Inter-limb Kinetic Asymmetries Differ Between Concentric and Eccentric Phases of the Vertical Jump
Abstract
Inter-limb asymmetries during the vertical jump (VJ) have been used to identify injury risk and performance deficits with >10% being a threshold. Force, or kinetic asymmetries have typically been studied for the concentric (propulsive) phase of the VJ while eccentric (loading) phase analyses are limited. The purpose of this study was to determine if there were differences in inter-limb asymmetry (%) in impulse (force * time) and peak force between VJ eccentric and concentric phases. Results may inform coaches and sport healthcare providers. Participants were 60 highly skilled males (age, 22.7±1.1yrs.; height, 186.4±6.8cm; mass, 103±21.2kg) undergoing training for the National Football League draft. They performed VJ on dual uniaxial force plates allowing for calculation of concentric impulse (CON-IMP), eccentric braking impulse (ECC-IMP), concentric peak force (CON-PF) and eccentric peak force (ECC-PF). Paired t-tests were used to reduce the data, p≤.05. ECC-IMP asymmetry (12.4±9.6%) was significantly greater than CON-IMP asymmetry (6.7±6.1%), t59=3.94, p<.001. On average, ECC-IMP asymmetry was 5.6% greater than CON-IMP (95% CI [8.5, 2.8]). ECC-PF asymmetry (10.3±7.8%) was significantly greater than CON-PF (4.3±4.1%), t59=5.92, p<.001. On average ECC-PF was 6.0% greater than CON-PF (95% CI [8.1, 4.0]). Kinetic asymmetries were greater in the eccentric phase and were >10% in this group; these would go unnoticed if only examining the concentric phase. The eccentric phase may pose increased challenge to achieve symmetry when muscles are lengthening during contraction. Results indicate the necessity of including eccentric kinetics in their VJ analyses to enhance injury prevention and monitoring, and to improve performance.
Faculty Sponsors
Dr. Monique Mokha
Project Type
Event
Location
Alvin Sherman Library
Start Date
4-6-2022 12:00 PM
End Date
4-7-2022 5:00 PM
Inter-limb Kinetic Asymmetries Differ Between Concentric and Eccentric Phases of the Vertical Jump
Alvin Sherman Library
Inter-limb asymmetries during the vertical jump (VJ) have been used to identify injury risk and performance deficits with >10% being a threshold. Force, or kinetic asymmetries have typically been studied for the concentric (propulsive) phase of the VJ while eccentric (loading) phase analyses are limited. The purpose of this study was to determine if there were differences in inter-limb asymmetry (%) in impulse (force * time) and peak force between VJ eccentric and concentric phases. Results may inform coaches and sport healthcare providers. Participants were 60 highly skilled males (age, 22.7±1.1yrs.; height, 186.4±6.8cm; mass, 103±21.2kg) undergoing training for the National Football League draft. They performed VJ on dual uniaxial force plates allowing for calculation of concentric impulse (CON-IMP), eccentric braking impulse (ECC-IMP), concentric peak force (CON-PF) and eccentric peak force (ECC-PF). Paired t-tests were used to reduce the data, p≤.05. ECC-IMP asymmetry (12.4±9.6%) was significantly greater than CON-IMP asymmetry (6.7±6.1%), t59=3.94, p<.001. On average, ECC-IMP asymmetry was 5.6% greater than CON-IMP (95% CI [8.5, 2.8]). ECC-PF asymmetry (10.3±7.8%) was significantly greater than CON-PF (4.3±4.1%), t59=5.92, p<.001. On average ECC-PF was 6.0% greater than CON-PF (95% CI [8.1, 4.0]). Kinetic asymmetries were greater in the eccentric phase and were >10% in this group; these would go unnoticed if only examining the concentric phase. The eccentric phase may pose increased challenge to achieve symmetry when muscles are lengthening during contraction. Results indicate the necessity of including eccentric kinetics in their VJ analyses to enhance injury prevention and monitoring, and to improve performance.
