A Wearable Medical System includes a support structure that is configured to be worn by a person. The WMS also includes an electronics module, a cable assembly, and at least one electrode that can be configured to be coupled to the support structure. The cable assembly includes a base member and a cable coupled to the base member. The support structure can be dimensioned relative to the person's body to be worn with tension, and be resiliently stretched under the tension. The stretching of the support structure can stretch the base member of the cable assembly, thus increasing the effective length of the cable, while reducing or even eliminating slack in the cable.