Running is one of the oldest defining physical capabilities of what it means to be human. For centuries, running has served purpose as a means for locomotion, hunting and gathering, physical activity, competition and recreational enjoyment. In the last few decades however, the desire to run further, faster and more frequently has contributed to a relatively high general incidence of injury.
Technological advances in elements like running shoe design, body-monitoring systems (heart rate monitors, pedometers, metronomes), GPS watches and more accessories have sought to improve performance and reduce injury rates. Yet, injury rates have remained relatively unchanged despite these innovations. It has been suggested that between 27-70% of runners will become injured in any one year period. This post will help to digest some of the current trends in the running world and provide some simple suggestions as to what the medical research suggests in order to reduce the occurrence of injury.
If you are runner, in any capacity, you have likely heard talk of barefoot or minimal running. For the past two decades, tossing out your standard running shoes and their inherently elevated, cushioned heel has been suggested as the Holy Grail for injury prevention. It’s been suggested that a shoe (or shoe-like covering) that brings the heel close to the ground and discards the “injury causing” cushioned mid sole can bring the muscles in the feet to life in order to revive the body’s natural ability to support and cushion the impact forces associated with running. The theory goes that if the body can support itself, why would we need running shoes? While this could be debated all day, it’s important to consider elements like running mechanics when putting this theory into practice; vital changes in such running mechanics must accompany any transition to minimalist or barefoot running.
Many reports attribute the evolution of the cushioning and support features in modern running shoes to have resulted in a change to the way in which we run. One change is an increased running stride length, which in turn, results in a more impactful heel strike. Further to this, when stride length increases, it has also been reported to result in a more straightened knee posture at impact, therefore reducing the body’s natural ability to absorb the impact through knee flexion.
With this in mind, many barefoot supporters suggested that simply pitching the shoes would cause the runner to revert back to a more natural running gait, owning to the fact that the runner would have to learn to cushion these impact forces on his or her own accord. For many barefoot advocates, that was where the story ended, toss the “normal” shoes and your gait will revert back to its “normal” or “natural” state, no questions asked. As is often the case, there is more to the story!
What does the Research Say?
When trends such as barefoot running emerge, it often takes research a few years to catch up and be able to provide a true understanding of what is happening. With barefoot and minimal running, it has just been in the last five to eight years that researchers have been able to measure things like impact forces and joint forces (moments) while running barefoot versus in shoes, and while running with a heel strike instead of a forefoot or midfoot strike. One of the most significant findings came in 2010 in a study led by Dr. Daniel E. Lieberman.Lieberman et al. found that landing with a mid or forefoot strike while running resulted in reduced impact forces, compared to when landing with a heel strike. The researchers attributed this to increased movements of the ankle and knee joints in order to absorb the impact forces associated with striking the ground.
This makes sense when we think about using the joints and muscles in the lower limb to help absorb the force of impact. To do this however, requires a very calculated and controlled stride. When the foot contacts the ground (either with the mid or forefoot), the calf muscles are used to control the lowering of the heel onto the ground (one of the key components of absorbing the impact force) and then again to forcefully push off the ground. Research was finally able to provide empirical evidence that barefoot/minimalist running reduces some of the harmful impact forces associated with running. Moreover, changing to a midfoot or forefoot strike changes a runner’s gait—this lends importance to the role of gait retraining. Additionally, focus must be concentrated on improving strength and endurance in order to effectively sustain these changes.
While forefoot or midfoot striking has been shown to aid with shock absorption, it also results in an increased demand or workload on the calf muscles needed to perform and sustain this style of running. Many observational studies have shown that a good majority of runners who start a marathon with a forefoot strike pattern often transition to a rear foot strike part way through the race and maintain it through the finish line. The simple explanation for this is muscular fatigue. As reported, forefoot-striking increases the demand placed on the calf muscles in order to absorb impact forces, so when the calf muscles reach fatigue, they simply aren’t able to sustain this style of gait and runners revert back to a heel strike.
So where do we take it from here? The answer is, there isn’t one simple solution that is applicable all individuals. Each person has intricacies that make their gait and running stride unique, necessitating an equally unique approach to training. One easily applicable and well cited improvement to running gait is to focus on stride length and cadence. Aiming to shorten your running stride length and intern, increase your stride rate (cadence), has been shown to reduce the impact each time your foot makes initial contact with the ground. If you are looking to make a change to your training regiment or running style, it is a good idea to do so with some educated guidance. The gait experts at SoleScience will be more than happy to assist by offering their unparalleled preventative advice, as well as any tools or further referrals to alleviate any present pain.