gistfile1.xml

   <joint name="rover_amalia_joint_chassis_leg_f_r" type="revolute">
      <child>rover_amalia_leg_bar_f_r</child>
      <parent>rover_amalia_chassis</parent>
      <axis>
        <xyz>0 1 0</xyz>
        <dynamics/>
      </axis>
      <physics>
        <ode>
          <provide_feedback>true</provide_feedback>
        </ode>
      </physics>
    </joint>
    ...
    <plugin name="ft_sensor" filename="libgazebo_ros_ft_sensor.so">
      <updateRate>100.0</updateRate>
      <topicName>ft_sensor_topic</topicName>
      <jointName>rover_amalia_joint_chassis_leg_f_r</jointName>
    </plugin>