What You Should Know About Extensor Tendonitis

We spoke to one of Hoag Orthopedic Institute's foot and ankle surgeons to get information about what extensor tendonitis is, causes, preventions, treatment options and when you should seek help from a medical professional.

Q: What is extensor tendonitis?

A: Almost every muscle in our body is associated with a tendon. The tendon is the terminal portion of muscle that attaches to bone and is responsible for human motion. The extensor tendons in your leg are responsible for lifting your foot during the gait cycle when walking or running.

The extensor tendons connect the bones of your toes to the muscles on the front part of your leg that cross over the ankle joint as tendons. The extensor tendons are what allows you to move your toes. The suffix –itis, in medical jargon, means inflammation or an inflammatory process is present. Extensor tendonitis involves inflammation of those muscle tendons that control lifting (dorsiflexion) the ankle, the big toe, and all the other toes of the foot.

Tendons need to glide over and around bone on their way to their attachment points. An overworked tendon can develop microscopic tears as it’s moving back and forth with repetitive motions. As we get older, tendons become more susceptible to developing these tears as they naturally lose their mechanical strength and elasticity. Inflammation is our body’s natural response to injury in order to prevent further damage by generating pain and facilitates healing by increasing blood flow which manifests as swelling.

Q: What causes extensor tendonitis?

A: Typically, extensor tendonitis happens to patients who spend a lot of time on their feet or people who wear shoes that are too tight. Poorly fitting running shoes, for example, may press too hard on the extensor tendon which can lead to inflammation and extensor tendonitis.

Q: What are potential treatments for this condition?

A: Controlling the inflammatory process is the goal of treatment. Stress and pressure on the tendons are key causes of inflammation. Activity modification with rest, icing to reduce pain and inflammation, and anti-inflammatory medication (NSAIDs) can help to reduce inflammation and allow the tendon to heal.. Gentle stretching and low impact exercises keep tendons and the joints they cross from getting stiff.

If inflammation is severe, your physician may prescribe an immobilization device such as a Controlled Ankle Motion (CAM) boot or a lace up ankle brace to reduce the work these tendons have to do during the gate cycle. Steroid injections around any tendon should be done with caution because this could lead to rupture, so it is typically not recommended.

There are various biologic injections such platelet rich plasma (PRP) or bone marrow aspirate concentrate (BMAC) that are used to deliver growth factors. These help the healing process in chronic inflammatory conditions and are not typically indicated for acute inflammatory pain. The efficacy of these biologic injections has not been proven for extensor tendonitis of the foot.

Q: Can running lead to pain on the outside of the foot? In what circumstances can this occur?

A: The outside portion of the foot is the part of the foot that is the most mobile. When running over uneven ground, it is responsible for accommodating and adjusting for impact on these surfaces. High impact exercise that involves pivoting, cutting, or jumping places also increases the stress over these areas. This can all lead to pain over the outside of the foot. Some individuals have a foot posture or shape with a high arch that loads the outside of the foot more than the average person and can lead to pain in these areas.

Q: How can you prevent or treat this form of foot pain from running?

A: Activity modification with lower impact exercise and running on softer, even surfaces such as a well-maintained grass field may help. Appropriate shoe wear is important to prevent and treat this form of foot pain. Shod runners will absorb that stress over uneven surfaces and with high impact through their shoes. On average, they may have less pain than the minimalist shoe or barefoot runner. If your foot has a flexible high arch, there are certain orthotics that well help balance and distribute weight across the entire foot. These orthotics typically have a recess for the first toe and lateral post at the base of the heel.