A wearable computing device comprising: a device body; and a band for affixing the device body to a user of the wearable computing device, wherein the device body comprises: a touch-sensitive display; a rotatable element about the touch-sensitive display; an encoder for detecting rotation of the rotatable element; one or more sensors; one or more processors; and a memory coupled to the processors and comprising instructions executable by the processors, the processors being operable when executing the instructions to: detect, by the one or more sensors of the wearable computing device when worn on a limb of a user, a gesture activating a component or an application of the wearable computing device; detect, by the one or more sensors of the wearable computing device when worn on the limb of the user, an initial position and a movement of the limb, the limb of the user being a wrist of the user; determine (6225, 6325) a gesture made by the user based at least in part on the movement; and process the gesture as an input to the component or the application of the wearable computing device, wherein the gesture made by the user is determined as one of a wrist rotational motion and an elbow rotational motion corresponding to a combination of the detected initial position and a radius of the movement of the limb. a device body; and a band for affixing the device body to a user of the wearable computing device, wherein the device body comprises: a touch-sensitive display; a rotatable element about the touch-sensitive display; an encoder for detecting rotation of the rotatable element; one or more sensors; one or more processors; and a memory coupled to the processors and comprising instructions executable by the processors, the processors being operable when executing the instructions to: detect, by the one or more sensors of the wearable computing device when worn on a limb of a user, a gesture activating a component or an application of the wearable computing device; detect, by the one or more sensors of the wearable computing device when worn on the limb of the user, an initial position and a movement of the limb, the limb of the user being a wrist of the user; determine (6225, 6325) a gesture made by the user based at least in part on the movement; and process the gesture as an input to the component or the application of the wearable computing device, wherein the gesture made by the user is determined as one of a wrist rotational motion and an elbow rotational motion corresponding to a combination of the detected initial position and a radius of the movement of the limb. a touch-sensitive display; a rotatable element about the touch-sensitive display; an encoder for detecting rotation of the rotatable element; one or more sensors; one or more processors; and a memory coupled to the processors and comprising instructions executable by the processors, the processors being operable when executing the instructions to: detect, by the one or more sensors of the wearable computing device when worn on a limb of a user, a gesture activating a component or an application of the wearable computing device; detect, by the one or more sensors of the wearable computing device when worn on the limb of the user, an initial position and a movement of the limb, the limb of the user being a wrist of the user; determine (6225, 6325) a gesture made by the user based at least in part on the movement; and process the gesture as an input to the component or the application of the wearable computing device, wherein the gesture made by the user is determined as one of a wrist rotational motion and an elbow rotational motion corresponding to a combination of the detected initial position and a radius of the movement of the limb. detect, by the one or more sensors of the wearable computing device when worn on a limb of a user, a gesture activating a component or an application of the wearable computing device; detect, by the one or more sensors of the wearable computing device when worn on the limb of the user, an initial position and a movement of the limb, the limb of the user being a wrist of the user; determine (6225, 6325) a gesture made by the user based at least in part on the movement; and process the gesture as an input to the component or the application of the wearable computing device, wherein the gesture made by the user is determined as one of a wrist rotational motion and an elbow rotational motion corresponding to a combination of the detected initial position and a radius of the movement of the limb.