Tendinitis of the Achilles tendon touches the strongest tendon in the body that connects the heel to the muscles of the leg.
By its structure and function, the Achilles tendon is frequently subject of acute or chronic hurts. Are described in the literature causes relating to a repetition of load-involving efforts. In fact, these dysfunctions are usually multifactorial, result from a combination of intrinsic and extrinsic factors.
Anatomically, the Achilles tendon is the distal tendon of the tricep sural muscle. The tendon fibers arise from the junction of medial and lateral gastrocnemius muscles (poly-articular muscles) with the soleus muscle (monoarticular). They follow the superficial posterior part of the lower half of the leg, about 15 cm posterior to the edge of the calcaneus. The structure of the tendon is composed of two blades, the first most posterior end of the gastrocnemius and the second, deeper after being in the soleus muscle, describes a 90 ° twist from top to bottom and back to the inside. It is the largest tendon in the human body, it is able to withstand during running (a speed of 6.5 m / s) a load equal to 12 times the body weight.
According to EMG studies, internal gastrocnemius muscle is most active during running, which explains its volume. With their poly-articular insertions, gastrocnemius have a mainly dynamic motor activity, versus the fibers of the Soleus muscle group which have similar characteristics to those of the majority of tonic fibers, type I, corresponding to a static motor function.
Studies of the Achille tendon’s microvasculature indicate that its portion positionned 1.5 to 7 cm from the calcaneus is relatively poorly vascularized.
Indeed arterioles are numerous in the immediate proximity of the osteo-tendinous junction. This has for consequence the appearence in this poorly vascularized area of degenerative process, inflammatory or not, an even ruptures. In addition to the tendon structure, this anatomical area may present various pain syndromes that must not be confused, such as retro-calcaneenne bursitis, pre-calcaneenne bursitis or Achilles insertion tendinitis.
They appear frequently during repeated movements of friction in cases such as using an inappropriate shoe. Concurrently, some anatomical peculiarities located on the posterior banks of the calcaneus called “deformations of Haglund” can also be the origin of these inflammatory diseases.
It is usually caused by running uphill or downhill, jumps and sports that require sudden starts and stops. Wearing shoes with a flexible heel or a very rigid sole can also promote this disease, especially in patients prone to sprains.
6 March 2018 - 10 h 21 min