Does limb specialization in track and field introduce asymmetry in dynamic stability?

Limb dominance is routinely assessed through self-report, often referring to the preferred limb for kicking a ball. Subjective classifications inform a priori limb assignments for quantitative contrasts in functional tasks. The purpose of this study was to explore hop landing kinetic profiles between limbs with respect to three limb dominance definitions: two self-report methods (Kicking Dominance vs. Sport Specialization) and an experimentally determined Functional Dominance (faster stabilizer) for the athletes, while kicking dominance was used in both self-report classifications in the non-athlete controls. To test limb and/or group effects, healthy male controls (N = 19) and varsity DIII Track & Field athletes (N = 20) that participated in a sprint, hurdle, or jump event performed forward hops onto a force platform. Limb*group interactions were observed when classifying limbs by sport-specific demands (e.g. take-off limb for a jumper). The athletes’ dominant limb performed better than their non-dominant limb while the opposite limb response was noted in the controls. Finally, limb dominance according to the faster stabilizing side identified meaningful limb effects. Faster stabilization was accomplished with a larger peak force, loading rate, and impulse compared to the slower stabilizing limb. These characteristics should be considered when defining limb dominance in biomechanics research, prescribing training, or making return to play decisions after injury, as limb definition choice can alter conclusions. Functional dominance in a biomechanical task, such as landing, may differ from self-reported dominance when the surveyed task represents a dissimilar neuromuscular task, such as kicking.