Key clinical summary
Sinus tarsi syndrome usually causes persistent outer ankle or hindfoot pain after a twist, especially on uneven ground or when the ankle feels unstable.
- The pain often sits slightly in front of and below the outer ankle bone rather than directly over the main lateral ligaments.
- People often describe an unstable, unreliable feeling on uneven ground or when changing direction.
- Ultrasound can help rule in associated soft-tissue pain generators and can support guided injection into the sinus tarsi when appropriate.
Typical presentation
Pain is often deep, localised and irritating rather than dramatically swollen. Many patients point to the soft area in front of the outer ankle bone and report discomfort with slopes, uneven paths, twisting or prolonged standing.
A sense of giving way can persist even when the original sprain has “healed”.
Why it happens
The sinus tarsi contains ligaments, fat and neural tissue that can remain irritated after inversion trauma or chronic subtalar instability.
Because the subtalar joint helps adapt the foot to uneven ground, patients often feel especially vulnerable on cambers, trails, grass or stairs when this region is irritated.
Assessment and differential diagnosis
Assessment should determine whether the pain is really centred in the sinus tarsi region and whether there is co-existing lateral ligament instability, peroneal tendon irritation or subtalar stiffness.
The diagnosis is rarely made well from imaging alone; the story, pain location and instability profile are what usually make the picture coherent.
Where ultrasound helps
Ultrasound is useful mainly to assess associated soft-tissue problems and to guide injection accurately into the sinus tarsi region if a diagnostic or therapeutic procedure is being considered.
It can also help exclude peroneal sheath pathology or more focal lateral soft-tissue lesions.
Treatment strategy
Treatment usually includes restoring ankle and subtalar control, balance work, calf and peroneal strength, confidence on uneven ground and a graded return to cutting or pivoting activity.
If pain remains localised despite good rehabilitation, ultrasound-guided injection into the sinus tarsi may be considered to reduce irritability and help the patient progress loading more effectively.
Evidence strength summary
Strongest support
Targeted rehabilitation, sensible load management and diagnosis-led decision making form the core of a strong evidence-based pathway for this condition.
Where ultrasound adds value
Ultrasound is most helpful when the scan result will change treatment, improve diagnostic confidence or increase the precision of a procedure.
Where injections fit
Injections only make sense when a clear pain generator has been identified and the procedure supports a wider plan rather than replacing rehabilitation.
Page-specific FAQs
Is sinus tarsi syndrome just another name for ankle sprain?
No. It is usually a persistent pain and instability problem that can follow a sprain but behaves differently from normal ligament recovery.
Why is uneven ground so uncomfortable?
The subtalar region helps adapt to uneven surfaces. If that region is irritated or unstable, those surfaces become much harder to tolerate.
Can the pain persist even if swelling has gone?
Yes. Many patients have deep local pain and instability with little obvious swelling.
Does ultrasound help here?
It can, especially when guiding injection or checking other lateral soft-tissue structures such as the peroneal tendons.
What if the ankle keeps rolling?
That usually means the broader stability problem still needs addressing through targeted rehabilitation and, in some cases, further specialist review.
Ready for a clearer diagnosis and treatment plan?
Book a specialist assessment, explore the patient hub or review injection options before you decide.
Harvard references
- Helgeson, K. (2009) Examination and intervention for sinus tarsi syndrome. North American Journal of Sports Physical Therapy, 4(1), pp.29–37.
- Taillard, W., Meyer, J.M. and Garcia, J. (1981) The sinus tarsi syndrome. International Orthopaedics, 5(2), pp.117–130.
- Oloff, L.M. et al. (2001) Sinus tarsi syndrome and injection treatment. Clinics in Podiatric Medicine and Surgery, 18(3), pp.399–412.
What to do next
If symptoms remain intrusive or keep recurring, the next useful step is a proper assessment rather than more guesswork. At Wellbeing & Health MSK Clinics the pathway combines clinical examination, diagnostic ultrasound where it genuinely adds value, and a plan that matches the problem rather than forcing every foot and ankle issue into the same template.
Most patients choose a same-visit diagnostic pathway
For suitable cases we can assess, explain the likely diagnosis, use ultrasound where it adds value, and discuss whether rehabilitation alone or rehabilitation plus a guided injection is the most sensible next step.