Thoughts from the journey… Excerpts from a day in the life of Sherry McLaughlin

6Nov/090

Achilles Tendonitis 501

I am kind of enjoying putting 501 at the end of my blog titles. I realize that is a weird way to start a blog, but at 5:30 in the morning anything can happen.

Today I wanted to talk about an often very misunderstood problem, Achilles Tendonitis. This is #3 on the top 5 running injuries.

Achilles tendonitis is defined as inflammation of the Achilles tendon. Often, the patient will complain of pain along the length of the tendon or at the insertion into the calcaneus. These, in fact, can be two very different problems.

The role of the Achilles tendon is to help decelerate dorsiflexion at the ankle shortly after heel strike by way of the gastroc/soleus complex. During running or stair climbing, forces in the lower extremity can reach upwards of seven times a person's body weight. Due to the shape of the calcaneus and its insertion point, it is also a mild decelerator of pronation of the foot.

If that was all it had to do, then there probably would never be a problem.

To solve the case of Achilles tendonitis, one must look up. Up to the knee, that is. The gastrocnemius muscle plays a role in the transverse plane at the knee, with the lateral head assisting in deceleration of internal rotation of the femur, which also occurs at heel strike. That means the lateral gastrocnemius (LG) is functionally synergistic with the gluteus maximus.

If the gluteus maximus is insufficient or neurologically inhibited (which can happen with trigger points in the iliopsoas or piriformis), then the LG has to work eccentrically at both ends during pronation of the limb. This creates a huge potential overuse scenario and may be classified as an overuse injury.

In common language, your Achilles tendonitis may be injured because of your weak butt!

The other scenario, the one which often causes pain at the insertion on the calcaneus is quite different. Usually, when the weak point of the tendon is its insertion at the calcaneus, this means the Achilles tendon is too tight. Adaptive shortening of the tendon usually occurs with a lack of pronation at the foot...an over supination problem.

When the foot hits the ground, the first contact point is the lateral calcaneus. This helps facilitate a fall into pronation, thereby eccentrically loading the lower extremity muscles. However, in the presence of subtalar joint eversion hypomobility (which may originate in the joint, or be due to a trigger point in the medial gastrocnemius), the weak link becomes the insertion point.

So, to recap. There are at least two possible causes for Achilles tendonitis:

1. Over pronation due to lateral gastroc overload from a weak gluteus maximus. Strengthen the gluteus medius first, then the gluteus maximus (first in the saggital plane) to help take the stress off of the tendon. This also tends to show up in a functionally longer leg (i.e. anteriorly rotated innominate).

2. Over supination due to subtalar joint hypomobility, a leg that feels to short or a medial gastroc tender point. Teach the subtalar joint to evert, lengthen the gluteus medius and load the gluteus maximus first in the transverse plane. If this is the case, ditch the motion control shoes!

In Greek mythology, Achilles was a war hero and the central figure of Homer's Iliad. He was known to be strong, handsome and a mighty warrior. When he was little, his mom, Thetis, tried to make him immortal by dipping him head first into the river, Styx. As a warrior, he was fierce, but he was taken down by an arrow shot through his heel, the only part of his body that didn't get dipped in the river.

I'm not trying to change Greek mythology, but perhaps someone should look into the story. I'm thinking his mom grabbed onto his waist and dipped him in head first...leaving his derriere high and dry.

Until next time...

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