A joint actuation device for adding torque to a joint of a user includes an actuation system having an actuator and a spring. A lever is configured to couple to the user's leg and to the actuation system. The lever configured to rotate at a device joint with respect to the actuation system. A first sensor measures a position of the device joint. A second sensor measures deflection in a spring. The actuator is positioned based on the position of the device joint and deflection in the spring. The actuator is configured to deflect the spring to apply a torque the device joint. The device joint aligns with the user's joint to add a torque to the user's joint during a gait activity. The actuator disengages the spring during a non-gait activity. The lever is configured to disengage from the actuator when the device joint exceeds a predetermined angle.