Between-Leg Mechanical Differences as Measured by the Bulgarian Split-Squat: Exploring Asymmetries and Relationships with Sprint Acceleration

Robert G Lockie; Fabrice G Risso; Adrina Lazar; Dominic V Giuliano; Alyssa A Stage; Tricia M Liu; Megan D Beiley; Jillian M Hurley; Ibett A Torne; John J Stokes; Samantha A Birmingham-Babauta; DeShaun L Davis; Ashley J Orjalo; Matthew R Moreno

doi:10.3390/sports5030065

Between-Leg Mechanical Differences as Measured by the Bulgarian Split-Squat: Exploring Asymmetries and Relationships with Sprint Acceleration

Sports (Basel). 2017 Sep 1;5(3):65. doi: 10.3390/sports5030065.

Authors

Affiliations

¹ Department of Kinesiology, California State University, Fullerton, CA, 92831, USA. rlockie@fullerton.edu.
² Department of Kinesiology, California State University, Fullerton, CA, 92831, USA. fabricerisso@csu.fullerton.edu.
³ Department of Kinesiology, California State University, Northridge, CA, 91330, USA. adrina.lazar.957@my.csun.edu.
⁴ Department of Kinesiology, California State University, Northridge, CA, 91330, USA. dominic.giuliano.871@my.csun.edu.
⁵ Department of Kinesiology, California State University, Northridge, CA, 91330, USA. alyssa.stage.634@my.csun.edu.
⁶ Department of Kinesiology, California State University, Northridge, CA, 91330, USA. tricia.tomita.228@my.csun.edu.
⁷ Department of Kinesiology, California State University, Northridge, CA, 91330, USA. meganbeiley@gmail.com.
⁸ Department of Kinesiology, California State University, Northridge, CA, 91330, USA. jillian.hurley.288@my.csun.edu.
⁹ Department of Kinesiology, California State University, Northridge, CA, 91330, USA. ibett.torne.734@my.csun.edu.
¹⁰ Department of Kinesiology, California State University, Northridge, CA, 91330, USA. john.stokes.91@my.csun.edu.
¹¹ Department of Kinesiology, California State University, Northridge, CA, 91330, USA. samantha.birminghambabauta.162@my.csun.edu.
¹² Department of Kinesiology, California State University, Fullerton, CA, 92831, USA. deshaunl.davis@csu.fullerton.edu.
¹³ Department of Kinesiology, California State University, Fullerton, CA, 92831, USA. ashley.orjalo@csu.fullerton.edu.
¹⁴ Department of Kinesiology, California State University, Fullerton, CA, 92831, USA. moreno.matthewr@csu.fullerton.edu.

Abstract

Between-leg strength differences can negatively influence sprint acceleration. The challenge is to find a method to measure this within a unilateral exercise. This study analyzed a five repetition-maximum (5RM) Bulgarian split-squat (BSS) to identify between-leg differences for the dominant and non-dominant legs in peak and mean power, force, and velocity as measured by a linear position transducer. Between-leg differences in these variables were correlated with 20-m (0⁻5, 0⁻10, 0⁻20 m intervals) sprint velocity. Eight men were assessed in the 5RM BSS and 20-m sprint. T-tests calculated between-leg differences in power, force, and velocity. Spearman's correlations calculated relationships between the between-leg differences in the mechanical variables with velocity over each interval. When comparing the dominant and non-dominant legs, there were significant (p = 0.002⁻0.056) differences in 11 of 12 variables. However, percentage differences were low (~0.3⁻12%). There was one large, non-significant correlation (best repetition mean force between-leg difference and 0⁻5 m velocity; ρ = -0.810) out of 36 relationships. The BSS can provide a profile of between-leg differences in power, force, and velocity. There were limited relationships between the BSS between-leg differences and 20-m sprint velocities. Smaller between-leg differences in BSS power, force, and velocity could ensure minimal impact on acceleration.

Keywords: force; power; single-leg; sprinting; unilateral strength; velocity.