Sinus Tarsi Syndrome After Repeated Ankle Sprains: Symptoms, Diagnosis, Treatment & Prevention

Although many athletes and active adults have never heard of it, sinus tarsi syndrome (STS) shows up in roughly one in ten people who suffer recurrent ankle sprains. The problem centres on a small, cone-shaped canal on the outer rear-foot that becomes painful, swollen, and unstable after repeated inversion injuries. Most patients describe a deep, nagging ache—“like I’m standing on a marble”—that persists long after the torn ligaments of the original sprain have supposedly healed. The single biggest risk factor is inadequate rehabilitation after each twist, yet the encouraging truth is that about eight out of ten cases calm down with a structured programme of bracing, proprioceptive exercise, and—when required—precisely guided injections.

The sinus tarsi (Latin for “hollow of the ankle”) is a short, funnel-shaped passage that sits between the talus on top and the calcaneus below. Inside this tight space lie two critical subtalar stabilisers—the cervical and interosseous talocalcaneal ligaments—plus a fat pad, small blood vessels, and a dense web of proprioceptive nerve endings. Together, these structures act like a hydraulic shock absorber and sophisticated motion sensor, helping you stay balanced on uneven ground. When an ankle rolls inward, the ligaments tear and bleed, the fat pad swells, and scar tissue creeps in. Because the canal is tiny, even a modest increase in volume creates high pressure, turning every step into a painful reminder that the ankle is not truly healed.

A single inversion sprain may bruise the sinus tarsi, but trouble usually appears after the second or third twist. Each new injury yanks at the subtalar ligaments, adding microscopic tears that gradually stretch the joint. The torn fibres leak blood and inflammatory chemicals into the canal, producing synovitis—an angry, thickened lining that hurts when compressed. As healing sputters along, the body lays down scar tissue. Adhesions tether once-sliding surfaces so the subtalar joint feels stiff and “sticky,” especially first thing in the morning. Pain, in turn, switches off the peroneal muscles—the ankle’s natural brakes—making another sprain more likely and locking the foot in a vicious cycle of instability, swelling, and pain.

People with sinus tarsi syndrome almost always point to the same spot: a thumb-sized divot just in front of the outer ankle bone (the lateral malleolus). Pressing here reproduces the chief complaint—a sharp, localised discomfort that can radiate slightly forward along the foot. Walking downhill, crossing loose sand, negotiating cobblestones, or slipping into high heels often ramps up symptoms because these activities pronate the subtalar joint and squeeze the swollen canal. Many patients also report a disconcerting sense that the ankle might “give way” on uneven ground; the deeper proprioceptive nerves in the sinus tarsi are simply not doing their job. Morning stiffness is common: overnight, fluid collects in the confined space, but as circulation improves, the joint loosens and the limp eases.

Good clinicians begin with a detailed history of ankle injuries, noting how many sprains occurred, how thoroughly each was rehabilitated, and whether the patient returned to sport too quickly. During the physical exam, gentle pressure over the sinus tarsi almost always elicits a sharp yelp, and forcing the ankle into inversion or eversion reproduces the pain. An anterior drawer or subtalar tilt test that feels “loose” supports the suspicion that stabilising ligaments have stretched.

Imaging refines the picture. Plain weight-bearing X-rays are useful for spotting fractures, malalignment, and tarsal coalitions. Magnetic resonance imaging (MRI) remains the gold standard because it shows bone bruises, fresh or chronic ligament tears, synovial hypertrophy, and fluid in exquisite detail, but computed tomography (CT) excels at identifying bony impingement if arthritis is suspected. Dynamic ultrasound, in experienced hands, reveals thickened synovium and is invaluable for guiding diagnostic or therapeutic injections.

A local anaesthetic–steroid mix injected directly into the sinus tarsi often serves a dual purpose. When more than 70 percent of the pain melts away within minutes, the diagnosis is virtually confirmed, and the steroid component typically provides weeks to months of relief—enough time to start a solid rehabilitation programme.

Relative rest combined with a figure-of-eight or lace-up brace limits inversion and gives inflamed tissues time to settle. Applying ice in short bursts—five minutes on, five off, repeated three times—reduces swelling without freezing the skin. Non-steroidal anti-inflammatory drugs or natural alternatives like turmeric and omega-3s ease discomfort so patients can begin gentle range-of-motion work.

