How to Run: Running with proper biomechanics
The simple question of how do you run is largely unanswered in the running community. You have a bunch of pseudo-guru styles like Pose or Chi, but the key to running correctly to maximize performance is a topic that is largely left to elite coaches or biomechanics experts. As Pete Larson pointed out in his blog. elite coaches like Alberto Salazar extol the benefits of working on running form, but no one has told the masses how. In the following article, it's my goal to unmask the "secrets" and provide the answers. The bulk of this article comes from information gleaned mostly from working with world class track coaches like Tom Tellez and a great High School coach in Gerald Stewert. Throw in some biomechanics classes in undergrad and graduate school and the picture is a little more complete.
The following is an early rough draft excerpt from a potential book I'm trying to get done. if I can figure out how to publish it :). Enjoy.
Running with proper biomechanics:
Distance runners and coaches seem to hate the topic of running form. Most subscribe to the idea that a runner will naturally find his best stride and that stride should not be changed. However, just like throwing a baseball or shooting a basketball, running is a skill that must be learned. The problem with learning how to run is that there are so many wrong ideas out there. This is partly due to the complexity of the process and partly due to a lack of understanding of biomechanics. It’s my belief that the wide range of “correct” ways to run has led to this apathetic attitude towards running form changes by most athletes and coaches.
The argument that running is a natural movement that should not be corrected is easy to dispel. First, we know that even simple outside influences such as what running shoe you where impacts gait dramatically. In a society where we grow up wearing shoes from a young age and spend most of our time walking around on man made surfaces, it is a stretch to think that a decade or more of living in this way does not change our mechanics. Second, if we look at the fields of motor control and motor learning more evidence can be seen. In learning movement we often learn by imitation of what we see and from sensory feedback. Since most people aren’t taking their kids to see world class runners at track meets, we are stuck with seeing the “joggers” in the neighborhood or horribly running players in more popular sports, such as baseball, as our childhood running models. Another method of motor learning is done by using feedback. A simple example is in learning not to touch something hot. The first time a child puts his hand on the hot stove, he learns quickly that wasn’t a good idea. Similarly, if a child develops correctly, he quickly would learn that landing heel first when running is not a good idea. It hurts to over stride and slam your heel down into the ground. But since we grow up wearing heavily cushioned shoes, the cushioning eliminates this negative feedback. There is no longer a consequence for heel striking, so why should we avoid it?
Lastly, motor control studies provide some interesting insights.
In comparing the controlling mechanisms or running and walking in humans and animals, some interesting differences are apparent. In animals such as cats, control at the spinal cord level plays a much larger part than in humans (Duysens & Van de Crommert, 1998). In animals that have spinal lesions, they can regain much of their gait functioning when trained on a treadmill, while humans with spinal lesions can only partially mimic the walking motion. The thought behind this is that humans rely more on a mixture of higher level control in the brain and lower level control in the spinal cord than animals do. Some have hypothesized this means that animal gaits are more reflexive and therefore naturally or instinctually ingrained than humans who rely more on higher level brain control.
The benefits of changing form are enormous. As discussed in the Science section of this book, changes in mechanics can enhance efficiency. Additionally, running correctly can reduce the injury risk, and perhaps most importantly increase basic speed. What I’ve found is that many distance runners who say they have no speed, in reality just don’t know how to use their natural speed. They never learned how to sprint correctly, so it is their mechanics holding them back not their speed. The goal of this section is to outline what proper running form is and note some of the common misconceptions. Unlike most methods of running, the following is based on research, science, observation, and practical experience. It is based on the system of world renowned biomechanics expert and sprint coach Tom Tellez has used for many years in developing gold medalist and world record setting runners, and I am much indebted for the information he provided.
For practical reasons, coaches and scientists separate the running stride into various phases. While this is needed so that the idea can be conceptualized it often promotes a fragmented approach to learning proper biomechanics. Instead, a whole body integrated approach is needed. Looking at the body as a whole is required because of how the body interacts. Every so called phase impacts the next phase, and the movement of one body segment impacts completely different body segments. When looking at running form from a segmented point of view, we are relying on the principle that each segment works in isolation and that is simply not true. Therefore, while breaking the stride into phases allows for better descriptive ability, when looking at how we function when running it is best to look at how the body interacts as a whole.
