Injury, Training, Biomechanical, and Physiological Profiles of Professional Breakdancers

# Background Breakdancing or breaking will enter the Olympics in 2024, however, there is a paucity of literature exploring the epidemiology, demands, and performance. # Purpose The purpose of this study was to describe injury and training profiles, along with the results of a short performance test battery, in a group of elite breakers. # Study Design Cross-sectional study (retrospective). # Methods Fourteen breakdancers (breakers) (4 Bgirls, 10 Bboys) participated in an interview regarding their injury and training history, endurance test (cycle VO~2max~ testing), counter movement jump, squat jump, drop jump, isometric hip abduction, adduction, shoulder external and internal rotation strength testing on a fixed-frame dynamometer. Breakers were divided into elite (n=10) and developing (n=4) based on their qualification for a world finals competition; Wilcoxen rank sums were used to compare the two groups, or in the case of strength testing between those with and without an injury history. # Results The breakers had a median 11.0 $$10.0 - 14.0$$ years breaking experience and trained 24.4 $$20.5 - 30.0$$ hours per week. The knee was the most commonly injured body part and most frequently injured joint, with the thigh being the most common site for muscle injuries. There were no differences in endurance testing or jump height testing results between elite and developing breakers. There was no difference in shoulder external or internal rotation strength between athletes with a history of shoulder injury and those without. Similarly, there was no difference in hip abduction or adduction strength in those with a history of hip injury and those without. # Conclusion The results of this study should be viewed with caution due to the small sample size. However, this study is the first to publish functional and physiological descriptives on breakers. The authors hope these results support clinicians treating breakers as well as encourages future research related to breaking. # Level of Evidence 2

Keeping athletes on the field: an examination of primary and secondary ACL injury prevention outcomes

Snyder-Mackler, LynnIn its three aims this dissertation explored the outcomes of a primary prevention program, rehabilitation and return to sport after ACL reconstruction, and a secondary ACL injury prevention program. The FIFA11+ is a primary prevention program that reduces knee injuries in men’s collegiate soccer, however has not been examined in women’s collegiate soccer and it remains unknown if the program is effective in changing movement patterns associated with ACL injuries. In its first aim this dissertation established smallest detectable change and minimal important difference values for motion analysis of a drop jump. Then using these values to provide clinical context, this study found that although effective in reducing non-contact lower extremity injuries, the FIFA11+ did not reduce knee injuries or change biomechanical risk factors. In the second aim this dissertation explored if professional male athletes in Major League Soccer (MLS) after ACL reconstruction were at an increased risk for injuries, beyond their known increased risk for a new knee injury, and how returning to play after ACL reconstruction affected their career length. This study found that although not at an increased risk for lower extremity injury, MLS athletes had shorter careers compared to age matched controls. Seemingly these athletes made a return to sport but not a return to their preinjury level of performance. In its third aim this study explored the outcomes of the Anterior Cruciate Ligament-Specialized Post-Operative Return to Sports (ACL-SPORTS) program, a secondary prevention program designed to help bridge the gap between physical therapy discharge and return to sport. This study found that both men and women had increases in objective and self-reported outcome measures over the course of the training program, with the exception of quadriceps strength limb symmetry. Men had an increase in quadriceps strength limb symmetry with the program, where women’s strength symmetry remained the same. Further examination of the men found that 95% returned to their preinjury level of sport and only one had a second ACL injury (incidence 2.5%) in the two years following ACL reconstruction.Ph.D.University of Delaware, Biomechanics and Movement Science Program