Quantitative Assessment of Proprioception Using Dynamometer in Incomplete Spinal Cord Injury Patients: A Preliminary Study

OBJECTIVE: To investigate the feasibility of a knee proprioception evaluation using a dynamometer as a tool for evaluating proprioception of the lower extremities in patients with incomplete spinal cord injury (SCI), and to explore its usefulness in predicting the ambulatory outcome. METHODS: A total of 14 SCI patients (10 tetraplegic, 4 paraplegic; all AIS D) were included in this study. The passive repositioning error (PRE) and active repositioning error (ARE) were measured with a dynamometer, along with tibial somatosensory evoked potential (SSEP) and abductor hallucis motor-evoked potential (MEP). Ambulatory capacity was assessed with the Walking Index for Spinal Cord Injury II (WISCI-II), both at the time of the proprioception test (WISCI_i) and at least 6 months after the test (WISCI_6mo). RESULTS: The PRE showed a negative correlation with WISCI_i (r=-0.440, p=0.034) and WISCI_6mo (r=-0.568, p=0.010). Linear multiple regression showed the type of injury, lower extremities motor score, MEP, and PRE accounted for 75.4% of the WISCI_6mo variance (p=0.080). CONCLUSION: Proprioception of the knee can be measured quantitatively with a dynamometer in patients with incomplete SCI, and PRE was related to the outcome of the ambulatory capacity. Along with the neurological and electrophysiological examinations, a proprioception test using a dynamometer may have supplementary value in predicting the ambulatory capacity in patients with incomplete SCI.