Effects of Leg Stiffness Regulated by Different Landing Styles on Vertical Drop Jump Performance

Abstract

The purpose of this study was to investigate the effects of stiffness regulated by landing styles on drop jump performance. Twenty-four male lacrosse athletes performed drop jumps with stiff (ST), self-selected (SS), and soft (SF) landing from a 0.42 m box. Leg stiffness, ground contact time, depth, jump height, maximum ground reaction force (GRF), GRF at the start of the propulsive phase, mean power, peak power, and the reactive strength index (RSI) were calculated. The results showed that jump height and the RSI had strong correlations to power production in all drop jump styles. Power would be a key factor to overall athletic performance. Repeated measures ANOVA showed significant differences (p < 0.05) in all variables among the three styles. Drop jumps with SS landing had comparable jump height to drop jumps with SF landing and power output to drop jumps with ST landing. Drop jumps with ST landing had significantly lower jump height, but higher GRF, power, and the RSI compared to drop jumps with SF landing. In drop jump testing, drop jumps with SS landing should be used if power and jump height were the major concerns; if the RSI was the major concern, drop jumps with ST landing should be used. Training with drop jumps, one of the main objectives should be increasing power output due to its significant correlation to jump height and the RSI in all conditions.

Relationship between Muscle-Tendon Stiffness and Drop Jump Performance in Young Male Basketball Players during Developmental Stages

“…These results are in line with a recent investigation by Ando, et al (2021) [ 21 ], which showed that medial gastrocnemius stiffness (measured during a 15 cm drop jump as the shear modulus through ultrasound shear wave elastography) correlated with the same performance parameters (RSI and JH) but not with the contact time. In addition, our results are in line with other studies [ 38 , 39 ] in which the authors demonstrated that drop jumps performed with different modes and instructions show different responses. In particular, the authors showed that when participants were asked to reach the maximum jump height or to make their best effort, without further instruction, they obtained the best JH, with no correlation with contact time.…”

Subsequent Jumping Increases the Knee and Hip Abduction Moment, Trunk Lateral Tilt, and Trunk Rotation Motion During Single-Leg Landing in Female Individuals

“…On the other hand, the peak vertical reaction force during SDVJ was smaller than that during SDL despite the same landing height between the two landings 13 . Additionally, the vertical ground reaction force during the landing phase is not correlated with jumping height in the drop vertical jump task 50 . The peak vertical ground reaction force is usually observed within 63.5 ms after initial contact during single-leg landing 34 and is not associated with subsequent jumping after landing.…”

Reliability of a Pendulum Apparatus for the Execution of Plyometric Rebound Exercises and the Comparison of Their Biomechanical Parameters with Load-Matching Vertical Drop Jumps

“…Stiffness, although its optimal regulation enhances performance and power output [59][60][61], was not found to be a determining feature for VDJ performance [7,62]. Nevertheless, K VERT was significantly higher in the VDJ than in the HPRJ.…”