Explore the vast range of titles available.

BackgroundLateral ankle sprains are common in indoor sports. High shoe–surface friction is considered a risk factor for non-contact lateral ankle sprains. Spraino is a novel low-friction patch that can be attached to the outside of sports shoes to minimise friction at the lateral edge, which could mitigate the risk of such injury. We aimed to determine preliminary effectiveness (incidence rate and severity) and safety (harms) of Spraino to prevent lateral ankle sprains among indoor sport athletes.MethodsIn this exploratory, parallel-group, two-arm pilot randomised controlled trial, 510 subelite indoor sport athletes with a previous lateral ankle sprain were randomly allocated (1:1) to Spraino or ‘do-as-usual’. Allocation was concealed and the trial was outcome assessor blinded. Match and training exposure, number of injuries and associated time loss were captured weekly via text messages. Information on harms, fear-of-injury and ankle pain was also documented.Results480 participants completed the trial. They reported a total of 151 lateral ankle sprains, of which 96 were categorised as non-contact, and 50 as severe. All outcomes favoured Spraino with incidence rate ratios of 0.87 (95% CI 0.62 to 1.23) for all lateral ankle sprains; 0.64 (95% CI 0.42 to 0.98) for non-contact lateral ankle sprains; and 0.47 (95% CI 0.25 to 0.88) for severe lateral ankle sprains. Time loss per injury was also lower in the Spraino group (1.8 vs 2.8 weeks, p=0.014). Six participants reported minor harms because of Spraino.ConclusionCompared with usual care, athletes allocated to Spraino had a lower risk of lateral ankle sprains and less time loss, with only few reported minor harms.Trial registration number NCT03311490.

Correspondence to Filip Gertz Lysdal, Sport Sciences, Department of Health Science and Technology, Aalborg University, Aalborg 9220, Denmark; fgly@hst.aau.dk Lateral ankle sprains are common in indoor sports, and most of these injuries occur via a ‘non-contact’ injury mechanism in which the only contact is between the shoe and the floor.1 2 Shoe–surface friction is generally high in indoor sports, and this attribute is considered a risk factor for non-contact lower extremity injuries.3 Spraino is a novel low-friction patch that is attached to the outside of sports shoes, specifically designed to prevent ‘friction-related’ ankle sprains in indoor sports by minimising friction at the lateral edge of the shoe sole. Match and training exposure, injury incidence and time loss were captured weekly via text messages over a 9-month period. The incidence and prevalence of ankle sprain injury: a systematic review and meta-analysis of prospective epidemiological studies.