Development of an Alternative Protocol to Study Muscle Fatigue

Area of Science:

• Muscle Physiology
• Biomechanical Engineering

Background:

• Measuring in vivo muscle fatigue using electromyography (EMG) presents challenges like sensor dislodgement and environmental interference.
• Developing reliable postmortem methods is crucial for consistent muscle fatigue research.

Purpose of the Study:

• To establish a postmortem in vivo methodology for inducing and measuring muscle fatigue using EMG.
• To evaluate the efficacy of electric stunning (ES) and electronic muscle stimulation (EMS) in simulating muscle fatigue.

Main Methods:

• Twenty barrows were divided into electric stunning (ES) or control (CON) groups.
• Bicep femoris (BF) and semitendinosus (ST) muscles underwent 20-minute electronic muscle stimulation (EMS) to simulate ambulatory movement.
• Muscle fatigue was assessed using EMG (median power frequency, root mean square) and muscle metabolite analysis (ATP concentration).

Main Results:

• Electronic muscle stimulation (EMS) effectively simulated muscle workload, indicated by changes in EMG parameters.
• No significant acceleration of postmortem muscle fatigue was observed with the electric stunning (ES) treatment.
• ATP concentrations varied between muscle types and treatments, with Semitendinosus (ST) showing a decrease post-EMS.

Conclusions:

• Electronic muscle stimulation (EMS) is a viable tool for simulating physical activity and muscle workload postmortem.
• Electric stunning (ES) does not appear to accelerate postmortem muscle fatigue onset.
• Further research may involve optimizing EMS parameters, such as duration, for more pronounced fatigue induction.