The term "sinus tarsi syndrome" was first applied in O’Connor in 1958 to a syndrome of post-traumatic lateral hindfoot pain and instability which was relieved by the injection of local anaesthetic into the sinus tarsi. The same diagnostic criteria seem to have been applied reasonably consistently throughout the literature. The incidence of sinus tarsi syndrome following ankle injury has not been published, but it is not very common. Some authors use the term "sinus tarsi syndrome" to refer to lateral hindfoot pain associated with inflammatory conditions or hindfoot valgus, but we prefer to refer to this as "lateral subtalar impingement".