Achilles tendon ruptures in National Basketball Association players: A sequential video analysis of injury mechanisms and biomechanical patterns

PURPOSE: Achilles tendon ruptures (ATR) are severe injuries in professional basketball, yet in-game mechanisms and biomechanical patterns remain insufficiently described. The purpose of the study is to characterise biomechanical patterns and basketball-specific contexts of ATR using sequential video analysis. METHODS: A systematic search identified 27 confirmed ATR cases between 1970 and 2025 in the NBA league. Contextual factors (court location, playing situation, movement and speed) were analysed for all cases. Frame-by-frame biomechanical assessment was conducted for 17 injuries (63%) with adequate video quality, documenting trunk, hip, knee and ankle angles of the injured limb at initial contact (IC) and the injury frame (IF). RESULTS: All ruptures occurred during closed-chain movements, mostly with noncontact mechanisms (81.5%), during offensive play actions (85.2%), at low horizontal speeds (63%) and moderate vertical speeds (44.4%). The most frequent action was the take-off/acceleration phase of running (74%), followed by the beginning jump (14.8%) and landing (7.4%). At the IC, players were in forefoot contact, the sagittal plane orientation of the trunk was 18.2° flexed, while the hip was 12.3° extended, the knee was 42.2° flexed and the ankle was 5.6° plantar flexed on the injured side. At IF, players displayed a more flexed torso (27.5°, 9.3° change from IC; p < 0.001), a more extended hip (26.8°, 14.5° change from IC; p = 0.001), a less flexed knee (26.7°, 15.5° change from IC; p = 0.004) and a more dorsiflexed ankle (41.6°, 47.2° change from IC; p < 0.001). CONCLUSIONS: Our study described basketball-specific movement patterns among NBA players who sustained ATRs. Supported the observations of forefoot loading and rapid dorsiflexion of the ankle joint, and introduced new concepts, extension movement of lower limb elements proximal to the ankle joint and proximal elongation of the musculotendinous complex. These findings enhance understanding of basketball-specific ATR mechanisms and may inform targeted prevention strategies such as combining eccentric calf training with functional exercises focusing on lumbopelvic and knee stability, while targeting explosive forefoot contact acceleration manoeuvres. LEVEL OF EVIDENCE: Level IV, retrospective case series.