Normally caused by poor technique shoulder dislocation is the most feared of shoulder canoeing injuries.
The fact that the shoulder is the most mobile joint in the body means that it has less inherent stability. Positions where the arm is above shoulder level, taken backwards and then force applied are where the shoulder is at most risk of dislocation. High brace or roll performed with poor technique puts the shoulder at risk.
Strengthening shoulder muscles is important, but even the strongest shoulder will dislocate if enough force is applied to it whilst it is in a vulnerable position.