Are Diminishing Potentiation and Large Extensor Moments the Cause for the Occurrence of the Sticking Region in Maximum Free-Weight Barbell Back Squats among Resistance-Trained Males?
(Roland van den Tillaar, Hallvard Nygaard Falch, Stian Larsen)

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Authors
Roland van den Tillaar, Hallvard Nygaard Falch, Stian Larsen
Abstract

This study compared the kinematics, surface electromyography (sEMG) and kinetics among isometric squats performed at 10 different heights of the upward part and a one-repetition maximum (1-RM) squat. Eleven males (age: 27.5 ± 3.4 years, body mass: 84.9 ± 8.1 kg, body height: 1.79 ± 0.06 m, 1-RM squat: 152.2 ± 20.55 kg) took part in this study. It was found that force output was lowest in the sticking region at around the event of peak deceleration for the 1-RM trial with force output at 2179 ± 212 N. For the isometric trial, the lowest force output occurred at the lowest barbell height (1735 ± 299 N). In addition, for the 1-RM condition hip extension moments peaked at the first four barbell heights (6.5–6.2 Nm/kg) representing the pre-sticking and the sticking region before significantly decreasing during the events representing the post-sticking region. Additionally, the sEMG amplitude peaked for the hip extensors at the barbell heights corresponding to the post-sticking region. Moreover, the sEMG amplitude was significantly higher for the 1-RM condition for all hip extensors, vastus lateralis, and calf muscles (F ≥ 2.7, p ≤ 0.01, ηp2 ≥ 0.25). Therefore, we suggest that the sticking region occurs because of reduced force output in the pre-sticking and the sticking region in back squats among resistance-trained males. The reduced force output is probably a combination of suboptimal internal moment arms, length-tension relationships of the gluteus maximus, hamstring and vastii muscles in the pre-sticking and sticking regions to overcome the large extensor moments together with diminishing potentiation from the pre-sticking to the sticking region.
DOI
DOI: 10.5114/jhk/185720
Citation
 APA 
van den Tillaar, R., Nygaard Falch, H., Larsen, S. (2024). Are Diminishing Potentiation and Large Extensor Moments the Cause for the Occurrence of the Sticking Region in Maximum Free-Weight Barbell Back Squats among Resistance-Trained Males?. Journal of Human Kinetics, 91, 105-119. https://doi.org/10.5114/jhk/185720
Key words
resistance exercise, sticking point, strength, kinetics, kinematics,

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