Assessment of Functional Improvement without Compensation for Human Spinal Cord Injury: Extending the Neuromuscular Recovery Scale to the Upper Extremities

The Neuromuscular Recovery Scale (NRS) is a tool for measuring functional recovery in spinal cord injured (SCI) persons based on tasks that test pre-injury functional capability. The NRS has been shown to be a valid, reliable, and responsive instrument for measuring functional recovery. The NRS has been updated to include three items measuring upper extremity function, and a new scoring mechanism has been defined. The purpose of this prospective, observational study was to explore the properties of the expanded NRS, introduce and evaluate the new scoring method, and to examine the score's relationship with other SCI outcome measures. The NRS and seven other SCI outcome measures were assessed at enrollment and after every 20 locomotor training sessions in 64 participants of the NeuroRecovery Network (NRN) of the Christopher and Dana Reeve Foundation (CDRF). The NRS exhibited a dominant first principal component that correlated strongly with the new NRS score, as well as a potential secondary component discriminating upper extremity function. The new NRS score and its empirical subscales were generally well-correlated with International Standards for the Neurological Classification of Spinal Cord Injury (ISNCSCI) motor scores and other established SCI functional measures, but exhibited substantial variability at their boundary values. The NRS score was more strongly correlated with other SCI functional measures than ISNCSCI motor scores were. The new NRS score was most responsive to change brought on by locomotor training. The expanded NRS appears to be a valuable tool in measuring functional recovery from SCI; further evaluation of its psychometric properties is warranted.