Background After description of injury epidemiology the description of injury etiology is the next step to identify relevant preventive approaches.

Objective What are common injury situations, mechanisms and characteristics?

Design Prospective video-based analysis of match injuries.

Setting Two highest German professional leagues in men's football.

Participants All first and second division football players who played at least one competitive club match (n=3,747) within the seasons 2010/11, 11/12, 12/13 and 14/15 were included.

Interventions Analysis of all moderate and severe match injuries (time-loss>7 days) that were registered by clubs or physicians with the VBG (German statutory accident insurance for the administrative sector) as part of the occupational accident reporting.

Main Outcome Measurements A surveillance sheet was evaluated containing six categories and 31 items describing general match and injury information (e.g. date, teams, name of injured player, position on pitch), match situation in moment of injury (e.g. ball possession, movement of injured player, type and direction of possible tackling), mechanism of injury (e.g. type of contact, trigger of injury) and referee's decision.

Results 217 moderate or severe match injuries were identified in the video footage. 52.4% of injuries were contact injuries, 20.4% indirect contact and 27.2% non-contact injuries. 17.2% of injuries result from opponent's and 14.3% from own foul play. Injuries mainly occurred during defending actions (sliding 22.1%, tackling 10.6%), shooting (18.6%), heading (13.3), dribbling (11.5%) or passing (11.5%). Moreover, six typical injury situations for thigh, knee, ankle, lower leg and foot injuries were recognized.

Conclusions Video analysis of injuries sustained in competition show that the share of injuries effected by irregular actions of the opponents is low. Thus there seems to be a high preventive potential to reduce number and severity of injuries in football. Thus particularly individual intrinsic risk factors needs to be identified within routinely screening measures.