When it comes to walking, most of us have a strong preference between walking outdoors, indoors, or on a treadmill. We tend to think these activities are interchangeable from a health perspective, but are they? The surfaces that we walk on change the experience of our body and the muscles that we use.
Walking overground should be powered by the backs of our legs with our torso vertical. In order to propel us forward, our muscles generate a pushing action behind us to push the ground away. On the other hand, a treadmill forces our body to do exactly the opposite, relying on a walking pattern driven by the muscles in the front of the hip and thigh to catch yourself because the “ground” is coming toward you. Therefore, treadmill walking is not the same as walking overground.
So Why Does This Matter?
For most of us, the muscles of the fronts of our hips are already shortened due to time spent sitting every day. Treadmill use encourages further shortening and overuse of these muscles. If you walk using the muscles of the front of the hip rather than the backs of the legs, you really are just falling through space and throwing a leg out in front of you to catch yourself. This is controlled falling rather than walking. Using the muscles at the fronts of the hips to power our walking also encourages a forward leaning of the trunk. This forward leaning alters balance, and can make certain health conditions worse.
We're not trying to demonize the treadmill, but instead bring awareness to the fact that your body has a different experience with one than other types of walking. There are also cases where you would want to avoid treadmill use to avoid contributing to certain health conditions. You should avoid using the treadmill for exercise if you have kyphosis, back pain, balance problems, arthritis, osteoporosis, or pelvic floor dysfunction. The walking pattern created by the use of a treadmill contributes to the underlying biomechanical causes of these problems.
And on a positive note, spaces to walk overground can be found for free while treadmill use requires either investment of owning a treadmill or a gym membership. If you are using a treadmill for exercise and have any of the above listed conditions, we recommend switching to walking on ground whether indoor or outdoors instead. We also recommend a strengthening program for the muscles of the backs of the legs.
Movement is always better than lack of movement, but not all movement is created equal.