The impact of cognitive-motor interference on balance and gait in hearing-impaired older adults: a systematic review

BACKGROUND

Hearing impairments are a rising burden in our aging society. Hearing loss is associated with reduced cognitive performance as well as decrements in balance and gait. Therefore, impaired hearing affects also dual tasking (DT). The aim of this review is to summarize the evidence for DT performance decrements of older adults with hearing impairments during maintaining balance or walking.

METHODS

The systematic literature research according to PRISMA guidelines was conducted using MEDLINE, APA Psych-Info, and Web of Science. Inclusion criteria were: Independent living older people ≥ 60 years with hearing impairments, use of a DT paradigm to test hearing impaired older adults within a balance or walking condition.

RESULTS

N = 57 studies were found within the databases. Eight studies were included (N = 456 participants (58% women), including n = 200 older hearing-impaired persons with different levels of hearing loss). Most of the included studies oriented their inclusion criteria for hearing-impairments at thresholds for mild hearing loss with Pure Tone Average (0.5-4 kHz) ≥ 25 and < 40 dB. Three of the studies focused on DT balance performance and five used DT walking comparing participants with and without hearing loss. For DT balance and gait performance, higher decrements for the hearing-impaired group were observed compared to healthy older adults. Performance decrements were accompanied by reduced compensatory strategies in balance performance.

CONCLUSION

More pronounced decrements in DT performance were observed for participants with hearing impairments compared to those without. This implies that hearing-impaired older adults might need specific interventions to reduce the cognitive-motor interference (CMI) to maintain balance control or walking stability in daily situations that require managing of cognitive and motor tasks simultaneously. However, taking all results into account the underlying mechanisms of CMI for this target group needs to be further examined.

TRIAL REGISTRATION

This review was registered at Prospero with the ID CRD42022340232.

Home-Based Balance Training on Balance and Mobility in Persons With Multiple Sclerosis: A Systematic Review and Meta-analysis

OBJECTIVES

To (1) examine the effects of home-based balance training on balance and mobility outcomes; (2) evaluate comparable effects between home- and center-based balance training; (3) determine the effects of different levels of supervision on treatment effects; and (4) investigate dose-response relationships of home-based balance training on balance and mobility performance in persons with multiple sclerosis (MS).

DATA SOURCES

Literature searches were conducted in MEDLINE, EMBASE, PsycINFO, SPORTSDiscus, and CINAHL in April 2023. Other literature sources included website and citation searches.

STUDY SELECTION

The study included randomized controlled trials of home-based balance training that included balance and mobility outcomes in persons with MS.

DATA EXTRACTION

Data extracted from each study included (1) number of participants; (2) dropout rate; (3) sex; (4) MS phenotype; (5) age; (6) Expanded Disability Status Scale (range); (7) exercise dose; (8) level of supervision; (9) type of intervention; (10) exercise progression; (11) type of control; and (12) outcomes measures. For the meta-analysis, mean and SD of the balance and mobility outcomes in both the intervention and control groups were used. The methodological quality of included studies was evaluated by Tool for the Assessment of Study Quality and Reporting in Exercise.

DATA SYNTHESIS

Eleven studies were identified in this systematic review and meta-analysis. Each balance and mobility outcome was standardized using Hedges' g.

CONCLUSIONS

This meta-analysis revealed comparable results between home- and center-based balance training in terms of balance and mobility improvement. There was also no evidence for the superiority of home-based balance training over no training except for static steady-state balance. This study revealed that training sessions (>36 sessions) and total exercise time (>1100min) were significant moderators for overall balance improvements. Results also indicated that, when designing future interventions, at least an indirect level of supervision (eg, weekly or biweekly phone/video calls) is warranted to maintain adherence.

Walking on a Balance Beam as a New Measure of Dynamic Balance to Predict Falls in Older Adults and Patients with Neurological Conditions

BACKGROUND

Beam walking is a new test to estimate dynamic balance. We characterized dynamic balance measured by the distance walked on beams of different widths in five age groups of healthy adults (20, 30, 40, 50, 60 years) and individuals with neurological conditions (i.e., Parkinson, multiple sclerosis, stroke, age: 66.9 years) and determined if beam walking distance predicted prospective falls over 12 months.

METHODS

Individuals with (n = 97) and without neurological conditions (n = 99, healthy adults, age 20-60) participated in this prospective longitudinal study. Falls analyses over 12 months were conducted. The summed distance walked under single (walking only) and dual-task conditions (walking and serial subtraction by 7 between 300 to 900) on three beams (4, 8, and 12-cm wide) was used in the analyses. Additional functional tests comprised grip strength and the Short Physical Performance Battery.

RESULTS

Beam walking distance was unaffected on the 12-cm-wide beam in the healthy adult groups. The distance walked on the 8-cm-wide beam decreased by 0.34 m in the 20-year-old group. This reduction was ~ 3 × greater, 1.1 m, in the 60-year-old group. In patients, beam walking distances decreased sharply by 0.8 m on the 8 versus 12 cm beam and by additional 1.6 m on the 4 versus 8 cm beam. Beam walking distance under single and dual-task conditions was linearly but weakly associated with age (R2 = 0.21 for single task, R2 = 0.27 for dual-task). Age, disease, and beam width affected distance walked on the beam. Beam walking distance predicted future falls in the combined population of healthy adults and patients with neurological conditions. Based on receiver operating characteristic curve analyses using data from the entire study population, walking ~ 8.0 of the 12 m maximum on low-lying beams predicted future fallers with reasonable accuracy.

CONCLUSION

Balance beam walking is a new but worthwhile measure of dynamic balance to predict falls in the combined population of healthy adults and patients with neurological conditions. Future studies are needed to evaluate the predictive capability of beam walking separately in more homogenous populations. Clinical Trial Registration Number NCT03532984.

Influences of smart glasses on postural control under single- and dual-task conditions for ergonomic risk assessment

Head worn displays have become increasingly popular at workplaces in logistics and assembly lines in recent years. Such displays are expected to improve productivity and safety at the workplace. However, their impact on balance in the workforce is still an open research question. Therefore, we investigated the influence of the Vuzix M400 and Realwear HMT1 smart glasses on postural control. A laboratory study was conducted with eleven participants. Balance parameters were recorded during bilateral quiet stance, together with parameters of cognitive load. The two different smart glasses used in this study were compared with a monitor and a tablet under single-task conditions and while performing a spatial 2-back task. As balance parameters, the prediction ellipse and sample entropy in anteroposterior as well as mediolateral direction of the center-of-pressure data were examined. No significant differences were observed in the cognitive task performance between the devices. The prediction ellipse of the smart glasses was smaller than the tablets but larger than the smartboard. The dynamic of sample entropy data suggests that the use of the spatial 2-back task induces postural sway in the participants. This effect was most profound when looking at the monitor and least recognizable in the data of the tablet.

Comparative efficacy of 24 exercise types on postural instability in adults with Parkinson's disease: a systematic review and network meta-analysis

OBJECTIVE

To compare, rank and evaluate the 24 exercise types that improve postural instability in patients with Parkinson's disease (PD).

METHODS

We searched the data in PubMed, MEDLINE, Embase, PsycINFO, Cochrane library, and Web of Science from their inception date to January 23, 2023. Randomized controlled trials (RCTs) that aimed at determining the effectiveness of physical activity interventions on postural instability in adults with PD. This review focused on different balance outcome categories: (a) balance test batteries (BBS); (b) static steady-state balance (sSSB); (c) dynamic steady-state balance (dSSB); (d) proactive balance (PB); (e) reactive balance (RB).

RESULTS

Among 10,474 records, 199 studies (patients = 9523) were eligible for qualitative synthesis. The random-effects NMA model revealed that the following exercise training modalities had the highest p score of being best when compared with control group: body-weight support treadmill training (BWS_TT) for BBS (p score = 0.97; pooled standardised mean difference (95% CI): 1.56 (0.72 to 2.39)) and dSSB (1.00; 1.53 (1.07 to 2.00)), aquatic exercise (AQE) for sSSB (0.85; 0.94 (0.33 to 1.54)), Pilates for PB (0.95; 1.42 (0.59 to 2.26)). Balance and gait training with the external cue or attention (BGT_ECA) and robotic assisted gait balance (RA_GT) had similar superior effects in improving RB. The confidence in evidence was often low according to Confidence in Network Meta-Analysis.

CONCLUSIONS

There is low quality evidence that BWS_TT, AQE, Pilates, BGT_ECA and RA_GT are possibly the most effective treatments, pending outcome of interest, for adults with PD.

