Your Screwed Up Joints
For most of us, our bodies don't move the way they should. Our joints are chronically tight and misaligned. As a result, we've lost a huge percentage of our range-of-movement in those joints and our posture sucks. As you might expect, this is a problem.
If you're an athlete, the problem is fairly obvious. Restricted range-of-motion impairs your agility and ability to produce power. No matter what your sport is, these effects will negatively impact your performance. The same applies to yogis, dancers, cross-fitters, etc, etc.
If you're not an athlete (or someone who cares a whole lot about physical performance), the effect of poor posture and range-of-movement might be less obvious - but I promise you, it negatively impacts you. The way we hold our bodies (posture) and the way our bodies move (range-of-movement) have a huge impact on our emotional states and cognitive performance. Obviously, if our bodies are uncomfortable that can make us testy and distract us from focused activities. But even if your body feels generally ok, poor posture and range-of-movement are likely still impacting your emotional states and mental performance. If your posture is slouching, your emotional state and energy levels often follow suit. If your hip joints are tight, you won't move as fluidly as you would if they were loose and strong. When we can move fluidly (i.e. naturally), we feel better, our energy levels are higher and our cognitive performance improves.
How They Got So Screwed
Living in western society has a lot of sneaky ways of causing restricted range-of-motion and bad posture. First and foremost, our muscles and joints operate on a "use it or lose it" basis. If we don't move our joints through their full range on a regular basis, our tissues progressively become shorter and less flexible. A well-rounded stretching regimen like yoga will help, but even yoga doesn't express full range of motion of a lot of the joints (a yoga posture tends to explore a stretch in one direction and then move on to the next posture. there is very little dynamic motion of extended joints and muscles). Finally, if you're stretching the muscles but still doing the things that caused them to be tight in the first place, it's kind of like trying to fill a bucket with a hole in it - you're only going to be un-doing and re-doing the damage and true progress will be slow.
So what's screwing up our joints and muscles so badly? I point to two things: sitting in chairs (instead of crouching as our bodies are meant to do) and wearing shoes. The sitting/crouching debate will be the topic of a future article. For today, let's focus on those joint-wrecking contraptions we all wear on our feet.
What Our Feet Should Be Doing
The human foot is a masterpiece of evolutionary engineering. When we house our feet in modern shoes, it's akin to driving a Porsche in sand - all of the beautiful engineering isn't allowed to work.
When a healthy foot is walking barefoot with good form, a number of things happen with each foot strike. First of all, good form is NOT heel striking, this is an unfortunate post-shoe innovation. We should be striking mid-foot, with a bit more of the weight towards the ball of the foot (see diagram).
As the foot moves through a step, it rolls along the outside edge of the foot and rolls a bit inwards towards the ball of the foot (pronates). The foot flattens a bit at the arch to provide cushioning and then spring for the next step. Then, the toes splay outward for balance and to improve how well we feel the ground we're walking on. The achilles stretches, also providing cushioning and spring for the next step. The diagram and video below illustrate these motions.
The foot as it's supposed to move.
We don't think of them this way, but our feet are designed to be sensory organs. We have over 200,000 nerve endings in our feet for a reason (more than almost anywhere else). Our feet are intended to give us feedback about the ground we're walking on so that our ankles, knees, hips, back, etc. can adjust accordingly. This is called proprioception. Most shoes effectively blindfold for your feet and all of the other joints involved in walking, causing them to adjust improperly to the motion of walking. Unsurprisingly, this creates problems.
Why Modern Shoes Suck
Modern, "technologically advanced" shoes hugely restrict the foot's ability to go through normal range of motion and perform proprioception. Running shoes are loaded with padding and suspension systems, usually with more padding in the heel that in the forefoot. This means the heel is higher than the forefoot, referred to as heel-toe "drop" (not good). Running shoes (and pretty much all shoes) also have narrow toe boxes that prevent the toes from splaying outward (not good). Arch support and "toe spring" (the toe of your running shoe tilts up a bit, preventing your toes from fully grabbing the ground). Both are, unsurprisingly, also not good. On top of that, the full-foot padding also effectively cuts proprioception to zero.
Athletic and casual shoes of other varieties have all of these same issues to different degrees. I shouldn't have to tell you that dress shoes with heels and stiff soles are bad for your feet - your feet probably tell you that.
The Foot Doesn't Exist In A Vacuum
All of these characteristics shared by essentially every shoe in existence take a toll on the foot over time. Arches become weak and inflexible, toes aren't able to splay as far. The achilles and other tendons in the foot become shorter and less flexible. Since most of us have been wearing traditional shoes our whole lives, we're not even aware of how poorly our feet are functioning.
