Specific joint angle dependency of voluntary activation during eccentric knee extensions
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Updated: Mar 9, 2026

Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations
Published on: May 1, 2018
Valentin Doguet1, Valentin Rivière1, Arnaud Guével1
1Laboratory "Movement, Interactions, Performance" (EA 4334), 25 bis Boulevard Guy Mollet, Faculty of Sport Sciences, University of Nantes, 44322, Nantes, France.
Introduction:
This study compared voluntary activation during isometric, concentric, and eccentric maximal knee extensions at different joint angles.
Methods:
Fifteen participants performed isometric, concentric, and eccentric protocols (9 contractions each). For each protocol, the central activation ratio (CAR) was randomly measured at 50°, 75°, or 100° of knee joint angle (0° = full knee extension) using superimposed supramaximal paired nerve stimulations during contractions.
Results:
CAR increased between 50° and 100° during isometric (93.6 ± 3.1 vs. 98.5 ± 1.4%), concentric (92.4 ± 5.4 vs. 99.2 ± 1.2%), and eccentric (93.0 ± 3.5 vs. 96.6 ± 3.8%) contractions. CAR was lower during eccentric than both isometric and concentric contractions at 75° and 100°, but similar between contraction types at 50°.
Conclusions:
The ability to activate muscle maximally is impaired during eccentric contractions compared with other contraction types at 75° and 100°, but not at 50°. Muscle Nerve 56: 750-758, 2017.
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