Reliability of assessing trunk motor control using position and force tracking and stabilization tasks

Abstract

System-based methods have been applied to assess trunk motor control in people with and without back pain, although the reliability of these methods has yet to be established. Therefore, the goal of this study was to quantify within- and between-day reliability of assessing trunk motor control using systems-based methods involving position and force tracking and stabilization tasks. Ten healthy subjects performed six tasks, involving tracking and stabilizing of trunk angular position in the sagittal plane, and trunk flexion and extension force. Tracking tasks involved following a one-dimensional, time-varying input signal displayed on a screen by changing trunk position (position tracking) or trunk force (force tracking). Stabilization tasks involved maintaining a constant trunk position (position stabilization) or constant trunk force (force stabilization) while a sagittal plane disturbance input was applied to the pelvis using a robotic platform. Time and frequency domain assessments of error (root mean square and H2 norm, respectively) were computed for each task on two separate days. Intra-class correlation coefficients (ICC) for error and coefficients of multiple correlations (CMC) for frequency response curves were used to quantify reliability of each task. Reliability for all tasks was excellent (between-day ICC ≥ 0.8 and CMC > 0.75, within-day CMC > 0.85). Therefore, position and force control tasks used for assessing trunk motor control can be deemed reliable.

Quantitative measures of sagittal plane head–neck control: A test–retest reliability study

“…Our findings are consistent with a previous study conducted by our group(Reeves et al, 2014) that used similar tasks and input signal characteristics for assessing trunk motor control. We observed similar trends to the Reeves et al (2014) study in which tracking tasks were shown to be more reproducible than a position stabilization task.…”

“…The methods used in this study were based on a previous publication by our group investigating trunk motor control(Reeves et al, 2014). We have adapted the same methods to investigate head-neck motor control and the description of these methods was taken from the published material with some slight modifications.…”

“…Various, systems-based measures of motor control have been shown to be reliable, including trunk control(Hendershot et al, 2012; Reeves et al, 2014) and standing balance(Cofre Lizama et al, 2013); however, we are unaware of any studies investigating the reliability of position- and force-controlled tasks of the head-neck system. Therefore, the purpose of this study was to determine the within- and between-day reliability of position tracking, position stabilization and force tracking tasks to quantify head-neck motor control (position refers to angular position throughout the paper).…”

Repeatability of kinematic and electromyographical measures during standing and trunk motion: How many trials are sufficient?

“…Relative reliability was quantified using intraclass correlation coefficients (ICCs), while the standard error of measurement (SEM) was calculated to quantify absolute reliability (Atkinson and Nevill, 1998), which indicates the precision of the measure (Weir, 2005). These measures have been employed to assess the reliability of various kinetic, kinematic, neuromuscular, and performance measures in biomechanical research (Dankaerts et al, 2004;Hidalgo et al, 2012;Montgomery et al, 2011;Ng et al, 2003;Pitcher et al, 2008;Reeves et al, 2014;Stevens et al, 2006). ICCs range from 0.00 to 1.00, with higher values indicating greater reliability.…”

Quantifying balance control during stance

“…These differences were explained by motor learning, changes in posture or stretching of the joints (Reeves et al, 2014;Lariviere et al, 2015;Popovich et al, 2015). In contrast, in a previous study no learning effects were found.…”