The nature of an upper limb function impairment following a cervical spinal cord injury (SCI) is bilateral and rather symmetric, which increases the impact of the injury on the independence and quality of life of the affected patient. Therefore, this disorder is very different from stroke and other damages within the peripheral nervous system. Physical training therapy is of high clinical importance in patients with a cervical SCI so as to increase neural plasticity, and thereby improve motor recovery. New rehabilitation therapies based on robots, passive workstations, and functional electrical stimulation (FES) systems have been developed. However, the overall clinical value of these new technology-based therapies in SCI patients needs to be evaluated. Different methods can be used to test or describe the condition of the upper limb function before and after a novel physical training therapy session. We present a detailed functional classification of the hand that can distinguish different levels of impairment with typical impacts on activities of daily living. In consequence, changes between these levels (improvement or deterioration) can be considered clinically meaningful. In addition, upper limb function following SCI can be assessed with measures of capacity and performance, as well as surrogates (electrophysiological and biomedical recordings). While performance tests target on clinically relevant changes by assessing activities related to daily life (i.e., hand function), measures of capacity and surrogates focus on detailed functions (motor and sensory scores, conduction velocity) that do not necessarily correlate with clinically meaningful changes. Nevertheless, capacity tests and surrogates can detect subtle changes induced by interventions that might be missed by clinical measures.