It would seem natural to assume that humans have an innate understanding of walking. However, as demonstrated by rheumatologists at Chicago’s Rush Medical College, through the regular use of footwear, we change our walking patterns. If you've spent most of your life walking in shoes, it might require some effort to recuperate natural human walking patterns.
At the beginning of every normal human stride, you first place the heel of your foot against the ground, a movement known as the heel strike. According to a 2006 study carried out by rheumatologists at Chicago’s Rush Medical College, wearing heavily padded shoes makes the heel strike more forceful. According to Dr. Najia Shakoor, the lead researcher of the investigation, the body collects information about the terrain and makes internal adjustments accordingly, based on the heel strike. As a result, when the cushioning is greater, the strike must use more force. If you walk barefoot after predominantly wearing shoes, you might start out striking the heels too harshly, causing preliminary pain. As you adjust to a more natural gait, you can adopt a gentler heel strike.
The function of the toes changes remarkably between barefoot and walking in shoes. Most shoes are designed with a toe spring, which is a slight upward inclination along the sole, just below the toes. This lets the shoe rock forward as you step. By contrast, in a barefoot gait, you rock forward smoothly to the ball of the foot, lifting your heel off the ground while keeping your toes on the ground. Finally, your toes press down and backward as they lift off, propelling your foot forward.
Another adjustment to normal barefoot walking is the degree to which you must flex your foot. According to William A. Rossi, a doctor of podiatry and a consultant to the footwear industry, the foot flexes 54 degrees, bending principally at the ball of the foot. When you walk with shoes, you reduce that flex by anywhere from 30 percent to 80 percent, depending on the shoe design and the rigidity of the sole. As a result, wearing shoes requires more effort by certain muscles of the foot. On the other hand, walking barefoot for a long time may also require a steep learning curve. In his article "You Walk Wrong" for New York Magazine, Adam Sternbergh reports extreme fatigue during his transition to barefoot walking, with a lightened heel strike and a fuller foot flex.
If you take a break from footwear, the biggest changes to your gait will be observable in your feet. However, the rest of your body will also adapt to the different manner of walking. According to a 1995 study by Free University Berlin and published in the Journal of Biomechanics, walking barefoot dramatically reduces the stress on the hip joints. If you have mobility issues or joint problems, consult with your doctor before making dramatic changes to your walking habits. You might benefit from joining a barefoot hiking group or working with a practitioner of a bodywork modality such as the Feldenkrais method or Alexander technique.