Study design: Cross-sectional study using a consecutive sample.
Objectives: To modify the Motor Assessment Scale (MAS) item 3 'balanced sitting' and the Sitting Balance Score (SBS) to ensure suitability for patients with spinal cord injury (SCI), and to assess the inter-rater reliability and validity of these instruments.
Setting: Spinal Care Unit, clinical setting.
Methods: Unsupported sitting was tested by three physiotherapists using MAS and SBS in 48 in-patients with SCI. The validity of the scales was tested using neurological level and extent of injury according to the International Standards for Neurological Classification of Spinal Cord Injury, time since injury and the patients' function, as measured by Functional Independence Measure (FIM) item 9-13 and Five Additional Mobility and Locomotor Items (5AML).
Results: The inter-rater reliability was for MAS (k(w)=0.83-0.91) and for SBS (k(w)=0.69-0.96). The correlation between the balance scales were in relation to; neurological injury level (r(s)=0.19-0.51), extent of injury (r(s)=0.57-0.68) and the functional tests as measured by FIM items 9-13 (r(s)=0.13-0.68, highest for going up and down stairs) and 5AML (r(s)=0.10-0.49). The spread of data on the scales was poor.
Conclusion: The inter-rater reliability of MAS and SBS was very good. The validity was little to moderate, probably because the chosen functional tests measured complex functional tasks and not only unsupported sitting. Both tests appear to be feasible in clinical settings, but will need major revisions. These results can therefore be used as a base for constructing new, better tests of unsupported sitting.