Single-leg mechanical performance and inter-leg asymmetries during bilateral countermovement jumps: A comparison of different calculation methods

Danica Janicijevic; Nejc Sarabon; Alejandro Pérez-Castilla; Darjan Smajla; Andrés Fernández-Revelles; Amador García-Ramos

doi:10.1016/j.gaitpost.2022.05.012

Single-leg mechanical performance and inter-leg asymmetries during bilateral countermovement jumps: A comparison of different calculation methods

Gait Posture. 2022 Jul:96:47-52. doi: 10.1016/j.gaitpost.2022.05.012. Epub 2022 May 10.

Authors

Danica Janicijevic¹, Nejc Sarabon², Alejandro Pérez-Castilla³, Darjan Smajla⁴, Andrés Fernández-Revelles³, Amador García-Ramos⁵

Affiliations

¹ Research Academy of Human Biomechanics, The Affiliated Hospital of Medical School of Ningbo University, Ningbo University, Ningbo, China; Faculty of Sports Science, Ningbo University, Ningbo, China; University of Belgrade, Faculty of Sport and Physical Education, The Research Centre, Belgrade, Serbia.
² University of Primorska, Faculty of Health Sciences, Izola, Slovenia; InnoRenew CoE, Human Health Department, Izola, Slovenia; S2P, Science to Practice, Ltd., Laboratory for Motor Control and Motor Behavior, Ljubljana, Slovenia.
³ University of Granada, Faculty of Sport Sciences, Department of Physical Education and Sport, Granada, Spain.
⁴ University of Primorska, Faculty of Health Sciences, Izola, Slovenia; InnoRenew CoE, Human Health Department, Izola, Slovenia.
⁵ University of Granada, Faculty of Sport Sciences, Department of Physical Education and Sport, Granada, Spain; Universidad Catolica de la Santísima Concepcion, Faculty of Education, Department of Sports Sciences and Physical Conditioning, Concepción, Chile. Electronic address: amagr@ugr.es.

PMID: 35569352
DOI: 10.1016/j.gaitpost.2022.05.012

Abstract

Background: The possibility to selectively assess the force exerted by each leg during bilateral jumps has allowed sport scientists to explore inter-leg asymmetries, this metric being a rich source of research due to its potential applications to improve sports performance and reduce the risk of injury. The purpose of this study was to explore the reliability and agreement of single-leg mechanical performance and inter-leg asymmetry variables obtained by two procedures of analysis (Synchronous [simultaneous jump detection for both legs] and Asynchronous [specific jump detection for each leg]) during bilateral countermovement jumps (CMJs).

Method: During a single testing session, 74 participants performed 5 maximal height bilateral CMJs on dual force platforms (Kistler, model 9260AA6, Winterthur, Switzerland), and the 2 trials that differed the least in terms of squat depth and jump height were considered for statistical analyses. The following mechanical variables were calculated separately for each leg using the Synchronous and Asynchronous procedures: mean force, peak force, and propulsive impulse.

Results: The procedures showed comparable reliability, except for mean force and propulsive impulse of the left leg (higher for the Asynchronous procedure). The agreement between the procedures was very high, while the most reliable mechanical variable was mean force (CV≈2.9%, ICC≈0.98), followed by peak force (CV≈4.4%, ICC≈0.96) and propulsive impulse (CV≈6.4%, ICC≈0.91). Reliability of inter-leg asymmetries was greater using mean and peak force (ICC range=0.74-0.82) than using propulsive impulse (ICC range = 0.65-0.66).

Significance: Both Synchronous and Asynchronous procedures can be used to evaluate single-leg mechanical performance (mean force, peak force, and propulsive impulse) and asymmetries, whereas mean force should be used to evaluate single-leg mechanical performance and mean or peak force to assess asymmetries.

Keywords: Bilateral deficit; Force platform; Kinetic; Testing.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Athletic Performance*
Humans
Leg*
Posture
Reproducibility of Results