Differences in Walking and Running: An informative guide for those in pain.

When discussing the gait cycle, you must understand that running isn’t the same as fast walking. The two movements have the same general idea, where the body functions to absorb ground forces upon contact and apply it to a forward propulsion. As we dissect the two movements, you will notice that while walking you always have one foot on the ground, while in running there is a “float” phase, where both feet are in the air. To appreciate the major differences let’s dive a little deeper into the comparison.

First, we must talk about the terminology. A gait cycle or stride, accounts for the events between successive foot contacts to the ground with the same foot. This cycle can be broken into further segments. In walking, the gait is split into a stance phase (time in contact with the ground) and swing phase (time when the foot is off the ground). While running has both a stance and swing phase, it also has a floating period after each of those phases. It is at this point that these two similar movements differ.

Walking is predominantly done in the stance phase relying on more balance and less force production, while running is the opposite and consists of a longer time in swing phase and less time in ground contact. This change in propulsion changes how we contact the ground and is a major controversial topic within the running bio-mechanics world.

A heel strike with a center of gravity forward and a slight flexed hip and knee is what we typically see while walking. This heel contact acts as a natural braking system and transfers more forces to the body, predominantly the knee. As speeds increase and you begin to start running, your center of gravity shifts closer to the body, ideally below you, and a midfoot or forefoot strike becomes more efficient. The change in foot strike reduces braking and uses the elastic recoil of the foot for propulsion. These increased forces in a midfoot or forefoot strike have to go somewhere, and due to the wiping of the foot towards the heel, the ankle and Achilles tendon get the short straw and take the brunt of the load.

We must also take in account the increased ranges of motion seen from walking to running. While you walk there is very little motion at the knees and the majority of motion comes from the hip and ankle. As you transition to running the knee range of motion drastically increases, which, in turn, increases the force produced. Another joint motion that is altered and important for injury prevention is hip extension during toe off. While running you back hip extends further back, while the opposite hip moves into higher degrees of flexion. Hip flexors are key muscles in this movement. If they aren't properly contracting and stretching, they limit the hip extension and don't allow the gluteus muscles to fully do their job. You body adapts to this limited extension and starts to get it via low back extension. Repetitive extension with rotation starts to irritate the lower back and is the major cause of running related back pain. 

Altering Gait with Pain

Understanding the way your foot hits the ground can be useful when dealing with injuries. If you have knee pain try using a midfoot or forefoot strike. Or if you have Achilles or midfoot pain, using a heel strike might be relieving. Another way of altering your gait for injuries can be done through a change in stride length. When you take a larger step, you must use excessive force to take that stride. By reducing the stride length and increasing the step frequency, you naturally reduce the load on your body and become more efficient. With this lessened load, you decrease the chances of overuse injuries.

Proper running progression is another important way to reduce injury or recover properly. Often, injury is associated with too much, too soon. An increase in running distances should be done in a smart and calculated way. If you haven't ran in weeks and then run for 10 miles, chances are your body isn't ready for it and you risk injury. A way to avoid these injuries is to properly scale your runs. Start at a lower distance and slowly add more miles over weeks and months. This technique is seen in marathon training and provides the best adaptation to your new loads. Injury recovery works in the opposite way. If you have areas of pain, then reducing your weekly mileage is for the best. Better to reduce your distance, but still run, rather than keep pushing and eventually having to completely stop to heal. 

Conclusion

After reading this article, you understand that walking and running are fairly different. In summary these differences include:

• Changes in gait with running having a float phase with no feet in contact with the ground and walking always having one foot on the ground. 
• Changes in foot contacts and center of gravity.
• Increased stride lengths and ground force production as speeds increase. 
• Increased joint ranges of motion in running 

The take away message from this is, when preparing to switch from walking to running, you should take in account the increased demand on your body and take note on your training form and distances. Running is a great way to stay healthy, so take control of your movements, listen to your body and plan accordingly.