STUDY TAKES RUNNING IN STRIDE
Key to reducing injuries isn’t switching from heel to forefoot strikes, researchers say
Running should be as simple as putting one foot in front of the other. But somewhere along the way, it became complicated. First came the science behind choosing the right shoe. Then came the science behind choosing no shoes.
And let’s not ignore the ongoing debate about which part of the foot should hit the ground first.
Much of this well-intentioned advice is based on the premise that a mid to forefoot strike reduces the impact stress on runners’ ankles, knees and hips compared to landing heel first.
As a result, there has been an explosion of training techniques and footwear geared toward encouraging heel strikers to change their ways. But for many runners, changing how they run isn’t without its own set of aches and pains as the body adapts to a whole new series of conditions.
Wading into the debate about how runners should run is a team of researchers from the Center for Gait and Motion Analysis in St. Paul, Minn., and Iowa State University. Their goal was to measure the impact of both types of foot strikes on the ankles, knees and hips. For good measure, they included another popular theory in the mix: the suggestion that a shorter stride is easier on the lower extremities than one that is long and loping.
The researchers gathered a group of recreational and competitive runners who logged a minimum of 16 kilometres per week, and asked them to run on a treadmill for three minutes using their natural foot strike and stride while wearing the shoes they normally wear on the run. Then the researchers asked the subjects to run another three minutes, this time using the alternative style of foot strike. Next they were asked to repeat the treadmill runs, but reducing their stride length by five and 10 per cent.
Joint loads and stride length were measured during all protocols. After the testing, runners were asked to fill out a questionnaire on the difficulty of changing the length of their stride.
Similar to what had been discovered in previous studies, the heel strikers experienced greater loads to most of the joints of the lower extremities compared to those who touched down mid to forefoot first. Also confirmed was that the stress of running shifted to the ankles of mid to forefoot strikers, while the outside part of the knee felt the brunt of the load among heel strikers.
But what’s unique to this study is that joint load didn’t ease up when heel strikers became mid to forefoot strikers, even though they were able to successfully incorporate the new technique. This led the researchers to suggest that a simple switch in foot strike is unlikely to result in the desired outcome, which is to reduce the risk of hip and knee injuries among runners.
But that’s not the only discovery they made. They also reported that rear foot strikers who shortened their stride were able to decrease the load on their joints to one similar to mid to forefoot strikers. This led the team to suggest that adopting a shorter stride is “a promising gait retraining intervention that may help runners decrease their joint loads.”
The researchers suggested their findings give credence to the theory that the often-touted decrease in joint load associated with barefoot running is probably due to the adoption of a shorter stride and not to its supposed shift to a mid to forefoot strike.
What does all this mean to the average runner? Well, if you’re one of the many heel strikers, don’t waste your time or effort trying to change how your foot hits the ground. Instead, work on shortening your stride.
How much shorter? The
researchers had their runners take 10 per cent off their stride length, though most runners admitted being more comfortable shortening their stride by half that length.
Also worth noting is that this study finally puts to rest any perceived benefit of running barefoot, as well as the idea that a change in footwear is the answer for heel strikers wanting to become forefoot strikers. Instead, invest your time and energy in shortening your stride while basking in the comfort of your favourite kicks.