IRCT20201206049627N1 IRCT 2021-01-01 The University of Kharazmi Investigation of the relationship between vertical stiffness and time to stability index during landing Investigation of the relationship between vertical stiffness and time to stability index during landing 2020-12-23 anticipated 20 Complete https://irct.ir/trial/52830 observational Randomization: N/A, Blinding: Not blinded, Placebo: Not used, Assignment: Single, Purpose: Other. N/A non. intervention group: Twenty healthy, active males of physical education and sport sciences of Kharazmi University . Each subject performed 15 consecutive hopping jumps bilaterally, unilaterally on dominant leg and unilaterally on non-dominant leg (nine variations in total) with three preferred, maximum and control strategies on the force plate and a single-legged landing test from a 30 cm platform on the force plate with three repetitions. Each subject in just one session in the laboratory performed 15 consecutive hopping jumps bilaterally and unilaterally with three preferred, maximum and control strategies barefoot and hand on waist on the force plate and then performed one-leg landing test on the force plate from a 30 cm platform with three repetitions.. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is non