Lateral ankle joint injuries in indoor and court sports – a systematic video analysis of 445 non-consecutive case series

Background: Lateral ankle sprains are one of the most common injuries in indoor and court sports. Self-reports and case studies have indicated that these injuries occur via both contact and non-contact injury mechanisms, typically due to excessive inversion in combination with plantarflexion and adduction of the foot. Video-based documentation of the injury mechanism exists, but the number of cases reported in the literature is limited. 

Purpose: This study aimed to retrieve and systematically analyse a large number of video-recorded lateral ankle injuries from indoor and court sports. More specifically, we aimed to describe injury mechanism, injury motion and injury pattern across different sports. 

Study Design: Explorative, observational, non-consecutive case-series study. 

Methods: A total of 445 unique video-recorded lateral ankle sprain injuries were retrieved from indoor and court sports of broadcasted levels of competition. The videos were independently analyzed by two different reviewers. Outcomes included classification of the injury mechanism according to the IOC consensus guidelines, primary and secondary motions of ankle joint distortion, as well as documentation of the fixation point (fulcrum) around which the foot rotates. 

Results: 298 (67%) injuries were direct contact, 113 (25%) were non-contact and 32 (7%) were indirect contact incidents. Direct contact injuries were especially prevalent in basketball (76%), handball (80%), and volleyball (82%), while non-contact injuries dominated in tennis and badminton (4% vs 96% across both). Inversion (65%) and internal rotation (33%) were the primary distortion motions, with the 3 lateral forefoot (53%) and lateral midfoot (40%) serving as the main fulcrums. Landing on another player’s foot was the leading cause of injury (n=246, 55%), primarily characterized by inversion (79%) around a midfoot fulcrum (54%). The non-contact landings on floor (n=144, 33%) were primarily characterized by a distortion around a forefoot fulcrum (69%). 

Conclusion: Two out of three ankle sprains from online video platforms are direct contact injuries, with most involving landing on another player’s foot. The distortion motion seems related to the injury mechanism and the fixation point between the foot and the floor. The injury mechanisms vary greatly between sports, and future studies should clearly differentiate and investigate the specific injury mechanisms.