Reliability analysis of a sensitive and independent stabilometry parameter set

Abstract

Recent studies have suggested reduced independent and sensitive parameter sets for stabilometry measurements based on correlation and variance analyses. However, the reliability of these recommended parameter sets has not been studied in the literature or not in every stance type used in stabilometry assessments, for example, single leg stances. The goal of this study is to evaluate the test-retest reliability of different time-based and frequency-based parameters that are calculated from the center of pressure (CoP) during bipedal and single leg stance for 30- and 60-second measurement intervals. Thirty healthy subjects performed repeated standing trials in a bipedal stance with eyes open and eyes closed conditions and in a single leg stance with eyes open for 60 seconds. A force distribution measuring plate was used to record the CoP. The reliability of the CoP parameters was characterized by using the intraclass correlation coefficient (ICC), standard error of measurement (SEM), minimal detectable change (MDC), coefficient of variation (CV) and CV compliance rate (CVCR). Based on the ICC, SEM and MDC results, many parameters yielded fair to good reliability values, while the CoP path length yielded the highest reliability (smallest ICC > 0.67 (0.54–0.79), largest SEM% = 19.2%). Usually, frequency type parameters and extreme value parameters yielded poor reliability values. There were differences in the reliability of the maximum CoP velocity (better with 30 seconds) and mean power frequency (better with 60 seconds) parameters between the different sampling intervals.

Comparison of Postural Sway, Plantar Cutaneous Sensation According to Saccadic Eye Movement Frequency in Young Adults

“…In this study, COP parameters, including the sway area (mm 2 ), path length (cm), and speed (cm/s) of COP displacement, were measured as primary outcomes ( Figure 2 A). COP parameters were reliable for 30 s in a bipedal position [ 25 , 26 ]. Therefore, the sampling duration of COP measurements was set to 60 s, as suggested by Carpenter et al [ 27 ], and was measured from 60 s after performing the SEM.…”

Parametric Study of Changes in Human Balancing Skill by Repeated Balancing Trials on Rolling Balance Board

“…In the literature, postural sway is often analysed using a force distribution measuring plate, which provides the two-dimensional wandering of the CoP in the AP and the ML directions [13,[33][34][35], which is then used to define stabilometry parameters [36][37][38]. In case of a uniaxial balance board, oscillations in ML direction are negligible compared to the those in the AP direction, consequently, the balancing task can be described as a one-dimensional motion.…”

“…Nagymáté et al [36,37] and Petró et al [38] collect the most often used stabilometry parameters that can be found in the literature for the characterization of human balancing ability in the AP and the ML directions. Here, we adopt these concepts to the changes in the angles φ a , φ h and φ b .…”

“…In Nagymáté et al [37], path length is determined as the length of the total CoP trajectory during the measurement. Adapting this concept to the one-dimensional balancing task, we define the normalized path length as the sum of the absolute value of the angular rotation increment φ i+1 − φ i at each time interval NPL = −…”

Mechanical Model for Human Balancing on Rolling Balance Board

“…Many different parameters can be found in the literature to characterize the performance during balancing tasks, such as mean power frequency, median frequency, frequency range power ratios, spectral power AP-ML ratio, largest amplitude and corresponding largest frequency, just to mention a few [29,30]. In a previous work of the authors [23], the standard deviation of the balance board angle was used as a measure of balancing skill.…”