Quantifying effects of age on balance and gait with inertial sensors in community-dwelling healthy adults

Use of the Brief-BESTest partially instrumented with accelerometry to detect balance deterioration in middle-age

BACKGROUND

Most standardized balance tests cannot detect subtle balance deterioration in middle age, or identify those at higher risk for accelerated balance decline due to a ceiling effect.

AIMS

To determine whether the Brief Balance Evaluation Systems Test (Brief-BESTest), partially instrumented with accelerometry, can detect balance deterioration in middle age and identify individuals with poor balance.

METHODS

We studied young (25.3 ± 2.3 years), early middle-aged (47.7 ± 2.6 years), and late middle-aged adults (60.6 ± 3.6 years), with 25 participants in each age group. Subjects wore an accelerometer on their lower back while performing the Brief-BESTest. Balance measurements included the Brief-BESTest total and sub-measures scores, and postural sway during the Brief-BESTest standing tasks, calculated by the 95% confidence ellipse trajectory of the center of mass (COM-95% ellipse).

RESULTS

Compared to the two middle-aged groups, young adults had better total Brief-BESTest and sub-measures scores, apart from the Stability-in-Gait sub-measure, and less postural sway during the Sensory-Orientation sub-measure. The total Brief-BESTest scores as well as the Biomechanical-Constraints and Sensory-Orientation sub-measures differed also between early and late middle-aged adults. Both the Brief-BESTest total scores and the Sensory-Orientation postural sway values demonstrated increased variation with age, allowing to identify subjects with poor balance. A moderate negative correlation (r = -0.43) was found between the Brief-BESTest total score and the COM-95% ellipse size, and a moderate agreement (k = 0.56) in identifying subjects with poor performance in the early but not the late middle age group.

CONCLUSIONS

The Brief-BESTest test combined with accelerometry could be a suitable screening tool to identify middle-aged people with early balance deterioration and potentially identify those with poor balance and a possible higher risk for falls. Clinicians and policymakers can use our findings to implement balance assessment programs in patients < 65 years, leading to preventive strategies before the risk increases.

Age-Related Influence on Static and Dynamic Balance Abilities: An Inertial Measurement Unit-Based Evaluation

Balance control, a complex sensorimotor skill, declines with age. Assessing balance is crucial for identifying fall risk and implementing interventions in the older population. This study aimed to measure age-dependent changes in static and dynamic balance using inertial measurement units in a clinical setting. This study included 82 healthy participants aged 20-85 years. For the dynamic balance test, participants stood on a horizontally swaying balance board. For the static balance test, they stood on one leg. Inertial measurement units attached to their bodies recorded kinematic data, with average absolute angular velocities assessing balance capabilities. In the dynamic test, the younger participants had smaller average absolute angular velocities in most body parts than those of the middle-aged and older groups, with no significant differences between the middle-aged and older groups. Conversely, in the single-leg stance tests, the young and middle-aged groups outperformed the older group, with no significant differences between the young and middle-aged groups. Thus, dynamic and static balance decline at different stages with age. These results highlight the complementary role of inertial measurement unit-based evaluation in understanding the effect of age on postural control mechanisms, offering valuable insights for tailoring rehabilitation protocols in clinical settings.

Age-related changes in gait, balance, and strength parameters: A cross-sectional study

BACKGROUND

Longevity is increasing worldwide due to improvements in healthcare and living standards. Aging is often associated with disability and multiple health concerns. To address these challenges, effective interventions are essential. This study investigated potential age-related declines in gait, balance, and strength. We also sought to assess any relationships between these three parameters and explore potential differences between women and men.

METHODS

Healthy individuals over 50 years of age were recruited for this cross-sectional study. Upper extremity (grip) strength and lower extremity (knee) strength of the dominant side were measured. Static balance was performed on the force plate in different situations each for 30 seconds: bilateral stance with eyes open, bilateral stance with eyes closed, as well as dominant leg and non-dominant leg unilateral stance with eyes open. Gait was measured during level walking using an optical motion capture system. Additionally, the dynamic stability margin (DSM) was calculated for the level walking trials.

RESULTS

The study results indicated that gait parameters were not significantly affected by age (p≥0.12), while knee and grip strength, along with several balance parameters, showed a significant decline with age. All individuals were able to maintain their bipedal balance, but their center of pressure movement increased significantly by age (p≤0.028). Z-scores were calculated to compare significant age parameters. Unipedal stance time was found to be the most affected by age compared to other contributing factors (p≤0.001). The duration of unipedal balance showed the most significant change per decade (non-dominant: -0.62 SDs; dominant: -0.53 SDs), while strength measures exhibited the lowest amount of change per decade (grip strength: -0.34 SDs; knee strength: -0.26 SDs). Sex differences were observed exclusively in strength parameters, with no discernible impact on the decline in balance parameters.

CONCLUSIONS

These findings suggest that the duration of unipedal stance can serve as a reliable and gender-independent measure of neuromuscular aging for both elderly male and female subjects.

