By Colby Smith DC
I’ve been getting quite a bit of interest in this topic from patients and even a few friends on this topic. One friend asked if this is just the latest fad or the new path the sport may be heading down. Honestly I wasn’t sure myself, so I decided to dive into the latest research and find out. It has been known for some time now that running shoes do alter foot strike and gait but there still seems to be some debate over what type of foot strike is correct in the first place.
For example, if we just look at the anatomy of the foot, the calcaneous or heel is the largest bone in the foot. This would make one think it had evolved to play the roll of absorbing the impact as the foot struck the ground, especially if we compare it to the size of the mid/forefoot which is made up of many smaller metatarsal bones. There is an old saying “form follows function.”
However, if you have ever walked barefoot you quickly realize that walking in this fashion is very uncomfortable. One study reported that the collision force was actually 1.5 – 3 times the body weight. Foot strike, when barefoot, tends to happen with more plantarflexion (foot pointed downward) as we land on the forefoot/midfoot. This reduces the amount of moving mass during deceleration and lessens the impact forces. It was also observed that average length of each stride was shorter and the ankle’s range of motion was broader which tended to help with energy transfer through the next stages of the gait. This motion through the ankle turns a large portion of the impact force into the normal rotational energy through the rear foot and lower leg. This also helps to load the foot through the arch, setting up for toe off, giving us that nice “spring” in our step. In comparison, when we land heel first the foot is already dorsiflexed (toes lifted up and back) and there is a loss of the rotational movement just mentioned.
Recent studies are not only showing functional changes in the feet but also throughout the entire leg, see the following study results from “The Effect of Running Shoes on Lower Extremity Joint Torques”:
“Knee Flexion Torque: 36% increase in the knee flexion torque with running shoes potentially increases the work of the quadriceps, increases strain through the patella tendon, and increases pressure across the patellofemoral joint.
Knee Varus Torque: 38% increase in the knee varus torque with shoes implies relatively greater compressive loading on the medial tibiofemoral compartment, an anatomical site prone to degenerative joint changes, as compared to the lateral compartment.
Hip Internal Rotation Torque: 54% increase in the hip internal rotation torque may have particularly high clinical relevance given prior findings that indicate that competitive running may elevate the risk of osteoarthritis of the hip joint.”
All this data is compelling and will be beneficial to help runners move toward better function and performance while decreasing the risk of injury. We are already seeing shoe manufacturers trying to account for this as they bring out the latest soft soled shoes that offer very little support but act more like a second skin to protect our feet from debris, glass and the like found alongside the road and trails.
Does this mean we should all discard our shoes? Hardly, shoes are an essential for our modern lives. They provide protection and comfort as we move through our day to day business. However, I believe barefoot running can be a valuable part of our workout routine should be incorporated into it. By training this way, we can translate the optimal functions gained over to our shod gait. You are going to want to slowly transition into this, even if you are a seasoned runner as the biomechanics of the entire lower body is being altered. You will be using muscles differently and putting demands on them that they are not accustomed to – which can set you up for injury if you over do it.
Here are some tips for getting started.
Try walking barefoot first. Go to the park or a grassy area and just walk for an amount of time that feels comfortable to you. You will start to feel sore in places you probably haven’t before.
Alternate between running shoes and barefoot/skins. Do your normal run but at the end switch to barefoot and jog a couple sets of 300-400 ft lengths. Start with 4-5 sets and progressively add a couple more sets till you can do 10 or more. You don’t want to sprint but you do want to move faster than a jog. Then you can try half mile jogs for the first couple of weeks eventually moving up to 1 mile. You can continue to build up your endurance this way, preparing for longer distances.
Train with a partner/trainer. Find someone who is already experienced in this area and learn from them. Use an athletic trainer, coach or someone who knows what they are doing to analyze your gait and help teach proper running techniques.