1. A joint driving apparatus comprising:a housing unit fixed to a first link;
a driving unit housed in the housing unit and adapted to rotationally drive a second link, an output shaft of the driving unit being connected to the second link;
a bearing fixed to the housing unit, the bearing (i) adapted to rotatably support the second link and (ii) configured to couple the second link to the housing unit; and
a supporting unit configured to couple the driving unit to the housing unit and configured to support the driving unit on the housing unit, the supporting unit including (i) an elastic body configured to deform according to a relative movement of the driving unit in relation to the housing unit in a rotating direction of the second link and (ii) a sensor configured to measure a torque based on the deformation of the elastic body.