Efficacy of aquatic vs land-based therapy for pain management in women with fibromyalgia: a randomised controlled trial

OBJECTIVE

To determine the efficacy of two physiotherapeutic interventions - aquatic therapy (AT) and land-based therapy (LBT) - for reducing pain in women with fibromyalgia.

DESIGN

Single-blind, randomised controlled, equivalence trial.

SETTING

Fibromyalgia, Chronic Fatigue Syndrome and Multiple Chemical Sensitivity Association in A Coruña, Spain.

PARTICIPANTS

Forty women with fibromyalgia were assigned at random in a 1:1 manner to two groups: AT (n = 20) and LBT (n = 20).

INTERVENTIONS

Two therapeutic exercise programmes, with 60-min sessions, were undertaken three times per week for 12 weeks. Sessions were carried out in groups by a trained physiotherapist.

OUTCOME

The primary outcome was pain intensity (visual analogue scale). The secondary outcomes were pressure pain threshold (algometer), quality of life (Revised Fibromyalgia Impact Questionnaire), sleep quality (Pittsburgh Sleep Quality Index), fatigue (Multidimensional Fatigue Inventory) and physical ability (6-Minute Walk Test). Patients were evaluated at baseline, 12 weeks (post-treatment) and 18 weeks (follow-up). The statistical analysis was per-protocol. P < 0.05 was considered to indicate significance. Effect size was calculated.

RESULTS

The mean age was 50 [standard deviation (SD) 9] years, with median body mass index of 27 [interquartile range (IQR) 25-30] kg/m2 and median symptom duration of 11 (IQR 6-15) years. No differences were observed between the groups post-treatment, but differences in favour of AT were found in pain intensity [2.7 (IQR 1.5-4.9) vs 5.5 (IQR 3.3-7.6); p= 0.023; large effect, Cohen's d= 0.8; 95% confidence interval (CI) 0.1-1.5] and sleep quality [12.0 (IQR 7.3-15.3) vs 15.0 (IQR 13.0-17.0); p= 0.030; large effect, Cohen's d= 0.8; 95% CI 0.1-1.5] at follow-up.

CONCLUSIONS

The results suggest that AT is better than LBT for reducing pain intensity and improving sleep quality after 6 weeks of follow-up. AT may be a good treatment option for women with fibromyalgia.

CLINICAL TRIALS REGISTRATION NUMBER

ClinicalTrials.gov NCT02695875 CONTRIBUTION OF THE PAPER.

Assessment of Mobility Trajectories Using Wearable Inertial Sensors During Autologous Hematopoietic Cell Transplant

OBJECTIVE

This study aimed to characterize mobility patterns using wearable inertial sensors and serial assessment across autologous hematopoietic cell transplant (autoHCT) and investigate the relation between mobility and perceived function in patients with hematologic cancer.

DESIGN

Prospective longitudinal study.

SETTING

Hospital adult transplant clinic followed by discharge.

PARTICIPANTS

78 patients with hematological cancer receiving autoHCT.

MAIN OUTCOME MEASURES

Mobility was measured across 3 clinical phases (pretransplant, pre-engraftment, and post-engraftment) in using inertial sensors worn during prescribed performance tests in the hospital. Perceived function was assessed using validated provider-reported (Eastern Cooperative Oncology Group [ECOG] Performance Status Scale) and patient-reported [European Organization for Research and Treatment of Cancer Quality of Life Questionnaire [EORTC QLQ-C30]) measures. Trajectories of 5 selected mobility characteristics (turn duration, gait speed, stride time variability, double support time, and heel strike angle) across the clinical phases were also evaluated using piecewise linear mixed-effects models.

RESULTS

Using Principal Components Analysis, 4 mobility patterns were identified pretransplant: Gait Limitation, Sagittal Sway, Coronal Sway, and Balance Control. Gait Limitation measured pretransplant was significantly inversely associated with perceived function reported by the provider- (β = -0.11; 95% CI: -0.19, -0.02) and patient- (β = -4.85; 95% CI: -7.72, -1.99) post-engraftment in age-adjusted linear regression models. Mobility characteristics demonstrated immediate declines early pre-engraftment with stabilization by late pre-engraftment.

CONCLUSION

Patients with hematological cancer experiencing gait limitations pretransplant are likely to have worse perceived function post-engraftment. Mobility declines in early phases post-transplant and may not fully recover, indicating an opportunity for timely rehabilitation referrals. Wearable inertial sensors can be used to identify early mobility problems and patients who may be at risk for future functional decline who may be candidates for early physical rehabilitation.

Turning speed as a more responsive metric of age-related decline in mobility: A comparative study with gait speed

BACKGROUND

Navigating your environment requires both straight-line gait as well as turning. Gait speed normative values are well established and utilized in determining a person's functional status, however, it has limitations. This study sought to examine whether turning speed declines with age and how it compared to gait speed age-related decline.

METHODS

A secondary analysis was performed on 275 community dwelling adults between the ages of 18-88 that performed a timed walking test with an inertial measurement unit on their lumbar spine. Turning speed and walking speed were extracted for each participant. A series of mixed models were compared, and Akaike's Information Criterion was used to determine the best fit model between age and turning speed and age and gait speed.

