Question

In voluntary contraction of the skeletal muscles, the muscle potential ranges from ________

(a) 50 uV – 5 mV

(b) 50 mV – 5 V

(c) 0.05 uV – 2 mV

(d) 50 mV – 500 mV

The question was asked during an interview.

This intriguing question originated from Electrodes for EMG topic in chapter Bioelectric Signal and Electrodes of Biomedical Instrumentation

Answer 1

The correct answer is (a) 50 uV – 5 mV

To explain I would say: In voluntary contraction of the skeletal muscles, the muscle potential ranges from 50 uV – 5 mV and duration from 2 to 15 ms. The values vary with the anatomic position of the muscle and the size and location of the electrode. In a relaxed muscle there are no action potentials.