Influence of Modern Studded and Bladed Soccer Boots and Sidestep Cutting on Knee Loading during Match Play Conditions

Abstract

Background The influence of modern studded and bladed soccer boots and sidestep cutting on noncontact knee loading during match play conditions is not fully understood. Hypothesis Modern soccer boot type and sidestep cutting compared with straight-ahead running do not significantly influence knee internal tibia axial and valgus moments, anterior joint forces, and flexion angles. Study Design Controlled laboratory study. Methods Fifteen professional male outfield soccer players undertook trials of straight-ahead running and sidestep cutting at 30° and 60° with a controlled approach velocity on a Fédération Internationale de Football Association (FIFA) approved soccer surface. Two bladed and 2 studded soccer boots from 2 manufacturers were investigated. Three-dimensional inverse dynamics analysis determined externally applied internal/external tibia axial and valgus/varus moments, anterior forces, and flexion angles throughout stance. Results The soccer boot type imparted no significant difference on knee loading for each maneuver. Internal tibia and valgus moments were significantly greater for sidestep cutting at 30° and 60° compared with straight-ahead running. Sidestep cutting at 60° compared with straight-ahead running significantly increased anterior joint forces. Conclusion Varying soccer boot type had no effect on knee loading for each maneuver, but sidestep cutting significantly increased internal tibia and valgus moments and anterior joint forces. Clinical Relevance Sidestep cutting, irrespective of the modern soccer boot type worn, may be implicated in the high incidence of noncontact soccer anterior cruciate ligament injuries by significantly altering knee loading.