The Immediate Effects of a Standardized Kettlebell Swing Protocol on Lumbar Paraspinal Muscle Function

Background: Kettlebell swings are commonly utilized to target the lumbar erector spinae and lower body musculature. This exercise exhibits distinct loading properties that requires cyclical contraction of the trunk extensors and posterior chain, potentially explaining its novel influence on muscle contractility. Tensiomyography (TMG) is a reliable, noninvasive, passive technique that may be used to examine muscular fatigue produced by kettlebell swings. Purpose: The purpose of this randomized control trial is to determine the extent of muscle fatigue in the lumbar erector spinae musculature secondary to a high-intensity interval kettlebell swing protocol utilizing TMG previously published by Jay et. al in 2011. Subjects: Forty-one adults between the ages of 18 and 45 were recruited. Inclusion criteria included subjects with no recent history of low back pain and clearance by the physical activity readiness questionnaire. Methods: Participants were randomly allocated to either a kettlebell swing group (KBS; n=21) or a control group (CON; n=20) who only performed the unloaded warm up. Participants were assessed at baseline, post-intervention, and 24-hours post-intervention for bilateral erector spinae fatigue, measured by five TMG parameters (Dm, Tc, Tr, Td, Ts).