FINDINGS

Turning speed and gait speed normative values were reported for each age decade. A linear model with a random intercept of "Condition" was used to assess the relationship between age and turning speed. The results indicated a significant negative relationship between age and turning speed (B = -0.66, p < 0.001). A spline-fit model determined a significant negative relationship between age and gait speed after the age of 65 (B = -0.0097, p = 0.002). The effect of age on gait speed before age 65 was not significant.

INTERPRETATION

Turning speed significantly declines with age in a linear fashion while gait speed begins to decline after age 65. Turning speed may be more responsive to age than gait speed. More research is needed to determine if the decline in turning speed with age is associated with a decline in function.

An Exploratory Study of Walking, Listening, and Remembering in Younger and Middle-Aged Adults

PURPOSE

The purpose of this study was to assess how needing to listen and remember information while walking affects speech perception, memory task performance, and gait in younger and middle-aged adults.

METHOD

Four gait parameters (stride duration, step variability, whole-body center of mass acceleration, and mediolateral head acceleration) were measured when younger and middle-aged participants stood or walked on a treadmill while they simultaneously completed a speech-on-speech perception task and a preload memory task, singly and in combination.

RESULTS

Speech perception was significantly poorer for middle-aged than for younger participants. Performance on the speech perception measure did not differ significantly between walking and standing for either group of participants, but the additional cognitive load of the memory task reduced performance on the speech perception task. Memory task performance was significantly poorer when combined with the speech perception task than when measured in isolation for both participant groups, but no further declines were noted when participants were also walking. Mediolateral head acceleration, which has been linked to loss of balance, was significantly greater during multitask trials, as compared to when participants were only walking without being required to listen or remember. Post hoc analysis showed that dual- and multitask influences on mediolateral head acceleration were more prominent for middle-aged than for younger participants. Stride duration was longer in the multitask condition than when participants were only walking.

CONCLUSIONS

Results of this exploratory study indicate that gait may be impacted when individuals (both younger and middle-aged) are listening and remembering while walking. Data also substantiate prior findings of early age-related declines in the perception of speech in the presence of understandable speech maskers.

Lower back muscle activity during weight-shifting is affected by ageing and dual-tasking

PURPOSE

Postural control deteriorates with age, especially under dual-task conditions. It is currently unknown how a challenging virtual reality weight-shifting task affects lower back muscle activity. Hence, this study investigated erector spinae neuromuscular control during mediolateral weight-shifting as part of an exergame during single- (ST) and dual-task (DT) conditions in young and older adults.

METHODS

Seventeen young and 17 older adults performed mediolateral weight-shifts while hitting virtual wasps in a virtual environment with and without a serial subtraction task (DT). Center of mass position was recorded in real-time using 3D motion capturing. Electromyography recorded bilateral activation of the lumbar longissimus and iliocostalis muscles.

RESULTS

Weight-shifting (p < 0.03) and targeting the wasps (p < 0.005) deteriorated with age and DT. Relative muscle activation during both quiet stance and weight-shifting increased with age, while the DT-effect did not differ consistently between age-groups. However, bilateral muscle co-contraction decreased with DT in young adults only. When switching direction and targeting the wasps, variability of muscle activation increased with age and DT and proved related to worse targeting performance. These effects were mainly visible at the non-dominant body side.

CONCLUSION

Older adults showed a higher erector spinae muscle contribution to perform weight-shifts with increased variability at the end of a shift, whereby muscle activity was modulated less well in older than in young adults in response to DT. Hence, the current findings point to the potential for developing postural training in which older adults learn to fine-tune trunk muscle activity to improve weight-shifting and reduce fall risk.

A Comparison of Walking Behavior during the Instrumented TUG and Habitual Gait

The timed up and go test (TUG) is a common clinical functional balance test often used to complement findings on sensorimotor changes due to aging or sensory/motor dysfunction. The instrumented TUG can be used to obtain objective postural and gait measures that are more sensitive to mobility changes. We investigated whether gait and body coordination during TUG is representative of walking. We examined the walking phase of the TUG and compared gait metrics (stride duration and length, walking speed, and step frequency) and head/trunk accelerations to normal walking. The latter is a key aspect of postural control and can also reveal changes in sensory and motor function. Forty participants were recruited into three groups: young adults, older adults, and older adults with visual impairment. All performed the TUG and a short walking task wearing ultra-lightweight wireless IMUs on the head, chest, and right ankle. Gait and head/trunk acceleration metrics were comparable across tasks. Further, stride length and walking speed were correlated with the participants' age. Those with visual impairment walked significantly slower than sighted older adults. We suggest that the TUG can be a valuable tool for examining gait and stability during walking without the added time or space constraints.

Using Wearable Inertial Sensors to Assess Mobility of Patients With Hematologic Cancer and Associations With Chemotherapy-Related Symptoms Before Autologous Hematopoietic Stem Cell Transplant: Cross-sectional Study

BACKGROUND

Wearable sensors could be a simple way to quantify and characterize mobility in patients with hematologic cancer scheduled to receive autologous hematopoietic stem cell transplant (autoHSCT) and how they may be related to common treatment-related symptoms and side effects of induction chemotherapy.

