Rights statement: This is the author’s version of a work that was accepted for publication in Journal of Electromyography and Kinesiology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Electromyography and Kinesiology, 34, 2017 DOI: 10.1016/j.jelekin.2017.03.002
Accepted author manuscript, 356 KB, PDF document
Available under license: CC BY-NC-ND
Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Interplay between body stabilisation and quadriceps muscle activation capacity
AU - Bampouras, Theodoros M.
AU - Reeves, Neil D.
AU - Baltzopoulos, Vasilios
AU - Maganaris, Constantinos N.
N1 - This is the author’s version of a work that was accepted for publication in Journal of Electromyography and Kinesiology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Electromyography and Kinesiology, 34, 2017 DOI: 10.1016/j.jelekin.2017.03.002
PY - 2017/6
Y1 - 2017/6
N2 - The study aimed to distinguish the effect of stabilisation and muscle activation on quadriceps maximal isometric voluntary contraction (MVC) torque generation. Nine subjects performed (a) an MVC with restrained leg and pelvis (Typical MVC), (b) a Typical MVC with handgrip (Handgrip MVC), (c) an MVC focusing on contracting the knee extensors only (Isolated knee extension MVC), and (d) an MVC with unrestrained leg and pelvis (Unrestrained MVC). Torque and activation capacity between conditions were compared with repeated measures ANOVA and dependent t-tests. EMG (from eleven remote muscles) was compared using Friedman’s and Wilcoxon. Typical MVC (277.2 ± 49.6 Nm) and Handgrip MVC (261.0 ± 55.4 Nm) were higher than Isolated knee extension MVC (210.2 ± 48.3 Nm, p < 0.05) and Unrestrained MVC (195.2 ± 49.7 Nm, p < 0.05) torque. Typical MVC (83.1 ± 15.9%) activation was higher than Isolated knee extension MVC (68.9 ± 24.3%, p < 0.05), and both Typical MVC and Handgrip MVC (81.8 ± 17.4%) were higher than Unrestrained MVC (64.9 ± 16.2%, p < 0.05). Only flexor carpi radialis, biceps brachii, triceps brachii and external oblique muscles showed EMG differences, with Isolated knee extension MVC consistently lower than Typical MVC or Handgrip MVC. Stabilisation of the involved segments is the prime concern allowing fuller activation of the muscle, reinforcing the need for close attention to stabilisation during dynamometry-based knee joint functional assessment.
AB - The study aimed to distinguish the effect of stabilisation and muscle activation on quadriceps maximal isometric voluntary contraction (MVC) torque generation. Nine subjects performed (a) an MVC with restrained leg and pelvis (Typical MVC), (b) a Typical MVC with handgrip (Handgrip MVC), (c) an MVC focusing on contracting the knee extensors only (Isolated knee extension MVC), and (d) an MVC with unrestrained leg and pelvis (Unrestrained MVC). Torque and activation capacity between conditions were compared with repeated measures ANOVA and dependent t-tests. EMG (from eleven remote muscles) was compared using Friedman’s and Wilcoxon. Typical MVC (277.2 ± 49.6 Nm) and Handgrip MVC (261.0 ± 55.4 Nm) were higher than Isolated knee extension MVC (210.2 ± 48.3 Nm, p < 0.05) and Unrestrained MVC (195.2 ± 49.7 Nm, p < 0.05) torque. Typical MVC (83.1 ± 15.9%) activation was higher than Isolated knee extension MVC (68.9 ± 24.3%, p < 0.05), and both Typical MVC and Handgrip MVC (81.8 ± 17.4%) were higher than Unrestrained MVC (64.9 ± 16.2%, p < 0.05). Only flexor carpi radialis, biceps brachii, triceps brachii and external oblique muscles showed EMG differences, with Isolated knee extension MVC consistently lower than Typical MVC or Handgrip MVC. Stabilisation of the involved segments is the prime concern allowing fuller activation of the muscle, reinforcing the need for close attention to stabilisation during dynamometry-based knee joint functional assessment.
KW - Electromyography
KW - Interpolated twitch technique
KW - Isometric knee extension
KW - Maximum voluntary contraction
KW - Quadriceps torque
U2 - 10.1016/j.jelekin.2017.03.002
DO - 10.1016/j.jelekin.2017.03.002
M3 - Journal article
VL - 34
SP - 44
EP - 49
JO - Journal of Electromyography and Kinesiology
JF - Journal of Electromyography and Kinesiology
SN - 1050-6411
ER -