Effect of Gender and Defensive Opponent on the Biomechanics of Sidestep Cutting

Abstract

A simulated defense player causes increased lower limb movements and forces, and should be a useful addition to laboratory protocols for sidestepping. Gender differences in the joint kinematics suggest that increased knee valgus may contribute to ACL injury risk in women, and that the hip and ankle may play an important role in controlling knee valgus during sidestepping. Consideration of the entire lower extremity contributes to an understanding of injury mechanisms and may lead to better training programs for injury prevention.

Sagittal plane biomechanics cannot injure the ACL during sidestep cutting

“…Specifically, all simulated variables fell within the pre-defined criteria of two standard deviations from the measured data. The lower limb joint kinematics quantified during sidestep cutting for each subject were also consistent with those reported previously (Colby et al, 2000;McLean et al, 1999McLean et al, , 2004aNeptune et al, 1999). Based on these results, optimized models RMS fit error corresponds to the average difference in terms of SD�s between simulated and measured data.…”

“…However, the above differences are consistent with those observed previously for gender comparisons of lower limb joint kinematics during sidestep cutting (Malinzak et al, 2001;McLean et al, 2004a,b) and jump landing (Ford et al, 2003) tasks. Such differences are suggested to stem from concomitant gender-based differences in lower limb anatomy (McLean et al, 1999) and NMC during movement execution (Boden et al, 2000;Griffin et al, 2000;McLean et al, 2004a). These assertions appear substantiated considering that in the current case, lower limb alignment and initial con tact (NMC) conditions for each model were subject spe cific.…”

“…5) also suggests that this variable may be an important contrib utor to the gender disparity observed in the risk of ACL injury. Recent kinematic (Ford et al, 2003;Malinzak et al, 2001;McLean et al, 1999McLean et al, , 2004a and prospective (Hewett et al, 2004) studies similarly propose knee val gus and valgus loading to be key predictors of ACL in jury in females. The means by which lower limb NMC parameters may manifest in terms of valgus loading dur ing movements such as sidestep cutting requires further investigation.…”

“…1). Specifi cally, subjects were required to land and sidestep cut off the right leg, such that that the cutting action moved the subject forward and to the left of the force plate at the appropriate angle (McLean et al, 1999(McLean et al, , 2004a) (see Fig. 1).…”

“…Another important component of the sagittal plane loading mechanism during execution of sports move ments is the presence of a large ground reaction force (GRF), which is directed posteriorly with respect to the tibial axis (McLean et al, 2004a). This force would help protect the ACL during the landing phase of these movements, but has not been taken into account in cur rent theories on sagittal plane contributions to ACL in jury.…”