As a practicing orthopedic physical therapist, I have seem many, many ankle injuries. However, I have been working at a clinic that is known for it’s expertise in the foot and the ankle for the past 8 years. Since then, I have seen even more foot and ankle injuries. I have learned to treat some of the lesser known conditions that can occur. These conditions can cause pain and dysfunction just like more well known conditions. This includes sinus tarsi syndrome which causes pain on the outside of the ankle. It commonly occurs after repeated ankle sprains. Read on to learn more about this sinus tarsi syndrome. Let’s start with anatomy!
Joints of the ankle
The ankle has two main joints. These are the talocrural and subtalar joints.
- The talocrural joint is made up of the talus and the lower ends of the tibia, and fibula. The talus is a bone that sits above the calcaneus (the heel bone). The tibia and fibula are the lower leg bones. This joint allows for plantar flexion (pointing the foot down) and dorsiflexion (pointing the foot up).
- The subtalar joint is made up of the talus and the calcaneus. This joint allows for pronation and supination. Pronation is when the ankle and arch roll inward and supination is when the ankle and arch roll outward
- All four motions of the ankle are vital in order for the foot and ankle to walk and move normally.
What is the sinus tarsi?
The sinus tarsi is a tunnel between the talus and the calcaneus. It is located on the outside of the ankle. This area is filled with ligaments, muscles, blood vessels, and nerves. These tissues provide stability and proprioception to the ankle. Proprioception is knowing where an area of the body is in space. For example, knowing whether your right foot is pointed or flexed right now without having to look at it.
What is sinus tarsi syndrome?
Sinus tarsi syndrome is pain or injury to the sinus tarsi. It has 2 main causes.
- Single traumatic ankle sprain or recurrent ankle sprains – This is the most common cause of sinus tarsi syndrome. Ankle sprains tear the ligaments that help stabilize the ankle joint. This will lead to instability of the subtalar joint which means that ankle will be harder to control. This instability can cause inflammation and pain in the sinus tarsi.
- Flat or overpronated feet – This can cause a compression injury to the sinus tarsi. As the ankle and arch roll in excessively while walking and standing, the outside of the ankle will be compressed. This can cause pain, inflammation, and potential arthritis in the sinus tarsi.
What are the symptoms of sinus tarsi syndrome?
There are several symptoms associated with sinus tarsi syndrome. These include:
- Pain on the outside of the ankle
- Pain that increases with standing and walking, especially on uneven ground
- Tenderness on the outside of the ankle – at the sinus tarsi
- A feeling of instability or potentially “giving way” of the ankle
- Swelling at the sinus tarsi
Are there risk factors for developing sinus tarsi syndrome?
There are a few risk factors for developing this condition. These include:
- History of ankle sprains
- Participating in sports that require jumping, sprinting, and cutting
- Flat feet
The incidence of sinus tarsi syndrome is unknown because it is usually caused by a previous injury and occurs simultaneously with another condition – chronic ankle instability. However it is probably fairly common and should be evaluated for anyone who has continual pain and instability at the ankle.
Who should I see?
- Physical therapy – This would be my first stop. Physical therapy can address the underlying cause of the sinus tarsi syndrome – which is most likely subtalar joint instability. Your PT can help decrease the pain and swelling. Abnormal joint mobility, weakness, instability, and flexibility will be evaluated and addressed. Your PT will also assess and correct your walking and running form to prevent the problem from happening again.
- Orthopedic physician – An orthopedist might be necessary if the condition is not responding to physical therapy. Anti-inflammatory medication or an injection might be needed to decrease the inflammation. Your orthopedist can also order imagining to determine the extent of injury to the ankle.
What can I do at home?
- Relative rest – Resting the area to decrease further pain and damage from occurring is one of the best ways to decrease inflammation at the sinus tarsi. Basically stay away from the activities that are causing pain until the pain and inflammation have subsided. This gives the area time to rest and heal. If you keep doing what is causing the inflammation, it is not going to get better. Swimming and biking would be good alternative activities that do not put much stress through the ankle and foot.
- Ice – Ice can help decrease the pain and swelling at the ankle. Ice the painful area for 15 to 20 minutes at a time. I would recommend using an ice pack several times per day if the pain is constant or preventing you from participating in an activity. Ice immediately after activity.
- Stretching – Stretching calf muscles can help improve the motion at the talocrural joint at the ankle. This joint can get stiff after an ankle sprain. See the video below.
- Strengthening – It is important to strengthen the muscles around the ankle, knee, and hip. All of these muscles work together to stabilize the ankle while running, cutting, and jumping. Using loop resistance bands , resistance bands and ankle weights can increase strength and difficulty of the exercises. See the videos below.
- Balance – Working on balance is important in strengthening the foot and ankle but also improving proprioception. Improving proprioception will help improve the overall stability of the ankle. See the video below.
- Bracing – Using a stability brace or ankle sleeve can be helpful to decrease pain and improve stabilization at the ankle. This is especially useful for those that have chronic ankle instability or who have suffered from previous ankle injuries.
- Compression socks – Compression socks can help decrease swelling and pain by improving circulation. It is important to put on compression socks after first waking up in the morning. This is usually when there is the least amount of swelling.
- Shoe wear and orthotics – Having flat feet is a risk factor for sinus tarsi syndrome because it compresses the outside of the ankle. Changing shoe wear or using orthotics to place the foot in a neutral position will help decrease the stress on the area. An overpronation shoe might help or you might need orthotics. Most running stores will evaluate your foot type and suggest appropriate shoe wear and/or orthotics. Your PT can also evaluate your foot and help determine appropriate shoe wear.
In review
- The ankle has two main joints.
- These are the talocrural and subtalar joints.
- The sinus tarsi is a tunnel between the talus and the calcaneus.
- This area is filled with ligaments, muscles, blood vessels, and nerves.
- These tissues provide stability and proprioception to the ankle.
- Sinus tarsi syndrome is pain or injury to the sinus tarsi.
- It has 2 main causes.
- Single traumatic ankle sprain or recurrent ankle sprains
- Flat or overpronated feet
- Symptoms include pain on the outside of the ankle.
- Physical therapy can help decrease symptoms of sinus tarsi syndrome by addressing the underlying causes.
- Orthopedist would be needed if the condition does not improve with physical therapy.
- There are things that you can do
- Relative rest
- Ice
- Stretching
- Strengthening
- Bracing
- Compression socks
- Shoe wear and orthotics
As always, If you have questions about the content of this post or any other musculoskeletal questions, please e-mail me.
Additional resources
https://www.physio-pedia.com/Sinus_Tarsi_Syndrome
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2953318/
https://sportdoctorlondon.com/sinus-tarsi-syndrome/