Related Experiment Video
Updated: Jun 8, 2026
13:07
Simultaneous Intracellular Recording of a Lumbar Motoneuron and the Force Produced by its Motor Unit in the Adult Mouse In vivo
Published on: December 5, 2012
Action potential velocity measurements in the upper trapezius muscle
1Division of Applied Work Physiology, National Institute of Occupational Health, S-171 84 Solna, Sweden.
Summary
Action potential velocity (APV) measurement in the upper trapezius is feasible using surface electrodes and a double differential technique. Reliable APV estimates were achieved in males, but challenges were noted in females.
Area of Science:
- Biomedical Engineering
- Neurophysiology
- Musculoskeletal Research
Background:
- Action potential velocity (APV) provides insights into nerve and muscle function.
- Surface electrode techniques are non-invasive but require methodological validation.
- The upper trapezius muscle is crucial for shoulder and neck movement, making its electrophysiological assessment relevant.
Purpose of the Study:
- To investigate the feasibility of measuring APV in the upper trapezius muscle using surface electrodes.
- To evaluate the effectiveness of a double differential amplifier system for APV estimation.
- To identify optimal electrode configurations for reliable APV measurements.
Main Methods:
- Utilized a four-bar electrode array connected to a double differential amplifier.
- Employed a polarity correlation algorithm on a PC for APV estimation.
- Tested five electrode locations (5 mm spacing) in six males and six females during horizontal arm abduction.
Main Results:
- Successful APV estimates were obtained in 5 out of 6 males, averaging 4.8 m/s (SD 0.9) in the two most distal electrode locations.
- Reliable APV measurements were challenging in the female group, potentially due to smaller muscle size and subcutaneous fat.
- The double differential technique proved essential, while single differential attempts were unsuccessful.
Conclusions:
- Surface electrode-based APV measurement in the upper trapezius is feasible, particularly in males.
- Optimal electrode placement is critical, with distal locations yielding better results.
- Methodological considerations, such as muscle dimensions and fat, may influence APV measurement reliability in different populations.
Related Concept Videos
01:24Generation of Action Potential in Skeletal Muscles
Every cell in the body maintains a membrane potential due to an uneven distribution of positive and negative charges across its plasma membrane. The membrane potential is measured in millivolts and quantifies the difference in charge across the membrane.
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the cell's...
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the cell's...
01:14Action Potential
Neurons communicate by firing action potentials—the electrochemical signal that is propagated along the axon. The signal results in the release of neurotransmitters at axon terminals, thereby transmitting information to the nervous system. An action potential is a specific "all-or-none" change in membrane potential that results in a rapid spike in voltage.
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...