Shoulder Injuries in Boxing. A systematic Review.

Abstract Background: High injury rates are to be expected in combat sports. Although case reports and epidemiological studies have documented shoulder injuries in boxers, numbers differ and there is currently no systematic review reporting injury prevalence. Purpose: The aim of this study was to offer an analysis of existing studies documenting shoulder injuries in boxing. Additionally, we wanted to evaluate, if chronic shoulder pathologies seen in former boxers, originate from acute injuries or result from chronic overuse syndromes.Study Design: Systematic ReviewMethods: We performed a systematic database research according to the PRISMA guidelines on PubMed, Scopus and Google Scholar for the keywords “boxing”, “injury” and “shoulder” or their respective synonyms. Any epidemiological cohort- and cross-sectional studies on boxing, that documented shoulder injuries and were published in German or English language up to January 2020, were included. Statistical analysis including individual and overall proportion with 95% Clopper-Pearson confidence intervals was performed to determine shoulder injury rates for amateur and professional cohorts separately.Results: Methodological quality was assessed using the STROBE statement and a modified Downs&Black's checklist. 13 studies were included, 10 of which met the criteria for statistical analyses. The heterogeneity in study design and cohort characteristics did not allow for detailed quantitative analysis. Overall, shoulder injuries occurred almost twice as often in amateur athletes than in professionals (overall proportion [95% CI]: amateur athletes: 9% [6%; 12%], professionals: 4% [2%; 8%]).Conclusion: No study investigating the long-term effects of boxing on shoulder pathologies was identified. Although specific information on injury type is mostly missing, the few studies addressing it report shoulder dislocations, strains, tendonitis, or chronic impingement syndromes. Unlike head trauma, shoulder injuries do not necessarily lead to cessation of fight, therefore at the ringside gross underreporting of shoulder pathologies must be taken into consideration.