Abstract
Introduction
This biomechanics investigation evaluated commercially available studded and bladed football boots to determine whether boot type influences potential non-contact ACL injury when football players sidestep cut.
Methods
Fifteen professional outfield male football players, without history of lower limb injury, with at least two consecutive injury-free seasons participated. Each undertook three trials of a straight line run and sidestep cuts at 30° and 60° with approach velocity 5.5ms-1 - 6.0ms-1 on a FIFA (Fédération Internationale de Football Association) approved artificial football surface. Four pairs of standardised football boots (two bladed and two studded) were investigated. Using 3D inverse dynamics analyses based on an eight camera gait analysis system (120Hz) synchronised with a force platform (960Hz), peak absolute knee internal tibial rotational moments (Mz), valgus moments (My) and anterior joint forces (Fx) were determined throughout the stance phase. Values were compared with cadaveric critical limits for ACL injury. A univariate repeated measures ANOVA quantified differences between the variables as a function of cutting angle and boot type.
Results
Comparisons between the investigated boots revealed Mz, My and Fx were similar for each manoeuvre. Straight line running using studded and bladed boots was associated with Mz, My and Fx insufficient for cadaveric injury. Sidestep cutting using studded and bladed boots resulted in Mz and My significantly greater than during straight line running (p < 0.001), Mz and Fx exceeding critical limits and My values which did not.
Conclusion
The boot type did not significantly alter potential non-contact ACL injury based on cadaveric critical limits. Sidestep cutting using studded and bladed football boots resulted in Mz and Fx sufficient for non-contact ACL injury. Sidestep cutting, when compared to straight line running, may influence potential non-contact ACL injury more than the boot type used by altering knee joint loading to a greater extent.
