Plantaris tendon

A slender tendon that plays a key role in the motion of the lower leg and foot.

The plantaris tendon is a thin, long tendon that is associated with the plantaris muscle. This muscle is small and located in the posterior compartment of the leg, lying alongside the larger gastrocnemius muscle. The plantaris tendon extends from the muscle belly, travels down the leg, and eventually inserts into the calcaneus, contributing to the Achilles tendon.

Terminologia Anatomica

tendo plantaris

System

Muscular system

Function

The primary function of the plantaris tendon is to assist in movements of the foot and ankle. Although it is relatively small compared to other tendons in the lower leg, it aids in plantar flexion, which is the action of pointing the toes and lowering the heel. This action is crucial for walking, running, and jumping. Additionally, the plantaris tendon provides slight assistance in knee flexion as it crosses the knee joint. While it may not play a dominant role in movement due to its size, the plantaris tendon helps to stabilize the ankle during various activities and provides proprioceptive feedback to the central nervous system, which is essential for coordination and balance.

Location

The plantaris tendon is located in the posterior compartment of the leg. It originates from the plantaris muscle, which typically arises from the lateral supracondylar ridge of the femur, just above the knee joint. The tendon runs between the gastrocnemius and soleus muscles, traveling down the calf before attaching to the calcaneus, or heel bone. It is positioned in close proximity to the Achilles tendon, which is a more prominent structure responsible for connecting the calf muscles to the heel. The length and course of the plantaris tendon can vary among individuals, as it may be considerably long in some and shorter in others.

Did You Know?

The plantaris muscle is sometimes referred to as a vestigial muscle, meaning it may not be essential for modern human function.
Not everyone has a plantaris muscle; about 10-20% of the population may be born without it.
Some athletes, particularly sprinters or jumpers, may have a more developed plantaris tendon, which could enhance their performance.