Plantar flexion is a movement in which the top of your foot points away from your leg. You use plantar flexion whenever you stand on the tip of your toes or point your toes.
Every person’s natural range of movement in this position is different. Several muscles control plantar flexion. Any injury to these muscles can limit your range of motion and affect your ability to do activities that require plantar flexion.
You use plantar flexion most when:
- You’re stretching and you point your foot away from you.
- You stand on your tiptoes, like when you’re trying to reach something on a high shelf.
- You press down on the gas pedal of your car.
- You ballet dance on the tips of your toes (on pointe).
To a lesser degree, you also use plantar flexion while walking, running, swimming, dancing, and riding a bicycle.
Plantar flexion involves a coordinated effort between several muscles in your ankle, foot, and leg. These include:
Gastrocnemius: This muscle makes up half of your calf muscle. It runs down the back of your lower leg, from behind your knee to the Achilles tendon in your heel. It’s one of the main muscles involved in plantar flexion.
Soleus: The soleus muscle also plays a major role in plantar flexion. Like the gastrocnemius, it’s one of the calf muscles in the back of the leg. It connects to the Achilles tendon at the heel. You need this muscle to push your foot away from the ground.
Plantaris: This long, thin muscle runs along the back of the leg, from the end of the thighbone down to the Achilles tendon. The plantaris muscle works in conjunction with the Achilles tendon to flex your ankle and knee. You use this muscle every time you stand on your tiptoes.
Flexor hallucis longus: This muscle lies deep inside your leg. It runs down the lower leg all the way to the big toe. It helps you flex your big toe so that you can walk and hold yourself upright while on your tiptoes.
Flexor digitorum longus: This is another one of the deep muscles in the lower leg. It starts out thin, but gradually widens as it moves down the leg. It helps to flex all the toes except for the big toe.
Tibialis posterior: The tibialis posterior is a smaller muscle that lies deep in the lower leg. It’s involved with both plantar flexion and inversion — when you turn the sole of the foot inward toward the other foot.
Peroneus longus: Also called fibularis longus, this muscle runs along the side of the lower leg to the big toe. It works with the tibialis posterior muscle to keep your ankle stable while you stand on tiptoe. It’s involved in both plantar flexion and eversion — when you turn the sole of the foot outward, away from the other foot.
Peroneus brevis: The peroneus brevis, also called the fibularis brevis muscle, is underneath the peroneus longus. “Brevis” means “short” in Latin. The peroneus brevis is shorter than the peroneus longus. It helps keep your foot stable while in plantar flexion.
An injury to any of the muscles that support plantar flexion can limit your ability to flex your foot or stand on tiptoe. Ankle injuries, including sprains and fractures, are one of the most common causes of plantar flexion problems.
These can happen in sports where you have to change direction very quickly — such as basketball — or in activities that involve jumping.
When you injure the muscles or bones of your ankles, the area swells up and becomes inflamed. The swelling limits movement. Depending on how severe the injury is, you might not be able to point your toe or stand on your tiptoes until it heals.
Mild ankle sprains are usually treated with the RICE method:
- Rest your ankle. Don’t put weight on the injured ankle. Use crutches or a brace to help you walk until the injury heals.
- Ice. Cover an ice pack with a cloth and hold it on the injured area for about 20 minutes at a time, several times a day. The cold will bring down the swelling. Use ice for the first 48 hours after an injury.
- Compression. Place an elastic bandage around the injured ankle. This will also help control swelling.
- Elevate. Prop up the injured ankle on a pillow to raise it above the level of your heart. Elevating the injury will help minimize swelling.
Sprains usually heal within a few days or weeks. If the ankle is fractured, you may need to wear a cast. More serious fractures could require surgery to reposition the broken bone. Surgeons sometimes use a plate or screws to hold the bone in place while it heals.
Strengthening the muscles in your ankle, leg, and foot that support plantar flexion will keep your foot flexible, protect your ankle, and prevent future injuries. A physical therapist can teach you how to do these exercises correctly.
Wearing proper footwear can also help you avoid injuries. Get fitted each time you buy a new pair of shoes. Avoid high heels — especially tall, narrow heels that don’t properly support your ankle.
See a podiatrist or orthopedic surgeon for advice on how to keep your feet and ankles healthy and prevent any plantar flexion problems before they can start.