Understanding the Running Gait Cycle

It could have been in the middle of a race, or on your local trail during a crowded weekend morning. Perhaps you were a spectator during a major event, or watching remotely from your television or computer. At some point, you were struck by just how different everyone looks while they run.

Your footprint is just as unique as your fingerprint. There are as many different gait cycles on display as there are runners on the road. A coach with a good eye can identify their athletes from a distance, based solely on the peculiarities of their gait.

But what do we know about the biomechanical nuances of the gait cycle? Quite a bit actually. Although your individual movement patterns differ (whether slightly or dramatically) from other runners, the underlying principles and concepts of the gait cycle are the same for everyone.

So, what’s going on when you run and why should you care?

Running is all about physics and geometry

To start, it’s important to understand the difference between kinetics and kinematics, which are sub-groups of biomechanics. Kinetics is the discipline that analyzes the forces acting on an object(s), while kinematics refers to the movements of the object(s) in question. It might help to think of it this way: kinetics is physics and kinematics is geometry.

It’s also important to note that the respective gait cycles of running and walking are as different as flamingos and orangutans (I exaggerate, but only slightly), and this discussion is focused on the running gait cycle specifically. We also won’t be discussing the fascinating (in my opinion) biomechanics of the foot itself during the gait cycle, like ankle pronation, arch collapse and toe splay. That’s a conversation for another day, but suffice it to say that what happens inside your shoes is just as important as what happens outside of them.

Finally, we will also necessarily be omitting the counter-balancing movements/rotations of the upper body that allow for the unilateral gait cycle to happen in a smooth, streamlined and metabolically-efficient way. Without rotation of the hips and spine, with a coordinated and opposing arm swing, running would simply be jumping from leg to leg like hopscotch.

A woman runs a race and is photographed in the stance phase of the gait cycle

Running Phases

Phase 1: Stance Phase

Let’s begin with the “stance phase.” The stance phase refers to the portion of the gait cycle when your body makes physical contact with the ground. To keep things simple, we can divide the stance phase into three distinct subsets: initial contact, mid stance and propulsion.

Initial contact:

As the name implies, this is when your foot starts to hit the ground. This can be visualized as the part of the gait cycle where you are cushioning your body, and absorbing the vibrations generated from the ground reaction forces created by your foot strike. For every action there is an equal and opposite reaction (Newton’s third law of motion), and in running these vibratory forces can be up to three times your bodyweight in magnitude. As you hit the ground, your subtalar joint (a joint between two tarsals on your foot) pronates slightly, your knee bends at an angle and your entire leg rotates internally to help absorb the impact and prepare for the next phase.

Coach’s Note: The debate over “heel striking” in pop culture has started to cool off recently, once we realized what scientists knew all along: the part of your foot that makes initial contact with the ground is less important as where that point of contact is in relation to your center of mass. Heel striking is just a symptom of an “over stride,” which places the point of initial contact TOO far in front of the rest of your body. This is why good coaches will always cue you to “lean from the ankles.”

Mid stance:

During the mid stance, your body’s full weight is supported on a single leg while your body moves over your lead foot and prepares for propulsion. These fractions of seconds have a profound impact on both your running economy and your resilience to injury, since you are simultaneously balancing on one leg and setting the stage to push off of that same leg. At mid stance the ankle starts to supinate (move laterally/outward), the foot flattens, the toes splay open and the body “resets” for the next phase.

Coach’s Note: This is why strength-conditioning programs for runners need to incorporate single-leg exercises, since bilateral movement likely leads to compensation by the dominant leg and does not strengthen the leg that needs it the most. Imbalance on the part of the runner will lead to discomfort or injury due to the unilateral loading pattern of the gait cycle.

Propulsion:

During propulsion, your foot starts to lift itself off the ground and stored elastic energy releases and creates a force that helps drive (propel) you forward. Weight is shifted into the front of the foot, your muscles contract and you move up and away from the ground.

The release of stored elastic energy combines with the force you generate and, along with the help of gravity from your “lean,” rockets your body forward and transitions the leg from the stance phase to the “swing phase.”

Coach’s Note: A common mistake often made is that runner’s believe that pushing harder against the ground (ie. exerting more muscular force) will directly translate to a longer stride length and faster pace. In fact, while it IS important for sprinters to be powerful athletes, the distance runner should be a more economical athlete.

It’s metabolically inefficient to attempt powerful muscular contractions over a long period of time. Rather, you should focus on being “fluid” and “smooth” in your movements, which will harness the power of your ligaments, tendons and fascia, not to mention the tremendous amount of stored (elastic) energy you have at your disposal.

