Background Studies indicate that the risk of shoulder injury in rugby union football is high and that the tackle is a leading cause of shoulder injury. Qualitative video analysis of the game events in rugby, such as the tackle, can provide important insights into the causes of injury and injury prevention.

Objective To describe shoulder injury mechanisms in rugby union football using a qualitative video analysis protocol.

Design A case control study design was applied using shoulder injury and other/no-injury cases collected prospectively from Super 14 matches between 2006 and 2008. A qualitative video analysis method was applied to code skill performance and injury risk factors.

Setting Professional provincial rugby competition (Super 14 competition) between 2006 and 2008.

Participants Professional Australian male rugby players.

Assessment of risk factors The analysis focused on the identification of shoulder loading patterns, either direct or indirect (eg, loading of the hand or arm). The characteristics were compared to an existing dataset in a case-control framework.

Main outcome measurements OR for skill and specific injury risk factors were calculated.

Results Two main shoulder injury mechanisms were (1) falling on an outstretched hand during a tackle and (2) direct impact to the tip of the shoulder during a tackle causing injuries to the glenohumeral joint and the acromioclavicular joint.

Conclusion The results provided valuable information in understanding the mechanism of shoulder injuries in rugby union football. Improvements in shoulder padding and tackle skills, for both the ball carrier and tackler, are required to reduce the incidence of shoulder injury.