Sitting is the new smoking. Yeah. That and fast food. If you haven’t heard, sitting is bad for you. The research has found decreased life expectancy for those sitting >3 hours a day and increased disc pressure at the lumbar spine, which can result in back pain and accelerated aging of the spine. The research is fairly clear on spine mechanics, but what about it’s effect on your ability to run? As a society we sit more than ever. We sit for breakfast, lunch, dinner, while driving, and for 8+ hours a day as a desk jockey. The sitting posture is a breeding ground for targeted tightness, particularly in the hips and thoracic spine. And although there’s no research (that I can find) proving that sitting can be a risk factor for hip flexor tightness, I’m going to run with it (pun intended).

Let’s face it. Our postures are awful. Sure, some are more awful than others, but even those who are sticklers about the way they sit are still forcing themselves into poor positioning. Regardless of good or bad posture, the hips and spine are forced to flex. There’s no way around it. If you’re sitting right now take a look at your pants. See the creases on the front? The tautness on the back? Now stand up. See how creases disappear? Well, unfortunately our body doesn’t follow suit. Like the front of our pants, our front muscles (hip flexors) slacken when we sit. Over time the tissue may adaptively shorten–the same way an ankle cast causes extreme stiffness upon removal. Sitting over the course of your career begins to add up.

The glutes are sexy. They get the limelight and all the press, but without a hip flexor you’ll be going nowhere fast–literally. Although our hip flexors aren’t propellers of motion, they have the ability to dampen the effectiveness of those who are. Hip flexors have an open door policy for compensation. Again, if you’re sitting a lot, there’s a good chance you’re hip flexors will adaptively shorten. Acquired compensations from shortened muscles will transform how you move (for the worse). Compensations become hard wired into the nervous system, forming habits, and leaking energy with every step. Leakage dampens your power output, which translates to being slower (boo).

Your body could really care less about your ambitions. The goal of the neuromuscular system is never task efficiency, but task completion. If you want to run the neuromuscular system, a two way street between the brain and muscles, will get you to put one foot in front of the other. Again, the task will be completed, but it may be accomplished with some compromise to efficiency. The body performs movement based on what’s available. The hip flexors, comprising of of three muscles (iliacus, psoas major, and psoas minor) are a breeding ground for compensations. With a diffuse attachment through the low back and pelvis, hip flexor tightness can cause an array of compensations as you progress towards push off.

Following the Path of Least Resistance

Attaching to the lumbar spine and pelvis, a tight hip flexor can influence both areas as you progress from midstance to push off. Remember, your body always follows the path of least resistance. Even as the hip flexor draws taut, the leg will continue to progress backwards. Without sufficient flexibility the body will find length through compensation. The path of least resistance is often an ugly, dirty path marked with unwanted spine and pelvis movement. A tight hip flexor(s) will cause your pelvis anterior tilt or backwards rotate to gain range of motion, both of which are not ideal. Sure, these motions can keep you strolling down the road, but they’re slowing you down and often risking your health.

Learn how sitting affects us and three stretches to unlock your hip:

The key here is to address the tightness (if it’s there). Try the stretches highlighted in the above video. They’ll teach your to find the tightness, while stretching the hip flexor in three planes of motion.