Many people of all ages have sustained cervical cord injury in traffic accidents or sport accidents, and con sequently suffered physical impairment. For individuals with paralysis of the lower limb who have also lost the ability to extend the elbow, many motions become difficult to perform in daily life, for example, independently operating a wheelchair or pushing open doors. In the future, wearable assist robots are expected to be incorporated into daily life. In order to be wearable, the assist robot must not limit the user's range of motion while being carried or used, and must be suitable for a wide range of situations. In this study, we developed an assist robot for upper limb movement which can assist wheelchair operation. To achieve this, we constructed a model of the upper limb during wheelchair operation with a manipulating force ellipsoid, and we developed an assistance control method for the upper limb using the device to apply force vectors. The effectiveness of the developed system is demonstrated experimentally.