How to run
To go through the entire running cycle, we’ll start with when foot contact is made and go through the full stride. Foot contact should occur on the outside edge of the foot and depending on speed either at the mid-foot or forefoot. The initial contact on the outside of the foot is generally not felt and instead for practical reasons should be thought of as a simple mid/whole foot landing. Contrary to what most people believe, initial foot contact should not occur on the heel even when running slow. As discussed in the Science section of this book, heel strike results in a higher braking force, reduced elastic energy storage, and a prolonged ground contact. By hitting forefoot or mid-foot the braking action is minimized and the initial impact peak is reduced. Additionally, the landing should occur in a neutral position at the ankle, as that sets up the calf and Achilles for optimal use of elastic energy. Once landing has occurred, it is important to allow the foot to load up. Often, the mistake is made in trying to get the foot off the ground as quickly as possible, but remember that it is when the foot is on the ground when force is transferred into the ground. While having a short ground contact time is beneficial it should be a result of transferring force faster and not getting quick with the foot. Loading up the foot means allowing it to move through the cycle of initial contact to fully supporting the body. Since initial contact is on the outside of the foot, the support will move inwardly. With forefoot strikers, the heel has to settle back and touch the ground to allow for proper loading. Holding the heel off the ground and staying on the forefoot will not allow for the stretch-reflex on the Achilles-calf complex to occur.
After the initial loading phase, propulsion starts to occur and the foot begins to come off the ground. The center of pressure should move towards with the big toe acting as a locking mechanism before the foot leaves the ground. This locking insures that the foot acts as one entire unit, allowing for greater propulsion. Unlike what many suggest, do not try and get any extra propulsion out of pushing off with the toes. It is too late in the running cycle to net any forward propulsion and will instead result in simply making your stride flatter. Instead, the forward propulsion should come from the hip and the foot should be thought of as being along for the ride, which we will discuss shortly. Essentially, once the hip is extended, leave the foot alone.
During this entire process, the calf and Achilles tendon can utilize the stretch shortening cycle and stretch reflex phenomenon. Upon foot contact the Achilles-calf complex goes from a neutral position to fully stretched upon mid-stance and the fully contracted upon toe off. This cycle allows for energy storage upon ground impact and release upon take off. In essence, the complex acts like a spring as it stores energy that comes with ground contact and then releases it when ground contact is broken. A common mistake is to stay too high up on the balls of the feet and never let the heel touch the ground. When this occurs, the Achilles-calf complex is not fully stretched and thus you are losing out on the elastic energy return. Similarly, if a runner is too quick with the foot, meaning they try and rush it off the ground, elastic energy is lost because the foot and Achilles were not properly allowed to store and the release energy. Likewise, the arch in the foot also stores elastic energy as it is initially compressed and then subsequently rebounds. This mechanism happens because of its elastic properties.
While foot contact is occurring, the emphasis in your mechanics should shift to the hip. The extension of the hip is where the power comes from, not from pushing with your toes or other mechanisms which are commonly cited. The hip should be thought to work in a crank like or piston like fashion. This speed and degree of hip extension is what will partially control the speed. A stronger hip extension results in more force application and greater speed, thus how powerfully and rapidly the hip is extended helps control the running speed. Once the hip is extended, the foot will come off the ground and the recovery cycle will begin.
In coming off the ground you are trying to optimize the vertical and horizontal component of the stride. If you think too much horizontally, you will flatten out and not come off the ground, thus losing air time and stride length. If you think too much vertically, you will be high up in the air for too long and almost bounce along, not having a very big stride length. Thus it is important to optimize the angle and extend the hip so that you have a slight bounce in your stride. A good cue for this is to look at the horizon. If it stays flat, you are too horizontal. If it bounces a lot, you are too vertical. The best analogy is to think back to your High School physics class and remember how to get the greatest distance when firing a cannon ball. The angle has to be optimized, not minimized.
Once the hip has extended, the recovery phase starts. When the hip is extended correctly it will result in the working of a stretch reflex mechanism. This is best thought of as a sling shot where you stretch the sling shot back and then let it go. The result will be that it shoots forward very rapidly. The hip works in much the same way. If you extend the hip you are putting it in a stretch position. With the sling shot, if instead of letting it go, you tried to move it forward, the sling shot band would come forward much more slowly. The same applies for the hip.
With the combination of the stretch reflex and the basic passive mechanical properties of the lower leg, the recovery cycle of the leg will happen automatically. The lower leg will lift off the ground and fold so that it comes close to your buttocks (how close depends on the speed you are running) then pass under your hips with the knee leading. Once the knee has led through, the lower leg will unfold and it is then the runner’s job to put it down underneath them. Ideal landing is close to the center of your body and directly underneath the knee.
