Updated: Dec 9, 2022
As summer gives way to fall, we may find ourselves hitting the hiking trails. Many times, these uneven surfaces can lead to foot and ankle issues. Many people have sprained their ankle in the past, and are aware what this feels like. A lateral ankle sprain is an acute twisting of the ankle (often an inversion injury or an inward twisting of the foot and heel as compared to the leg). However, there is another condition which can cause pain on the lateral (outside) part of the foot, which many people will incorrectly refer to as “ankle pain”. I am referring to a pathology know as sinus tarsi syndrome.
The ankle joint consists of three bones, the Tibia, the Fibula, and a bone called the Talus. There are several ligaments working to help support the ankle which are very commonly sprained or ruptured with inversion sprains. However, sometimes there is only a small trauma, or repetitive micro-trauma from uneven surfaces that can affect another joint. The Sinus Tarsi (sometimes referred to as the “eye of the foot due to its appearance on an x-ray) is a very specific part of a joint called the subtalar joint.
This is the joint between a bone called the talus and the heel bone (known as the calcaneus). This portion of the joint contains many ligamentous attachments between the talus and calcaneus themselves, and between these two bones and the other bones of the mid-foot. When this joint is injured, there is often nagging pain along the lateral foot or across the ankle joint. Patients will often complain of pain in the morning or after periods of rest. They may find themselves hurting at the beginning or a run or hike, with the pain actually subsiding after getting warmed up. Certain motions like stepping off a curb, or walking up and down steps may cause sharp sudden pain.
Two tendons know as the peroneal tendons border the outside foot and ankle and help invert and evert the foot. When the sinus tarsi of the subtalar joint is painful, these tendons often over act, leading to a tendinitis which can even extend all the way to the lateral calf. Patients may complain of a pulling or stretching pain which extends to the outside calf. Often, when people complain of an “ankle pain” but have a difficult time expressing just how they hurt, direct palpation of the sinus tarsi will recreate the symptoms.
Treatments often include the standard RICE therapy (rest, ice compression, elevation), range of motion exercises (often pretending the big toe is the tip of a pen and tracing the letters of the alphabet in broad motions), oral anti-inflammatory medications, or steroid injections into the sinus tarsi itself. Also, many times supporting the foot with an orthotic is extremely beneficial and/or wearing supportive shoe gear with increased shock absorption.
So the next time you have a lingering “ankle pain” that just doesn’t seem to be getting better, ask your foot care professional about a possible sinus tarsi syndrome.