Wearable electronics undergo stretching, flexing, bending, and twisting during the process of being put on and while being worn. In addition, wearable textile electronics also need to survive under cyclic washing. During such processes, it is necessary to ensure that the electronics as well as the conductors and various other supporting materials remain reliable. In this work, mechanical characterization of various materials in a commercially available smart shirt is presented. The serpentine conductor used in the smart shirt has been carefully examined to understand the strain distribution at various locations under stretching. Both analytical formulations and numerical simulations have been carried out to determine the strain distribution in the serpentine structure, and the results from the simulations have been compared against experimental data obtained through two-dimensional digital image correlation (2D DIC). Various design configurations of the semicircular serpentine structure have been studied in this work, and a relationship between width and the neutral line radius of the semicircular serpentine structure has been obtained to reduce maximum strains in the serpentine structure under stretching.