The Body

Grown-ups

Calf muscles

Gastrocnemius and soleus, said gas-trok-NEE-mee-us and SOH-lee-us

Your calf muscles on the back of your lower leg lift your heels so you can tiptoe and jump.

Leg muscles work in teams: the front of your thigh straightens your knee and the back bends it. Try Kick! and Tiptoe, or tap a muscle!

Two muscles, one tendon

The gastrocnemius is the rounded muscle you can see near the top of the back of your lower leg. It has two heads, side by side, that make a diamond shape when they squeeze.

Its name comes from Greek words that mean 'belly of the leg,' because it bulges out like a little belly.

Under it is a flatter muscle, the soleus. Its name likely comes from the sole, a flat fish.

At the bottom, both muscles join into one thick cord: your Achilles tendon. It ties onto your heel bone.

Tiptoe!

Try it: stand up and rise onto your tiptoes. Feel the back of your lower leg get hard? Your calves just lifted your whole body!

Every step you take, your calves push off from the ground. They help you skip, jump, hop and dance.

Two different jobs

The two calf muscles share the work in different ways.

The soleus is great at working for a long time without getting tired. It keeps you steady when you stand.

The gastrocnemius gives quick, springy power for jumping and running fast.

The 'second heart'

When you walk, your calf muscles squeeze the veins in your legs. That helps push blood back up toward your heart.

Tiny flaps inside your veins stop the blood from sliding back down, a bit like one-way doors.

Because of this, some people call the calf muscles your 'second heart.' On long car rides, wiggling your feet keeps this pump going.

🤩 Wow facts

  • Gastrocnemius comes from Greek words that mean 'belly of the leg.'
  • Your calf muscles lift your whole body every time you stand on tiptoe.
  • When you walk, your calf muscles squeeze your leg veins and help push blood back up to your heart.
  • Some people call the calf muscles your 'second heart.'
  • The soleus is great for standing a long time. The gastrocnemius gives quick spring for jumps.
  • Both calf muscles pull on the same tendon: the Achilles, the strongest tendon in your body.

💚 Look after it

  • On long car rides, wiggle your feet and point and flex your toes.
  • Jump rope, skip and play hopscotch to keep your calves springy.
  • Stretch your calves: step one foot back, keep that heel down and lean gently into a wall.
  • Wear shoes that fit well for running and sports.

🩹 When something goes wrong

A calf cramp. Sometimes a calf muscle squeezes tight all by itself, even at night. Gently pull your toes up toward your knee and rub the muscle. It usually lets go soon. If cramps happen a lot, tell a grown-up.

Achy legs at night. Some kids get achy legs in the evening or at night. People call these growing pains, though growing isn't really the cause. A grown-up can help you feel better. If the aches are strong or happen in the daytime too, see a doctor.

🙋 Questions kids ask

Why is it called a calf?

It's a very old word. It came into English from Old Norse, the language of the Vikings.

Why do my calves hurt after jumping a lot?

Jumping makes your calves lift your whole body again and again. They're tired and need a rest.

🧠 Quick quiz

Question 1 of 2Which tendon do the calf muscles share?

🔗 It works with

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