Increased load computerized dynamic posturography in prefrail and nonfrail community-dwelling older adults

Frequency analyses of posturography using logarithmic translation

Background: Power-spectral analysis of the centre of pressure (CoP) frequencies of posturography provides exponentially approximated distributions, whereas logarithmic translation enables linear approximation.Objectives: Frequency analyses were adopted for posturography of healthy subjects and patients with spinocerebellar degeneration (SCD) using logarithmic translation to determine its clinical usefulness for managing the elderly and patients with disequilibrium.Material and methods: We included 172 healthy subjects and 47 SCD patients. Posturography was performed with the eyes fixated and closed, with and without foam rubber. The power-spectral data of the CoP were obtained with the maximum entropy method. Power-spectral data were logarithmically translated for quantitative evaluation.Results: For teenagers, high-frequency fluctuations were dominant and attributable to proprioceptive compensation due to immature postural control. In elderly populations, the increased frequency in the lateral direction was characterised by three peaks indicating postural disturbances attributed to three sensory inputs. The disappearance of one peak in the anteroposterior fluctuation indicates a decrease in vestibular contribution. The foam rubber and the closed-eye condition enhanced fluctuations in two peaks. There were differences in power-spectral distributions of two peaks between the healthy subjects and SCD patients.Conclusions: Logarithmic power-spectral data distribution could provide an age- and disease-specific novel and visually-comprehensible parameter.

Reliability and validity of a force-instrumented treadmill for evaluating balance: A preliminary study of feasibility in healthy young adults

Background:

With the development of computer technology, computerized dynamic posturography provides objective assessments of balance and posture control under static and dynamic conditions. Although a force-instrumented treadmill-based balance assessment is feasible for balance evaluations, currently no data exists.

Objective:

This study was undertaken to assess the reliability and validity of balance evaluations using a force-instrumented treadmill.

Methods:

Ten healthy adults participated in evaluations using both the treadmill and the EquiTest. Four balance evaluations were conducted: Modified Clinical Test of Sensory Interaction on Balance, Unilateral Stance, Weight Bearing Squat, and Motor Control Test.

Results:

All balance evaluations using the force-instrumented treadmill method shared good reliability (intraclass correlation coefficient ≥0.6). The Modified Clinical Test of Sensory Interaction on Balance, Unilateral Stance, and Weight Bearing Squat evaluations had a correlation of r < 0.5 with EquiTest, whereas the Motor Control Test balance evaluation had moderate correlations (r > 0.5) with the EquiTest.

Conclusion:

The results demonstrated that all balance evaluations using the force-instrumented treadmill were reliable, and that the Motor Control Test evaluation was moderately correlated with the EquiTest. Therefore, the use of a force-instrumented treadmill in balance evaluations might provide a certain level of value to clinical practice.

Biopsychosocial Characteristics, Using a New Functional Measure of Balance, of an Elderly Population with CLBP

This study examined the biopsychosocial characteristics of chronic low back pain (CLBP) in an understudied but increasingly larger part of the population: the elderly (i.e., 65 years and older). A new innovative physical functioning measure (postural control, which is a proxy for the common problem of slips and falls in the elderly) was part of this biopsychosocial evaluation. Also, the National Institutes of Health (NIH)-developed Patient-Reported Outcome Measurement Information System (PROMIS) was also part of this comprehensive evaluation. Two demographically-matched groups of elderly participants were evaluated: one with CLBP (n = 24); and the other without (NCLBP, n = 24). Results revealed significant differences in most of these measures between the two groups, further confirming the importance of using a biopsychosocial approach for future studies of pain and postural control in the elderly.

Can we predict the risk of falls in elderly patients with instability?

OBJECTIVE

The aim of this study is to determine whether clinical and instrumental examination of balance can predict the risk of falls in elderly patients with instability.

METHODS

STUDY DESIGN

It is a case control study, with cases defined by falls in the last year, developed in a third level university hospital.

PATIENTS

Seventy patients aged 65 years or more who met at least one of the following inclusion criteria: (a) at least one fall in the last year; (b) spend more than 15s during the timed up and go test (TUG); (c) a score of less than 68% average balance in the sensory organisation test (SOT) of the computerised dynamic posturography (CDP); or (d) at least one fall in the CDP-SOT.

INTERVENTION

TUG test, CDP-SOT, CDP centre of gravity balancing (CG) and limits of stability (LOS), Dizziness Handicap Inventory (DHI) test and short FES-I test.

MAIN OUTCOME MEASURES

Number of steps and time (TUG), average balance and use of sensorial information (CDP-SOT), speed and directional control (CDP-CG and LOS), DHI score and short FES-I score.

RESULTS

Comparing subjects without falls (non-fallers) vs subjects with at least one fall (fallers) in the last year, fallers obtain worse scores than non-fallers in condition 2 (p=0.043) and use of somatosensory information (p=0.039). Comparing subjects with five falls or less (non-multiple-fallers) vs subjects with more than five falls (multiple-fallers), multiple-fallers obtain worse scores than non-multiple-fallers in overall balance (p=0.023), condition 6 (p=0.036), directional control (swaying (p=0.006) and LOS (p=0.023)) and short FES-I score (p=0.007).

CONCLUSION

The three most useful parameters for identifying unstable elderly patients at particularly high risk of repeated falls are mean balance in the CDP SOT, directional control of CDP LOS and short FES-I score.