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Is there a critical rate of torque development?
Leonardo Henrique Perinotto Abdalla1, Camila Coelho Greco2, Benedito Sérgio Denadai2
1Human Performance Laboratory, UNESP, Av. 24 A, 1515, Bela Vista, Rio Claro, SP, CEP-13506-900, Brazil. leonardo.abdalla@unesp.br.
European Journal of Applied Physiology
|November 20, 2024
Summary
Neuromuscular fatigue impacts the rate of torque development (RTD) and maximal voluntary contraction (MVC) similarly. The extent of this effect depends on muscle group size, with differences observed even after normalizing for muscle volume.
Area of Science:
- Exercise Physiology
- Neuromuscular Physiology
- Biomechanics
Background:
- Neuromuscular fatigue is a complex physiological state affecting muscle force production.
- Understanding how fatigue influences the rate of torque development (RTD) is crucial for optimizing athletic performance and rehabilitation.
Purpose of the Study:
- To investigate the relationship between neuromuscular fatigue and the rate of torque development (RTD) in knee extensors (KE) and plantar flexors (PF) muscles.
- To compare the effects of fatigue on isometric torque and RTD.
Main Methods:
- Nine male participants underwent 5-minute all-out isometric tests for KE and PF muscles.
- Maximal voluntary contraction (MVC) and RTD were measured to determine end-test torque (ET) and critical RTD.
- Submaximal constant-torque tests to task failure were also performed.
Main Results:
- Both MVC and RTD demonstrated hyperbolic behavior, reaching an asymptote at the end of the 5-minute test.
- Relative MVC and RTD values post-fatigue were similar between muscle groups, but statistically different when normalized by muscle volume.
- Torque and RTD post-constant-torque test mirrored ET and critical RTD values, respectively.
Conclusions:
- Neuromuscular fatigue affects RTD and isometric torque in a comparable manner.
- The magnitude of fatigue's impact on torque and RTD is influenced by muscle size.
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