OBJECTIVE

We aimed to conduct a cross-sectional study comparing mobility in patients scheduled to receive autoHSCT with that in healthy, age-matched adult controls and determine the relationships between patient mobility and chemotherapy-related symptoms.

METHODS

Patients scheduled to receive autoHSCT (78/156, 50%) and controls (78/156, 50%) completed the prescribed performance tests using wearable inertial sensors to quantify mobility including turning (turn duration and number of steps), gait (gait speed, stride time, stride time variability, double support time, coronal trunk range of motion, heel strike angle, and distance traveled), and balance (coronal sway, coronal range, coronal velocity, coronal centroidal frequency, sagittal sway, sagittal range, sagittal velocity, and sagittal centroidal frequency). Patients completed the validated patient-reported questionnaires to assess symptoms common to chemotherapy: chemotherapy-induced peripheral neuropathy (Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity subscale), nausea and pain (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire), fatigue (Patient-Reported Outcomes Measurement Information System Fatigue Short Form 8a), vertigo (Vertigo Symptom Scale-short form), and depression (Center for Epidemiological Studies-Depression). Paired, 2-sided t tests were used to compare mobility between patients and controls. Stepwise multivariable linear regression models were used to evaluate associations between patient mobility and symptoms.

RESULTS

Patients aged 60.3 (SD 10.3) years had significantly worse turning (turn duration; P<.001), gait (gait speed, stride time, stride time variability, double support time, heel strike angle, stride length, and distance traveled; all P<.001), and balance (coronal sway; P<.001, range; P<.001, velocity; P=.02, and frequency; P=.02; and sagittal range; P=.008) than controls. In patients, high nausea was associated with worse stride time variability (ß=.001; P=.005) and heel strike angle (ß=-.088; P=.02). Pain was associated with worse gait speed (ß=-.003; P=.003), stride time variability (ß=.012; P=.02), stride length (ß=-.002; P=.004), and distance traveled (ß=-.786; P=.005). Nausea and pain explained 17% to 33% and 14% to 36% of gait variance measured in patients, respectively.

CONCLUSIONS

Patients scheduled to receive autoHSCT demonstrated worse mobility in multiple turning, gait, and balance domains compared with controls, potentially related in part to nausea and pain. Wearable inertial sensors used in the clinic setting could provide granular information about mobility before further treatment, which may in turn benefit from rehabilitation or symptom management. Future longitudinal studies are needed to better understand temporal changes in mobility and symptoms across the treatment trajectory to optimally time, design, and implement strategies, to preserve functioning in patients with hematologic cancer in the long term.

Ability of Wearable Accelerometers-Based Measures to Assess the Stability of Working Postures

With the rapid development and widespread application of wearable inertial sensors in the field of human motion capture, the low-cost and non-invasive accelerometer (ACC) based measures have been widely used for working postural stability assessment. This study systematically investigated the abilities of ACC-based measures to assess the stability of working postures in terms of the ability to detect the effects of work-related factors and the ability to classify stable and unstable working postures. Thirty young males participated in this study and performed twenty-four load-holding tasks (six working postures × two standing surfaces × two holding loads), and forty-three ACC-based measures were derived from the ACC data obtained by using a 17 inertial sensors-based motion capture system. ANOVAs, t-tests and machine learning (ML) methods were adopted to study the factors’ effects detection ability and the postural stability classification ability. The results show that almost all forty-three ACC-based measures could (p < 0.05) detect the main effects of Working Posture and Load Carriage, and their interaction effects. However, most of them failed in (p ≥ 0.05) detecting Standing Surface’s main or interaction effects. Five measures could detect both main and interaction effects of all the three factors, which are recommended for working postural stability assessment. The performance in postural stability classification based on ML was also good, and the feature set exerted a greater influence on the classification accuracy than sensor configuration (i.e., sensor placement locations). The results show that the pelvis and lower legs are recommended locations overall, in which the pelvis is the first choice. The findings of this study have proved that wearable ACC-based measures could assess the stability of working postures, including the work-related factors’ effects detection ability and stable-unstable working postures classification ability. However, researchers should pay more attention to the measure selection, sensors placement, feature selection and extraction in practical applications.

