By now, you’ve probably heard of the importance of stride frequency when it comes to injury prevention.
When you increase your stride frequency, taking more steps per minute, you decrease your stride length (assuming you maintain the same speed). This means you don’t have to do as much mechanical work each step, and a number of studies have connected this with a decreased risk of injury.
It’s also pretty easy to measure and adjust—you can manually count the number of times your foot hits the ground in sixty seconds, and you can use a metronome to precisely adjust your stride frequency.
However, there’s a new avenue in biomechanics research: focusing on stride width in addition to stride length.
The length of your stride is a pretty intuitive concept, but what about width?
Stride width is formally defined as the distance between your heels when each heel is at its lowest point during the stride (i.e. when your foot is on the ground). In practice, you can think of it as the lateral separation between your left and right footprints on the ground when you run.
Higher Risk of IT Band Syndrome
Two recent studies have illuminated the role of stride width in determining the stress on your body when you run. The first was published in 2012 by Stacey Meardon, Samuel Campbell, and Timothy Derrick at the University of Wisconsin-La Crosse and Iowa State University.1 Their study examined the role of step width on the forces in your IT band.
The authors started by recording the biomechanics of fifteen recreational runners during normal running. Next, they had the runners increase or decrease their stride width by adopting a “wider” or “narrower” stance and recorded changes in running mechanics. The difference between the wide, narrow, and normal stride widths was about 3.5 inches each way.
By applying a biomechanical model to the data from the runners’ hip, knee, and ankle mechanics, Meardon, Campbell, and Derrick were able to calculate the change in length of the IT band during the stance phase of running: greater change in length implied a greater strain on the IT band.
The data showed that a narrower stride width created more stress on the IT band.
Though the mechanics of it are a little more complicated than this, it’s easy to visualize how running with a “crossover” stride, where your leg crosses the center of your body when you hit the ground, could stretch out the IT band and put more strain on it.
We have a post on how to correct your crossover gait to reduce IT band problems if you are interested in learning how to make the change.
Other research has indicated that higher IT band strain is associated with a significant increase in your risk for IT band syndrome, so it makes sense to try to avoid running with a stride that is too narrow.2
Higher Tibial Stress
Another paper by two of the same researchers, published in April of last year, investigated how step width could affect stress in your tibia.3 Using a similar experimental design, Meardon and Derrick examined tibial stress in fifteen runners using their normal stride width, then compared it to narrower and wider stride widths.
Again, a wider stride was associated with less stress on the tibia, whereas a narrower stride created more stress on the tibia. Meardon and Derrick proposed that a wider stance prevented the kinds of bending stresses on the tibia that have been connected to stress fractures and shin splints.
Injuries to the tibia and the IT band make up a substantial proportion of running injuries as a whole, so changes in stride width represent a promising new area for treating and preventing running injuries.
This work is still in the early stages, and there are a lot of questions still to be answered. Is there an “ideal” stride width? Is it possible for your stride to be too wide?
Meardon and Derrick cite research that showed increasing your stride width increases the metabolic cost of running, which means that it will probably slow you down a little, but wider strides could also mean dispersing forces elsewhere in the body.
Much like a forefoot strike lowers stress on the knee, shin, and heel, but increases stress on the metatarsals, Achilles, and calf muscles; an increased stride width might also transfer stress away from the IT band and tibia to elsewhere in the legs.
Conclusion
It will take a few years for us to see more research come in on stride width. But while we wait, if you have a history of shin or IT band problems, you might consider positioning your feet further apart when you run, especially if you have what’s known as a “crossover stride.”
Fortunately, you don’t need a biomechanics lab to see whether your feet cross over each other. All you need is a flat stretch of pavement and some water. If you live in a cold climate, a fresh coating of snow will also work!
Splash some water onto the pavement, then run through it at your normal run pace. Continue for long enough to get a set of footprints on dry pavement, then stop and examine them.
Is your left footprint aligned with your right footprint?
To decrease stress on your IT band and tibia, the research suggests that your footprints should overlap only a little bit, if at all. If your footprints cross over each other by several inches, straightening out your footstrike could help reduce your risk of injury.
