2.4.2. Trunk Stability Assessment
Trunk Impairment Scale
The Trunk Impairment Scale (TIS) is a tool consisting of 17 items that evaluate static and dynamic trunk control and coordination while sitting. The total score ranges from 0 to 23 points, with higher scores indicating better trunk control ability. The inter-rater reliability (r) of the TIS ranges from 0.87 to 0.96, and its intra-rater reliability (r) ranges from 0.85 to 0.99, indicating high reliability and internal validity [