Brain Activation During Active Balancing and Its Behavioral Relevance in Younger and Older Adults: A Functional Near-Infrared Spectroscopy (fNIRS) Study

Age-related deterioration of balance control is widely regarded as an important phenomenon influencing quality of life and longevity, such that a more comprehensive understanding of the neural mechanisms underlying this process is warranted. Specifically, previous studies have reported that older adults typically show higher neural activity during balancing as compared to younger counterparts, but the implications of this finding on balance performance remain largely unclear. Using functional near-infrared spectroscopy (fNIRS), differences in the cortical control of balance between healthy younger (n = 27) and older (n = 35) adults were explored. More specifically, the association between cortical functional activity and balance performance across and within age groups was investigated. To this end, we measured hemodynamic responses (i.e., changes in oxygenated and deoxygenated hemoglobin) while participants balanced on an unstable device. As criterion variables for brain-behavior-correlations, we also assessed postural sway while standing on a free-swinging platform and while balancing on wobble boards with different levels of difficulty. We found that older compared to younger participants had higher activity in prefrontal and lower activity in postcentral regions. Subsequent robust regression analyses revealed that lower prefrontal brain activity was related to improved balance performance across age groups, indicating that higher activity of the prefrontal cortex during balancing reflects neural inefficiency. We also present evidence supporting that age serves as a moderator in the relationship between brain activity and balance, i.e., cortical hemodynamics generally appears to be a more important predictor of balance performance in the older than in the younger. Strikingly, we found that age differences in balance performance are mediated by balancing-induced activation of the superior frontal gyrus, thus suggesting that differential activation of this region reflects a mechanism involved in the aging process of the neural control of balance. Our study suggests that differences in functional brain activity between age groups are not a mere by-product of aging, but instead of direct behavioral relevance for balance performance. Potential implications of these findings in terms of early detection of fall-prone individuals and intervention strategies targeting balance and healthy aging are discussed.

A Lifespan Approach to Balance in Static and Dynamic Conditions: The Effect of Age on Balance Abilities

Postural control is a complex sensorimotor skill that is fundamental to our daily life. The abilities to maintain and recover balance degrade with age. However, the time decay of balance performance with age is not well understood. In this study, we aim at quantifying the age-dependent changes in standing balance under static and dynamic conditions. We tested 272 healthy subjects with ages ranging from 20 to 90. Subjects maintained the upright posture while standing on the robotic platform hunova®. In the evaluation of static balance, subjects stood on the fixed platform both with eyes open (EO) and eyes closed (EC). In the dynamic condition, subjects stood with eyes open on the moving foot platform that provided three different perturbations: (i) an inclination proportional to the center of pressure displacements, (ii) a pre-defined predictable motion, and (iii) an unpredictable and unexpected tilt. During all these tests, hunova® measured the inclination of the platform and the displacement of the center of pressure, while the trunk movements were recorded with an accelerometer placed on the sternum. To quantify balance performance, we computed spatio-temporal parameters typically used in clinical environments from the acceleration measures: mean velocity, variability of trunk motion, and trunk sway area. All subjects successfully completed all the proposed exercises. Their motor performance in the dynamic balance tasks quadratically changed with age. Also, we found that the reliance on visual feedback is not age-dependent in static conditions. All subjects well-tolerated the proposed protocol independently of their age without experiencing fatigue as we chose the timing of the evaluations based on clinical needs and routines. Thus, this study is a starting point for the definition of robot-based assessment protocols aiming at detecting the onset of age-related standing balance deficits and allowing the planning of tailored rehabilitation protocols to prevent falls in older adults.

Relationship Between the Choice of Clinical Treatment, Gait Functionality and Kinetics in Patients With Comparable Knee Osteoarthritis

Objective: The objective of this study was to investigate the relationship between the choice of clinical treatment, gait functionality, and kinetics in patients with comparable knee osteoarthritis.

Design: This was an observational case-control study.

Setting: The study was conducted in a university biomechanics laboratory.

Participants: Knee osteoarthritis patients were stratified into the following groups: clinical treatment (conservative/total knee replacement (TKR) planned), sex (male/female), age (60–67/68–75), and body mass index (BMI) (&lt;30/≥30). All patients had a Kellgren–Lawrence score of 2 or 3 (N = 87).

Main Outcome Measures: All patients underwent gait analysis, and two groups of dependent variables were extracted:

• Spatiotemporal gait variables: gait velocity, stride time, and double-support time, which are associated with patient functionality.

• Kinetic gait variables: vertical, anterior–posterior, and mediolateral ground reaction forces, vertical free moment, joint forces, and moments at the ankle, knee, and hip. Multifactorial and multivariate analyses of variance were performed.

Results: Functionality relates to treatment decisions, with patients in the conservative group walking 25% faster and spending 24% less time in the double-support phase. However, these differences vary with age and are reduced in older subjects. Patients who planned to undergo TKR did not present higher knee forces, and different joint moments between clinical treatments depended on the age and BMI of the subjects.

Conclusions: Knee osteoarthritis is a multifactorial disease, with age and BMI being confounding factors. The differences in gait between the two groups were mitigated by confounding factors and risk factors, such as being a woman, elderly, and obese, reducing the variability of the gait compression loads. These factors should always be considered in gait studies of patients with knee osteoarthritis to control for confounding effects.

Assessment of postural sway with a pendant-mounted wearable sensor

BACKGROUND

Body-worn inertial measurement unit (IMU) sensors have been widely used in postural stability and balance studies because of their low cost and convenience. In most of these studies, a single IMU sensor is attached to a waist belt near the body's center of mass. Some populations such as pregnant women, however, may find a waist belt challenging in terms of fit and comfort. For this reason it may be useful to identify an alternative location for placement of an IMU and a more comfortable means for attaching the sensor to the body. Research question Does placing an IMU sensor in a pendant worn around the neck permit discrimination between conditions with varying postural stability?

