How well are we equipped to run? - 3. Other equipment April 20 2016, 0 Comments
So far, we have looked at the legs and feet, so it is probably time to look at the other anatomical aids we have for long-distance running.
Let's start with breathing. If you watch fast-running four legged animals you can see that at the two extremes of their stride they either stretch or crunch, and this can have a dramatic effect on their breathing.
If you are at full stretch, it is much easier to breathe in than out, and if you are crunched up, exhaling is the most comfortable option. So breathing is linked to pace, and that is an intrinsic limitation. Cheetahs are astonishingly fast, but they run out of puff pretty quickly. Being bipedal enables us to disconnect our breathing from our pace. We may choose to breathe in time with our stride, but if push comes to shove we can double or triple our respiration rate without affecting our running, a handy trick if you want to maintain a pace for a long distance.
Another thing that you will notice with most animals is that they pant to cool themselves down, and this also has limitations. Running generates heat, and if you are pursued by an animal until you cannot cool down as fast or faster than you heat up, eventually you simply have to stop. If the animal pursuing you happens to be homo sapiens, he has the major advantage of being able to sweat across the full breadth of his skin, and the evaporation of the sweat cools him and gives him many more miles of distance before he overheats. The evidence suggests that we were on a high-protein diet (meat) long before we invented tools and weapons, and that running after animals until they simply lay down from exhaustion was how we caught our food.
Finally, in our necks we have a nuchal ligament, something that his found almost exclusively in running animals. It serves to support the weight of the head without muscular effort, and to hold the head still while running.
So the anatomical evidence is looking pretty strong that we were built to run. In the next instalment we shall look at what we can do that supports the man-as-long-distance-runner theory. In the meantime, you might like to have a look at some of ZEMgear shoes that protect your feet but still allow you to run as nature intended.
How well are we equipped to run? - 2. Lower legs and feet. April 12 2016, 0 Comments
From our previous discussion, our upper legs are designed to help us with locomotion on the ground, and I'd like to now build the case that we are actually designed to run.
Casting our attention south to the lower legs and feet, and again comparing with the apes, we can see that we have a very chunky calf muscle and a considerably bigger achilles tendon.
Tendons connect bones to muscles and are elastic, often being placed to absorb and store energy for later use. For walking, where we normally plant the heel and then roll forward on the foot to pushing off into the next step, there doesn't seem to be much need for a large, impact-absorbing tendon. For running, on the other hand, especially if we accept the case for a front-foot landing, the absorption of energy as the heel is lowered warrants a very much larger tendon, such as we have. The elastic energy stored can then be used for the push-off into the next stride.
The case becomes stronger when considered with the structure of the foot. One of our feet has 26 bones, 33 joints and more than 100 muscles. Many of these are located in the arch, which acts as a bridge between the ball and heel of the foot. When we land on the front foot in running, the muscles in the arch and the achilles tendon together tense and absorb the impact of the step so that the heel lands much more lightly. This prevents a jarring impact at the heel being transferred upwards to the ankle and knee and the lower back. One of the best illustrations of this are the videos taken by Dr Daniel Lieberman's group at the skeletal lab at Harvard University. Follow the link for a heel strike. You can see that the total impact of landing is about two and a half times the body weight, when the heel lands about one and a half times the body weight occurs in the first, jarring impact by the heel, shown by a vertical line on the impact/time trace at the bottom.
With a front-foot landing, the impact trace has a much more gradual slope, showing a steady transfer of weight, rather than a sudden one. Furthermore, adding a big wad of padding to the sole of your foot doesn't significantly reduce the sudden impact of a heel strike.
So our calves, achilles tendons and feet are admirably suited to provide us with a cushioned ride during running. And we have other equipment that helps us to run, as we shall discuss in the next blog. In the mean time you might like to check out our ZEMgear shoes, which protect your feet, but allow them and your legs to run as nature intended.
How well are we equipped to run? - 1. Upper legs. April 06 2016, 0 Comments
I'm not talking about shoes or clothing now, but about how we are built and how this helps us to run.
Theory has it that we run because that was how we caught our food. Interestingly, most of our potential food, down to animals as small as rabbits, can run much faster than we can. So our strategy could not be about speed. Rather, it is about stamina. We are reputed to be able to run most other animals to a standstill because of a unique combination of anatomical features. And here, while the evidence is still circumstantial, it is considerable.
Firstly, let's look at how our upper legs are built. If you watch our recent ancestors chimpanzees walk, they are obviously uncomfortable in standing motion on the ground. Their legs come straight down from the hip, which confers a wider range of movement for climbing, but means that they have to rock from side to side to put their centre of gravity over the leg during walking. We, on the other hand, have thigh bones that slope inward so that our legs are already under us and as we walk or run we can transfer weight from one leg to another much more smoothly. Our legs are much longer comparative to our bodies, increasing for us the importance of locomotion over distances.
At the top of our legs are the gluteus maximus muscles, our buttocks, the biggest muscles in the body. Compared to a chimp, they are enormous. They provide the power for both forward movement and agility across the ground and the importance of this for us is very apparent from the size of the muscle. If you have ever played a hard game of squash after a long break, the extreme mobility needed during the game often leads to 'squash buttock', an aching pot that can make a punishment out of sitting down for the next couple of days.
So the upper leg structure suggests that we might be designed to run. We shall continue this anatomical exploration in the next blog or two. In the mean time, feel free to browse our range for shoes that work with our wonderfully designed running bodies.