Test-retest reliability of a novel method for trunk position sense measurement in older adults with and without...

Although the importance of trunk position sense as a clinical outcome measure related to spinal alignment has been established, there is no study evaluating the reliability of measurement techniques for trunk position sense in older adults. Hyperkyphosis is most prevalent in this population and is associated with adverse consequences.

This study aimed to investigate the test-retest reliability of a measurement technique consisting of photogrammetry and angle calculation in older adults with and without hyperkyphosis.

Fifty-three older adults completed the tests. Participants actively reproduced a trunk neutral position (TNP) from both a trunk extended position and a trunk flexed position. Absolute error (AE) and variable error (VE) indices were calculated to quantify position sense acuity. Intraclass Correlation Coefficient was used to estimate relative reliability. Absolute reliability was assessed by calculating Standard Error of the Measurements (SEM) and Minimal Detectable Change (MDC).

The digital photogrammetry showed excellent reliability for horizontal and global components of AE in both hyperkyphosis and control groups while reproducing the TNP from trunk flexion. Also, there was good reliability for AE and VE in the hyperkyphosis group when moving to the TNP from the trunk extension. The MDC values for AE ranged from 0.32 to 0.44 while reproducing the TNP from trunk flexion. The MDC values for AE ranged up to 0.96 when reproducing the TNP from trunk extension.

This study suggests that digital photogrammetry is a reliable method with clinical applicability, which allows the detection of changes after clinical interventions.