Video analysis of the biomechanics of a bicycle accident resulting in significant facial fractures.
BACKGROUND
This study aimed to use video analysis techniques to determine the velocity, impact force, angle of impact, and impulse to fracture involved in a video-recorded bicycle accident resulting in facial fractures. Computed tomographic images of the resulting facial injury are presented for correlation with data and calculations. To our knowledge, such an analysis of an actual recorded trauma has not been reported in the literature.


METHODS
A video recording of the accident was split into frames and analyzed using an image editing program. Measurements of velocity and angle of impact were obtained from this analysis, and the force of impact and impulse were calculated using the inverse dynamic method with connected rigid body segments. These results were then correlated with the actual fracture pattern found on computed tomographic imaging of the subject's face.


RESULTS
There was an impact velocity of 6.25 m/s, impact angles of 14 and 6.3 degrees of neck extension and axial rotation, respectively, an impact force of 1910.4 N, and an impulse to fracture of 47.8 Ns. These physical parameters resulted in clinically significant bilateral mid-facial Le Fort II and III pattern fractures.


CONCLUSIONS
These data confer further understanding of the biomechanics of bicycle-related accidents by correlating an actual clinical outcome with the kinematic and dynamic parameters involved in the accident itself and yielding a concrete evidence of the velocity, force, and impulse necessary to cause clinically significant facial trauma. These findings can aid in the design of protective equipment for bicycle riders to help avoid this type of injury.
From the *Western University Schulich School of Medicine and Dentistry, Victoria Hospital; †Western University Hand and Upper Limb Centre, St Joseph's Health Care; ‡Western University Department of Mechanical and Materials Engineering; and §Division of Plastic Surgery, London Health Sciences Centre, Victoria Hospital, London, Ontario, Canada.
Shameer H
SH
Syed
Ryan
R
Willing
Thomas R
TR
Jenkyn
Arjang
A
Yazdani
D000054:Acceleration; D001265:Athletic Injuries / Q000503:physiopathology* / Q000601:surgery; D001642:Bicycling / Q000293:injuries*; D001696:Biomechanical Phenomena; D005147:Facial Bones / Q000293:injuries* / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D012887:Skull Fractures / Q000145:classification / Q000503:physiopathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed; D014741:Video Recording