Trying to actively move the leg through the recovery phase
is another common mistake and will only result in wasted energy and the a slower cycling of the leg through the recovery phase. Two other common mistakes are to try and lift the knees at the end of the recovery cycle and to kick the lower leg to the butt at the beginning of the recovery cycle. Neither idea is sound, as they are essentially like trying to push the sling shot forward in our analogy instead of just letting it go. Active lifting of the knee lengthens the recovery cycle with no added stride length benefits. Instead, the knee should be allowed to cycle through and lift on its own. It should not be forced upwards because that cycle through of the knee is a result of the stretch reflex. Similarly, pulling the lower leg to the butt simply wastes energy as the hamstrings have to be put to work in doing this action. Instead, the folding up of the leg should be thought of as a passive activity. How close the lower leg comes to the butt depends on the amount of hip extension.
This phenomenon may seem strange and is sometimes a hard concept to grasp. After all, who has the patience to not do anything during the recovery phase? But research has demonstrated that both muscle activity during the recovery phase and energy use (the recovery phase only uses 15% of the whole strides energy) show that the leg is largely cycling through entirely because of reflex like phenomenon and passive mechanics.
Research on patients with spinal lesions has demonstrated the effect of the stretch reflex and passive dynamics on gait. Even though the patients have lost the use of their lower legs, if put on a treadmill their legs will work in walking motion as long as hip extension is initiated by someone. If a therapist simply manually extends the hip and then lets it go, the leg will have a slight folding up as it cycles forward automatically. The forward movement and folding up of the leg is a result of the stretch reflex on the hip and passive mechanics. The fact that the leg folds up slightly at all shows that it is a simple mechanical issue and does not occur due to active muscle contraction. As a simple experiment, play around with a simple two jointed object, pushing the top joint forward and see what the lower joint segment does. If it’s moving forward at sufficient velocity, it’s going to fold up because of simple physics and mechanics.
Once the knee has cycled through, the lower leg should drop to the ground so that it hits close to under your center of gravity. When foot contact is made, it should be made where the lower leg is 90 degrees to the ground. This puts it in optimal position for force production. The leg does not extend outwards like is seen in most joggers and there is no reaching for the ground. Reaching out with the lower leg results in over striding and creates a braking action. Another common mistake is people extending the lower leg out slightly and then pulling it back in a paw like action before ground contact. They are trying to get quick with the foot and create a negative acceleration. This is incorrect and does not lead to shorter ground contact times or better positioning for force production. Instead the paw back motion simply engages the hamstrings and other muscles to a greater degree than necessary, thus wasting energy. The leg should simply unfold and drop underneath the runner.
This pawback phenomenon was originally taught because of the idea of trying to create backwards acceleration. This concept does not hold up as the braking forces are still the same upon foot contact. Secondly, the pawback was created through misinterpretation of scientific data. Coaches saw that the hamstrings were active during the latter portion of the in flight recovery phase and assumed that meant the hamstrings were contracting, thus pulling the lower leg back. Instead, the hamstrings were active due to stiffening the muscle-tendon unit in preparation for ground contact and in aiding the slow down of the unfolding of the lower leg. The muscle stiffness manipulation occurs for two reasons, first to absorb elastic energy as a stiff system can utilize elastic energy better, and secondly because of a process called muscle tuning. Muscle tuning is the body’s way of preparing for landing. In essence it acts as an in built cushioning system to minimize the muscle vibrations that occur during landing. The body uses feedback and sensory information to tune the cushioning so that ground reaction forces are essentially the same whether in a cushioned shoe or when running barefoot. When running barefoot, muscle tuning takes place so that the in built cushioning is modulated to absorb more of the force.
So far we have only talked about the lower body, but the lower and upper body is linked together as one unit. The interaction between the upper and lower body plays a very large role. First, you should run with an upright body posture with a very slight lean forward from the ground, not from the waist. The arms and legs should work in a coordinated fashion. When the left leg is forward, the right arm should be forward and vice versa for the left arm and leg. But it goes beyond just the arms and legs working opposition, when they both stop forward and backwards motion is also coordinated. When the arm stops moving forward and is about to reverse direction, the opposite leg should reach its maximum knee height before starting its downward movement. Similarly, when the arm reaches its maximum backwards movement before switching directions and coming forward, the opposite leg and hip should be at their maximum extension backwards.
The arm swing occurs from the shoulders, so that the shoulders do not turn or sway. It is a simple pendulum like forward and backward motion without shoulder sway or the crossing of the arms in front of your body. On the forward upswing the arm angle should decrease slightly with the hands in a relaxed fist. On the backswing they should swing back to just above and behind your hip joint for most running speeds. As the running speed increases, the arm will swing back more, eventually culminating in going back and upwards in sprinting.