Different neuromuscular control mechanisms regulate static and dynamic balance: A center-of-pressure analysis in young adults

The analysis of the center of pressure (CoP) trajectory, derived from force platforms, is a widely accepted measure to investigate postural balance control. The CoP trajectory could be analyzed as a physiological time-series through a general stochastic modeling framework (i.e., Stabilogram Diffusion Analysis (SDA)). Critical point divides short-term from long-term regions and diffusion coefficients reflect the level of stochastic activity of the CoP. Sample Entropy (SampEn) allows quantifying the CoP complexity in terms of regularity. Thus, this study aimed to understand whether SDA and SampEn could discriminate the neuromuscular control mechanisms underpinning static and dynamic postural tasks. Static balance control and its relationship with dynamic balance control were investigated through the CoP velocity (Mean Velocity) and the area of the 95th percentile ellipse (Area95). Balance was assessed in 15 subjects (age: 23.13 ± 0.99 years; M = 9) over a force platform under two conditions: static (ST) and dynamic, both in anterior-posterior (DAP) and medio-lateral (DML) directions. During the DAP and DML, subjects stood on an unstable board positioned over a force platform. Short-term SDA diffusion coefficients and critical points were lower in ST than in DAP and DML (p < 0.05). SampEn values resulted greater in ST than in DAP and DML (p < 0.001). As expected, lower values of Area95 (p < 0.001) and Mean Velocity (p < 0.001) were detected in the easiest condition, the ST, compared to DAP and DML. No significant correlations between static and dynamic balance performances were detected. Moreover, differences in the diffusion coefficients were detected comparing DAP and DML (p < 0.05). In the anterior-posterior direction, the critical point occurred at relatively small intervals in DML compared to DAP (p < 0.001) and ST (p < 0.001). In the medio-lateral direction, the critical point differed only between DAP and DML (p < 0.05). Overall, SDA analysis pointed out a less tightly regulated neuromuscular control system in the dynamic tasks, with closed-loop corrective feedback mechanisms called into play at different time intervals in the three conditions. SampEn results reflected more attention and, thus, less automatic control mechanisms in the dynamic conditions, particularly in the medio-lateral task. The different neuromuscular control mechanisms that emerged in the static and dynamic balance tasks encourage using both static and dynamic tests for a more comprehensive balance performance assessment.

Use of Lower Limb Exoskeletons as an Assessment Tool for Human Motor Performance: A Systematic Review

Exoskeletons are a promising tool to support individuals with a decreased level of motor performance. Due to their built-in sensors, exoskeletons offer the possibility of continuously recording and assessing user data, for example, related to motor performance. The aim of this article is to provide an overview of studies that rely on using exoskeletons to measure motor performance. Therefore, we conducted a systematic literature review, following the PRISMA Statement guidelines. A total of 49 studies using lower limb exoskeletons for the assessment of human motor performance were included. Of these, 19 studies were validity studies, and six were reliability studies. We found 33 different exoskeletons; seven can be considered stationary, and 26 were mobile exoskeletons. The majority of the studies measured parameters such as range of motion, muscle strength, gait parameters, spasticity, and proprioception. We conclude that exoskeletons can be used to measure a wide range of motor performance parameters through built-in sensors, and seem to be more objective and specific than manual test procedures. However, since these parameters are usually estimated from built-in sensor data, the quality and specificity of an exoskeleton to assess certain motor performance parameters must be examined before an exoskeleton can be used, for example, in a research or clinical setting.

Neurometabolic correlates of posturography in normal aging and older adults with mild cognitive impairment: Evidence from a 1H-MRS study

Proton magnetic resonance spectroscopy (¹H-MRS) holds promise for revealing and understanding neurodegenerative processes associated with cognitive and functional impairments in aging. In the present study, we examined the neurometabolic correlates of balance performance in 42 cognitively intact older adults (healthy controls - HC) and 26 older individuals that were diagnosed with mild cognitive impairment (MCI). Neurometabolite ratios of total N-acetyl aspartate (tNAA), glutamate-glutamine complex (Glx), total choline (tCho) and myo-inositol (mIns) relative to total creatine (tCr) were assessed using single voxel ¹H-MRS in four different brain regions. Regions of interest were the left hippocampus (HPC), dorsal posterior cingulate cortex (dPCC), left sensorimotor cortex (SM1), and right dorsolateral prefrontal cortex (dlPFC). Center-of-pressure velocity (Vcop) and dual task effect (DTE) were used as measures of balance performance. Results indicated no significant group differences in neurometabolite ratios and balance performance measures. However, our observations revealed that higher tCho/tCr and mIns/tCr in hippocampus and dPCC were generic predictors of worse balance performance, suggesting that neuroinflammatory processes in these regions might be a driving factor for impaired balance performance in aging. Further, we found that higher tNAA/tCr and mIns/tCr and lower Glx/tCr in left SM1 were predictors of better balance performance in MCI but not in HC. The latter observation hints at the possibility that individuals with MCI may upregulate balance control through recruitment of sensorimotor pathways.

A novel dual-task paradigm with story recall shows significant differences in the gait kinematics in older adults with cognitive impairment: A cross-sectional study

Objective

Cognitive and motor dysfunctions in older people become more evident while dual-tasking. Several dual-task paradigms have been used to identify older individuals at the risk of developing Alzheimer's disease and dementia. This study evaluated gait kinematic parameters for dual-task (DT) conditions in older adults with mild cognitive impairment (MCI), subjective cognitive decline (SCD), and normal cognition (NC).

Method

This is a cross-sectional, clinical-based study carried out at the Zhongshan Rehabilitation Branch of First Affiliated Hospital of Nanjing Medical University, China.

Participants

We recruited 83 community-dwelling participants and sorted them into MCI (n = 24), SCD (n = 33), and NC (n = 26) groups based on neuropsychological tests. Their mean age was 72.0 (5.55) years, and male-female ratio was 42/41 (p = 0.112). Each participant performed one single-task walk and four DT walks: DT calculation with subtracting serial sevens; DT naming animals; DT story recall; and DT words recall.

Outcome and measures

Kinematic gait parameters of speed, knee peak extension angle, and dual-task cost (DTC) were obtained using the Vicon Nexus motion capture system and calculated by Visual 3D software. A mixed-effect linear regression model was used to analyze the data.

Results

The difference in gait speed under DT story recall and DT calculation was -0.099 m/s and - 0.119 m/s (p = 0.04, p = 0.013) between MCI and SCD, respectively. Knee peak extension angle under DT story recall, words recall, and single task was bigger in the MCI group compared to the NC group, respectively (p = 0.001, p = 0.001, p = 0.004). DTC was higher in the DT story recall test than all other DT conditions (p < 0.001).

Conclusion

Kinematic gait parameters of knee peak extension angle for the DT story recall were found to be sensitive enough to discriminate MCI individuals from NC group. DTC under DT story recall was higher than the other DT conditions.

Effects of Modified-Otago Exercise Program on Four Components of Actual Balance and Perceived Balance in Healthy Older Adults

Falls are a serious problem for older adults, leading to adverse injuries and decreased quality of life. Balance impairment is a key factor in falls. The Otago Exercise Program (OEP) is a promising intervention for preventing falls, thereby improving balance and gait. Previous studies reported improved effects on balance using the OEP conducted in a group setting, and recommended additional walking. Walking is a feasible exercise that benefits both fall-related physical and physiological functions. This study aims to investigate the effects of a modified-Otago Exercise Program (modified-OEP) on four components of actual balance (static, dynamic, proactive, and reactive balance) and perceived balance in healthy older adults, by conducting the modified-OEP in a groupsetting, and including additional walking in one session to gain better efficacy. Participants aged 60–85 years old were randomly assigned to the modified-OEP group or the control group (CT). The modified-OEP consisted of 60 min sessions made up of 30 min of OEP and 30 min of walking, three times a week for 12 weeks, while no intervention was assigned to the control group. The modified-OEP group showed significant improvement in the four components of actual balance and in perceived balance. Furthermore, the modified-OEP group outperformed the control group in all parameters except for dynamic balance, after 12 weeks. The present study highlights the beneficial effects of a modified-OEP on all balance components. Additionally, this study is the first to demonstrate the measurement of all actual balance components as well as perceived balance.

Do the dual-task "8-foot up and go" tests provide additional predictive value for early detection of cognitive decline in community-dwelling older women?

BACKGROUND

The 8-Foot Up and Go (8UG) test is a widely used mobility assessment. Some dual-task mobility assessments have been developed to help detect cognitive decline.

