Achilles tendon

The Achilles tendon is a thick, round tendon that transfers force from the calf muscles at the back of the lower leg to the foot. It is the strongest tendon in the body, measuring about 15 cm in length. This tendon enables us to stand on our toes, jump, run, and properly roll off the foot.

The calf muscles and the Achilles tendon

Three muscles attach to the Achilles tendon: the musculus gastrocnemius medialis and lateralis and the musculus soleus. Together, these muscles are known as the musculus triceps surae. These muscles are powerful and have great endurance, enabling them to sustain daily (sports) activities for extended periods.

Gradually, the muscle fibers transition into tendon fibers, which together form the Achilles tendon. The Achilles tendon is firmly attached to the heel bone (calcaneus). Small branches of blood vessels and nerves supply blood flow and sensation to the Achilles tendon.

Around the Achilles tendon, there are two bursae: one between the tendon and the bone, and the other between the tendon and the skin. These bursae ensure that the tendon moves with minimal friction between the skin and bone.

The Achilles tendon can absorb, store, and reuse elastic energy generated by movement, making it highly efficient.

Division of the Achilles tendon

The Achilles tendon consists of three zones:

• Insertion
• Mid-portion
• Muscle-tendon junction

The insertion is the part of the tendon that attaches to the heel bone, marking the transition from tendon tissue to bone tissue. Above the insertion is the mid-portion, which consists purely of tendon tissue. The tendon tissue then merges into the muscle tissue of the calf muscles, forming the muscle-tendon junction.

Disorders of the Achilles tendon

Unfortunately, injuries such as Achilles tendinopathy and a ruptured Achilles tendon are common, especially among runners. These injuries often lead to long-lasting and recurrent complaints.

Make an appointment with a physiotherapist promptly to address your Achilles tendon issues.