METHODS

Twenty-six healthy participants performed three standing tasks (double-leg, tandem, and single-leg standing) under eyes-open and eyes-closed vision conditions to preliminarily assess the ability of the pendant sensor to discriminate between balance conditions. Discrimination based upon data from a belt-mounted IMU was assessed in the same trials. Differences in standard deviation of acceleration components, sway area, and jerkiness due to trial condition and sensor were evaluated using analysis of variance followed by post hoc comparisons. These data were also incorporated into receiver-operator characteristic (ROC) curve analysis to assess the effectiveness of each sensor at discriminating between conditions.

RESULTS

Stability was found to vary across conditions, but there was no interaction between stability and sensor location (all p ≥ 0.323). ROC curve analysis showed that sensors in both locations were good discriminators between conditions. Significance Placing an IMU in a pendant may be feasible for studying and monitoring postural instability. This approach may be especially valuable when considering populations for which wearing a belt is uncomfortable.

The Mediating Role of Vision in the Relationship between Proprioception and Postural Control in Older Adults, as Compared to Teenagers and Younger and Middle-Aged Adults

The aim of this study is to analyze the mediating role of vision in the relationship between conscious lower limb proprioception (dominant knee) and bipedal postural control (with eyes open and closed) in older adults, as compared with teenagers, younger adults and middle-aged adults.

METHODS

The sample consisted of 119 healthy, physically active participants. Postural control was assessed using the bipedal Romberg test with participants' eyes open and closed on a force platform. Proprioception was measured through the ability to reposition the knee at 45°, measured with the Goniometer Pro application's goniometer.

RESULTS

The results showed an indirect relationship between proprioception and postural control with closed eyes in all age groups; however, vision did not mediate this relationship.

CONCLUSIONS

Older adults outperformed only teenagers on the balance test. The group of older adults was the only one that did not display differences with regard to certain variables when the test was done with open or closed eyes. It seems that age does not influence performance on proprioception tests. These findings help us to optimize the design of training programs for older adults and suggest that physical exercise is a protective factor against age-related decline.

Analysis of the Stability of the Body in a Standing Position When Shooting at a Stationary Target-A Randomized Controlled Trial

Postural stability of the body depends on many factors. One of them is physical activity. It is especially important in the case of sports or professional work, which combine mobility with the accuracy of a shot in a standing position. The smaller the body fatigue, the more accurate the shot. The aim of the study was the assessment of the impact of physical effort on the center of gravity deflection and length of the COP (center of pressure) path, as well as the reaction of ground forces in people who do not engage in systematic physical activity. The study group included 139 people (23.1 ± 5.2 yr; M: 46.8%; F: 53.2%). The test consisted of performing a static test twice, shooting at the target in a multimedia shooting range. Group X performed the Harvard test between the static tests. Group Y made no effort. The reaction parameters of the ground forces were assessed using the Zebris PDM-L Platform. In Group X performing the Harvard test, an increase in the average COP, VCOP, and 95% confidence ellipse area was noted. The path length and the average velocity of COP speed increased. There were no differences in Group Y (p > 0.05). Physical effort significantly affected the postural stability of the studied people, increasing the average parameters assessing balance when adopting static firing position.

Relationship Between Brain Volumes and Objective Balance and Gait Measures in Parkinson's Disease

BACKGROUND

Instrumented measures of balance and gait measure more specific balance and gait impairments than clinical rating scales. No prior studies have used objective balance/gait measures to examine associations with ventricular and brain volumes in people with Parkinson's disease (PD).

OBJECTIVE

To test the hypothesis that larger ventricular and smaller cortical and subcortical volumes are associated with impaired balance and gait in people with PD.

METHODS

Regional volumes from structural brain images were included from 96 PD and 50 control subjects. Wearable inertial sensors quantified gait, anticipatory postural adjustments prior to step initiation (APAs), postural responses to a manual push, and standing postural sway on a foam surface. Multiple linear regression models assessed the relationship between brain volumes and balance/gait and their interactions in PD and controls, controlling for sex, age and corrected for multiple comparisons.

RESULTS

Smaller brainstem and subcortical gray matter volumes were associated with larger sway area in people with PD, but not healthy controls. In contrast, larger ventricle volume was associated with smaller APAs in healthy controls, but not in people with PD. A sub-analysis in PD showed significant interactions between freezers and non-freezers, in several subcortical areas with stride time variability, gait speed and step initiation.

CONCLUSION

Our models indicate that smaller subcortical and brainstem volumes may be indicators of standing balance dysfunction in people with PD whereas enlarged ventricles may be related to step initiation difficulties in healthy aging. Also, multiple subcortical region atrophy may be associated with freezing of gait in PD.

Discriminative Mobility Characteristics between Neurotypical Young, Middle-Aged, and Older Adults Using Wireless Inertial Sensors

Age-related mobility research often highlights significant mobility differences comparing neurotypical young and older adults, while neglecting to report mobility outcomes for middle-aged adults. Moreover, these analyses regularly do not determine which measures of mobility can discriminate groups into their age brackets. Thus, the current study aimed to provide a comprehensive analysis for commonly performed aspects of mobility (walking, turning, sit-to-stand, and balance) to determine which variables were significantly different and furthermore, able to discriminate between neurotypical young adults (YAs), middle-aged adults (MAAs), and older adults (OAs). This study recruited 20 YAs, 20 MAAs, and 20 OAs. Participants came into the laboratory and completed mobility testing while wearing wireless inertial sensors. Mobility tests assessed included three distinct two-minute walks, 360° turns, five times sit-to-stands, and a clinical balance test, capturing 99 distinct mobility metrics. Of the various mobility tests assessed, only 360° turning measures demonstrated significance between YAs and MAAs, although the capacity to discriminate between groups was achieved for gait and turning measures. A variety of mobility measures demonstrated significance between MAAs and OAs, and furthermore discrimination was achieved for each mobility test. These results indicate greater mobility differences between MAAs and OAs, although discrimination is achievable for both group comparisons.

Between-site equivalence of turning speed assessments using inertial measurement units

BACKGROUND

Turning is a component of gait that requires planning for movement of multiple body segments and the sophisticated integration of sensory information from the vestibular, visual, and somatosensory systems. These aspects of turning have led to growing interest to quantify turning in clinical populations to characterize deficits or identify disease progression. However, turning may be affected by environmental differences, and the degree to which turning assessments are comparable across research or clinical sites has not yet been evaluated.

RESEARCH QUESTION

The aim of this study was to determine the extent to which peak turning speeds are equivalent between two sites for a variety of mobility tasks.

METHODS

Data were collected at two different sites using separate healthy young adult participants (n = 47 participants total), but recruited using identical inclusion and exclusion criteria. Participants at each site completed three turning tasks: a one-minute walk (1 MW) along a six-meter walkway, a modified Illinois Agility Test (mIAT), and a custom clinical turning course (CCTC). Peak yaw turning speeds were extracted from wearable inertial sensors on the head, trunk, and pelvis. Between-site differences and two one-sided tests (TOST) were used to determine equivalence between sites, based on a minimum effect size reported between individuals with mild traumatic brain injury and healthy control subjects.

RESULTS

No outcomes were different between sites, and equivalence was determined for 6/21 of the outcomes. These findings suggest that some turning tasks and outcome measures may be better suited for multi-site studies. The equivalence results are also dependent on the minimum effect size of interest; nearly all outcomes were equivalent across sites when larger minimum effect sizes of interest were used.

SIGNIFICANCE

Together, these results suggest some tasks and outcome measures may be better suited for multi-site studies and literature-based comparisons.

Post-Drive Standing Balance of Vehicle Passengers Using Wearable Sensors: The Effect of On-Road Driving and Task Performance

Postural sway has been demonstrated to increase following exposure to different types of motion. However, limited prior studies have investigated the relationship between exposure to normative on-road driving conditions and standing balance following the exposure. The purpose of this on-road study was to quantify the effect of vehicle motion and task performance on passengers’ post-drive standing balance performance. In this study, trunk-based kinematic data were captured while participants performed a series of balance exercises before and after an on-road driving session in real-time traffic. Postural sway for all balance exercises increased following the driving session. Performing a series of ecologically relevant visual-based tasks led to increases in most post-drive balance metrics such as sway position and velocity. However, the post-drive changes following the driving session with a task were not significantly different compared to changes observed following the driving session without a task. The post-drive standing balance performance changes observed in this study may increase vulnerable users’ risk of falling. Wearable sensors offer an opportunity to monitor postural sway following in-vehicle exposures.

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.

Compromised Brain Activity With Age During a Game-Like Dynamic Balance Task: Single- vs. Dual-Task Performance

Background: Postural control and cognition are affected by aging. We investigated whether cognitive distraction influenced neural activity differently in young and older adults during a game-like mediolateral weight-shifting task with a personalized task load.

Methods: Seventeen healthy young and 17 older adults performed a balance game, involving hitting virtual wasps, serial subtractions and a combination of both (dual-task). A motion analysis system estimated each subject's center of mass position. Cortical activity in five regions was assessed by measuring oxygenated hemoglobin (HbO₂) with a functional Near-Infrared Spectroscopy system.

Results: When adding cognitive load to the game, weight-shifting speed decreased irrespective of age, but older adults reduced the wasp-hits more than young adults. Accompanying these changes, older adults decreased HbO₂ in the left pre-frontal cortex (PFC) and frontal eye fields (FEF) compared to single-tasking, a finding not seen in young adults. Additionally, lower HbO₂ levels were found during dual-tasking compared to the summed activation of the two single tasks in all regions except for the right PFC. These relative reductions were specific for the older age group in the left premotor cortex (PMC), the right supplementary motor area (SMA), and the left FEF.

