By now any runner with a social media account would have seen the recent research that linked maximalist shoes (shoes like the Hoka Bondi) and increased external loading forces during running. The implied association is one of a harmful increase in forces generated on impact. Perhaps the maximalist shoe, with its extra cushioning, was inadvertently causing us to generate greater forces on the leg joints and bones? But this research finding is nothing new and it’s not what it seems!
So what does the research say?
Research conducted as early as the mid 1990s found that the properties of the shoe lead to adjustments in running biomechanics. The brain accounted for the shoe’s ability to absorb force and altered the leg position on landing. That’s a fancy way of saying if the shoe is going to provide more cushioning, you don’t need to absorb as much force with the muscles of the leg. This allows you to land with a stiffer leg positions. Vice versa, if the shoe has very little cushioning, you tend to decrease the impact force on the leg by increasing the amount of muscle work on landing. So the overall force may change when we adjust for the shoe but the net force acting on the limb is fairly consisent.
Put in simpler terms, the latest research finding, along with previous research on the topic, confirms that a more cushioned shoe allows you to land with a stiffer leg and not have to work as hard to absorb the impact.
Are maximalist shoes right for me?
If maximalist shoes were being used to decrease shock loading forces on bone, for example to prevent stress fractures, then it’s not necessarily the case due to our altered loading profile. If however maximalist shoes were being used to decrease the amount of muscle work required, particularly during fatigued running in marathons and ultra marathons, then it works a treat.
So before we sensationalize the increase in overall loading based on one study, we need to keep in mind the previous 20+ years worth of research. The results have always found that the brain’s ability to adjust for the shoe’s properties maintain a fairly consistent force profile acting on the body.