Does the Spraino low-friction shoe patch prevent lateral ankle sprain injury in indoor sports? A pilot randomised controlled trial with 510 participants with previous ankle injuries

Br J Sports Med. 2021 Jan;55(2):92-98. doi: 10.1136/bjsports-2019-101767. Epub 2020 Aug 12.

Abstract

Background: Lateral 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.

Methods: In 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.

Results: 480 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.

Conclusion: Compared 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.

Keywords: ankle; injury prevention; randomised controlled trial; sports; sprain.

Publication types

  • Randomized Controlled Trial
  • Video-Audio Media

MeSH terms

  • Adult
  • Ankle Injuries / epidemiology
  • Ankle Injuries / etiology
  • Ankle Injuries / prevention & control*
  • Ankle Injuries / psychology
  • Arthralgia / rehabilitation
  • Athletic Injuries / epidemiology
  • Athletic Injuries / etiology
  • Athletic Injuries / prevention & control*
  • Athletic Injuries / psychology
  • Basketball / injuries
  • Fear
  • Female
  • Foot Orthoses* / adverse effects
  • Friction*
  • Humans
  • Male
  • Outcome Assessment, Health Care
  • Pilot Projects
  • Proof of Concept Study
  • Prosthesis Design
  • Racquet Sports / injuries
  • Shoes* / adverse effects
  • Sprains and Strains / epidemiology
  • Sprains and Strains / etiology
  • Sprains and Strains / prevention & control*
  • Sprains and Strains / psychology
  • Time Factors

Associated data

  • ClinicalTrials.gov/NCT03311490