Reliability of the sub-components of the instrumented timed up and go test in ambulatory children with traumatic brain injury and typically developed controls.

BACKGROUND: Studies have evaluated the test-re-test reliability of subcomponents of the timed up and-go test in adults by using body-worn inertial sensors. However, studies in children have not been reported in the literature. RESEARCH QUESTION: To evaluate the within-session reliability of subcomponents of a newly developed electronically augmented timed 'upand-go' test (EATUG) in ambulatory children with traumatic brain injury (TBI) and children with typical development (TD). METHOD: The timed up and go test was administered to twelve consecutive ambulatory children with moderate to severe TBI (6 males and 6 females, age 10.5 ±â€¯1.5 years, range 8-13 years, during inpatient rehabilitation at 27.0 ±â€¯11.8 days following injury) and 10 TD age and sex-matched children (5 males and 5 females, 10.4 ±â€¯1.3 years, range 8-11 years). Participants wore a single chest-mounted inertial measurement sensor package with custom software that measured angular and acceleration velocity and torso flexion and extension angles, while they performed 6 trials of the EATUG test. Measures were derived from the overall time to complete the TUG test, angular velocity and angular displacement data for torso flexion and extension during sit-to-stand and stand-to-sit segments and both mean and peak angular velocities for two turning segments (i.e. turning around a cone and turning-before-sitting). RESULTS: Within-session reliability of the subcomponents of the TUG test for children with TBI assessed by the intra-class correlation coefficient was ICC (1,1) = 0.84, (range 0.82-0.96), and for TD children ICC (1,1) = 0.73, (range 0.53-0.89). Scores on Total Time, maximum torso flexion/extension angle and peak flexion angular velocity during sit-tostand, and peak turn angular velocity for both turns around the cone and turns before sitting were lower for children with TBI than for TD children (p ≤ 0.05). SIGNIFICANCE: The EATUG test is a reliable measure of physical function in children with TBI who are being discharged from inpatient rehabilitation.