Utilizing a handheld electrode array for localized muscle impedance measurements

Electrical impedance myography (EIM) is a noninvasive technique used for assessment of muscle health in which a high‐frequency, low‐amplitude electric current is applied to the skin overlying a muscle, and the resulting surface voltage is measured. We have previously used adhesive electrodes, application of which is inconvenient. We present data using a handheld electrode array (HEA) that we devised to expedite the EIM procedure in a clinical setting. Methods: Thirty‐four healthy volunteers and 24 radiculopathy subjects underwent EIM testing using the HEA and adhesive electrodes. Results: The HEA was shown to have good test–retest reproducibility, with intraclass correlation coefficients as high as 0.99. HEA data correlated strongly with data from adhesive electrodes, ρ = 0.85 in healthy volunteers ( P < 0.001) and ρ = 0.75 in radiculopathy subjects ( P < 0.001). Conclusions: These data support the potential use of a handheld array for performing rapid localized surface impedance measurements. Muscle Nerve 46: 257–263, 2012