A wearable medical system configured to be worn by a person, comprising a support structure configured to be worn by the person, a monitoring device configured to monitor at least one physiological parameter of the person, wherein the at least one physiological parameter includes an electrocardiogram (ECG) reading of the person, an electrode coupled to the support structure, an energy storage device configured to store an electric charge for use in delivering a shock to the person through the electrode, and a biasing mechanism comprising at least one of an inflatable device, a hydraulic device, an electromagnetic device, and/or a screw gun device, the biasing mechanism configured to transition from the unbiased state to the biased state responsive to a value of the at least one physiological parameter reaching a threshold. The electrode is more movable with respect to the person's body in the unbiased state than the biased state.