A compelling study by Kerrigan et al. found that subjects who ran in neutral running shoes with a raised heel had a concerning increase in joint torque at the hip, knees, and ankles.
The objective of the study was to build upon earlier reports showing that a cushioned-elevated heel of a neutral running shoe was the culprit for increasing lower extremity torque compared to running barefoot.
The Brooks Adrenalin, the shoe used in the study, was found to increase knee flexion torque by 36% which increased the work of the quadriceps which in turn, increased strain through the patella tendon and pressure across the patellofemoral joint.
Neutral Running Shoes Increases Joint Susceptibility to Arthritis
Unlike the barefoot runners in the study, subjects in the Brooks neutral running shoe had a 38% increase in knee torque, indicative of greater compressive loading on the medial tibiofemoral compartment.
- high compressive loading on the medial tibiofemoral compartment is concerning since this area is highly prone to degenerative changes
- degenerative changes to joint and tissue structures are susceptible to arthritis
But wait, the plot thickens. The researchers found that the Brooks neutral shoe led to a 54% increase in hip internal rotation which may increase susceptibility to arthritis in the hip-joint.
Heel Strike Running Increases Joint Torque
As expected, subjects who ran in the Brooks neutral shoe had a longer stride compared to the barefoot runners. Though, increased stride-length was poorly correlated with torque production, the mass of the neutral running shoe prompted a heavier foot strike which increased torque production.
In most cases, habitual barefoot runners forefoot strike which mechanically provides greater impact reduction than heel striking. Nevertheless, a forefoot strike landing probably accounted for the significant reduction in joint torque observed in the barefoot runners.
The Take Home Message
The long list of joint torque and impact variables associated with the Brooks neutral shoe makes it tempting to draw conclusions that running in a neutral shoe would be less than smart.
Statistical data does not lie, but unfortunately shoe companies do, claiming their shoe technology corrects ‘this’ and ‘that’, enabling you to run safely, allegedly.
Yet, to date, no clinical evidence supports that correctional and protective features, such as heel cushioning, prevents injury, or promotes long-term health in runners.
- It’s Not About Running Barefoot vs Shod Running. It’s About Forefoot Striking vs Heel Striking
- Heel Striking Generates Bone Breaking Repetitive Stress Shocks and Torque
- Heavier Running Shoes Increase Ground-Contact Time and Force Production in Mid-Foot Strikers
- Proper Running Shoes for Forefoot Running
Run forefoot because you are faster than you think!
Franz et al. (2008). The influence of arch supports on knee torques relevant to knee osteoarthritis. Med Sci Sports Exerc 40, 913-7.
Kerrigan et al. (1998). Knee osteoarthritis and high-heeled shoes. Lancet. 9113, 1399-401.
Kerrigan et al. (2005). Moderate-heeled shoes and knee joint torques relevant to the development and progression of knee osteoarthritis. Arch Phys Med Rehabil 86, 871-5.
Kerrigan et al. (2009). The Effect of Running Shoes on Lower Extremity Joint Torques. PM&R 12, 1058-1063.
Reilly, DT and Martens, M. (1972). Experimental analysis of the quadriceps muscle force and patello-femoral joint reaction force for various activities. Acta Orthop Scand 43, 126-37.
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.