Between-session reliability of performance and asymmetry variables obtained during unilateral and bilateral countermovement jumps in basketball players

Abstract

This study aimed to evaluate the between-session reliability of single-leg performance and asymmetry variables during unilateral and bilateral countermovement jumps (CMJ). Twenty-three basketball players completed two identical sessions which consisted of four unilateral CMJs (two with each leg) and two bilateral CMJs. Mean and peak values of force, velocity and power, impulse, and jump height were obtained separately for each leg using a dual force platform. All performance variables presented an acceptable reliability (CVrange = 4.05–9.98%) with the exceptions of jump height for the unilateral CMJs and mean power, peak velocity, peak power, and impulse for the left leg during the bilateral CMJ (CV≥11.0%). Nine out of 14 variables were obtained with higher reliability during the unilateral CMJ (CVratio≥1.16), and 4 out of 14 during the bilateral CMJ (CVratio≥1.32). Asymmetry variables always showed an unacceptable reliability (ICCrange = 0.15–0.64) and poor/slight levels of agreement in direction (Kapparange = -0.10 to 0.15) for the unilateral CMJ, while an acceptable reliability (ICCrange = 0.74–0.77) and substantial levels of agreement in direction (Kapparange = 0.65 to 0.74) were generally obtained for the bilateral CMJ. These results suggest that single-leg performance can be obtained with higher reliability during the unilateral CMJ, while the bilateral CMJ provides more consistent measures of inter-limb asymmetries.

Effect of a High-Intensity Handball-Specific Fatigue Protocol Focused on the Leg Contralateral to the Throwing Arm on Interlimb Asymmetries

“…Subjects were allowed to use a self-selected squat depth in all CMJ trials (5,15). Unilateral and bilateral CMJ techniques have been reported in detail elsewhere (30). A rest period of 20 seconds was implemented between consecutive jumps.…”

“…The following dependent variables were calculated: maximal instantaneous (1 ms) value of force recorded during the jump, mean value of force during the propulsive phase (i.e., from the first instant in which the velocity of the center of mass was positive [i.e., positive force impulse was equal to the negative force impulse] until the take-off), and the propulsive impulse (mean force of the propulsive phase 3 duration of the propulsive phase). These variables were calculated separately for the right and left legs during both unilateral and bilateral CMJs following standard procedures (30). The propulsive phase duration was also presented to interpret more easily which component (force or time) could be responsible for a change in the propulsive impulse.…”

Associations between Force-Time Related Single-Leg Counter Movement Jump Variables, Agility, and Linear Sprint in Competitive Youth Male Basketball Players

“…Subsequently, after performing a “counter-movement” reaching a self-determined depth (braking), the athlete was instructed to jump as high as possible (take-off). The test trial ended by landing on the plate with the tested leg following the take-off phase [ 34 ] ( Figure 1 ). During the take-off phase, the athletes were not permitted to swing or move the opposite leg in any form and this situation was cautiously monitored by a study researcher.…”

The Ecological Validity of Countermovement Jump to On-Court Asymmetry in Basketball

“…Moreover, with the use of bilateral force plates, CMJ testing may offer the opportunity to identify between-limb differ ences that exist during jump performance. Interlimb asymmetry has been used extensively in rehabilitative settings to help athletes to suc cessfully return to sport and may provide a marker of injury suscep tibility, although the extent to which jump asymmetries relate to risk of injury is equivocal [10][11][12][13][14][15][16][17]. Furthermore, lowerextremity injury is often multifactorial [18][19][20][21][22], and thus it is difficult to determine in jury susceptibility and ultimately flag potential impeding injuries using a univariate measure such as asymmetry obtained from CMJ testing and associated force plate analyses.…”