Prevalence

• Primary shoulder dislocate peaks in the second and sixth decade

• 98% of cases, shoulder displaces anteriorly

• 2% of cases, shoulder displaces posteriorly

• 95% of first-time shoulder dislocations result from either a forceful collision, falling on an outstretched arm or a sudden wrenching movement

• 5% of dislocations have an atraumatic origin (minor incidents such as raising the arm or moving during sleep

• 70% of people who have dislocated can expect to dislocate again within 2 years of the initial injury

• Younger and older subjects have a comparable incidence of primary shoulder dislocation

• Incidence of recurrent dislocation is much more frequent in adolescent population

• Dislocation reported to recur in:

  • 66% to 100% of people aged 20 years or under

  • 13% to 63% of people aged between 20 and 40 years old

  • 0% to 16% of people aged 40 years or older

References

Hayes K, Callanan M, Walton J, Paxinos A, Murrell GAC. Shoulder Instability: Management and Rehabilitation. J Orthop Sport Phys Ther. October 2002.