Remember Newton’s third law; the ground exerts what’s called a “braking force” when you hit it as a result of the energy you are putting into the ground, but you can harness this “reaction” or “braking force” and use it to your advantage during the propulsion cycle.

A runner in On shoes on a treadmill photographed in the swing phase of running

Phase 2: Swing Phase

Once your foot has left the ground, the leg moves into what is called the “swing phase.” During the walking gait cycle, the swing phase takes slightly less time than the stance phase. When you run, however, the opposite is true, and you spend more time in the air than on the ground.

At toe off, and during the first part of the swing phase, your ankle is plantarflexed (toes pointed down) and your knee is in about 40 degrees of flexion (slightly bent). As your leg moves through the swing phase, the degree of knee flexion becomes greater while your ankle moves into a position of dorsiflexion (toes pointed up) to prepare for the next stance phase.

The hip flexes and extends during the swing phase to move the leg forward. A great visual example of the relationship between the ankle, knee and hip during the swing phase is to picture a horse pawing at the ground with their front leg.

To define our terms, we can say that concentric muscular contractions shorten a muscle while eccentric contractions lengthen the muscles. So for every movement of a joint, there are different muscles acting in different fashions to move that joint through the desired range of motion.

For example, as the degree of flexion in the knee increases the hamstrings are behaving concentrically, while the quadriceps are acting in an eccentric fashion. As you move through the swing phase, the hamstrings will then eccentrically contract while the quadriceps concentrically contract to control the extension of the knee in preparation for landing.

Your glute muscles are also active at the end of the stance phase (propulsion) and at the end of the swing phase right before the foot hits the ground. This is an important fact to recognize, as most runners are predominantly “front wheel drive” machines and try to generate most of their power from the quadriceps. In general, runners should make a sincere effort to activate their glutes and become “rear wheel drive” machines. The glutes are a huge muscle group that can generate a ton of power and are highly resistant to fatigue.

On top of that, they take a little bit of a break during the swing stance of the gait cycle, which means they give you the ability to go further faster with less effort. In order to prime your system for efficient and economical movement during the gait cycle, it helps to perform muscle activation exercises prior to activity. This will not only help warm up your system, but also open up the neuromuscular pathways and allow for better communication between your brain and the rest of your body.

Coach’s Note: An increased stride rate of five to 10 percent more than what a runner typically “prefers” is suggested as a possible strategy to avoid running-related injuries. Most runners tend to “over stride” and purposefully “reach” their legs out in front in order to take longer strides. This results in biomechanically inefficient movement patterns, superfluous loads on the musculature and a compromised position at the initial point of contact. Increasing stride rate, or turnover, tends to eliminate the overstride, which allows the body to move more economically, and the muscles to move efficiently.

A young runner in New Balance spikes in mid-air on the track

Phase Three: Flight Phase

The “flight phase” refers to the time in the running gait cycle when both feet are in the air and the body is no longer in contact with the ground. The primary goal of developing good running biomechanics is to create more power in less time on the ground, and extend the duration of the flight phase.

Coach’s note: Leaping and bounding drills can be a good way to practice this, but you shouldn't try to replicate the leaping/bounding mechanics into your running gait since it would result in an overstride. You can use a short, steep hill to practice leaping drills in a safe fashion, and this will help create shorter ground contact time but a higher rate of force production.

Obviously there is a great deal of nuance in the running gait cycle, and it can be a lot to think about while you’re in the middle of your workout, so I like to cue runners to simply stay “loose and relaxed.” We want to keep things simple, and allow the body to do what the body does best. Overthinking or over analyzing can lead to increased tension and stress, which will compromise your ability to move naturally and fluidly.

Developing a general idea of the kinetics and kinematics involved in running can help you identify weaknesses or imbalances, in addition to helping you troubleshoot pain points or identify areas for development. At the end of the day, your body has its own “preferred path of movement” (the footprint), which is uniquely your own.

I once coached a collegiate runner who we jokingly referred to as “Mario.” This runner had an unmistakably high degree of vertical oscillation (bounce) combined with a slightly dramatic arm swing (hence the nickname). We joked that his “magic mushroom” would be to take the energy used to move his body up, and use it to propel his body forward instead.

But that’s the catch. Dramatically altering your individual gait cycle can place stress or workloads on parts of the body that are unaccustomed or incapable of handling it. You should never try to change your established movement pathways, but simply to streamline or smooth out, what already exists.

Your footprint is just as unique as your fingerprint, so don’t try to mimic the person running beside you in the race. Otherwise, your friends and family might never be able to pick you out of the crowd to cheer you on!

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