A regional oximetry sensor can have a sensor head configured to secure to skin of a user and a stem extending from the sensor head. The sensor head can include an emitter configured to transmit optical radiation into the skin and at least one detector configured to receive the optical radiation after attenuation by blood flow within the skin. The stem can be configured to transmit electrical signals from the sensor head to a cable. A plurality of notches can extend from a perimeter of the sensor head towards an interior thereof. The plurality of notches can form a plurality of independently flexible cutouts in the sensor head configured to allow for movement of at least a portion of the skin of the user underlying the sensor head when the regional oximetry sensor is in use.