Are your shoes to blame for your achy back?
Unhealthy shoes can cause problems well above your foot - in your legs, back, and shoulders.
Natural Standing and Walking
Before discussing shoes, let’s first talk about how we should stand and walk naturally. When I say “natural” I’m referring to the ideal way a person should walk or stand - this is different from “normal” which just means that a person walks like most other people, which may or may not be ideal or “natural”.
Natural = Ideal
Normal = an accepted standard or average
When barefoot, our weight is balanced equally front to back on the foot. The front of the foot equally distributes your weight laterally across the foot. Standing barefoot also allows the ankles, knees, hips, spine, and shoulders to naturally align to create our upright posture.
Walking barefoot allows you to sense the ground and react to it. During natural gait (without shoes), the heel strikes the ground first – with the middle of the heel making initial contact with the ground. Next, our foot uses its flexible motion to contact the ground as follows: heel -> lateral (outside) edge -> ball -> big toe which pushes off to end that portion of the gait cycle.
Now that we have a better understanding of how natural stance and gait are supposed to occur. Let’s look at how shoes can interfere with natural gait.
Heels
Heels elevate the rear foot and require your ankles, knees, hips, spine, and head adjust to compensate for raising the heel off the ground. Wearing heels for long periods of time can lead to aches in your legs, back, and shoulders.
In addition to visible changes in posture, there are internal effects as well. For example, natural barefoot female forward hip tilt is 25 degrees. Here are the resulting forward hip tilts for females wearing different sized heels:
| Heel Height | Female forward pelvic (hip) tilt |
|---|---|
| 1" | 30 degrees |
| 2" | 45 degrees |
| 3" | 65 degrees |
As you can see, a small change in heel height can have a large impact to hip angle, which affects posture as well as internal organ position.
Impact to Running Stamina
Heels also shorten the Achilles tendon and calf muscles – both of which are important muscles involved in walking, running and contribute to stamina when walking or running. Tight Achilles and calves can negatively impact walking and running performance.
Weight Distribution
Bare feet balance weight equally front to back. As you increase heel height, there is an uneven sharing of the body weight. When wearing a 3” heel, the balance between the ball and heel shifts from 50%/50% to 90% on the ball of the foot and only 10% on heel - now you know why your feet hurt at the end of long say in dress shoes (this applies to men’s shoes too!)
Shoe Design - Toe Spring & Inflare
For a shoe siting flat on the ground, if the toe has an up-tilted toe, this is known as “toe spring.” When barefoot, your foot is naturally flexible, but shoemakers know that their shoes are not as flexible as a bare foot. Instead, they use toe spring to compensate for the shoe’s lack of flexibility at the ball of the foot.
Toe spring pulls the toes away from the ground (between 5-25 degrees) which prevents your toes from “grasping” the ground as you push off. Toe spring also minimizes muscular involvement in walking (since nearly all our feet’s tendons attach at the toe) and results in using fewer foot muscles for walking than should be used and relying on other muscles that wouldn’t be involved in “natural” walking.
Shoes have an internal component, called a last, which forms the shape of the shoe. Natural feet are straight, while the last on most shoes have “inflare” or are bowed slightly inward. As soon as you put them on there is a conflict between the natural shape of your foot and the shape of the shoe. This difference leads to shoes wearing “out of shape” since the shoe and foot were mismatched from the beginning.
Barefoot straightness versus a shoe with inflare
Flexibility
Toe spring can be used to make up for lack of shoe flexibility, but there are problems caused by a shoe’s rigidity.
Lack of flexibility causes you to “push off” from your mid-foot vs your toes. This can cause undue stress on the midfoot and causes unnatural gait. Without the ability to push off correctly, your body recruits your propulsion power from other parts of your body – legs, thighs, hips, and possibly forward lean from your torso. Getting assistance from all these body parts has a cost – unnecessary strain all from helping compensate for poor foot mechanics.
Where Does Your Shoe Flex?
Your bare foot flexes about 55 degrees when walking in natural gait. Most shoes only allow 30-80% of your natural foot flexion at the ball of your foot. One thing to note, most shoes that claim “flexibility” don’t flex at the ball (as they should). However, most shoes flex behind the ball of your foot – which would break your foot if it bent at that point.
Top image - Shoe flexes behind the ball of the foot - BAD
Bottom image - Shoe flexes at the ball, where your foot naturally flexes - GOOD
Narrow Toe Box
Most shoe lack a wide toe box to accommodate your toes comfortably without crowding. This can lead to mechanical deformities (bunions) and contribute to poor balance and gait. Additionally, most people wear tight fighting shoes that don’t allow your foot’s natural expansion to absorb the impact of your bodyweight as you walk.
What can you do?
First and most obviously, minimize your time in shoes! There are numerous benefits outside of foot health and posture from direct contact with the earth.
When selecting a shoe, there are a few things to look for:
Wide toe box
Zero (or near zero) drop
Flexible (at the ball and side-to-side)
Minimal cushioning to enhance your foot’s ability to offer sensory input
Here’s a video covering these topics:
If you have problems caused from wearing crappy shoes:
Change your shoes
Upgrade your foot recovery game - using mobility balls or other tools
Get manual therapy to deal with pain and/or limited movement
Resources:
Why Shoes Make "Normal" Gait Impossible - Dr. William A. Rossi