forefoot

Forefoot striking does not extend a shoe’s life.

Weight on the midsole causes a shoe to die, whether the forefoot or the heel strikes the ground first.

Midsoles are thin and pliable. They are commonly made from about 2/3 of an inch of a material called ethylene vinyl acetate (EVA), which is soft enough to be completely rolled up.

Standing on a midsole places weight on it. The average-sized man and woman in the US will place well over 150 pounds on a midsole. Imagine placing a 100-pound dumbbell on a midsole—on a strip of soft material less than an inch thick. What would happen?

I decided to find out.

 

The midsole under pressure!

 

 

forefoot

 

I measured the highest point of the midsole of one of my shoes. Then I put a 100-pound dumbbell on it so that the length of the dumbbell was perpendicular with the ground. But the dumbbell repeatedly fell off the shoe. So I put one of the dumbbell heads on the shoe while the other head rested on the ground. So, not more than 50 pounds was on the midsole.

The 50 pounds compressed the midsole by 1/16 of an inch.

That’s what weight does to an EVA midsole—it compresses it. When the weight is removed, the midsole rebounds.

How much compression under 100 pounds?

But I weigh a lot more than 100 pounds—I’m closer to 200 pounds than 100 pounds. How much compression under 200 pounds?

When walking, each foot strike is 1.5 times bodyweight. How much compression under 300 pounds?

When running, each foot strike is about 3 times bodyweight. How much compression under 600 pounds?

As the weight on the midsole increases we can assume that the compression increases, perhaps not proportionately, but to some degree. The midsole will rebound but less so over time. At some point, the compression won’t rebound and the shoe will no longer feel comfortable.

 

The same happens during forefoot striking

 

 

forefoot

 

Forefoot striking does not reduce compression. There will still be a weight on the midsole, regardless if the weight is only over the front of the midsole.

And the weight probably won’t just be under the forefoot. When a gait is filmed and reviewed frame by frame, the foot that first strikes at the forefoot normally flattens out after foot strike.

Furthermore, I have seen runners strike the ground with a flat foot although they felt that they were striking on the forefoot.

There is no getting around it: Wearing the shoe will kill a shoe. And the shoe will die at the same rate regardless of the foot strike.

The only good sneaker is a new sneaker that fits. Don’t try to extend the life of a dead shoe. Come to Run and buy a new one!

Posted in

Phil Clark