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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.


Running on different surfaces September 02 2015, 0 Comments

I grew up in a place where many people went barefoot about their daily lives, and coped effortlessly with stones, gravel and other potentially uncomfortable surfaces. They had a thicker layer of skin on the bottom of their feet, and more padding in their foot soles than you will find amongst shod people living a modern lifestyle. Barefoot shoes work for people who are normally shod during the day, with the sensitivity in their feet that that implies, but still want to run or walk barefoot-style when the opportunity offers.

So how do we cope with different surfaces? We can look at this from the point of view of the quality of the surface, and then the slope. I'm going to start by assuming that you run with a front- or mid-foot strike as explained here - if you cannot help heel-striking in barefoot shoes, you would probably be better going back to standard shoes as explained here .

Soft surfaces such as grass normally do not pose a problem unless it is the hidden stone or doggie-bomb, from both of which barefoot shoes will protect you. It is a common misconception that hard, smooth surfaces such as pavement or tarmac are somehow worse. However, if you are running correctly, the foot and calves are acting to absorb the impact, and you should find it no less comfortable than running on grass. Barefoot shoes allow you to run barefoot-style, but protect the feet from heat, cold and debris such as broken glass. Broken surfaces such as uneven trails and rocks require much more concentration, variation in stride length and direction, and normally a reduction in pace to allow you time to read your path. The feet will be landing at different angles and so if you are early in your barefoot-style running career and have not yet built up the strength in your ankles, feet and legs to cope with this, more caution is advised. If stony/gravelly ground is uncomfortable, shorten your stride so that you are not airborne for so long on each step, and flatten the foot to spread the load.

Running on varying slopes can actually be less tiring than running a long way on the flat as you use slightly different muscle groupings and can rest the ones not being emphasised at that moment. Uphill running is good for working on your front-foot landing as it is pretty difficult to heel-plant when you are leaning into a hill. Going downhill, point your toes and if necessary pick your knees up a little more. I have run alongside someone trying to land on the front-feet with standard shoes, but the padding in the heel did not allow him to point his foot enough. Downhill on stony ground can be pretty uncomfortable because of the higher landing impact on the stones. Two approaches might help here, one being a shorter stride to reduce the impact, and the other being to land with a short slide to dissipate the impact. If it really is uncomfortable, check the wear on your shoes - I have a friend who had worn the soles down to about a millimetre thick and wondered why he was having difficulty coping with the stony ground.

Different surfaces sometimes need different running styles, and quite often we adopt this instinctively, lengthening or shortening stride and landing more or less flatly in order to cope with them.


What is the difference between walking and running? July 07 2015, 0 Comments

Weight transfer in walking does not exceed total body weight as the transition from one foot to the other involves a stage with both feet on the ground. With running, we are airborne for most of the time, so weight transfer includes the impact of landing which is typically two-and-a-half times body weight. The feet and legs have developed to absorb this impact, and cleverly to store energy from the landing for use in the next take-off.