Feet are a masterpiece of engineering perfectly designed to support a healthy, strong, lean, agile, nimble and pain-free body.
Healthy footwear should have no negative impact on our health, while poorly-designed footwear can lead to unhealthy posture and even injury.
A Look At The Arch
The arch is among the strongest of all weight-bearing structures and has appeared in nature and in architecture for all of time. Most people using arch support believe it to be a way to solve their podiatry issues. The truth is, orthotics are nothing more than a crutch that prevent your foot from doing its job properly. 
Yes, you might feel less pain wearing orthotics, but this is because the artificial arch is artificially locking your foot and preventing your foot muscles from moving. These muscles become weaker, old injuries never heal, and you're put at an even higher risk for future injuries. 
The entire weight of our body rests on the arches in our feet, which were designed to handle this load. When you load the arch from the top, as intended, it causes all parts to mesh together tighter, increasing structural integrity.
In addition to arch support, most modern footwear is constructed with cushioned soles and a raised heel.
Raised heels & narrow toe-boxes can lead to overextended posture.
Whether it’s a 1/4-inch heel on a pair of loafers or 3-inches on a pair of boots, heel lift shifts your weight forward onto the balls of your feet. This shifts your hips forward and over-extends your back, which leads to pain, injury, and in extreme cases: permanent joint damage. 
A responsive and tactile sole allows your foot to sense all the texture it was designed to experience.
Thick, cushioned soles also deprive your feet and body of biofeedback (sensory input from feeling the ground). The sole of the foot is richly covered with some 1,300 nerve endings per square inch -- making them crave texture! The foot is the vital link between the person and the Earth, which could be thought of as a kind of radar-sonic base.
Along with elevated heels, cushioned soles encourage you to take big strides and land with most of your weight on your heels. This constant and unnaturally forceful impact radiates up your knees, hips, spine and even to your neck. A proper barefoot stride actually starts as you step down with your pinky toe; and your heel landing last. 
Your Footwear Matters
Most modern shoes prevent natural movement of the foot, which causes the lower body to atrophy and deadens proprioception. Minimalist footwear uses less assistive technology and provides ample foot freedom and biofeedback, allowing for more natural movement and development of the feet. Your feet affect all of your other moments and are the lowest hanging fruit to leverage a healthy lifestyle.
When barefoot or in minimalist footwear, our feet can sense the environment underfoot, and react precisely to the complex multitude of different conditions. Earth Runners sandals strive to strike a fine balance of freedom and security. They allow maximal freedom for natural movement, proprioception and full-range of motion, while offering the security to adventure to your sole's content, (mostly) barefoot.
1. Lieberman et. al. Foot strike patterns and collision forces in habitually barefoot versus shod runners. Nature. 2010 28;463(7280):531-5.