Ever experienced pain in your knees, hips, or lower back with running? (Ever had it bad enough that it makes you dread every step?)
You certainly wouldn’t be alone.
Lots of runners experience the same — and we mean lots. Statistics show that up to 80% of runners will experience some form of injury.
There are plenty of factors that contribute to a runner’s risk of injury, but there’s one particular aspect that we’ve consistently seen amongst our runners: the inability to properly control the load placed on their bodies.
It’s not the first thing we think of when we consider training factors, but it should be.
Running is an impact sport, and depending on your workout, it can create anywhere from 2.5 to 5 times your body weight in loading forces. And that happens with every single step, so it’s no small thing. (Even walking 1 mile with double your body weight is pretty intense, let alone multiple miles while running.)
This excess load often affects your joints first. We can’t tell you how many runners we’ve worked with that have complained about feeling it in their knees with every step, or feeling like they need more supportive shoes to help with the jolt of impact.
If you’ve ever thought the same, you’re in the right place! Here’s the breakdown of actionable steps you can take to avoid that joint pain down the line.
How to Decrease Impact Forces with Running
Technically, there are a number of different ways you can approach softer running (plenty of running resources will tell you that). But the true key to decreasing those impact forces and preserving your joint health boils down to one primary aspect of your lower body:
The angle of your knee, particularly during initial contact.
Your knee flexion (the amount of bend in your knee) plays a major role in proper running biomechanics, and it’s an imperative facet of ensuring proper shock absorption and injury prevention.
During initial contact (i.e., when your foot first makes contact with the ground), your body is landing from a free fall (albeit a fairly small one). This is the point where your body experiences the initial impact of loading forces as it bears the sudden brunt of twice your bodyweight.
At this phase of your gait, the straighter your leg, the more impact forces are absorbed by the bony joints of the leg and lower back.
Ideally, the angle of your knee should be around 20 degrees of bend when you land; this will allow for sufficient shock absorption without negatively impacting your performance.
Thankfully, there are two easily accessible techniques to help you achieve these optimal mechanics — and, they benefit your running biomechanics well beyond your knee flexion, as well.
So, let’s get to it!
1. Increase Your Cadence
This technique probably sounds familiar, right?
It’s common for running resources to suggest an increased cadence at one point or another, and for good reason: higher cadence is associated with optimal running biomechanics (and a lower risk of injury!).
If you aren’t already familiar with the term, cadence simply refers to how many steps you take per minute while running. And while step count isn’t necessarily the most important metric for your training, it can provide good insight into the efficiency of your running form.
With a lower step count, your body has to work much harder to cover the distance of your run. This often shows up the common error known as over-stride, where you are quite literally trying to cover more ground with every step to make better time. In the long run, this impacts your body’s ability to properly absorb energy and propel yourself forward more efficiently.
Over-stride is a major contributor to decreased knee flexion (as the error itself typically promotes a straighter knee during initial contact). The less flexion at your knee, the less your muscles are primed for shock absorption, meaning that the passive structures in your body — like your bones and joints — are taking the brunt of the impact forces. (Which is NOT what they were built to do.)
So, a higher cadence is a helpful method for improved form; increasing your step rate by as little as 5% can decrease the forces at your knee by approximately 20%. When your body’s turning over its step cycle at a faster rate, it will naturally bring your point of initial contact closer to your center of gravity and prevent you from overextending your strides. With continued cadence retraining, your knee flexion will increase as well, priming your muscles for optimal shock absorption and contraction.
2. Increase Your Trunk Lean
In tandem with an improved cadence, you’ll also want to focus on improving the degree of your forward trunk lean. (We know, it doesn’t sound like the most intuitive correlation between the knee and the torso… but hear us out.)
Remember that human biomechanics is not just complex, it’s also deeply interconnected — especially within the kinetic chain of your lower extremity. When one biomechanical aspect of your movement is off, it can set off a chain reaction for the rest of your movement, too.
But, there’s a plus side to that; when you improve a part of your movement, it’ll have a positive impact on the rest of your biomechanics, too! Which is exactly what happens with the correlation between the degree of your trunk lean and the degree of your knee flexion.
Here’s the basic idea: when you run with an upright trunk posture, it increases the load on your quadriceps muscles. Because the quads attach to and around the knee joint, this increase in load naturally transfers to the knee and causes excess force and aggravation over time.
So, proper running form demands a slight forward trunk lean to alleviate those misplaced loading forces. By leaning into your run just a little, you end up transferring the workload from your quadriceps back to your gluteal muscles (and the calf muscles, to a certain extent). This will alleviate the strain on your thighs, and consequently, the loading at your knees.
Establishing this slight angle in your trunk is a quick adjustment to your running form that can pay a high return in the long run. As you practice leaning during your runs, keep in mind that the ideal range lands between 8-10 degrees of forward lean. That’s a very specific number, and it’s also not a very big number. To help you achieve the ideal amount of lean, just think about running into a stiff wind, or pretend you’re Clark Kent pulling his shirt open to reveal the Superman “S”.
3. Additional Tips for Softer Running
Focusing on your cadence and trunk lean are the two most effective methods for decreasing the impact on your knees.
Since these solutions are rooted in biomechanics, they have the most long-lasting effects on your entire form. (And, it doesn’t hurt that they don’t take long to implement.) There are, however, a couple of other considerations that may supplement your quest for improved knee flexion:
Listen to how hard your feet land — It seems simple, but it makes sense, right? If you’ve been struggling with joint pain from running, there’s a good chance you can actually observe how hard you’re hitting the ground whenever you land.
The next time you’re on a run (whether it’s out on the pavement or on your treadmill), spend some time trying to listen to your steps. Lots of runners find themselves surprised at how obvious their hard landings sound in the midst of a workout, and simply being aware of the habit can help you make more conscious changes to your form to allow for softer or lighter steps.
Running with a forefoot strike — this one comes with a bit of a caveat. If you’ve ever read up on the best method for foot landing, you’ve likely read about the infamous “heel strike” and how you should avoid it at all costs.
In reality, though, that’s actually a misconception; heel striking itself is not inherently bad. It gets its bad reputation because it’s typically associated with the issue of over-striding, since you’re reaching too far out in front of you and taking on the brunt of the impact forces through your heels and joints.
As runners adapt their form to eliminate over-stride, many of them naturally transition towards a forefoot strike. This is often a result of your foot landing closer to your center of gravity, allowing it to make contact with the ground closer to the ball of your foot and promote a greater degree of knee flexion upon initial contact.
(Keep in mind though: if you still heel strike after you eliminate your over-stride, don’t switch to forefoot running! It’s still entirely possible to run safely with heel strike, and changing your foot strike beyond what’s needed can exacerbate your running biomechanics in the long-term. Essentially, don’t switch to forefoot for the pure sake of it, but if you happen to become a forefoot runner while fixing your overstride, don’t fight it!)
Train Hard, Run Soft
Running pain covers a wide range of pathologies and biomechanical errors, but pain in the joints is often one that demands more immediate action to remedy. Your muscles and tendons can regenerate and rebuild themselves stronger, but joints can sustain significantly longer term damage if they’re placed under excessive load time and time again.
So, if you’re feeling joint pain with your running workouts, take the time to properly address it. Focus on running lighter and increasing the bend at your knees whenever you land your steps (via those form adjustments mentioned above!).
And if you’re looking for specifics about proper knee flexion, cadence retraining, and optimal trunk lean, you can always consider speaking to our running gait specialists. We provide a comprehensive gait analysis that will help you ensure that you’re running soft enough and side-stepping an increased risk of injury.