot:
How Forefoot Running Helps ITBS Sufferers
Why You Must Always Bend Your Knees While You Run
Always Go Minimal During Training Protocols
Forefoot Running Shoes
Arensde et al. Reduced eccentric loading of the knee with the pose running method. Med Sci Sports Exerc, 2004; 36(2):272-7.
Weidekamm et al. Incidence of chronic knee lesions in long distance runners based on training level: findings at MRI. Euro J Radiol, 2006; 58, 286-93.
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.