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Updated: Aug 14, 2026
14:02
Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles
Published on: November 1, 2012
Muscle fatigue induced by stimulation with and without doublets
B Bigland-Ritchie1, I Zijdewind, C K Thomas
1Department of Pediatrics, Yale University Medical School, New Haven, CT, USA.
Muscle & Nerve
|August 22, 2000
Summary
Initial doublets in muscle stimulation trains reduce fatigue and force loss. This finding is crucial for designing effective electrical stimulation for muscle strengthening and rehabilitation.
Area of Science:
- Neuromuscular Physiology
- Biomedical Engineering
Background:
- Muscles are typically stimulated at constant rates.
- Human thenar motor units show optimal force with initial impulse train doublets.
Purpose of the Study:
- To investigate if initial doublets influence fatigue rate in thenar muscles.
- To determine the effect of pulse train composition on force reduction during fatigue.
Main Methods:
- Matched thenar force-time integral using two pulse patterns, one with a doublet.
- Compared fatigue rates between doublet-containing and 40-Hz stimulation trains.
- Assessed force loss after delivering an equal number of pulses.
Main Results:
- Fatigue induced by doublet trains showed slower force and integral reduction.
- Doublet stimulation led to smaller increases in half-relaxation time.
- Force loss was significantly less with doublet-containing pulse trains.
Conclusions:
- Initial doublets in stimulation trains mitigate muscle fatigue.
- Stimulation protocols incorporating doublets are more effective for muscle strengthening and driving paralyzed muscles.
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