06 Nov Runner’s and Athlete’s Achilles Heel
A common injury for endurance athletes is “Achilles tendonitis”. Runner’s and Triathletes are frequently affected. To be fair, for most of these athletes this is an umbrella term that does not accurately describe the actual structures involved. In most cases, it really isn’t a tendonitis as “itis” implies acute inflammation such as that occurring after an acute ankle sprain or fracture or muscle tear. With many so called ” Achilles tendonitis ” cases, the injury is often a repetitive strain injury that occurs over time due to the accumulation of microtrauma from running and to a lesser degree from cycling. A more accurate description is tendinosis which means chronic degenerative changes occurring in the tendon from prolonged repetitive use. In these cases the usual “RICE” treatments and anti-inflammatory medications are not very helpful. The reason is there is not an acute inflammatory process involved. What has happened is the body developed some “strain” to the soft tissues around the heel, maybe even the Achilles tendon itself. The body’s initial response to microtrauma and even more significant tearing or sprain type injuries is to form scar tissue. This scar tissue is made up of type III collagen which is inelastic and different from the normal type I collagen present in our muscles and tendons. Over time with exercise and activity this area of scar tissue continues to be irritated, resulting in more scar tissue formation and reduced blood flow. Decreased blood flow causes decreased oxygenation of the tissues which is a catalyst for more fibrous scar tissue formation. Dr. William Brady has written about this in his blog “Hypoxic Fibrous Adhesion Production“. This cycle becomes perpetual without proper treatment. At Potomac Physical Medicine, we use the LightForce Pro Deep Tissue Laser. This high tech Class IV laser speeds healing by increasing circulation and oxygenation to the tissue at the cellular level. Bottom line is this laser delivers more energy, deeper to assist the body in healing faster and better. Stretching alone does not effectively release the tissue. Imagine tying a knot in a shoe string and then attempting to stretch the ends of the string apart. What would result is the knot getting tighter. And that is exactly what happens when you attempt to stretch a muscle that has scar tissue in it or when two or more muscles are stuck together. With regard to “Achilles tendonitis” or tendinosis, often times the Achilles tendon is not the real culprit. There are three muscles in the deep compartment of the posterior lower leg, the flexor hallicus longus, tibialis posterior, and flexor digitorum longus. The FHL is responsible for flexing the big toe during toe off. The FDL is involved in flexing the other toes and for gripping during gait and running. The tibialis posterior is essential for supporting the medial longitudinal arch of the foot. Overtime with running these muscle can get overused, and eventually tighten and develop scar tissue. This is especially true with runners who overpronate(flat feet), or who have rigid supinated(high arched) feet, or runners who have a combination of the two. These faults often result in twisting of the foot during running and gait and cause repetitive stress to the muscles of the lower leg and arch. What happens as these deep posterior tibial muscles become tightened is that they rub against the back of the soleus tendon and the Achilles tendon. This can result in irritation of the fascia around the tendons, causing more friction, ultimately leading to pain. This friction may occur only after so many miles after a threshold is reached. This is why some people only have pain after running for a certain distance. If the problem is bad enough, you may experience pain immediately after you start your run. The pictures below show the layers of muscle, from superficial to deep: Gastrocnemius, soleus, then the deep layer made up of flexor digitorum, tibialis posterior, and flexor hallicus longus. It is this deep layer most commonly injured in runners resulting in shin splints and “Achilles tendonitis”. 
Posterior tibialis
You can see in this picture that there are 3 layers of muscle beneath the plantar fascia, and these muscles are frequently injured from overuse and are scarred up. It is these musclles that result in plantar fasciitis. The muscle on the front of the shin, the tibialis anterior works together with the tibialis posterior to form a sling that supports the arch of the foot. These muscles are often overworked due to faulty foot and ankle mechanics and can result in shin splints. Bottom line is stretching the calves will not solve this problem. Using a foam roller can improve tissue quality and even using a frozen water bottle to roll the arch of the foot will help. These help to improve the tissue density and stiffness and loosen the tissue so that you can get more stretching when you stretch. And you should stretch. What you are actually stretching is the fascia that covers all the individual muscle fibers that make up each muscle, fascia covers the entire muscles themselves, and fascia connect muscles together in a series of lines to create synchronized movement. Fascia connects tendons deep into bones and envelops all our soft tissues. The fascia is heavily innervated by proprioceptors(little nerve receptors that relay information about positioning to your brain) and nociceptors(pain nerve fibers). So the fascia is an important structure in human movement and pain.
To learn more about RECOVERY and the best treatments to resolve these injuries, like how Active Release Techniques can effectively and quickly resolve scar tissue and get you back in the game, check out these links:
Movement Prep for Achilles Tendonitis/Plantar Fasciitis
The Pathology and Healing of Tendinosis
Tendonitis, Tendinosis-New Terminology
References
- Kumar V & Ramzi Cotran. Robbins Basic Pathology 7thed. Elsevier; pp 69-77.
- Falanga V, & Kirsner RS. Low oxygen stimulates proliferation of fibroblasts seeded as single cells. J of Cellular Physiology. 1993 Mar; 154(3):506-10.
- Leahy PM, Active Release Techniques: Soft Tissue Management System. 2nd Ed. 2008; pp 8-16.
- www.activerelease.com
- Hinz, B. The myofibroblast: paradigm for a mechanically active cell. J of Biomechanics 2010 Jan 5;43(1):146-55.
- 6. The First International Fascia Research Congress. 2007 Harvard Medical School www.fascia2007.com
- 3. The Second International Fascia Research Congress. 2009 Vrije Universiteit http://www.fasciacongress.org/2009/