Background: A standard method of assessing postural control is to measure while standing. However, its implementation is usually limited. Recording postural control directly on the trunk in a seated position could provide an alternative diagnostic method for quantifying neuromuscular control. Methods: A comparison of center of pressure (CoP) measurements in the standing and sitting positions was performed on 66 healthy adult subjects. The reliability of the measurements in the sitting position was tested in 23 subjects. In addition, the extension force of all test subjects was recorded. Results: The assessments of CoP fluctuations in standing and seated positions showed adequate agreement (deviation 9.1%). Furthermore, good internal consistencies with a sufficient test–retest reliability could be demonstrated for the measurements in seated position. Both CoP measurement methods showed a comparable Spearman correlation to obtained extension force measurements (standing: 0.24, seated: 0.23). Conclusions: Our results show that recording CoP fluctuations in the sitting position is a reliable and valid adjunct to single-leg stance measurements. It could serve as an additional alternative to quantify neuromuscular control in impaired patients who cannot adequately perform the single-leg stance. In addition, measurement in the seated position allows direct recording of neuromuscular control at the trunk.
A standard method assessing postural control is the measurement in standing position. However, the implementation is usually only possible to a limited extent. Recording of postural control directly on the trunk, in seated position, could provide an alternative diagnostic method for quantifying neuromuscular control. Comparison of the measurements of Center of Pressure (CoP) in standing and seated position was performed on 66 healthy adult subjects. Reliability of measurements in seated position was tested on 23 subjects. In addition, the extension force of all test subjects was recorded. The assessments of CoP fluctuations in standing and seated position showed adequate agreement (deviation 9.1%). Furthermore, good internal consistencies with a sufficient test re test reliability could be demonstrated for the measurements in seated position. Both CoP measurement methods showed a comparable Spearman correlation to obtained extension force measurements (standing: 0.24, seated: 0.23). Our results show that recording CoP flucutations in the seated position is a reliable and valid additional method to measurements in the single legged stance. It could serve as an additional alternative to quantify neuromuscular control in impaired patients in whom single-leg stance cannot be performed adequately. In addition, the measurement in sitting position enables the direct recording of neuromuscular control on the trunk.