AIMS

This study developed a dual-task version of 8UG test to investigate the dual-task 8UG performance and to evaluate the ability of dual-task 8UG test in detecting cognitive decline.

METHODS

A total of 101 eligible community-dwelling women aged 60-74 years were grouped into the mild cognitive impairment group (MCI, n = 49) and the non-cognitive impairment group (NCI, n = 52). The 8UG tests under single-task (ST), manual dual-task (MT), and cognitive dual-task (CT) conditions were performed respectively. The dual-task cost (DTC) and the correct response rate (CRR) were calculated to quantify the dual-task interference.

RESULTS

Participants spent more time in performing the 8UG test under dual-task conditions. No differences were observed between NCI and MCI groups for 8UG parameters under ST and MT conditions (p > 0.05). When executing CT, significant differences were found in the number of correct answers and CRR (p < 0.05). CRR showed the strongest ability to predict MCI with a cut-off point of 0.50 (71.2% sensitivity and 61.2% specificity).

DISCUSSION

Both manual and cognitive dual-task were found to interfere with the 8UG performance. CRR with cutoff point of 0.50 could be a potential predictor of MCI in community-dwelling older women.

CONCLUSIONS

The CRR of the cognitive dual-task 8UG test could be recommended as a potential predictor for the early detection of MCI in community-dwelling older women.

Effects of fixed versus variable task prioritization during short-term dual task practice on motor and cognitive task performance in young adults

OBJECTIVE

It has been shown that variable compared to fixed task prioritization during dual task practice more effectively improves motor (i.e., postural control) and cognitive (i.e., memory) performance in older adults. However, it is unclear whether this finding is also valid in young adults. Thus, the present study examined the effect of fixed (allocate equal priority on both tasks) versus variable (vary priority between both tasks) priority during short-term motor-cognitive dual task practice on single and dual task performance in healthy young adults (age range: 20-30 years).

RESULTS

During two days of practice, significant improvements of motor (i.e., balance task: reduced root mean square error; p < 001, η_p² = .72) and cognitive (i.e., arithmetic task: increased serial three subtractions; p < .001, η_p² = .78) task performance were observed and that was irrespective of group ("fixed priority" and "variable priority"). Further, the statistical analysis of post-practice single and dual task performance revealed no significant differences between groups, irrespective of task (i.e., motor or cognitive). This indicates that in young as opposed to old adults, single and dual task performance improvements are independent of task prioritization (i.e., fixed or variable priority) during short-term motor-cognitive dual task practice.

The acute effects of mental fatigue on balance performance in healthy young and older adults - A systematic review and meta-analysis

Cognitive resources contribute to balance control. There is evidence that mental fatigue reduces cognitive resources and impairs balance performance, particularly in older adults and when balance tasks are complex, for example when trying to walk or stand while concurrently performing a secondary cognitive task. We conducted a systematic literature search in PubMed (MEDLINE), Web of Science and Google Scholar to identify eligible studies and performed a random effects meta-analysis to quantify the effects of experimentally induced mental fatigue on balance performance in healthy adults. Subgroup analyses were computed for age (healthy young vs. healthy older adults) and balance task complexity (balance tasks with high complexity vs. balance tasks with low complexity) to examine the moderating effects of these factors on fatigue-mediated balance performance. We identified 7 eligible studies with 9 study groups and 206 participants. Analysis revealed that performing a prolonged cognitive task had a small but significant effect (SMDwm = -0.38) on subsequent balance performance in healthy young and older adults. However, age- and task-related differences in balance responses to fatigue could not be confirmed statistically. Overall, aggregation of the available literature indicates that mental fatigue generally reduces balance in healthy adults. However, interactions between cognitive resource reduction, aging and balance task complexity remain elusive.

Does body posture reduce the Stroop effect? Evidence from two conceptual replications and a meta-analysis

Standing compared to sitting, for instance at work, is associated with positive physical and mental health consequences. Indeed, studies suggest that performance in cognitive conflict tasks (e.g., Color Stroop tasks) is improved when subjects perform the task while standing compared to sitting (Rosenbaum et al., 2018; Smith et al., 2019). However, a recent study failed to replicate these findings in five attempts (Caron et al., 2020). We aimed to shed light on these discrepant results by means of two conceptual replications and a meta-analysis. Replication experiments showed typical congruency effects in the Color Stroop task, but failed to find any influence of posture on the Stroop effect even when we subjected data to a more sensitive analysis that controlled for individual variances between participants. Additionally, an explorative Bayesian analysis confirmed that both replications provided strong evidence against an interaction between body posture and the Stroop effect. Meta-analytic results showed that the confidence interval of the overall effect size for a modulation of the Stroop effect by body posture includes the null. Together, our results question whether standing modulates the Stroop effect in Color Stroop tasks and points out limitations of the influence of body posture on cognitive control tasks.

The Effect of 2 Different Dual-Task Balance Training Methods on Balance and Gait in Older Adults: A Randomized Controlled Trial

OBJECTIVE

The purpose of this study was to compare the effects of integrated and consecutive cognitive dual-task balance training in older adults on balance, fear of falling, and gait performance.

METHODS

Fifty-eight participants (age >65 years) were randomly assigned to an integrated dual-task training group (IDTT) (n = 29) and consecutive dual-task training group (CDTT) (n = 29). Balance exercises and cognitive tasks were performed simultaneously by the IDTT group and consecutively by the CDTT group for 8 weeks. Balance was assessed using the Berg Balance Scale as a primary outcome measure and the Timed "Up & Go" Test (TUG) (standard-cognitive), fear of falling was assessed using the Tinetti Falls Efficacy Scale, and gait speed was assessed using the 10-Meter Walk Test (10MWT) (under single-task and dual-task conditions). All tests were performed before and after the training.

RESULTS

There was no difference in group-time interaction in the Berg Balance Scale, TUG-standard, 10MWT-single task, and 10MWT-dual task tests. Group-time interaction was different in the TUG-cognitive and Tinetti Falls Efficacy Scale scores. Also, the effect of time was significantly different in all scales except for the 10MWT-single task in both groups.

CONCLUSION

At the end of the 8-week training period, the impact of integrated and consecutive dual-task balance training on balance and gait performance in older adults was not statistically significantly different. This study suggests that consecutive dual-task balance training can be used as an alternative method to increase balance performance and gait speed in older adults who cannot perform integrated dual-task activities.

IMPACT

There were no significant differences between the effects of the 2 dual-task training methods on balance and gait speed, suggesting that the consecutive dual-task balance training method can be used to improve the balance and gait of older adults. CDTT can be performed safely and considered as an alternative method for use in many rehabilitation training programs with older adults who cannot perform simultaneous activities.

Does Time of Day influence postural control and gait? A review of the literature

BACKGROUND

Like many physiologic processes, Time of Day may influence postural control and gait. A better understanding of diurnal variations in postural control and gait may help to improve diagnoses, reduce falls, and optimize rehabilitation and training routines. This review summarizes the current literature that addresses these questions.

RESEARCH QUESTION

Does time of day affect postural control and gait?

METHODS

We searched PubMed, Google Scholar, and IEEE using a combination of keyword and MeSH terms. We included papers that studied human subjects and assessed gait or postural control as a function of time of day. We evaluated the quality of the identified papers based on nine assessment criteria and analyzed them considering the topic (postural control or gait), age, and characteristics of the conducted assessments. We then quantitatively synthesized the results across studies using a meta-analytical approach (i.e., Hedges' g model).

RESULTS

Twenty-two papers considered the relationship between time of day and postural control, and eleven considered the relationship between time of day and gait. Six studies found that postural control was best in the morning, four described postural control being best in the afternoon, four described optimal postural control in the evening, and eight reported no time of day effect. Two studies found gait best in the morning, five described gait best in the afternoon, two described optimal gait in the evening, and two reported no time of day effect. The results of the quantitative analysis suggest that both postural control and gait were best in the evening.

SIGNIFICANCE

While there is no clear consensus on whether there is a time of day effect for postural control and gait, the findings of this review provide initial evidence suggesting that a small but statistically significant effect exists in favor of the evening. Standardized testing, including repeated and continuous evaluations, may help provide more definitive information on time of day influences on postural control and gait.

Visual-related training to improve balance and walking ability in older adults: A systematic review

Evidence has emerged about the use of visual-related training as an intervention to improve mobility that could implicate fall prevention in the older population. The objective of this systematic review was to investigate whether visual-related interventions are effective in improving balance and walking ability in healthy older adults. An electronic database search was conducted using Pubmed, Embase, CINAHL Plus, Web of Science, PsycINFO, and SportDiscus. Seventeen studies out of a total of 3297 studies were identified in this review that met the inclusion criteria of (1) adopting a longitudinal design with at least one control comparison group, (2) targeting healthy older adults (age 60 or above), (3) primary focus targeting visual element, and (4) the primary outcome(s) were measures indicating walking and/or balance ability. Our results indicated that visual-related training generally led to improvements in balance and walking ability in healthy older adults. It seems necessary that visual-related training should at least involve mobility-related movement component(s), or form a part of a multi-component training to achieve a beneficial effect on balance and walking. The effectiveness and feasibility of these visual-related training in clinical practice for rehabilitation has been discussed and needs to be investigated in future studies. (197/200).

Identification of Neuromuscular Performance Parameters as Risk Factors of Non-contact Injuries in Male Elite Youth Soccer Players: A Preliminary Study on 62 Players With 25 Non-contact Injuries

Introduction: Elite youth soccer players suffer increasing numbers of injuries owing to constantly increasing physical demands. Deficits in neuromuscular performance may increase the risk of injury. Injury risk factors need to be identified and practical cut-off scores defined. Therefore, the purpose of the study was to assess neuromuscular performance parameters within a laboratory-based injury risk screening, to investigate their association with the risk of non-contact lower extremity injuries in elite youth soccer players, and to provide practice-relevant cut-off scores. Methods: Sixty-two elite youth soccer players (age: 17.2 ± 1.1 years) performed unilateral postural control exercises in different conditions, isokinetic tests of concentric and eccentric knee extension and knee flexion (60°/s), isometric tests of hip adduction and abduction, and isometric tests of trunk flexion, extension, lateral flexion and transversal rotation during the preseason period. Non-contact lower extremities injuries were documented throughout 10 months. Risk profiling was assessed using a multivariate approach utilizing a Decision Tree model [Classification and Regression Tree (CART) method]. Results: Twenty-five non-contact injuries were registered. The Decision Tree model selected the COP sway, the peak torque for knee flexion concentric, the functional knee ratio and the path of the platform in that hierarchical order as important neuromuscular performance parameters to discriminate between injured and non-injured players. The classification showed a sensitivity of 0.73 and a specificity of 0.91. The relative risk was calculated at 4.2, meaning that the risk of suffering an injury is four times greater for a player, who has been classified as injured by the Decision Tree model. Conclusion: Measuring static postural control, postural control under unstable condition and the strength of the thigh seem to enable a good indication of injury risk in elite youth soccer players. However, this finding has to be taken with caution due to a small number of injury cases. Nonetheless, these preliminary results may have practical implications for future directions in injury risk screening and in planning and developing customized training programs to counteract intrinsic injury risk factors in elite youth soccer players.

The effects of the Otago Exercise Programme on actual and perceived balance in older adults: A meta-analysis

Objective

Falls are serious issues in older populations. Balance problems are a major cause of falls and may lead to fear of falling and decreased balance confidence. The Otago Exercise Programme (OEP) is an effective fall prevention program that benefits balance function and fear of falling. The primary aim of the meta-analysis was to investigate the effectiveness of the OEP intervention on actual balance performance (i.e., static, dynamic, proactive or reactive balance) and perceived balance ability (i.e., balance confidence or fear of falling) for older adults; the secondary aim was to examine which OEP protocol most improves balance in older adults.

Methods

A systematic electronic review search was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines to identify randomized controlled trials (RCTs) investigating the effects of the OEP on actual balance performance and perceived balance ability in healthy older adults, and examining which OEP training protocol and intervention format most improves balance.

Results

A total of 12 RCTs were included in the analyses. The OEP exerted significant effects on static balance (Hedges’s g = 0.388; 95% confidence interval [CI] = 0.131 to 0.645), dynamic balance (g = -0.228; 95% CI = -0.352 to -0.1.4), proactive balance (g = 0.239; 95% CI = 0.061 to 0.416) and perceived balance (g = -0.184; 95% CI = -0.320 to -0.048) in older adults. Subgroup analysis indicated that the group format for the OEP was more effective for improving static (p = 0.008), dynamic (p = 0.004) and perceived balance (p = 0.004) than was the individual format. Sessions of >30 minutes were more effective in improving static (p = 0.007) and perceived balance (p = 0.014) than were sessions of ≤30 minutes. However, the effects of the OEP on balance were unrelated to the types of control group, training frequency and training period.

Discussion

The OEP is helpful for improving actual balance including static, dynamic, and proactive balance; enhancing confidence in balance control; and reducing fear of falling in older adults. In particular, administrating the OEP in a group setting in >30-minute sessions may be the most appropriate and effective exercise protocol for improving balance.

Postural Control While Listening in Younger and Middle-Aged Adults

OBJECTIVES

The motivation for this research is to determine whether a listening-while-balancing task would be sensitive to quantifying listening effort in middle age. The premise behind this exploratory work is that a decrease in postural control would be demonstrated in challenging acoustic conditions, more so in middle-aged than in younger adults.

DESIGN

A dual-task paradigm was employed with speech understanding as one task and postural control as the other. For the speech perception task, participants listened to and repeated back sentences in the presence of other sentences or steady-state noise. Targets and maskers were presented in both spatially-coincident and spatially-separated conditions. The postural control task required participants to stand on a force platform either in normal stance (with feet approximately shoulder-width apart) or in tandem stance (with one foot behind the other). Participants also rated their subjective listening effort at the end of each block of trials.

RESULTS

Postural control was poorer for both groups of participants when the listening task was completed at a more adverse (vs. less adverse) signal-to-noise ratio. When participants were standing normally, postural control in dual-task conditions was negatively associated with degree of high-frequency hearing loss, with individuals who had higher pure-tone thresholds exhibiting poorer balance. Correlation analyses also indicated that reduced speech recognition ability was associated with poorer postural control in both single- and dual-task conditions. Middle-aged participants exhibited larger dual-task costs when the masker was speech, as compared to when it was noise. Individuals who reported expending greater effort on the listening task exhibited larger dual-task costs when in normal stance.

CONCLUSIONS

Listening under challenging acoustic conditions can have a negative impact on postural control, more so in middle-aged than in younger adults. One explanation for this finding is that the increased effort required to successfully listen in adverse environments leaves fewer resources for maintaining balance, particularly as people age. These results provide preliminary support for using this type of ecologically-valid dual-task paradigm to quantify the costs associated with understanding speech in adverse acoustic environments.

Cognitive-Postural Multitasking Training in Older Adults - Effects of Input-Output Modality Mappings on Cognitive Performance and Postural Control

Older adults exhibit impaired cognitive and balance performance, particularly under multi-task conditions, which can be improved through training. Compatibility of modality mappings in cognitive tasks (i.e., match between stimulus modality and anticipated sensory effects of motor responses), modulates physical and cognitive dual-task costs. However, the effects of modality specific training programs have not been evaluated yet. Here, we tested the effects of cognitive-postural multi-tasking training on the ability to coordinate task mappings under high postural demands in healthy older adults. Twenty-one adults aged 65-85 years were assigned to one of two groups. While group 1 performed cognitive-postural triple-task training with compatible modality mappings (i.e., visual-manual and auditory-vocal dual n-back tasks), group 2 performed the same tasks with incompatible modality mappings (i.e., visual-vocal and auditory-manual n-back tasks). Throughout the 6-weeks balance training intervention, working-memory load was gradually increased while base-of-support was reduced. Before training (T0), after a 6-week passive control period (T1), and immediately after the intervention (T2), participants performed spatial dual one-back tasks in semi-tandem stance position. Our results indicate improved working-memory performance and reduced dual-task costs for both groups after the passive control period, but no training-specific performance gains. Furthermore, balance performance did not improve in response to training. Notably, the cohort demonstrated meaningful interindividual variability in training responses. Our findings raise questions about practice effects and age-related heterogeneity of training responses following cognitive-motor training. Following multi-modal balance training, neither compatible nor incompatible modality mappings had an impact on the observed outcomes.

Functional objective parameters which may discriminate patients with mild cognitive impairment from cognitively healthy individuals: a systematic review and meta-analysis using an instrumented kinematic assessment

BACKGROUND

a systematic review in 2015 showed kinematic gait and balance parameters which can discriminate patients with mild cognitive impairment (MCI) from cognitively healthy individuals.

OBJECTIVE

this systematic review and meta-analysis aims to summarise and synthesise the evidence published after the previous review about the functional objective parameters obtained by an instrumented kinematic assessment which could discriminate patients with MCI from cognitively healthy individuals, as well as to assess the level of evidence per outcome.

METHODS

major electronic databases were searched from inception to August 2019 for cross-sectional studies published after 2015 examining kinematic gait and balance parameters, which may discriminate patients with MCI from cognitively healthy individuals. Meta-analysis was carried out for each parameter reported in two or more studies.

RESULTS

Ten cross-sectional studies with a total of 1,405 patients with MCI and 2,277 cognitively healthy individuals were included. Eight of the included studies reported a low risk of bias. Patients with MCI showed a slower gait speed than cognitively healthy individuals. Thus, single-task gait speed (d = -0.44, 95%CI [-0.60 to -0.28]; P < 0.001), gait speed at fast pace (d = -0.48, 95%CI [-0.72 to -0.24]; P < 0.001) and arithmetic dual-task gait speed (d = -1.20, 95%CI [-2.12 to -0.28]; P = 0.01) were the functional objective parameters which best discriminated both groups.

CONCLUSION

the present review shows kinematic gait parameters which may discriminate patients with MCI from cognitively healthy individuals. Most of the included studies reported a low risk of bias, but the grading of recommendations assessment, development and evaluation criteria showed a low level of evidence per outcome.

How cognitive loads modulate the postural control of older women with low back pain?

BACKGROUND

The capacity of postural control is a key factor related to falling in older people, particularly in older women with low back pain (LBP). Cognitive involvement in postural control increases with age. However, most scholars have not considered different difficulty levels of cognitive loads when exploring the effects of cognition on postural control in older patients with LBP. The present study is to investigate how different levels of cognitive loads modulate postural control in older women with LBP.

METHODS

This was a cross-sectional study. Twenty older women with LBP were recruited into the LBP group, and 20 healthy older women without the history of LBP were recruited into the healthy control group. Balance parameters were computed to quantify postural control. All participants underwent the balance test, which required the participant to maintain stability during standing on a force platform with or without a concurrent cognitive task. The balance test included three levels of difficulties of posture tasks (eyes-open vs. eyes-closed vs. one-leg stance) and three cognitive tasks (without cognitive task vs. auditory arithmetic task vs. serial-7 s arithmetic task).

RESULTS

A repeated-measure analysis of variance (3 postural tasks × 3 congnitive tasks× 2 groups) testing the effects of the different congnitive task levels on the performance in different postural conditions. Older women with LBP had worse postural control (as reflected by larger center of pressure (COP) parameters) than control group regardless of postural or cognitive difficulties. Compared with the single task, the COP parameters of participants with LBP were larger during dual tasks, even though the difficulty level of the cognitive task was low. Larger COP parameters were shown only if the difficulty level of the cognitive task was high in control group. Correlations between sway area/sway length and the number of falls were significant in dual tasks.

CONCLUSION

Our findings shed light on how cognitive loads modulate postural control for older women with LBP. Compared with control group, cognitive loads showed more disturbing effects on postural control in older women with LBP, which was associated with falling.

Early aging and postural control while listening and responding

It is not unusual for communication to take place while people are involved in another activity. This paper describes a study that measures the impact of listening while also completing an active postural control task. The focus was on whether the combination of listening and balancing was more detrimental to middle-aged adults than it was to younger adults as age-related changes in both hearing and postural control can occur within this age range. Speech understanding in the presence of noise and speech maskers was measured when participants (n = 15/group) were simply standing still, as well as when they were asked to complete a balancing-with-feedback postural control task, requiring different levels of effort. Performance on the postural control task also was measured in isolation. Results indicated that dual-task costs for postural control were larger when the masker was speech (vs noise) for the middle-aged group but not for the younger group. Dual-task costs in postural control increased with degree of high-frequency hearing loss even when age was controlled. Overall, results suggest that postural control in middle-aged adults can be compromised when individuals are communicating in challenging environments, perhaps reflecting an increased need for cognitive resources to successfully understand messages.

Does attention switching between multiple tasks affect gait stability and task performance differently between younger and older adults?

Gait stability and secondary task performance are affected by the need to share attention when dual-tasking. Further decrements may result from the need to switch attention between multiple secondary tasks. The aim of the current study was to determine the effects of attention switching upon gait stability and task performance in healthy younger and older adults. Ten healthy younger and ten healthy older adults walked on a treadmill at their preferred speed during three trials including: (1) baseline walking; (2) non-switching task walking, requiring response to an auditory-spatial or visual-spatial cue presented in an expected order; and (3) switching task walking, which required response to an auditory-spatial or visual-spatial cue presented in an unexpected order. Response time and accuracy, the margin of stability in the frontal (MoS_ML) and sagittal planes (MoS_A: anterior, MoS_P: posterior), step width and step length were calculated for non-switching and switching tasks. The MoS_ML, MoS_A, MoS_P, step width and step length during non-switching and switching tasks were normalized to baseline walking. Older adults took significantly longer to respond to cues and made more errors during the switching task compared to younger adults. Younger adults took narrower steps (p < 0.01) and displayed a reduction in MoS_ML (p < 0.01) during the switching task compared with the non-switching task. Conversely, older adults displayed no differences in MoS_ML between tasks. These findings suggest that attention switching results in different task prioritization strategies in younger and older adults during walking.

Dual-Task Conditions on Static Postural Control in Older Adults: A Systematic Review and Meta-Analysis

Dual-task (DT) consists of the performance of two tasks simultaneously. An index of DT difficulty has been linked to decreased postural control. Because a wide range of DT is employed, this study aimed to evaluate its effects in static balance in older adults. PubMed, Web of Science, and Scopus were screened, and the secondary tasks were grouped as manual, reaction time, discrimination and decision making, mental tracking, verbal fluency, working memory, or "other" tasks. A total of 66 studies have been included. The meta-analysis was conducted on 28 effects and showed a significant mean effect size of d = 0.24 (p = .02, SE = 0.10; confidence interval [0.04, 0.44]), indicating a worsening in stability during DT. In conclusion, postural control was worsened by the Stroop test and the arithmetic tasks improved it. The results do not underpin any conclusive statement on the impact of DT, and a standard operating procedure was created.

Effects of a 16-week multimodal exercise program on gait performance in individuals with dementia: a multicenter randomized controlled trial

Background

There is a high prevalence of gait impairments in individuals with dementia (IWD). Gait impairments are associated with increased risk of falls, disability, and economic burden for health care systems. Only few studies have investigated the effectiveness of physical activity on gait performance in IWD, reporting promising but inconsistent results. Thus, this study aimed to investigate the effectiveness of a multimodal exercise program (MEP) on gait performance in IWD.

Methods

In this parallel-group randomized controlled trial, we enrolled 319 IWD of mild to moderate severity, living in care facilities, aged ≥ 65 years, and being able to walk at least 10 m. The control group (n = 118) received conventional treatment, whereas the intervention group (n = 201) additionally participated in a 16-week MEP specifically tailored to IWD. We examined the effects of the MEP on spatiotemporal gait parameters and dual task costs by using the gait analysis system GAITRite. Additionally, we compared characteristics between positive, non-, and negative responders, and investigated the impact of changes in underlying motor and cognitive performance in the intervention group by conducting multiple regression analyses.

Results

Two-factor analyses of variance with repeated measurements did not reveal any statistically significant time*group effects on either spatiotemporal gait parameters or dual task costs. Differences in baseline gait performance, mobility, lower limb strength, and severity of cognitive impairments were observed between positive, non-, and negative responders. Positive responders were characterized by lower motor performance compared to negative and non-responders, while non-responders showed better cognitive performance than negative responders. Changes in lower limb strength and function, mobility, executive function, attention, and working memory explained up to 39.4% of the variance of changes in gait performance.

Conclusions

The effectiveness of a standardized MEP on gait performance in IWD was limited, probably due to insufficient intensity and amount of specific walking tasks as well as the large heterogeneity of the sample. However, additional analyses revealed prerequisites of individual characteristics and impacts of changes in underlying motor and cognitive performance. Considering such factors may improve the effectiveness of a physical activity intervention among IWD.

Trial registration

DRKS00010538 (German Clinical Trial Register, date of registration: 01 June 2016, retrospectively registered, https://www.drks.de/drks_web/setLocale_EN.do).

Postural stability after treadmill and overground walking in young and elderly

BACKGROUND

Ageing commonly disrupts the balance control and compensatory postural responses that contribute to maintaining balance and preventing falls during perturbation of posture. Improvement of compensatory postural responses during walking is one of the main goals in fall prevention programs which often include treadmill walking training. However, during treadmill walking, there is a sensory (visualsomatosensory and vestibular-somatosensory) conflict that can evoke aftereffects of self-motion sensation and could alter postural stability after training.

RESEARCH QUESTION

The aim of this study was to compare the effect of overground and treadmill walking on postural stability in healthy young and elderly subjects.

METHODS

Postural responses of 31 Young and 19 healthy Elderly before and after overground and treadmill walking were assessed by a force platform in four stance conditions: firm and foam surface with eyes open and eyes closed.

RESULTS

In Elderly group, velocity parameters significantly increased after treadmill walking but not after overground walking. This increase was found particularly in the conditions with eyes open in both types of surfaces (firm, foam). The velocity parameters values (expect Vx) were significantly increased in Elderly compared to Young almost in all four conditions after treadmill and overground walking.

SIGNIFICANCE

Our study suggests that Elderly become more unstable after treadmill walking and have greater difficulties to adapt to new balance circumstances caused by sensory conflict associated with treadmill walking. It seems that during treadmill walking and subsequent stance, vision is the major factor contributing to posture stabilization. Thus, the suitability of treadmill walking as a part of training programs for elderly adults with higher fall risk should be seriously considered.

Age-related differences in bimanual coordination performance

Purpose. The purpose of this article was to determine how characteristics of bimanual coordination tasks affect the quality of performance and to determine the impact of these characteristics on muscular activation of the upper limbs, with consideration of age-related differences. Methods. The research was carried out on two groups consisting of 25 people aged 20-30 and 60-67 years. The subjects performed seven tasks that varied in coordination mode, tracking mode and outline-tracing. The main measures of task performance were calculated on the basis of the difference between the position of the target and tracing cursors. Cohen's d value was calculated to show differences in measures between groups. Results. There were higher values of error and variability measures for elderly people compared to young. Complex tasks showed the largest difficulty, which suggests that, when performed, such tasks have the greatest potential to improve coordination skills. Tasks during which both limbs contribute to the movement of one cursor proved the most appropriate. Conclusion. The tracking mode is of great importance for the quality of performance in motor coordination tasks, while the performance of tasks with imposed speed is much more strongly age-sensitive than performance with a freely chosen speed.

Effects of Corrective Exercise for Thoracic Hyperkyphosis on Posture, Balance, and Well-Being in Older Women: A Double-Blind, Group-Matched Design

BACKGROUND AND PURPOSE

The purpose of this study was to identify the effects of a corrective exercise for thoracic hyperkyphosis on posture, balance, and well-being in Korean community-dwelling older women.

METHODS

Fifty women 65 years of age and older, recruited from 2 senior centers, participated in this study. Participants were assigned to either the experimental group (EG) or the control group (CG) on the basis of convenience of location, and 22 in each were analyzed. Participants in the EG underwent a thoracic corrective exercise program 1 hour each session, twice per week for 8 weeks (a total of 16 sessions), which consisted of specific exercises to enhance breathing, thoracic mobility and stability, and awareness of thoracic alignment. The CG received education on the same thoracic corrective exercise program and a booklet of the exercises. Outcome measures included the extent of postural abnormality (angle of thoracic kyphosis, kyphosis index calculated both in relaxed- and best posture using flexicurve, the ratio of the kyphosis index calculated best posture/relaxed posture, craniovertebral angle, and tragus-to-wall distance), balance (Short Physical Performance Battery and limit of stability), and well-being (Geriatric Depression Scale Short Form and the 36-Item Short Form Health Survey [SF-36]). All data were collected by 6 blinded assessors at baseline, at 8 weeks after the completion of intervention, and at 16 weeks for follow-up.

RESULTS AND DISCUSSION

For participants of the EG, means of all parameters showed significant improvements over time (P < .05), with improved values both in comparison of baseline to postintervention and baseline to follow-up. Means of CG parameters were significantly improved in only the angle of thoracic kyphosis and the tragus-to-wall distance (P < .05). Furthermore, in all parameters, percent change between baseline and postintervention data was significantly (P < .05) higher for the EG than that for the CG, except for the limit of stability and SF-36 which improved but not significantly. All parameters between baseline and follow-up data were significantly (P < .05) higher for the EG than those for the CG, except for the limit of stability.

CONCLUSIONS

The findings of this study suggest that a well-designed exercise program may be beneficial to improve spinal posture, balance, and well-being in older women with thoracic hyperkyphosis. We recommend the use of the therapeutic strategies utilized in this study to enhance thoracic posture, balance, and well-being of older women with thoracic hyperkyphosis. Future research is needed to apply this exercise protocol on a larger and more diverse population.

Gait Analysis of Patients After Allogeneic Hematopoietic Cell Transplantation Reveals Impairments of Functional Performance

Background: After allogeneic hematopoietic cell transplantation (alloHCT), patients often report functional impairments like reduced gait speed and muscle weakness. These impairments can increase the risk of adverse health events similar to elderly populations. However, they have not been quantified in patients after alloHCT (PATs). Methods: We compared fear of falling (Falls Efficacy Scale–International) and temporal gait parameters recorded on a 10-m walkway at preferred and maximum gait speed and under dual-task walking of 16 PATs (aged 31-73 years) with 15 age-matched control participants (CONs) and 17 seniors (SENs, aged >73 years). Results: Groups’ gait parameters especially differed during the maximum speed condition: PATs walked slower and required more steps/10 m than CONs. PATs exhibited greater stride, stance, and swing times than CONs. PATs’ swing time was even longer than SENs’. The PATs’ ability to accelerate their gait speed from preferred to fast was smaller compared with CONs’. PATs reported a greater fear of falling than CONs and SENs. Conclusion: Gait analysis of alloHCT patients has revealed impairments of functional performance. Patients presented a diminished ability to accelerate gait and extending steps possibly related to a notable strength deficit that impairs power-generation abilities from lower extremities. Furthermore, patients reported a greater fear of falling than control participants and even seniors. Slowing locomotion could be a risk-preventive safety strategy. Since functional disadvantages may put alloHCT patients at a higher risk of frailty, reinforcing appropriate physical exercises already during and after alloHCT could prevent adverse health events and reduce the risk of premature functional aging.

Association between trunk muscle strength and static balance in older women

The aim of this study was to determine the relationship between trunk muscle strength and balance ability in both simple and dual-task conditions in older women. Sixty-seven older women (age: 67.2 ± 1.1 years) volunteered in this study. Each participant performed isometric trunk muscle strength testing in standing position (extension, flexion, and lateral flexion) and balance testing in semitandem stance for 30 seconds in two conditions: with and without an additional cognitive task (counting down by 3 from 300). Balance was quantified via force plate as a mean velocity of center of pressure (CoP) displacement over 30 seconds. We found a statistically significant correlation between the trunk extensor strength and mean velocity of CoP displacement, both without (r = 0.5, p < .05) and with an additional cognitive task (r = 0.4, p < .05). There were no statistically significant correlations between trunk flexor and lateral flexors strength and balance measures (r < 0.2; p > .05). These results indicate that trunk extensor muscle strength is related to balance ability of healthy older women. Although additional studies are needed, our findings suggest that trunk strength training could be of importance in prevention of falls and fall-related injuries in seniors.

The evaluation of dual-task conditions on static postural control in the older adults: a systematic review and meta-analysis protocol

BACKGROUND

In postural stability evaluation, the dual-task concept is often adopted in order to create a more challenging situation. The dual-task consists of performing simultaneously two tasks, a primary static or dynamic motor task and an additional secondary cognitive task. Usually, a multitask condition leads to a reduction in the postural control performance, especially in older adults. Considering the wide spectrum of secondary task conditions existing in scientific literature, the present manuscript aims to write a peer-reviewed protocol that will be used in a systematic review and meta-analysis performed to identify the effects of different secondary tasks conditions in a population of older adults during static postural stability.

METHODS

The study will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and for this manuscript, the PRISMA Protocol. PICOS criteria (population, intervention, comparison, outcomes, study design) will be also followed. The population examined will be healthy older adults over 60 years of age and all quantitative, qualitative, and mixed methods study design will be included. Original articles will be also included if written in English, while no restriction criteria will be applied to the country of origin. Instead, reviews, meta-analysis, abstracts, citations, scientific conferences, opinion pieces, books, books reviews, statements, letters, editorials, non-peer reviewed journals articles, and commentaries will be excluded. The research of literature will be performed using PubMed, Web of Science, and Scopus with words related to the topic. From each included study, information previously agreed will be extracted and inserted into a spreadsheet and a narrative synthesis containing summary tables and graphs will describe the articles taken in examination. Furthermore, a meta-analysis will be performed to establish which DT condition has a greater effect following the Hedges and Olkin approach, extension of Glass' method and Cohen's d will be calculated.

DISCUSSION

The present manuscript wants to provide the protocol that will be used in the systematic review and meta-analysis with the intent to inform the researchers and professionals about the dual-task condition effects. Such will lead future investigations in using the most appropriate dual-task condition.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018116597.

Behavioral and Neural Correlates of Cognitive-Motor Interference during Multitasking in Young and Old Adults

The concurrent performance of cognitive and postural tasks is particularly impaired in old adults and associated with an increased risk of falls. Biological aging of the cognitive and postural control system appears to be responsible for increased cognitive-motor interference effects. We examined neural and behavioral markers of motor-cognitive dual-task performance in young and old adults performing spatial one-back working memory single and dual tasks during semitandem stance. On the neural level, we used EEG to test for age-related modulations in the frequency domain related to cognitive-postural task load. Twenty-eight healthy young and 30 old adults participated in this study. The tasks included a postural single task, a cognitive-postural dual task, and a cognitive-postural triple task (cognitive dual-task with postural demands). Postural sway (i.e., total center of pressure displacements) was recorded in semistance position on an unstable surface that was placed on top of a force plate while performing cognitive tasks. Neural activation was recorded using a 64-channel mobile EEG system. EEG frequencies were attenuated by the baseline postural single-task condition and demarcated in nine Regions-of-Interest (ROIs), i.e., anterior, central, posterior, over the cortical midline, and both hemispheres. Our findings revealed impaired cognitive dual-task performance in old compared to young participants in the form of significantly lower cognitive performance in the triple-task condition. Furthermore, old adults compared with young adults showed significantly larger postural sway, especially in cognitive-postural task conditions. With respect to EEG frequencies, young compared to old participants showed significantly lower alpha-band activity in cognitive-cognitive-postural triple-task conditions compared with cognitive-postural dual tasks. In addition, with increasing task difficulty, we observed synchronized theta and delta frequencies, irrespective of age. Task-dependent alterations of the alpha frequency band were most pronounced over frontal and central ROIs, while alterations of the theta and delta frequency bands were found in frontal, central, and posterior ROIs. Theta and delta synchronization exhibited a decrease from anterior to posterior regions. For old adults, task difficulty was reflected by theta synchronization in the posterior ROI. For young adults, it was reflected by alpha desynchronization in bilateral anterior ROIs. In addition, we could not identify any effects of task difficulty and age on the beta frequency band. Our results shed light on age-related cognitive and postural declines and how they interact. Modulated alpha frequencies during high cognitive-postural task demands in young but not old adults might be reflective of a constrained neural adaptive potential in old adults. Future studies are needed to elucidate associations between the identified age-related performance decrements with task difficulty and changes in brain activity.

Validity and Reliability of a Novel Integrative Motor Performance Testing Course for Seniors: The "Agility Challenge for the Elderly (ACE)"

Background: Assessing traditional neuromuscular fall risk factors (i.e., balance, gait, strength) in the elderly has so far mainly been done independently. Functional and integrative testing approaches are scarce. The present study proposes an agility course for an integrative assessment of neuromuscular and also cardiocirculatory capacity in seniors – and tests its criterion validity and reliability.

Methods: Thirty-six seniors (age: 69.0 ± 2.8 years; BMI: 25.4 ± 3.5 kg/m²; sex: 19 males/17 females; weekly physical activity: 9.4 ± 5.5 h) participated. They completed four trials of the Agility Challenge for the Elderly (ACE)-course in two sessions separated by 1 week. The course consists of three segments focusing on different agility aspects. Cardiovascular capacity was assessed by 6-min walk test (6MWT), neuromuscular capacity by static, dynamic and perturbed standing balance tasks, habitual gait speed assessment, and rate of torque development testing. Parameters’ predictive strength for the ACE performance was assessed by regression analysis. Reliability was calculated with intraclass correlation coefficients and coefficients of variation.

Results: Men completed the course in 43.0 ± 5.7 s and women in 51.9 ± 4.0 s. Overall and split times were explained by 6MWT time (ηp2 = 0.38–0.44), gait speed (ηp2 = 0.29–0.43), and to a lesser extent trunk rotation explosive strength (ηp2 = 0.05–0.12). Static and dynamic balance as well as plantar flexion strength explained the performance in some segments to a very small extent (ηp2 = 0.06–0.08). Good between- and within-day reliability were observed for total course and split times: The ICC for the between-day comparison was 0.93 (0.88–0.96) and ranged between 0.84 and 0.94 for split times. The within-day ICC was 0.94 (0.91–0.97) for overall time and 0.92–0.97 for split times. Coefficients of variation were smaller than 5.7% for within and between day analyses.

Conclusion: The ACE course reflects cardiocirculatory and neuromuscular capacity, with the three ACE segments potentially reflecting slightly different domains of neuromuscular (static and dynamic balance, ankle, and trunk strength) performance, whereas cardiocirculatory fitness and gait speed contribute to all segments. Our test can detect changes in overall performance greater than 5.7% and can thus be useful for documenting changes due to interventions in seniors.

Beam Walking to Assess Dynamic Balance in Health and Disease: A Protocol for the "BEAM" Multicenter Observational Study

BACKGROUND

Dynamic balance keeps the vertical projection of the center of mass within the base of support while walking. Dynamic balance tests are used to predict the risks of falls and eventual falls. The psychometric properties of most dynamic balance tests are unsatisfactory and do not comprise an actual loss of balance while walking.

OBJECTIVES

Using beam walking distance as a measure of dynamic balance, the BEAM consortium will determine the psychometric properties, lifespan and patient reference values, the relationship with selected "dynamic balance tests," and the accuracy of beam walking distance to predict falls.

METHODS

This cross-sectional observational study will examine healthy adults in 7 decades (n = 432) at 4 centers. Center 5 will examine patients (n = 100) diagnosed with Parkinson's disease, multiple sclerosis, stroke, and balance disorders. In test 1, all participants will be measured for demographics, medical history, muscle strength, gait, static balance, dynamic balance using beam walking under single (beam walking only) and dual task conditions (beam walking while concurrently performing an arithmetic task), and several cognitive functions. Patients and healthy participants age 50 years or older will be additionally measured for fear of falling, history of falls, miniBESTest, functional reach on a force platform, timed up and go, and reactive balance. All participants age 50 years or older will be recalled to report fear of falling and fall history 6 and 12 months after test 1. In test 2, seven to ten days after test 1, healthy young adults and age 50 years or older (n = 40) will be retested for reliability of beam walking performance.

CONCLUSION

We expect to find that beam walking performance vis-à-vis the traditionally used balance outcomes predicts more accurately fall risks and falls.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03532984.

Associations Between Types of Balance Performance in Healthy Individuals Across the Lifespan: A Systematic Review and Meta-Analysis

Background: The objective of this systematic review and meta-analysis was to quantify and statistically compare correlations between types of balance performance in healthy individuals across the lifespan. Methods: Literature search was performed in the electronic databases PubMed, Web of Science, and SPORTDiscus. Studies were included if they investigated healthy individuals aged ≥6 years and reported measures of static/dynamic steady-state, proactive, and/or reactive balance. The included studies were coded as follows: age group, gender, and balance type, test, parameter. Pearson's correlation coefficients were extracted, transformed (i.e., Fisher's z-transformed r _z -value), aggregated (i.e., weighted mean r _z -value), back-transformed to r-values, classified according to their magnitude, and statistically compared. The methodological quality of each study was assessed using the Appraisal tool for Cross-Sectional Studies. Results: We detected twenty-six studies that examined associations between types of balance and exclusively found small-sized correlations, irrespective of the age group considered. More specifically, the weighted mean r _z-values amounted to 0.61 (back-transformed r-value: 0.54) in old adults for the correlation of dynamic steady-state with proactive balance. For correlations between dynamic and static steady-state balance, the weighted mean r _z-values amounted to 0.09 in children (r-value: 0.09) and to 0.32 in old adults (r-value: 0.31). Further, correlations of proactive with static steady-state balance revealed weighted mean r _z-values of 0.24 (r-value: 0.24) in young adults and of 0.31 (r-value: 0.30) in old adults. Additionally, correlations between reactive and static steady-state balance yielded weighted mean r _z-values of 0.21 (r-value: 0.21) in young adults and of 0.19 (r-value: 0.19) in old adults. Moreover, significantly different correlation coefficients (z = 8.28, p < 0.001) were only found for the association between dynamic and static steady-state balance in children (r = 0.09) compared to old adults (r = 0.31). Lastly, we detected trivial to considerable heterogeneity (i.e., 0% ≤ I² ≤ 83%) between studies. Conclusions: Our systematic review and meta-analysis showed exclusively small-sized correlations between types of balance performance across the lifespan. This indicates that balance performance seems to be task-specific rather than a "general ability." Further, our results suggest that for assessment/training purposes a test battery/multiple exercises should be used that include static/dynamic steady-state, proactive, and reactive types of balance. Concerning the observed significant age differences, further research is needed to investigate whether they are truly existent or if they are caused by methodological inconsistencies.

Contribution of the Lateral Prefrontal Cortex to Cognitive-Postural Multitasking

There is evidence for cortical contribution to the regulation of human postural control. Interference from concurrently performed cognitive tasks supports this notion, and the lateral prefrontal cortex (lPFC) has been suggested to play a prominent role in the processing of purely cognitive as well as cognitive-postural dual tasks. The degree of cognitive-motor interference varies greatly between individuals, but it is unresolved whether individual differences in the recruitment of specific lPFC regions during cognitive dual tasking are associated with individual differences in cognitive-motor interference. Here, we investigated inter-individual variability in a cognitive-postural multitasking situation in healthy young adults (n = 29) in order to relate these to inter-individual variability in lPFC recruitment during cognitive multitasking. For this purpose, a one-back working memory task was performed either as single task or as dual task in order to vary cognitive load. Participants performed these cognitive single and dual tasks either during upright stance on a balance pad that was placed on top of a force plate or during fMRI measurement with little to no postural demands. We hypothesized dual one-back task performance to be associated with lPFC recruitment when compared to single one-back task performance. In addition, we expected individual variability in lPFC recruitment to be associated with postural performance costs during concurrent dual one-back performance. As expected, behavioral performance costs in postural sway during dual-one back performance largely varied between individuals and so did lPFC recruitment during dual one-back performance. Most importantly, individuals who recruited the right mid-lPFC to a larger degree during dual one-back performance also showed greater postural sway as measured by larger performance costs in total center of pressure displacements. This effect was selective to the high-load dual one-back task and suggests a crucial role of the right lPFC in allocating resources during cognitive-motor interference. Our study provides further insight into the mechanisms underlying cognitive-motor multitasking and its impairments.

Day-to-Day Variability of Postural Sway and Its Association With Cognitive Function in Older Adults: A Pilot Study

Introduction: Increased variability in motor function has been observed during the initial stages of cognitive decline. However, the natural variability of postural control, as well as its association with cognitive status and decline, remains unknown. The objective of this pilot study was to characterize the day-to-day variability in postural sway in non-demented older adults. We hypothesized that older adults with a lower cognitive status would have higher day-to-day variability in postural sway. Materials and Methods: A Nintendo Wii balance board (WBB) was used to quantify postural sway in the home twice daily for 30 days in 20 non-demented, community-dwelling older adults: once under a single-task condition and once under a dual-task condition (using a daily word search task administered via a Nook tablet). Mean sway distance, velocity, area, centroidal frequency and frequency dispersion were derived from the center of pressure data acquired from the WBB. Results: Linear relationships were observed between the day-to-day variability in postural sway and cognitive status (indexed by cognitive global z-scores). More variability in time-domain postural sway (sway distance and area) and less variability in frequency-domain postural sway (centroidal sway frequency) were associated with a lower cognitive status under both the single- and dual-task conditions. Additionally, lower cognitive performance rates on the daily word search task were related to a lower cognitive status. Discussion: This small pilot study conducted on a short time scale motivates large-scale implementations over more extended time periods. Tracking longitudinal changes in postural sway may further our understanding of early-stage postural decline and its association with cognitive decline and, in turn, may aid in the early detection of dementia during preclinical stages when the utility of disease-modifying therapies would be greatest.

Effects of Single Compared to Dual Task Practice on Learning a Dynamic Balance Task in Young Adults

Background: In everyday life, people engage in situations involving the concurrent processing of motor (balance) and cognitive tasks (i.e., “dual task situations”) that result in performance declines in at least one of the given tasks. The concurrent practice of both the motor and cognitive task may counteract these performance decrements. The purpose of this study was to examine the effects of single task (ST) compared to dual task (DT) practice on learning a dynamic balance task.

Methods: Forty-eight young adults were randomly assigned to either a ST (i.e., motor or cognitive task training only) or a DT (i.e., motor-cognitive training) practice condition. The motor task required participants to stand on a platform and keeping the platform as close to horizontal as possible. In the cognitive task, participants were asked to recite serial subtractions of three. For 2 days, participants of the ST groups practiced the motor or cognitive task only, while the participants of the DT group concurrently performed both. Root-mean-square error (RMSE) for the motor and total number of correct calculations for the cognitive task were computed.

Results: During practice, all groups improved their respective balance and/or cognitive task performance. With regard to the assessment of learning on day 3, we found significantly smaller RMSE values for the ST motor (d = 1.31) and the DT motor-cognitive (d = 0.76) practice group compared to the ST cognitive practice group but not between the ST motor and the DT motor-cognitive practice group under DT test condition. Further, we detected significantly larger total numbers of correct calculations under DT test condition for the ST cognitive (d = 2.19) and the DT motor-cognitive (d = 1.55) practice group compared to the ST motor practice group but not between the ST cognitive and the DT motor-cognitive practice group.

Conclusion: We conclude that ST practice resulted in an effective modulation of the trained domain (i.e., motor or cognitive) while only DT practice resulted in an effective modulation of both domains (i.e., motor and cognitive). Thus, particularly DT practice frees up central resources that were used for an effective modulation of motor and cognitive processing mechanisms.

Age-related decrements in dual-task performance: Comparison of different mobility and cognitive tasks. A cross sectional study

This cross-sectional study investigated the age-related differences in dual-task performance both in mobility and cognitive tasks and the additive dual-task costs in a sample of older, middle-aged and young adults. 74 older adults (M = 72.63±5.57 years), 58 middle-aged adults (M = 46.69±4.68 years) and 63 young adults (M = 25.34±3.00 years) participated in the study. Participants performed different mobility and subtraction tasks under both single- and dual-task conditions. Linear regressions, repeated-measures and one-way analyses of covariance were used, The results showed: significant effects of the age on the dual and mobility tasks (p<0.05) and differences among the age-groups in the combined dual-task costs (p<0.05); significant decreases in mobility performance under dual-task conditions in all groups (p<0.05) and a decrease in cognitive performance in the older group (p<0.05). Dual-task activity affected mobility and cognitive performance, especially in older adults who showed a higher dual-task cost, suggesting that dual-tasks activities are affected by the age and consequently also mobility and cognitive tasks are negatively influenced.

Age-Related Interference between the Selection of Input-Output Modality Mappings and Postural Control-a Pilot Study

Age-related decline in executive functions and postural control due to degenerative processes in the central nervous system have been related to increased fall-risk in old age. Many studies have shown cognitive-postural dual-task interference in old adults, but research on the role of specific executive functions in this context has just begun. In this study, we addressed the question whether postural control is impaired depending on the coordination of concurrent response-selection processes related to the compatibility of input and output modality mappings as compared to impairments related to working-memory load in the comparison of cognitive dual and single tasks. Specifically, we measured total center of pressure (CoP) displacements in healthy female participants aged 19–30 and 66–84 years while they performed different versions of a spatial one-back working memory task during semi-tandem stance on an unstable surface (i.e., balance pad) while standing on a force plate. The specific working-memory tasks comprised: (i) modality compatible single tasks (i.e., visual-manual or auditory-vocal tasks), (ii) modality compatible dual tasks (i.e., visual-manual and auditory-vocal tasks), (iii) modality incompatible single tasks (i.e., visual-vocal or auditory-manual tasks), and (iv) modality incompatible dual tasks (i.e., visual-vocal and auditory-manual tasks). In addition, participants performed the same tasks while sitting. As expected from previous research, old adults showed generally impaired performance under high working-memory load (i.e., dual vs. single one-back task). In addition, modality compatibility affected one-back performance in dual-task but not in single-task conditions with strikingly pronounced impairments in old adults. Notably, the modality incompatible dual task also resulted in a selective increase in total CoP displacements compared to the modality compatible dual task in the old but not in the young participants. These results suggest that in addition to effects of working-memory load, processes related to simultaneously overcoming special linkages between input- and output modalities interfere with postural control in old but not in young female adults. Our preliminary data provide further evidence for the involvement of cognitive control processes in postural tasks.