Related Experiment Video
Updated: Aug 7, 2026
Performing In Vivo and Ex Vivo Electrical Impedance Myography in Rodents
Published on: June 8, 2022
Electrical impedance myography: transitioning from human to animal studies
Rui Nie1, N Abimbola Sunmonu, Anne B Chin
1Department of Neurology, Division of Neuromuscular Diseases, Harvard Medical School, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, TCC 810, Boston, MA 02215, USA.
Objective:
To determine the feasibility of performing electrical impedance myography (EIM) in rats.
Methods:
EIM was performed on the hamstring muscles of 6 healthy adult rats with applied frequencies of 2-300 kHz. Studies were performed over a 6-week period, with 3 rats having recordings made from the skin (surface EIM) and 3 with recordings directly from the muscle (direct-muscle EIM). In addition, sciatic nerve crush was performed on one rat and comparisons made pre- and post-injury. Reactance and resistance were measured and the primary outcome variable, the phase angle (theta), calculated.
Results:
EIM patterns in the rat hamstring muscles were qualitatively similar to those observed in human subjects. This held true for both surface and direct-muscle recordings, although direct-muscle data appeared less repeatable. Sciatic nerve crush data in the single rat showed a dramatic reduction in phase and a relative loss of frequency-dependence.
Conclusions:
EIM data similar to that obtained from human subjects can be acquired from rat muscles with surface recordings proving more consistent and easier to obtain than direct-muscle recordings. Changes seen with sciatic nerve crush mirror those seen in patients with neurogenic injury.
Significance:
These results support the possibility of performing EIM on rat models of neuromuscular disease.
