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Activation of human quadriceps femoris during isometric, concentric, and eccentric contractions.
J Appl Physiol (1985). 2001 Dec; 91(6):2628-34.JA

Abstract

Maximal and submaximal activation level of the right knee-extensor muscle group were studied during isometric and slow isokinetic muscular contractions in eight male subjects. The activation level was quantified by means of the twitch interpolation technique. A single electrical impulse was delivered, whatever the contraction mode, on the femoral nerve at a constant 50 degrees knee flexion (0 degrees = full extension). Concentric, eccentric (both at 20 degrees /s velocity), and isometric voluntary activation levels were then calculated. The mean activation levels during maximal eccentric and maximal concentric contractions were 88.3 and 89.7%, respectively, and were significantly lower (P < 0.05) with respect to maximal isometric contractions (95.2%). The relationship between voluntary activation levels and submaximal torques was linearly fitted (P < 0.01): comparison of slopes indicated lower activation levels during submaximal eccentric compared with isometric or concentric contractions. It is concluded that reduced neural drive is present during 20 degrees /s maximal concentric and both maximal and submaximal eccentric contractions. These results indicate a voluntary activation dependency on both tension levels and type of muscular actions in the human knee-extensor muscle group.

Authors+Show Affiliations

Groupe Analyse du Mouvement, Unité de Formation et de Recherche Sciences et Techniques des Activités Physiques et Sportives, Université de Bourgogne, BP 27877, 21078 Dijon Cedex, France. Nicolas.Babault@u-bourgogne.frNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

11717228

Citation

Babault, N, et al. "Activation of Human Quadriceps Femoris During Isometric, Concentric, and Eccentric Contractions." Journal of Applied Physiology (Bethesda, Md. : 1985), vol. 91, no. 6, 2001, pp. 2628-34.
Babault N, Pousson M, Ballay Y, et al. Activation of human quadriceps femoris during isometric, concentric, and eccentric contractions. J Appl Physiol. 2001;91(6):2628-34.
Babault, N., Pousson, M., Ballay, Y., & Van Hoecke, J. (2001). Activation of human quadriceps femoris during isometric, concentric, and eccentric contractions. Journal of Applied Physiology (Bethesda, Md. : 1985), 91(6), 2628-34.
Babault N, et al. Activation of Human Quadriceps Femoris During Isometric, Concentric, and Eccentric Contractions. J Appl Physiol. 2001;91(6):2628-34. PubMed PMID: 11717228.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Activation of human quadriceps femoris during isometric, concentric, and eccentric contractions. AU - Babault,N, AU - Pousson,M, AU - Ballay,Y, AU - Van Hoecke,J, PY - 2001/11/22/pubmed PY - 2002/2/13/medline PY - 2001/11/22/entrez SP - 2628 EP - 34 JF - Journal of applied physiology (Bethesda, Md. : 1985) JO - J. Appl. Physiol. VL - 91 IS - 6 N2 - Maximal and submaximal activation level of the right knee-extensor muscle group were studied during isometric and slow isokinetic muscular contractions in eight male subjects. The activation level was quantified by means of the twitch interpolation technique. A single electrical impulse was delivered, whatever the contraction mode, on the femoral nerve at a constant 50 degrees knee flexion (0 degrees = full extension). Concentric, eccentric (both at 20 degrees /s velocity), and isometric voluntary activation levels were then calculated. The mean activation levels during maximal eccentric and maximal concentric contractions were 88.3 and 89.7%, respectively, and were significantly lower (P < 0.05) with respect to maximal isometric contractions (95.2%). The relationship between voluntary activation levels and submaximal torques was linearly fitted (P < 0.01): comparison of slopes indicated lower activation levels during submaximal eccentric compared with isometric or concentric contractions. It is concluded that reduced neural drive is present during 20 degrees /s maximal concentric and both maximal and submaximal eccentric contractions. These results indicate a voluntary activation dependency on both tension levels and type of muscular actions in the human knee-extensor muscle group. SN - 8750-7587 UR - https://www.unboundmedicine.com/medline/citation/11717228/Activation_of_human_quadriceps_femoris_during_isometric_concentric_and_eccentric_contractions_ L2 - http://www.physiology.org/doi/full/10.1152/jappl.2001.91.6.2628?url_ver=Z39.88-2003&amp;rfr_id=ori:rid:crossref.org&amp;rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -