Impact of sensory reweighting strategies on postural control using the sensory organization test in older adults with and without fall risks

BACKGROUND

The Sensory Organization Test (SOT), an integral part of computerized dynamic posturography, plays a crucial role in evaluating postural stability under various altered sensory conditions. Despite its importance, there have been noted inconsistencies in the results pertaining to equilibrium and sensory system evaluations. This study aimed to compare four sensory analysis scores and equilibrium indices between older adults with and without fall risks.

METHODS

The study included 34 participants identified as being at risk of falls and 42 control subjects. To categorize individuals between the two groups, we performed area under the receiver operating characteristic curve analyses. This classification was based on scores from the Modified Falls Efficacy Scale (MFES) and the composite scores obtained from the SOT. In addition, we used the Tampa Scale for Kinesiophobia (TSK) as well as the level of disability.

RESULTS

The fall risk group demonstrated significantly higher TSK scores (39.39 ± 15.24 for control group vs. 54.65 ± 10.70 for fall risk group; t = -5.09, p = 0.001). The groups demonstrated a significant interaction on the equilibrium index (F = 4.59, p = 0.03), which was lower in the fall risk group in Condition 6 with a moving surface and surround and eyes open (t = 2.29, p = 0.01). The fall risk group demonstrated a higher somatosensory score (t = -1.73, p = 0.04).

CONCLUSIONS

The fall risk group had a lower equilibrium index score in Condition six of the SOT, which was useful for identifying deficits in vestibular function to integrate sensory information under challenging conditions for postural adaptation. This strategy suggested that the fall risk group could compensate for their risk of falls by utilizing more effective somatosensory reweighting strategies compared with the control group.

Normalized stability time analysis within the boundaries between adults with and without fear of falling

BACKGROUND

The unilateral stance test, measured by the center of pressure (COP), has been widely used to identify balance deficits. However, there is a critical gap in understanding the specific COP thresholds on postural stability in adults with a fear of falling (FOF).

AIMS

To investigate the normalized stability time, which was defined as the ratio of time spent within stability boundaries to the total test duration, under different visual conditions and specific thresholds between adults with and without FOF.

METHODS

Twenty-one older adults with FOF and 22 control subjects completed the unilateral limb standing test in eyes-open and eyes-closed conditions. Normalized stability times were computed based on five pre-determined COP sway range thresholds: 10 mm, 15 mm, 20 mm, 25 mm, and 30 mm.

RESULTS

Receiver operating characteristic analysis determined the diagnostic accuracy of FOF. There were significant differences in the effects of both visual conditions (F = 46.88, p = 0.001) and threshold settings (F = 119.38, p = 0.001) on stability time between groups. The FOF group significantly reduced normalized stability time at the 10 mm COP threshold under eyes-closed conditions (t = - 1.95, p = 0.03).

DISCUSSION

The findings highlight the heightened sensitivity of the 10 mm COP threshold in identifying group variances in postural stability when eyes are closed. Moreover, the FOF group displayed a marked reduction in stability duration based on visual scenarios and normalized thresholds.

CONCLUSION

The study highlights the need to account for both COP boundaries and visual conditions in adults with FOF. When assessing postural control during unilateral stances, clinicians must also give attention to non-visual cues.

Postural adaptations within normalized stability between older adults with and without chronic low back pain

BACKGROUND

Adaptations of dynamic balance performance are related to sway excursions in older adults with chronic low back pain (LBP). However, there is a lack of understanding on postural control within different thresholds of radius from the center of pressure (COP).

PURPOSE

This study was conducted to compare the normalized stability based on the time-in-boundary (TIB) during repeated unilateral limb standing trials between subjects with and without chronic LBP.

METHODS

There were 26 older adults with LBP and 39 control subjects who completed three trials of repeated unilateral limb standing on a force plat.

RESULTS

The TIB based on the seven thresholds was analyzed, and the groups demonstrated a significant interaction on thresholds for TIB (F = 8.76, p = 0.01). The TIB was significantly different in the 10 mm (F = 4.01, p = 0.04), 15 mm (F = 5.21, p = 0.03), and 20 mm (F = 4.48, p = 0.04) radius of thresholds only in the second trial. However, there was no group difference on TIB at the first and third trials due to potential compensatory and/or adaptive reactions to avoid fall risks.

CONCLUSION

The LBP group lacked postural stability within the thresholds less than a 20 mm radius at the second trial of unilateral standing. The significant group interaction with the thresholds indicates an adaptation strategy on sway thresholds. This postural reaction from repeated trials should be considered with sway excursion adjustments and fall prevention in older adults with LB.

Effectiveness of virtual reality-based balance and gait in older adults with fear of movement: A systematic review and meta-analysis

OBJECTIVE

To summarize the current evidence from randomized controlled trials (RCTs) regarding the effectiveness of Virtual Reality (VR) training and functional mobility in older adults with fear of movement. TYPE: Systematic review and meta-analysis of randomized clinical trials.

METHODOLOGY

An electronic search was performed using PubMed, Embase, Medline, SPORTDiscus, Scopus, and CINAHL. A data search from January 2015 to December 2022 and a manual electronic literature search were conducted to identify published RCTs. The effectiveness of VR-based balance training for balance and gait was evaluated in older adults with a fear of movement, which was measured by the Timed Up and Go (TUG) test and the Falls Efficacy Scale (FES). Three reviewers independently performed the study selection, and the quality assessment of the included studies was performed using the Physiotherapy Evidence Database (PEDro) scale. The reporting was based on the new Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Guidelines.

SYNTHESIS

The search product produced 345 results, from which 23 full text articles were studied. Seven RCTs of good methodological quality, including 265 participants, were included in the review. Overall, the studies reported that VR had a significant improvement on the TUG (Cohen's d = -0.91 [-1.38; -0.44], p = 0.001), while the FES was not significantly different (Cohen's d = -0.54 [-1.80; 0.71] p = 0.40). The average for PEDro scores (6.14) was good, and the risk of bias revealed that more than one-third of the studies correctly described the random sequence generation and allocation concealment procedures.

CONCLUSION

VR-based training is effective on balance or gait training based on the TUG; however, there were mixed results to improve FES scores following VR intervention. These inconsistent results might be limited due to variations in the studies, including heterogeneous training paradigms, sensitive outcome measures, small sample sizes, and short intervention durations, which limit the validity of our findings. Future investigations should compare different VR protocols to help establish better guidelines for clinicians.