Abstract
OBJECTIVE: Japanese Orthopaedic Association (JOA) scoring systems were developed to evaluate the neurological function of patients with cervical or lumbar degeneration. As patient-based and multi-dimensional clinical evaluation tools, these systems should be capable of reflecting the walking disability of patients. The association between JOA scores and gait parameters, however, are not well characterized. The purpose of this study was to determine the correlations between JOA scores and gait parameters of patients with cervical spondylotic myelopathy (CSM) and lumbar intervertebral disc herniation (LDH). METHODS: A total of 32 CSM and 30 LDH patients with gait dysfunction were recruited for the present study. All patients were diagnosed by two senior orthopaedic doctors and evaluated with JOA scoring systems. A body-mounted motion analyzer, the Intelligent Device for Energy Expenditure and Activity (IDEEA), was applied to measure gait parameters of patients across 30 m of flat floor in an orthopaedic ward. A linear regression model was used to determine the correlations between JOA scores and gait parameters. Multiple linear regressions were used to identify the relationships between subsections of the JOA systems and gait parameters. RESULTS: Japanese Orthopaedic Association scores of LDH patients from the JOA lumbar scoring system are significantly correlated with gait speed (R (2) = 0.557, P < 0.001) and stride length (R (2) = 0.544, P < 0.001). JOA scores are also correlated with double support duration, step duration, cycle duration and cadence, and weakly correlated with single support duration. For the four subsections of the JOA lumbar scoring system, "restriction of activities of daily living" is the significant predictor of all gait parameters, especially gait speed (R (2) = 0.573, P < 0.001) and stride length (R (2) = 0.553, P < 0.001). However, JOA scores of CSM patients from the JOA cervical scoring system are only weakly correlated with these measures (all R (2) < 0.3). For the four subsections of the JOA cervical scoring system, "motor function of the lower extremity" is a weak predictor of gait parameters (all R (2) < 0.3). CONCLUSIONS: There is a significant correlation between gait parameters and functional disability as measured by the JOA lumbar scoring system, which indicates that the JOA lumbar scoring system can reflect gait impairment. The JOA cervical scoring system, however, may need to be improved for efficiently evaluating the walking ability of CSM patients in the assessment of motor function of the lower extremity.