Millions of people worldwide suffer from various disabilities of upper extremities and require daily assistance. However, currently there are no light and portable devices which can provide assistance for shoulder, elbow and hand motions, and the rehabilitation nowadays is mainly limited to hospital environment. In order to address these issues, we developed novel light and highly portable exoskeletons for shoulder and hand assistance and rehabilitation. The shoulder exoskeleton is based on a novel type of actuators called twisted string actuators, which are light, cheap, quiet, and mechanically simple. As a result, the exoskeleton is compact, provides upper limb assistance in 3 degrees of freedom for shoulder and elbow, and is compliant, which improves it safety during interaction with humans. The total weight of the device is less than 3 kg, and all of the power and actuator modules are located at the back of the patient. The device for hand assistance is also completely untethered, supports bidirectional motion of 4 fingers and weighs about 300 grams, including actuators and control electronics.