Validity of the trunk assessment scale for spinal cord injury (TASS) and the trunk control test in individuals with spinal cord injury.

Background: The Trunk Assessment Scale for Spinal Cord Injury (TASS) and the Trunk Control Test for individuals with a Spinal Cord Injury (TCT-SCI) are highly reliable assessment tools for evaluating the trunk function of individuals with SCIs. However, the potential differences in the validity of these two scales are unclear.Objectives: To evaluate the criterion validity of the TASS and the construct validity of the TASS and TCT-SCI.Participants and Methods: We evaluated 30 individuals with SCIs (age 63.8 ± 10.7 yrs, 17 with tetraplegia). To evaluate criterion validity, we calculated Spearman's rho between the TASS and the gold standard (the TCT-SCI). To determine construct validity, we used the following hypothesis testing approaches: (i) calculating Spearman's rho between each scale and the upper and lower extremity motor scores (UEMS, LEMS), the Walking Index for SCI-II (WISCI-II), and the motor score of the Functional Independence Measure (mFIM); and (ii) determining the cut-off point for identifying ambulators with SCIs (≥ 3 points on item 12 of Spinal Cord Independent Measure III) by a receiver operating characteristics analysis.Results: A moderate correlation was confirmed between the TASS and the TCT-SCI (r = 0.68). Construct validity was supported by six of the eight prior hypotheses. The cut-off points for identifying ambulators with SCIs were 26 points (TASS) and 18 points (TCT-SCI).Conclusion: Our results indicate that the contents of the TASS and the TCT-SCI might reflect the epidemiological characteristics of the populations in which they were developed.