Form is determined by function… and function by design.
The Human foot
The human foot is a masterpiece of 2 million years of evolution.
As a result of standing on two feet, we developed an ‘s’ shaped spine, large hip muscles, short parallel toes, straight legs and long tendons, when we compare ourselves to other primates.
These adaptations to our physical form occurred under the constant stimulus of gravity and have resulted in a wonderfully complex yet adjustable foot.
Challenges that we faced were the forces applied on the physical body as our speed of bipedal locomotion increased. The human foot has evolved an adjustable system, allowing our feet to execute three very distinct forms of locomotion: WALKING, RUNNING and SPRINTING.
Walking Running Sprinting
When we walk, the foot and ankle create three ‘rockers’, or pivot points. These work together to allow smooth horizontal displacement of the body’s centre of mass. This is the classic ‘heel-toe’ biomechanical behaviour.
When we run, the foot’s mechanical behaviour essentially reverses. Instead of landing on the heels, we land on the ball of the foot and then the heel. Using the elastic recoil of the Achilles tendon, the plantar fascia (a supportive tissue) and ligaments, our foot and ankle work like a powerful spring. This elasticity greatly reduces the amount of energy required to run and is used by all animals, especially ‘running specialists’ like horses and dogs. In fact, these animals have taken this feature even further; only the toes or forefoot touches the ground and a tendon runs up the whole lower leg.
When we sprint, we actually use a very similar forefoot landing technique – touching the ground with only the ball of the foot
So What about Jogging?
Jogging is a modern invention!
The typical jogging style is a combination of the heel-toe walking movement but done at a running speed. This, slow, sticky heel-strike is not a natural movement and is responsible for countless runners’ injuries.
As we speed up our locomotion from a walk to a run, our feet are meant to let us know when to change from landing on our heel to landing on our forefoot. Proprioceptive feedback from the feet informs the brain of the forces encountered (plantar pressure) and triggers a change to the most appropriate form of locomotion.
In other words, it hurts to heel-strike? in the walking pattern so we switch to the running pattern. All animals use a similar sensory cue to change locomotive patterns. However, padded running shoes restrict our foot’s sensory feedback and stop the movement hurting.
Because the heel-toe movement is only designed to cope with the relatively light forces that are present when we walk, using that same form of locomotion as a way to run leads to lots of potential injuries throughout the body.
Using your running anatomy unnaturally or beyond its structural capabilities is a root cause of all running injuries.
Did you know that we’re more likely to injure ourselves on soft surfaces than hard ones?
It makes no difference whether you’re in conventional trainers, minimalist shoes or barefoot…softer surfaces reduce the efficiency of our elastic recoil and cause excessive muscle activity…one of the main causes of runners’ injuries.
We are designed to run… now learn to