Reliability of dynamic sitting balance tests and their correlations with functional mobility for wheelchair users with chronic spinal cord injury

The purpose of this study is to develop a reliable and valid tool for measuring the dynamic sitting balance of wheelchair users with spinal cord injury. The balance tests were performed in nine patients with chronic spinal cord injury (average of 17.2 years postinjury) between levels C6 and L1, while they were sitting in their wheelchairs and on a standardized stool (unsupported sitting), twice, 7 days apart. Limits of stability (LOS) and sequential weight shifting (SWS) were designed in this study. The balance tests measured participants' volitional weight shifting in multiple directions within their base of support. Their mobility scores on the Spinal Cord Independence Measure III were correlated with the balance test results. The LOS results showed moderate to excellent test–retest reliability (intraclass correlation coefficients ranged from 0.673 to 0.990) for both the wheelchair and the unsupported sitting. The SWS results showed moderate to excellent reliability (intraclass correlation coefficients ranged from 0.688 to 0.952). The LOS results correlated significantly with the Spinal Cord Independence Measure III mobility scores only in case of unsupported sitting, but the SWS test results showed significant correlations in both sitting conditions. To sum up, the sitting LOS and SWS tests are reliable and valid tools for assessing the dynamic sitting balance control of patients with spinal cord injury.