Biomechanical analysis and injury prevention of circus artists and acrobats; preliminary study
Résumé
The purpose of our study was to establish an anthropometric, neuromuscular, and physiological characterization of circus student-artists as well as design the most appropriate injury prevention and performance optimization programs to preserve the health of circus artists and acrobats. To do so, a biomechanical analysis intending to reveal the parasitic movements to be avoided during circus and acrobatic figures to prevent injuries to the upper limbs and the trunk was performed associated to an exploration of the neuromuscular component (i.e., proprioception) in order to reveal problems of instability in equilibrium postures (i.e. lower and upper limbs). An evaluation of the strengths of the large muscular chains was also performed to disclose the imbalance between the anterior and posterior chains. Thirty student-artists (13 women and 17 men, 22.5 ± 2 years) participated voluntarily in this study. They were divided into two groups: 15 aerials (dangling trapeze, stated trapeze, outfielders, Chinese mast, aerial fabrics, aerial webbing, smooth rope, and flying rope) and 15 non-aerials (banquine, bascule, carried acrobatic, cyr wheel, acrobatics, and acrobatic juggling). To start, an injury report for the year 2016 was performed and biometric measurements of all body segments were collected. During the specialties sessions the effective engagement time on the apparatus and the periods of poses were quantified. Just after the specific warm-up and at the end of the session, a measurement of the hand-grip force (HGF) and the maximum voluntary contraction (MVC) of the quadriceps muscle (right and left) were performed. Statistical Analysis: All data are presented as means ± SD. The data follow a normal distribution. Paired T test was used to assess the differences between the two groups. Results: more than three-quarters of student-artists had previously been injured with an average of two injuries per student. All injuries were reported during specialties sessions. 44% of these injuries affected the lower limb, 32% the upper limb, 16% the trunk and 8% the neck. Anthropometric measurements showed significant differences between the two groups at the height (p \textless005) and span (p \textless0.05). A significant difference in arm circumference (p \textless0.05) was also observed in non-aerials between left and right arms, and not among the aerials. Significant differences were, however, observed in HGF at the beginning and end of the sessions between the two groups (p\textless0.01), which was not the case for the MVC. These last two parameters showed an increase in more than half of the student-artists (all disciplines) between before and the end of the sessions. Conclusion: These findings might have practical implications for both training and injury prevention.