"Fighter's shoulder" part I: impact on shoulder motion and scapular movement in judo and jiu-jitsu athletes.

BACKGROUND

Martial arts athletes, such as judo and jiu-jitsu, often develop musculature asymmetry due to repetitive movements over the years of practice. Common injuries include strains, sprains, and fractures, with shoulder and upper-arm injuries being particularly prevalent. The objective of this study was to identify potential changes in the shoulder range of motion (ROM) of martial arts athletes and to associate these changes with years of practice, belt graduation, and scapular dyskinesis. The scapular dyskinesis was evaluated and classified according to the Kibler classification.

METHODS

A cross-sectional study including martial arts athletes. The shoulder ROM was evaluated using a goniometer through elevation and internal and external rotation at 0° and 90° of abduction. The analysis was performed on both shoulders. The Kibler classification was used to classify scapular dyskinesis.

RESULTS

Among 133 belt-ranked combat athletes (54% black belts; mean age 27.8 years), 73% showed scapular dyskinesis (predominantly type I). Years of practice independently predicted reduced dominant-shoulder ROM: anterior elevation -0.320°/year, external rotation at 0° -0.556°/year, and at 90° -0.612°/year (all P < .001). Internal rotation decreased -0.612°/year plus -5.5° in international competitors (P = .030).

CONCLUSION

Years of sustained judo/jiu-jitsu practice were associated with progressive loss of dominant-shoulder ROM, with a concurrent trend toward scapular dyskinesis. These time-linked biomechanical and anatomical adaptations suggest a distinct entity named "Fighter's shoulder." Clarifying its causes and chronology through longitudinal studies is essential to guide targeted screening, preventive programming, and sport-specific rehabilitation.