One-leg stance in healthy young and elderly adults: A measure of postural steadiness?
ABSTRACT To investigate postural steadiness during 30 s of one-leg stance in healthy young and elderly adults, by analysing the pattern of the ground reaction force variability.
A laboratory set-up was used to analyse the variability of the ground reaction forces in relation to time as a measure of postural steadiness.
The one-leg stance test is a measure considered to assess postural steadiness in a static position by a temporal measurement. The common notion is that a better postural steadiness, i.e. less force variability, allows for longer time standing on one leg. However, there is lack of evidence how postural steadiness during one-leg stance changes over time.
Twenty-eight healthy elderly and 28 healthy young adults were tested by means of force plates assessing ground reaction forces while performing one-leg stance.
During one-leg stance, two phases could be identified in both groups: First a dynamic phase, a rapid decrease of force variability, and thereafter a static phase, maintaining a certain level of force variability. During the first 5 s of one-leg stance the force variability decreased significantly more in the young group resulting in a lower force variability level during the static phase than in the elderly.
The difficulties in maintaining the static position in elderly seems dependent on the reduced initial decrease in force variability and/or musculoskeletal components. We suggest that the first 5 s are crucial when assessing balance during one-leg stance.
Physiotherapy 05/2015; 101:e176. DOI:10.1016/j.physio.2015.03.332 · 1.91 Impact Factor
- "Raw data for mediolateral ground reaction force variability in individual participants with multiple sclerosis P. Ilett et al. Balance and Gait in People with Multiple Sclerosis stability (Goldie et al., 1989, Goldie et al., 1992, Jonsson et al., 2004 "
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- "We believe that our study provides a relationship between the results of Parreira et al. (2013) and Jonsson et al. (2004) who assumed that the difficulties of the older adults to maintain the SLS position depend on the initial five-second time frame. Our results show that older adults have not only increased initial values, but also less ability to reduce sway during the initial phase of SLS. "
ABSTRACT: Balance deteriorates with age and fall related injuries are often linked to long-term disability and loss of independence in older adults. This study focuses on the task of establishing single leg stance, which requires the ability to shift the center of mass onto the supporting leg.Methods Fifteen younger adults and eight older adults participated in the study. Subjects performed a step with self-selected step length onto the force plate to establish a single leg stance (SLS) on their dominant leg. The first four seconds of SLS were analyzed to investigate age related temporal dependencies of sway area, sway velocity, anterior-posterior sway, and medio-lateral sway.FindingsYounger adults show a rapid decrease of sway area, anterior-posterior sway, medio-lateral sway, and sway velocity within the first fours seconds while older adults show elevated initial values in anterior-posterior sway and sway velocity and less decrease over time.InterpretationOlder adults have not only diminished initial sway, but also less ability to control sway during the initial phase of single leg stance. The early phase of single leg stance is rather dynamic in older adults compared to younger adults who maintain their balance after three seconds with small adjustments.Clinical Biomechanics 11/2014; 30(1). DOI:10.1016/j.clinbiomech.2014.10.010 · 1.97 Impact Factor
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- "Approximately 90% of adults exhibit right-side dominance in manipulative functions of the upper limb  and in mobilizing functions of the lower limb, such as when kicking or juggling a ball [4-6]. However, when the lower limb is used as a postural support during single-leg stance, there is no clear lateral dominance in postural stability, even though the dominant side in maintaining stability is often shown at the individual level [7,8]. These findings regarding the postural support function have been assessed primarily by the measure of fluctuation of center of pressure (CoP) during stance on a stable surface (that is, a static balance condition). "
ABSTRACT: Background We investigated lateral dominance in the postural stability of single-leg stance with anteroposterior floor oscillations at various frequencies. Methods Thirty adults maintained a single-leg stance on a force platform for 20 seconds per trial. Trials were performed with no oscillation (static condition) and with anteroposterior floor oscillations (2.5-cm amplitude) at six frequencies: 0.25, 0.5, 0.75, 1.0, 1.25 and 1.5 Hz (dynamic condition). A set of three trials was performed on each leg in each oscillation frequency in random order. The mean speed of the center of pressure in the anteroposterior direction (CoPap) was calculated as an index of postural stability, and frequency analysis of CoPap sway was performed. Footedness for carrying out mobilizing activities was assessed with a questionnaire. Results CoPap speed exponentially increased as oscillation frequency increased in both legs. The frequency analysis of CoPap showed a peak <0.3 Hz at no oscillation. The frequency components at 0.25-Hz oscillation included common components with no oscillation and those at 1.5-Hz oscillation showed the maximum amplitude among all conditions. Postural stability showed no significant difference between left- and right-leg stance at no oscillation and oscillations ≤1.25 Hz, but at 1.5-Hz oscillation was significantly higher in the right-leg stance than in the left-leg stance. For the lateral dominance of postural stability at individual levels, the lateral difference in postural stability at no oscillation was positively correlated with that at 0.25-Hz oscillation (r = 0.51) and negatively correlated with that at 1.5-Hz oscillation (r = -0.53). For 70% of subjects, the dominant side of postural stability was different at no oscillation and 1.5-Hz oscillation. In the subjects with left- or right-side dominance at no oscillation, 94% or 38% changed their dominant side at 1.5-Hz oscillation, with a significant difference between these percentages. In the 1.5-Hz oscillation, 73% of subjects had concordance between the dominant side of postural stability and that of mobilizing footedness. Conclusion In static conditions, there was no lateral dominance of stability during single-leg stance. At 1.5-Hz oscillation, the highest frequency, right-side dominance of postural stability was recognized. Functional role in supporting leg may be divided between left and right legs according to the change of balance condition from static to dynamic.Journal of PHYSIOLOGICAL ANTHROPOLOGY 08/2014; 33(1):25. DOI:10.1186/1880-6805-33-25 · 1.27 Impact Factor