The achilles tendon bridges the gap between the calf muscle and the calcaneus and is the largest tendon in your body. An achilles tendon injury can happen to anyone, whether you’re an athlete or just going about your everyday life.
The range of pain can stretch from a faint pulling pain to a severe burning pain. If the tendon is torn you will hear a loud sound and can dig into the tendon with your fingers without much resistence.
Possible causes of problems:
Starting without warming up, in combination with an abrupt acceleration, is very often the cause of a pulled achilles tendon.
Solution: Use a kineo tape and support the tendon. I have found DMSO cream to be exceptionally good in cases of inflamations.
The wrong shoe
The right shoe is very important. Every runner has a different foot. Some are pronating (the foot turns more inward than normal), while others are supinating (foot is rotating outwards), while others have a normal foot. If you are a strong “pronator" or "supinator" and you run for a long time with the wrong shoe, your Achilles gets an extra challenge and you might end up with an irritation.
Solution: Get the right shoe! Some shoes have an enforced medial part of their sole and are made for “pronators”, some have it lateral (“supinators”), while others have just a normal sole. It is also good to have different brands of shoe, so that you are not getting the same pressures on your foot every day. A change of shoe model places a slightly different stress on your foot than what went before.
Heelbox pushing against tendon
If you are running in a multiday race so many small issues can build up over days and weeks, culmninating in a problem. For example the upper end of the heel box can push against your tendon. This small irritation does not have any effect if you run your everyday 10km run, but if you run for 50-100km for few days in a multiday race it can cause a problem.
Solution: cut the upper part of the top heel box, removing the two 'peaks' at the top
Not enough drop in the shoe
Some shoes have a zero drop or a a 2-4mm drop. If you are not used to this kind of drop, this can strain the achilles tendon and can create problems.
Solution: If you feel the pull, put something under the heel to lift it up. You can buy silicon wedges or simply use some cardboard, cut into a 'D' shape to fit the heel and then placed under the insole. You may need to use 2 or 3 pieces of cardboard taped together, of different sizes to create a gradual rise towards the back of the heel.
The calcaneus can shift during a longer race and can cause an irritation of the tendon. One year, I had Achilles problems for a few days, and I could not figure out what the cause was. One of the other runners asked his chiropractor, who said said that my calceneus was moving and that this was the cause of the irritation of the Achilles.
Solution: Tape your foot starting on top of the foot and continue in a '8' shape around the heel and back to the top. That helps to keep the calcaneus in place.
Ongoing cramps in the calves can create a pull on the tendon and cause problems.
Solution: Find the cause of the cramps (for example a lack of Magnesium) and also elevate your heel.
As the last point I would like to add a story from one of my 700 mile races.
I was 8 days into the race and doing really good according to my standards. Suddenly my achilles tendon started to swell and nearly doubled in size. I went to the medical tent and luckily there was a kineseologist, who checked me out. Suddenly he said, that the problem comes from my bladder. I have too much tension and I have to let go of that tension. He told me that there is an energetic connection from the bladder to the tendon. He gave me a homeopathic remedy and within a few hours the swelling was gone, despite the fact that I had been running the whole time.
The general point here is that our physical well-being is very much connected with our thoughts...the longer the races get, the more importance you have to give to this aspect.