Author(s): CRESPEAU, S., MIYAZAKI, T., MORIN, J.B., EDOUARD, P., NAGAHARA, R., Institution: UNIVERSITÉ JEAN MONNET, Country: FRANCE, Abstract-ID: 1372

INTRODUCTION:
Sprint running places significant load on the hamstring muscles, and kinematic features like anterior pelvic tilt, trunk flexion and overstriding have been associated with muscle injuries. The risk of hamstring injuries was reported to be higher in male compared to female athletes. Sex-specific differences from both a physiological and a performance standpoint could lead to different sprint running pattern and thus, different loading of the hamstring muscles, and consequently different hamstring injury risk. Quantifying sex-specific sprint mechanical differences could help tailor injury risk management strategies. The aim of this study was to investigate the differences in sprint running sagittal plane kinetics and kinematics in female and male national-level track & field sprinters.
METHODS:
Female (n=29) and male (n=31) athletes performed a 60-m sprint on an instrumented track. The participants kinematics were captured by a 3D marker-based system comprised of 16 infrared cameras sampling at 250Hz. Force plates embedded in the track were used to capture the athletes ground reaction forces at 1000Hz. Joint and segment angles, torques and muscle-tendon unit lengths were computed with biomechanical modeling. Data was normalized over 100 time points for both the stance and swing phase. Statistical parametric mapping was used to identify significant kinetic and kinematic differences between female and male athletes.
RESULTS:
During the stance phase, female athletes adopted a significantly different posture than males: greater trunk and hip flexion, smaller anterior pelvic tilt angles during the whole phase and less plantar flexion prior to take-off (69-96%). Different force production was also observed during the stance phase, with less hip extension and plantar flexion torque at midstance for females. Differences in posterior chain muscle-tendon unit length were also noted with female athletes displaying longer muscle-tendon unit lengths for gluteus maximus, biceps femoris long head, semi-tendinous and semi-membranous during ground contact. During the swing phase, greater trunk flexion and smaller anterior pelvic tilt angles were observed in female athletes during the whole phase. The hip angle pattern was also different, with a later hip flexion peak (73% of swing for female athletes and 71% for male athletes), and more flexion after take-off (0-4%) and prior to touchdown (83-100%) in female athletes. For the same muscles, swing phase muscle-tendon unit lengths followed a similar trend to the stance phase with longer muscle-tendon unit lengths in female athletes along the whole swing phase.
CONCLUSION:
These preliminary results indicate significant sagittal plane kinetic and kinematic differences between female and male track & field athletes. Acknowledging these differences could help tailor training and injury prevention strategies for female athletes.