A pulse oximetry system for measuring at least one physiological parameter includes a wearable device configured to be secured to a subject's foot, a sensor hub that is removably securable to the wearable device, and a sensor strap connected to the sensor hub and configured to be wrapped around the subject's foot and secured to the wearable device. In some implementations, the wearable device is configured such that the cavity is positioned adjacent a bottom portion of the subject's foot. The system further includes one or more emitters arranged within the sensor hub and configured to face toward said bottom portion of the subject's foot and one or more detectors arranged within the sensor strap and configured to be positioned adjacent a top portion of the subject's foot.