Cole-impedance parameters representing biceps tissue bioimpedance in healthy adults and their alterations following eccentric exercise

Abstract

The purpose of this study is to identify if participation in an eccentric exercise protocol altered the Cole-impedance model parameters that represent localized bicep tissue bioimpedance. This supports continued efforts to identify which features of tissue bioimpedance may be effective markers to non-invasively identify skeletal muscle damage. Here, the Cole-impedance model parameters that best fit the localized electrical impedance of exercised (using an eccentric stimulus) and unexercised biceps of 6 participants (collected before, immediately after and at 24 h, 48 h, 72 h and 96 h) are determined using a numerical optimization technique. Statistical tests comparing the pre-exercise and post-exercise model parameters report significant decreases in $R_{\infty }$ and $R_1$ with significant increases in C at 72 h and 96 h post-exercise for exercised biceps (aligning with noted periods of peak swelling). These changes in $R_{\infty },R_1$ , and C were not observed in the unexercised biceps. These results support that the C parameter of the Cole-impedance model fit to bioimpedance data may be a suitable marker for identifying skeletal muscle damage.

Keywords: Bicep tissue; Bioimpedance; Cole-impedance model; Eccentric exercise; Injury Biomarker; Numerical optimization.