But the foot is only the first part of a complex system that moves in a highly coordinated fashion with each step. The ankles, knees, hips and back all engage in a highly specific manner throughout the walking process. To move properly, these joints take feedback from the foot and engage appropriately according to the type of surface you're walking on and your type of movement. If the foot is not allowed to move naturally, the first part of this complex system is not working properly and any subsequent sections are forced to work improperly as a result. When joints are consistently working improperly, they stiffen and range of motion is lost.
Just as one example, here is the cascade of effects that happen in the body as a result of wearing shoes with a heel-toe drop: Less ankle dorsiflection (extension) is needed, so this ability is lost over time. Knee extension is less needed and is also lost. Hips rotate forward and stiffen in that position. Because the hip is no longer sitting perfectly in the joint and muscles and ligaments tighten accordingly, a huge amount of range-of-motion is lost in the hips. Because hips are rotated forward, lumbar lordosis (the natural curve forward) increases. Again, this leads to muscles tightening around improperly aligned joints (yes, your spine is a series of joints) and loss of range-of-motion. Thoracic curve (mid-back) also increased with similar effects.
These are just the effects of heel-toe drop. Restricted toe splay, impaired arch flex, etc. have their own cascade of negative effects.
The Solution: Barefoot Shoes
Walking barefoot is actually the solution, but since this isn't a practical option for almost anyone, we need the next best thing.
It's important to note that the term "barefoot" is used to refer to a huge number of shoes these days ranging from Vibram FiveFingers and Vivobarefoot - true barefoot shoes, which are more-or-less just a layer of thin, puncture-resistant rubber under your feet - to a shoe like the Nike Free, which has less cushioning and a ton more flex than most running shoes, but still restricts the foot in a lot of ways.
I'll speak to the benefits of "true" barefoot shoes like the Vibrams and Vivobarefoots here. The more a shoe resembles a traditional running shoe (cushion, heel-toe drop, narrow toe-box, etc), the less you'll experience the benefits.
Walking in true barefoot shoes allows the foot to move much closer to it's natural barefoot movement. The foot can flex as it hits the ground, toes can splay, proprioception kicks back in and the foot, ankle, knee and hip are able to react dynamically to walking in a way that was impossible previously. Tendons lengthen and joints begin to return to proper alignment. Because the joints are not tightening out of alignment, flexibility is easier to regain (still have to stretch, though) and range-of-motion improves. When joints are aligned and flexibility improves, posture improves with it.
Easing Into Barefoot
It's important to remember that because you've spent your whole life in cushioned shoes, your feet currently suck. They're weak and they won't flex the way they're supposed to. Going straight to full-on barefoot shoes will be too intense for some people. Your feet will hurt, and because the muscles and tendons in your knees and hips are tight around the walking patterns associated with cushioned shoes, they might not have the necessary flexibility right away.
You can ease into barefoot shoes two ways. One, you can start with an transitional "barefoot" shoe like the Nike Free. This shoe is still quite cushioned, and will be easier on your weak feet and joints. But you'll start to build up strength in the foot because the shoe is considerably more flexible than a normal shoe. If you think you have particularly weak feet or inflexible joints, this might be your best entry point.
Shoes like the New Balance Men's Minimus or Merrell Barefoot offer better entry points unless you have serious concerns about your foot strength and flexibility. Both have minimal heel-toe drop (around 4mm rather than the 12-20mm of a normal running shoe), wide toe boxes and flexible low-stack-height soles.
The other strategy (and the one I recommend) for easing into barefoot shoes, is to go for a full-on barefoot shoe like ones by Vibram FiveFingers and Vivobarefoot and simply wear them only as much as you can without causing major discomfort. Your feet will adapt and you'll be able to wear them more and more over time. Initially, wearing them only every other day (and not when you have to do major walking) is a good way to ease in, strengthen your feet, and return joints to proper alignment gradually.
Learning To Walk Again
Getting rid of your cushioned shoes is certainly essential, but it's only part of the process of fixing your body from the damage of a lifetime of shitty shoes. Leaning to walk properly (or perhaps un-learning to walk poorly) is the other part of the process.
Most of us are heel strikers, which is generally terrible for the foot and all of the other joints that have anything to do with the walking process. Learning to midfoot strike takes time, but the improvements in posture that come as a result of fixing your stride are huge. The video below is for running, but the same general principles apply to midfoot strike walking.