Effects of lead leg selection on bilateral landing force‐time characteristics: Return to sport testing implications

We quantified the effect of lead leg selection on landing force–time characteristics during a vertical drop landing (VDL) initiated with a step‐off. Plyometric‐trained subjects (male: n = 8; female: n = 5; age =23 ± 3.3 years; body mass =74.4 ± 11.2 kg) performed 6 step‐off‐initiated VDLs from a 45‐cm box ( n = 3/lead leg). Pooled and lead leg stratified between‐limb comparisons of limb‐specific initial ground contact timing, peak vertical ground reaction force (Fz peak ), and early landing‐phase impulse (Impulse 100ms ) were assessed by a two‐factor, within‐subject ANOVA, and limb symmetry indexes were calculated ( α = 0.05). Pooled data showed that the lead leg made contact prior to the trail leg and contributed a greater fraction to Fz peak compared with the trail leg. Stratifying trials by lead leg selection led to significant between‐limb differences in Fz peak ( p < 0.05) and Impulse 100ms ( p < 0.01) with the right leg leading but not with the left leg leading. Lead leg selection in step‐off‐initiated VDLs influenced landing performance and limb symmetry indexes of variables associated with lower limb injury risk, suggesting the need to control for lead leg selection in these tasks. A step‐off may not be a suitable technique to initiate landing tasks when assessing limb symmetry.