Logo image
Back
Electromyographic activity in superficial muscles of the thigh and hip during the back squat to three different depths with relative loading
Journal article   Open access   Peer reviewed

Electromyographic activity in superficial muscles of the thigh and hip during the back squat to three different depths with relative loading

Benjamin Hammond, Pascual Marques-Bruna, Eric Chuahan and Craig Bridge
Journal of Fitness Research, Vol.5(3), pp.57-67
2016
pdf
PDF - Published Version484.96 kBDownloadView
Published VersionPDF - Published Version Open Access

Abstract

Human Movement and Sports Science biceps femoris gluteus maximus squat depth surface EMG vastus lateralis vastus medialis oblique.
Introduction: Inconclusive previous research on squat depth and the evoked electromyography (EMG)activity muddles our understanding of muscle recruitment in the back squat. This study determined EMGactivity as a function of squat depth in four superficial muscles of the lower limb using relative loading. Method: Eight resistance trained males (mean±SD age: 21±1 years) performed back squats to partial,parallel and full depth using depth-relative 5-repetition-maximum loads. Muscle activity in the vastus medialis oblique (VMO), vastus lateralis (VL), gluteus maximus (GM), and biceps femoris (BF) during the concentric and eccentric phases of the squat was determined using surface electromyography. Peak (PeakEMG), mean (Mean EMG), and integrated (iEMG) EMG normalised to their respective maximum voluntary isometric contraction (MVIC) for each muscle were evaluated. Results: Three-way Anovas and Sidak post-hoc analysis revealed significant effects for squat type (p =0.021 - 0.001), squat phase (p = 0.001), and muscle (p = 0.001). The significant differences were between the partial and the parallel squat (p = 0.016 - 0.001); for iEMG significant effects were also found between the partial and full squat (p = 0.001). The VMO elicited the highest EMG activity (e.g., Peak EMG 93.4±36.9%MVIC; parallel squat, concentric) and the BF the lowest (e.g., Peak EMG 49.9±14.7%). Greater GM activity occurred in parallel squats compared to full squats (mean difference in Peak EMG = 9.1% MVIC). Conclusion: The findings suggest that squatting to the parallel position or lower induces optimal contractile stimulation of the quadriceps. Squatting to parallel depth maximises EMG activation of the GM, possibly due to a more advantageous external moment arm or a reduction in neural drive.

Details

Metrics

282 File views/ downloads
842 Record Views
Logo image