Once baseline pain is manageable, manual therapy becomes central. Mobilising the talocrural and subtalar joints with gentle distraction restores glide, while soft-tissue release of tight peroneal muscles allows proper activation during balance drills. Proprioceptive work starts with simply standing on one leg and progresses to wobble boards or foam pads. Resistance-band eversion exercises rebuild the everter group, and calf stretches maintain length in the gastrocnemius–soleus complex. Shoes with firm heel counters and a slight lateral wedge shift weight off the sinus tarsi, and customised foot orthoses fine-tune alignment for those with flat or over-pronated feet.

If pain flares during higher-level drills, an ultrasound-guided corticosteroid plus hyaluronic-acid injection can calm the synovitis and lubricate the subtalar joint, buying time for ligaments to mature. Emerging evidence suggests platelet-rich plasma (PRP) may further accelerate healing. Shock-wave therapy—a series of high-energy sound pulses—stimulates blood flow and has shown promising results when combined with exercise.

Roughly 15–20 percent of patients continue to limp after six months of diligent rehabilitation and one or two well-placed injections. For them, surgery is a reasonable next step. The least invasive procedure, arthroscopic sinus-tarsi debridement, involves inserting a tiny camera and shaver through two five-millimetre portals to remove scar tissue and inflamed synovium. Most people can bear weight in a boot within two weeks and begin physiotherapy soon after.

If the underlying problem is frank instability, surgeons may reconstruct the cervical and interosseous ligaments using a modified Broström technique, sometimes augmented with suture tape or tendon grafts. Pronounced hind-foot valgus that perpetuates impingement calls for a calcaneal osteotomy to realign the heel bone. As a last resort, subtalar fusion (arthrodesis) abolishes motion and pain but sacrifices inversion and eversion, making it appropriate only for severe arthritis or deformity.

Even after surgery, rehabilitation is essential. By the end of week two, most patients walk comfortably in a supportive brace. Light jogging on a flat surface typically resumes at week four, provided hopping on the affected leg ten times is pain-free. Sport-specific cutting and pivoting drills start between weeks six and eight once the Y-Balance or Star Excursion test is within ten percent of the uninjured side. Competitive return generally follows at three months, but maintaining proprioceptive drills twice weekly for at least six more months cuts the risk of another sprain in half.

A robust warm-up that activates the calves, glutes, and hip rotators prepares the entire kinetic chain for sudden directional changes. Balance training on unstable surfaces three times a week sharpens the nervous system’s ability to right the foot during mis-steps. Strengthening hip abductors and external rotators is crucial because weak hips force the ankle to compensate. Swapping shoe pairs before the midsole collapses, choosing level training surfaces when fatigued, and wearing a lace-up brace during high-risk activities—such as basketball games or trail runs—cut sprain incidence dramatically.

Sinus tarsi syndrome is a surprisingly common yet under-recognised consequence of repeated ankle sprains. Its hallmark is a stubborn ache in the hollow just in front of the outer ankle bone, coupled with a sense of instability on uneven ground. Early diagnosis through careful examination and targeted imaging lets clinicians start rehabilitation before chronic inflammation sets in. A phased treatment plan—rest, manual therapy, proprioceptive exercise, and, when indicated, image-guided injections—solves most cases without scalpel blades. For those who need surgery, minimally invasive debridement or ligament reconstruction usually restores pain-free motion within three months, provided post-operative physiotherapy is meticulous.

Mild cases improve in six to eight weeks with dedicated therapy; longstanding cases may need three to six months, and surgical recoveries average twelve weeks before full sport.

Pounding the pavement too soon perpetuates inflammation. Switch to low-impact cardio—cycling, swimming, deep-water running—until you can hop ten times on the affected leg without sharp pain.

Research indicates that wearing a brace during high-risk sessions prevents sprains without causing lasting strength loss, as long as you keep up your strengthening routine.

If you are still limping months after what doctors labelled a “minor” sprain, do not resign yourself to chronic pain. Ask a sports-medicine professional about sinus tarsi syndrome. The earlier you identify and treat this hidden culprit, the sooner you can stride—rather than hobble—toward your next personal best.

Also Read:

• Sinus Tarsi Syndrome: Causes, Symptoms, Treatment, Recovery, Exercises
• Still Limping After Ankle Sprain? Check Sinus Tarsi