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Infographic. Does the Spraino low-friction shoe patch prevent lateral ankle sprain injury in indoor sports? A 510-participant pilot RCT
  1. Filip Gertz Lysdal1,2,
  2. Thomas Bandholm3,4,
  3. Janne Schurmann Tolstrup5,
  4. Mikkel Bek Clausen6,7,
  5. Stephanie Mann3,
  6. Pelle Baggesgaard Petersen8,
  7. Thor Buch Grønlykke2,
  8. Uwe G Kersting1,9,
  9. Eamonn Delahunt10,11,
  10. Adam Virgile12,
  11. Kristian Thorborg4,7
  1. 1Sport Sciences, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
  2. 2Spraino ApS, Copenhagen, Denmark
  3. 3Clinical Research Centre, Amager-Hvidovre Hospital, University of Copenhagen, Copenhagen, Denmark
  4. 4Department of Physical and Occupational Therapy, Physical Medicine and Rehabilitation Research-Copenhagen, Amager-Hvidovre Hospital, University of Copenhagen, Copenhagen, Denmark
  5. 5National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark
  6. 6School of Physiotherapy, Department of Midwifery, Physiotherapy, Occupational Therapy and Psychomotor Therapy, Faculty of Health, University College Copenhagen, Kobenhavn, Denmark
  7. 7Department of Orthopedic Surgery, Sports Orthopedic Research Center-Copenhagen, Amager-Hvidovre Hospital, University of Copenhagen, Copenhagen, Denmark
  8. 8Section for Surgical Pathophysiology 7621, Rigshospitalet, Copenhagen, Denmark
  9. 9Institute of Biomechanics and Orthopaedics, German Sport University Cologne, Cologne, Germany
  10. 10School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland
  11. 11Institute for Sport and Health, University College Dublin, Dublin, Ireland
  12. 12College of Nursing and Health Sciences, University of Vermont, Burlington, Vermont, USA
  1. Correspondence to Filip Gertz Lysdal, Sport Sciences, Department of Health Science and Technology, Aalborg University, Aalborg 9220, Denmark; fgly{at}

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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. The minimised friction causes a reorientation of the ground reaction force vector, bringing it closer towards the joint centre, resulting in a lower joint torque, which could mitigate the risk and severity of lateral ankle sprains.4

In our recent pilot randomised controlled trial (RCT), published in British Journal of Sports Medicine, …

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  • Twitter @FilipGertz, @TBandholm, @MikkelBek, @EamonnDelahunt, @adamvirgile, @KThorborg

  • Contributors FGL, TB, JST, MBC, SM, PBP, TBG, UK, ED and KT wrote the original paper on which this text and infographic is based. AV designed the infographic for this paper. All authors approved the final version.

  • Funding The original research (on which this infographic is based) was funded by Copenhagen Center for Health Technology (CACHET), grant number RFH-15–00013 and Innovation Fund Denmark, grant number 7038-00087A.

  • Competing interests TBG is the founder of Spraino ApS. FGL is a paid employee in Spraino ApS. Spraino ApS was responsible for provision of Spraino in the original study. The conflict was accommodated by restricting Spraino ApS and authors FGL and TBG from having any deciding role in the design of the study, in the execution, analyses, interpretation of data or decision to submit results. Statistical analyses were performed externally by JST who was blinded to group allocation. KT had full authority of the trial administration. The three senior clinical researchers (KT, TB and ED) had full authority in terms of submission for publication. Copenhagen Center for Health Technology (CACHET) and Innovation Fund Denmark had no scientific role in the trial. KT is an Associate Editor of the British Journal of Sports Medicine. ED is a Senior Associate Editor of the British Journal of Sports Medicine in the area of foot and ankle injuries.

  • Patient consent for publication Not required.

  • Ethics approval Ethics approval was obtained from The North Denmark Region Committee on Health Research Ethics on 5 July 2017.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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