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Knee angle-dependent oxygen consumption of human quadriceps muscles during maximal voluntary and electrically evoked contractions.
Eur J Appl Physiol. 2008 Jan; 102(2):233-42.EJ

Abstract

Fatigability and muscle oxygen consumption (mVO(2)) during sustained voluntary isometric knee extensions are less at extended (30 degrees knee angle; 0 degrees , full extension) versus flexed knee angles (90 degrees). This lower energy consumption may partially result from lower neural activation at extended knee angles. We hypothesized a smaller difference in mVO(2) between extended and flexed knee angles during electrical stimulation, which guaranteed maximal activation, than during maximal voluntary contractions (MVC). In eight healthy young males, MVC extension torque was obtained at 30 degrees, 60 degrees and 90 degrees knee angles. mVO(2) of the rectus femoris (RF), vastus lateralis (VL) and medialis muscle was measured using near-infrared spectroscopy during tetanic (10 s) and maximal voluntary (15 s) contractions (MVC(15)). For electrically induced contractions, steady state mVO(2) was reached at similar (P > 0.05) times after torque onset (4.6 +/- 0.7 s) at all knee angles. In contrast, during MVC(15) at 30 degrees mVO(2) was reached at 7.1 +/- 1.1 s, significantly later compared to 60 degrees and 90 degrees knee angles. The knee angle dependent differences in mVO(2) were not lower in electrically induced contractions (as hypothesised) but were similar as in voluntary contractions. Normalized mVO(2) at 30 degrees (percentage 90 degrees knee angle) was 79.0 +/- 9.4% (across muscles) for electrically induced and 79.5 +/- 7.6% (across muscles) for voluntary contractions (P < 0.05). We conclude that the slower onset of mVO(2) during voluntary effort at 30 degrees may have been due to a lower maximal activation. However, because steady state mVO(2) both during electrically induced and voluntary contractions was approximately 20% less at extended versus flexed knee angles, the causes for the lower mVO(2) must reside within the muscle itself.

Authors+Show Affiliations

Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Van der Boechorststraat 9, 1081 BT, Amsterdam, The Netherlands.No affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article

Language

eng

PubMed ID

17962975

Citation

Kooistra, R D., et al. "Knee Angle-dependent Oxygen Consumption of Human Quadriceps Muscles During Maximal Voluntary and Electrically Evoked Contractions." European Journal of Applied Physiology, vol. 102, no. 2, 2008, pp. 233-42.
Kooistra RD, de Ruiter CJ, de Haan A. Knee angle-dependent oxygen consumption of human quadriceps muscles during maximal voluntary and electrically evoked contractions. Eur J Appl Physiol. 2008;102(2):233-42.
Kooistra, R. D., de Ruiter, C. J., & de Haan, A. (2008). Knee angle-dependent oxygen consumption of human quadriceps muscles during maximal voluntary and electrically evoked contractions. European Journal of Applied Physiology, 102(2), 233-42.
Kooistra RD, de Ruiter CJ, de Haan A. Knee Angle-dependent Oxygen Consumption of Human Quadriceps Muscles During Maximal Voluntary and Electrically Evoked Contractions. Eur J Appl Physiol. 2008;102(2):233-42. PubMed PMID: 17962975.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Knee angle-dependent oxygen consumption of human quadriceps muscles during maximal voluntary and electrically evoked contractions. AU - Kooistra,R D, AU - de Ruiter,C J, AU - de Haan,A, Y1 - 2007/10/26/ PY - 2007/09/13/accepted PY - 2007/10/27/pubmed PY - 2009/2/28/medline PY - 2007/10/27/entrez SP - 233 EP - 42 JF - European journal of applied physiology JO - Eur J Appl Physiol VL - 102 IS - 2 N2 - Fatigability and muscle oxygen consumption (mVO(2)) during sustained voluntary isometric knee extensions are less at extended (30 degrees knee angle; 0 degrees , full extension) versus flexed knee angles (90 degrees). This lower energy consumption may partially result from lower neural activation at extended knee angles. We hypothesized a smaller difference in mVO(2) between extended and flexed knee angles during electrical stimulation, which guaranteed maximal activation, than during maximal voluntary contractions (MVC). In eight healthy young males, MVC extension torque was obtained at 30 degrees, 60 degrees and 90 degrees knee angles. mVO(2) of the rectus femoris (RF), vastus lateralis (VL) and medialis muscle was measured using near-infrared spectroscopy during tetanic (10 s) and maximal voluntary (15 s) contractions (MVC(15)). For electrically induced contractions, steady state mVO(2) was reached at similar (P > 0.05) times after torque onset (4.6 +/- 0.7 s) at all knee angles. In contrast, during MVC(15) at 30 degrees mVO(2) was reached at 7.1 +/- 1.1 s, significantly later compared to 60 degrees and 90 degrees knee angles. The knee angle dependent differences in mVO(2) were not lower in electrically induced contractions (as hypothesised) but were similar as in voluntary contractions. Normalized mVO(2) at 30 degrees (percentage 90 degrees knee angle) was 79.0 +/- 9.4% (across muscles) for electrically induced and 79.5 +/- 7.6% (across muscles) for voluntary contractions (P < 0.05). We conclude that the slower onset of mVO(2) during voluntary effort at 30 degrees may have been due to a lower maximal activation. However, because steady state mVO(2) both during electrically induced and voluntary contractions was approximately 20% less at extended versus flexed knee angles, the causes for the lower mVO(2) must reside within the muscle itself. SN - 1439-6327 UR - https://www.unboundmedicine.com/medline/citation/17962975/Knee_angle_dependent_oxygen_consumption_of_human_quadriceps_muscles_during_maximal_voluntary_and_electrically_evoked_contractions_ L2 - https://dx.doi.org/10.1007/s00421-007-0573-x DB - PRIME DP - Unbound Medicine ER -