What is an electrodiagnosis assessment of the activity of skeletal muscles called?

The assessment of the activity of skeletal muscles through an electrodiagnostic evaluation is referred to as electromyography. This technique involves using small electrodes to detect and record the electrical activity of muscle fibers as they contract and at rest. The data collected can help in diagnosing various neuromuscular disorders and injuries by identifying abnormalities in muscle function and signaling.

In contrast, electrocardiography is the measurement of electrical activity in the heart, which is not related to muscle activity in the skeletal system. Electroencephalography records electrical activity in the brain, and while it's also an important diagnostic tool, it focuses on neurological functions rather than muscular activity. Ultrasonography employs sound waves to visualize structures within the body, particularly soft tissues, but does not measure electrical activity. Thus, electromyography is distinct in its focus on the electrical signals of skeletal muscles, making it the correct answer.