Achilles Tendon Injury – causes & treatment By Esther Gallick, HCPC Registered & Chartered Physiotherapist at JRM Physiotherapy. What is the Achilles and what are Achilles tendon injuries? The Achilles is a tendon. A tendon is a rough fibrous cord of tissue that attaches muscles to bone. The Achilles tendon is the thickest and strongest in the body. It attaches the gastrocnemius and soleus muscles (calf muscles) to the calcaneus (heel bone). The Achilles pulls on the heel when the […]