The Effect of Active Physical Training Interventions on Reactive Postural Responses in Older Adults: A Systematic Review

Comparing the Effects of Two Perturbation-Based Balance Training Paradigms in Fall-Prone Older Adults: A Randomized Controlled Trial

INTRODUCTION

There is increasing evidence that perturbation-based balance training (PBT) is highly effective in preventing falls at older age. Different PBT paradigms have been presented so far, yet a systematic comparison of PBT approaches with respect to feasibility and effectiveness is missing. Two different paradigms of PBT seem to be promising for clinical implementation: (1) technology-supported training on a perturbation treadmill (PBTtreadmill); (2) training of dynamic stability mechanisms in the presence of perturbations induced by unstable surfaces (PBTstability). This study aimed to compare both program's feasibility and effectiveness in fall-prone older adults.

METHODS

In this three-armed randomized controlled trial, seventy-one older adults (74.9 ± 6.0 years) with a verified fall risk were randomly assigned into three groups: PBTtreadmill on a motorized treadmill, PBTstability using unstable conditions such as balance pads, and a passive control group (CG). In both intervention groups, participants conducted a 6-week intervention with 3 sessions per week. Effects were assessed in fall risk (Brief-BEST), balance ability (Stepping Threshold Test, center of pressure, limits of stability), leg strength capacity, functional performance (Timed Up and Go Test, Chair-Stand), gait (preferred walking speed), and fear of falling (Short FES-I).

RESULTS

Fifty-one participants completed the study. Training adherence was 91% for PBTtreadmill and 87% for PBTstability, while no severe adverse events occurred. An analysis of covariance with an intention-to-treat approach revealed statistically significant group effects in favor of PBTstability in the Brief-BEST (p = 0.009, η2 = 0.131) and the limits of stability (p = 0.020, η2 = 0.110) and in favor of PBTtreadmill in the Stepping Threshold Test (p < 0.001, η2 = 0.395). The other outcomes demonstrated no significant group effects.

CONCLUSION

Both training paradigms demonstrated high feasibility and were effective in improving specific motor performances in the fall-prone population and these effects were task specific. PBTtreadmill showed higher improvements in reactive balance, which might have been promoted by the unpredictable nature of the included perturbations and the similarity to the tested surface perturbation paradigm. PBTstability showed more wide-ranging effects on balance ability. Consequently, both paradigms improved fall risk-associated measures. The advantages of both formats should be evaluated in light of individual needs and preferences. Larger studies are needed to investigate the effects of these paradigms on real-life fall rates.

Feasibility, Psychosocial Effects, Influence, and Perception of Elastic Band Resistance Balance Training in Older Adults

This study utilised feedback from older adults during balance-challenging, elastic band resistance exercises to design a physical activity (PA) intervention.

METHODS

Twenty-three active participants, aged 51-81 years, volunteered to perform a mini balance evaluation test and falls efficacy scale, and completed a daily living questionnaire. Following a 10 min warm-up, participants performed eight pre-selected exercises (1 × set, 8-12 repetitions) using elastic bands placed over the hip or chest regions in a randomised, counterbalanced order with 15 min seated rests between interventions. Heart rate (HR) and rate of perceived exertion (RPE) were measured throughout. Participant interview responses were used to qualify the experiences and opinions of the interventions including likes, dislikes, comfort, and exercise difficulty.

RESULTS

Similar significant (p < 0.01) increases in HR (pre- = 83-85 bpm, mid- = 85-88 bpm, post-intervention = 88-89 bpm; 5-6%) and RPE (pre- = 8-9, mid- = 10, post-intervention = 10-11) were detected during the PA interventions (hip and chest regions). Interview data revealed that participants thought the PA interventions challenged balance, that the exercises would be beneficial for balance, and that the exercises were suitable for themselves and others. Participants reported a positive experience when using the PA interventions with an elastic band placed at the hip or chest and would perform the exercises again, preferably in a group, and that individual preference and comfort would determine the placement of the elastic band at either the hip or chest.

CONCLUSION

These positive outcomes confirm the feasibility of a resistance band balance program and will inform intervention design and delivery in future studies.

Which Exercise Interventions Can Most Effectively Improve Reactive Balance in Older Adults? A Systematic Review and Network Meta-Analysis

BACKGROUND

Reactive balance is the last line of defense to prevent a fall when the body loses stability, and beneficial effects of various exercise-based interventions on reactive balance in older adults have been reported. However, their pooled evidence on the relative effects has yet to be described.

OBJECTIVE

To review and evaluate the comparative effectiveness of various exercise-based interventions on reactive balance in older adults.

METHODS

Nine electronic databases and reference lists were searched from inception to August 2021. Eligibility criteria according to PICOS criteria were as follows: (1) population: older adults with the mean age of 65 years or above; (2) intervention and comparison: at least two distinct exercise interventions or one exercise intervention with a no-exercise controlled intervention (NE) compared in each trial; (3) outcome: at least one measure of reactive balance; (4) study: randomized controlled trial. The main network meta-analysis was performed on data from the entire older adult population, involving all clinical conditions as well as healthy older adults. Subgroup analyses stratified by characteristics of participants (healthy only) and reactive balance outcomes (simulated slip or trip while walking, simulated forward falls, being pushed or pulled, and movable platform) were also conducted.

RESULTS

Thirty-nine RCTs (n = 1388) investigating 17 different types of exercise interventions were included in the network meta-analysis. Reactive balance training as a single intervention presented the highest probability (surface under the cumulative ranking (SUCRA) score) of being the best intervention for improving reactive balance and the greatest relative effects vs. NE in the entire sample involving all clinical conditions [SUCRA = 0.9; mean difference (95% Credible Interval): 2.7 (1.0 to 4.3)]. The results were not affected by characteristics of participants (i.e., healthy older adults only) or reactive balance outcomes.

SUMMARY/CONCLUSION

The findings from the NMA suggest that a task-specific reactive balance exercise could be the optimal intervention for improving reactive balance in older adults, and power training can be considered as a secondary training exercise.