Original articles  EXERCISE PHYSIOLOGY AND BIOMECHANICS 

The Journal of Sports Medicine and Physical Fitness 2007 December;47(4):377-84

Copyright © 2007 EDIZIONI MINERVA MEDICA

language: English

Lower extremity kinematics and kinetics of Division III collegiate baseball and softball players while performing a modified pro-agility task

Wallace B. J. ^{1, 2}, Kernozek T. W. ¹, Bothwell E. C. ²

¹ Department of Health Professions University of Wisconsin-La Crosse, La Crosse, WI, USA 2 Department of Exercise and Sport Science University of Wisconsin-La Crosse, La Crosse, WI, USA

Aim. Females experience at least twice as many non-contact anterior cruciate ligament (ACL) injuries as males. The aim of this study was to investigate if males and females exhibited different characteristics while performing a modified pro-agility test.
Methods. Collegiate Division III male baseball (n=14) and female softball (n=13) players performed 4 trials of a modified pro-agility task, which consisted of running toward a force platform target for 5 steps, planting their right foot, and propelling themselves off of the target with their left foot. Kinematic and kinetic parameters were compared using a multivariate analysis of variance between gender with the level of significance set at P<0.05.
Results. Males and females exhibited similar knee valgus angles. Females had a greater maximum knee extension angle (10.14° vs 17.43°), and greater knee range of motion (46.12° vs 40.12°). Both groups reached maximum knee flexion at 52% of stance. Females had significantly more maximum hip flexion than males (28.86° vs 22.75°). Females had significantly smaller minimum internal knee varus moments than their male counterparts (1.12 Nm/kg vs 1.55 Nm/kg). Vertical ground reaction forces as a percentage of bodyweight, and stance time, were not statistically different. The female group displayed an external knee rotation angle (2.49°) during the beginning of their stance, which was significantly different than the internal rotation angle (4.11°) in the male group. Early in stance knee rotation angle was highly correlated with the lack of internal knee varus moment (males R2=0.75, females R2=0.88).
Conclusion. Females displayed knee moments and kinematics that may place them at greater risk for ACL injury during a stop-cut task. Females should be coached to perform stop cuts with more knee flexion and a more neutral knee rotation angle upon foot contact in an effort to reduce moments that may place the ACL at risk.