The integration of the arms and legs is crucial. A lot of time we see something happening with the leg that is incorrect and immediately work on fixing the problem by adjusting how that particular leg is working. For example, if an athlete extends out with the lower leg, we immediately try and correct them by having them put their foot down sooner. Instead, the problem seen with the leg could simply be the symptom. The real cause could be in the arm swing. A delayed arm swing or one with a hitch in it causes a delay or hitch in the opposite lower leg. If you watch someone run, the arms and legs are timed up so they work perfectly in synch. If the runner has a problem with their arm swing that causes a delay in the typical forward and backward motion, such as turning it inwards or shoulder rotation, then the opposite leg must compensate for this delay. In many cases, the opposite leg extends outwards as a form of compensation. Therefore, it is important to look at the whole body and understand that the arms and legs are synched together and interact so that a problem in one of them, might simply be a way of compensation.
Summary of Running Form:
1. Body Position- upright, slight lean from ground. Head and face relaxed.
2. Feet- As soon as knee comes through, put the foot down underneath you. Land mid or forefoot underneath knee, close to center of the body.
3. Arm stroke- controls rhythm, forward and backwards from the shoulder without side to side rotation
4. Hip extension- extend the hip and then leave it alone.
5. Rhythm- Control rhythm and speed through arm stroke and hip extension.
Changing your mechanics:
Knowing how to run is one thing, but how do you go about changing running form. One popular method is to break the running stride into segments and do drills to improve that segment. However, this method does not work. If you recall, each part of the running cycle impacts the next. The body works as a whole, not as a bunch of different segments. When drills are used, they may mimic visually what happens when running, but that is all. Due to doing drills in isolation, the muscle fiber recruitment pattern is much different. There is little contribution of the stretch reflex, the stretch shortening cycle, or elastic energy storage and return. An example would be the use of butt kicks. When doing the drill, the lower leg kicking to the butt is done by contracting the hamstring. When the lower leg coils up towards the butt when actually running, it’s a result of the hip extension and some stretch reflex, among other contributors. Therefore, the drill has very little actual transfer to the actual running. For this reason, drills are not useful for improving mechanics because they do not replicate the running form biomechanically, neurally, or muscle recruitment wise. Instead running form should be worked on when actually running.
To accomplish this, cues are provided to the runner. A cue is a simple task to focus on while running. Possible examples including putting the feet down, dropping the foot beneath you, extend the hip, or any other cue that helps reinforce proper running technique. What cues are used depends on what problem needs corrected. The athlete should focus on one or two possible cues at a time so that they do not get overwhelmed.
The goal is to ingrain proper running form to the point where they no longer need the cues.
The process of using cues is simple and consists of a trial and error method. The first step is to identify what is wrong with a runner’s stride and then figure out how to change it. This will help identify what cue to focus on. Sometimes when giving cues it helps to overemphasize the point, such as telling a runner to feel like they are putting their feet down behind them when correcting foot strike. Since “normal” is incorrect, such as reaching out and heel striking in this example, sometimes over-correcting is necessary initially.
The athlete should do short strides focusing on one cue at a time. Each stride should be video taped or analyzed by the coach. If after a cue is given, the runner makes a positive change in the running form, then that cue is successful for that athlete and they should focus on that cue until it becomes ingrained. If that particular cue does not result in the desired change, the coach should come up with a slightly different cue, essentially a different way of communicating the desired effect. All runners will respond to a cue slightly differently, that is why it is important to come up with several different ways to say the same thing. An example of several different cue’s to tell a runner who needs to switch from heel striking to a flat foot or mid-foot strike are: put your feet down underneath you; put your feet down behind you; drop the foot as soon as the knee stops going up; when the knee comes through start thinking foot down; feel choppy with your stride.
Once a successful cue is found, then the goal is to ingrain that running style. To do this, start slowly. For distance runners, have the athlete focus for short periods of times during distance runs. Breaking it down into short segments of focusing on form does not make the task feel as daunting for a distance runner. Additionally, during aerobic intervals or rhythm work, have a few intervals where the focus is on running correctly, regardless of time. Also, use strides before or after workouts as a means of getting in some extra form work time to ingrain good mechanics. The last step is transitioning those changes to stressful situations. When running under stress, such as in a race, we tend to revert back to old habits. Having the focus of running with good mechanics during low key competitions or during a time trial setting is a good way to start this transition. As long as it is gradually and consistently worked on, changes in running form can happen.