Conclusion: Older adults showed more compromised neural activity than young adults when adding a distraction to a challenging balance game. We interpret these changes as competitive downgrading of neural activity underpinning the age-related deterioration of game performance during dual-tasking. Future work needs to ascertain if older adults can train their neural flexibility to withstand balance challenges during daily life activities.

Relationship of the sacral slope with early gait derangements in robust older women

BACKGROUND

Trunk pelvic dissociation is fundamental to the compensatory mechanism for muscle weakness during body bending. We carried out an early investigation of gait changes in a sample of community-dwelling women ≥60 years without gait complaints. The primary objective was to correlate spine and pelvic angles with performance tests and accelerometry parameters. The secondary objective was to correlate performance tests with accelerometry.

METHODS

In this cross-sectional study, 54 community-dwelling women ≥60 years were subjected to Falls Efficacy Scale-International (FES-I), performance tests (Berg Balance Scale, Timed Up and Go, and Gait analysis), and radiographic analysis of sagittal alignment (Thoracic and Lumbar Cobb, Pelvic Incidence, Sacral Slope, and Pelvic Tilt angles). Gait speed was assessed in a 10-m comfortable walk, and accelerometry parameters were obtained in a 30-m walk distance.

RESULTS

The sample, aged 72 ± 6 years, exhibited moderate correlation between Sacral Slope and Step Length (+ 0.615). Sacral Slope weakly correlated with FES-I (- 0.339), Berg Balance Scale (+ 0.367), and with further accelerometry data in the AP plane: RMS, (+ 0.439) and Stride Regularity (+ 0.475), p < 0.05, all. Lumbar Cobb weakly correlated with the following accelerometry data in the AP plane: Step Length (+ 0.405), RMS, (+ 0.392), and Stride Regularity (+ 0.345), p < 0.05, all. Additionally, Stride Regularity in AP moderately correlated with FES-I (0,561, p < 0.05), among other weak correlations between performance tests and accelerometry data in AP.

CONCLUSIONS

Early alterations in Sacral Slope and gait abnormalities in the AP plane may provide understanding of the early gait changes in robust older women.

Middle-age people with multiple sclerosis demonstrate similar mobility characteristics to neurotypical older adults

BACKGROUND

Clinical trials often report significant mobility differences between neurotypical and atypical groups, however, these analyses often do not determine which measures are capable of discriminating between groups. Additionally, indirect evidence supports the notion that some mobility impaired populations demonstrate similar mobility deficits. Thus, the current study aimed to provide a comprehensive analysis of three distinct aspects of mobility (walking, turning, and balance) to determine which variables were significantly different and were also able to discriminate between neurotypical older adults (OA) and middle-aged people with multiple sclerosis (PwMS), and between middle-aged neurotypical adults and PwMS.

METHODS

This study recruited 21 neurotypical OA, 19 middle-aged neurotypical adults, and 30 people with relapsing remitting MS. Participants came into the laboratory on two separate occasions to complete mobility testing while wearing wireless inertial sensors. Testing included a self-selected pace two-minute walk, a series of 180˚ and 360˚ turns, and a clinical balance test capturing a total of 99 distinct mobility characteristics. We determined significant differences for gait and turning measures through univariate analyses and a series of repeated measures analysis of variance in determining significance for balance conditions and measures. In determining discrimination between groups, the Area Under the Curve (AUC) was calculated for all individual mobility measures with a threshold of 0.80, denoting excellent discrimination. Additionally, a stepwise regression of the top five AUC producing variables was performed to determine whether a combination of variables could enhance discrimination while accounting for multicollinearity.

RESULTS

The results between neurotypical OA and middle-aged PwMS demonstrated significant differences for three gait and one turning variable, with no variable or combination of variables able to provide excellent discrimination between groups. Between middle-age neurotypical adults and PwMS a variety of mean and variability gait measures demonstrated significant differences between groups; however, no variable or combination of variables met discriminatory threshold. For turning, five 360˚ turn variables demonstrated significant differences and furthermore, the combination of 360˚ mean turn duration and variability of peak turn velocity were able to discriminate between groups. Finally, the majority of postural sway measures demonstrated significant group differences and the ability to discriminate between groups, particularly during more challenging balance conditions where participants stood on a compliant surface.

CONCLUSION

These results offer a comprehensive analysis of mobility differences and measures capable of discriminating between middle-age neurotypical adults and PwMS. Additionally, these results provide evidence that OA and middle-age PwMS display similar movement characteristics and thus a potential indicator of advanced aging from a mobility perspective.

Integrating Technology Into Clinical Practice for the Assessment of Balance and Mobility: Perspectives of Exercise Professionals Practicing in Retirement and Long-term Care

Objective

To explore exercise professionals’ perspectives on technology integration for balance and mobility assessment practices in retirement and long-term care.

Setting

A private residential care organization in Ontario, Canada, with 18 sites providing accommodation and services for older adults.

Design

A qualitative descriptive approach was used including semistructured focus group interviews. Open-ended questions explored perceptions of technology integration along with factors influencing its adoption. Analysis involved preliminary coding based on research questions, review and discussion of emerging themes, and final, resultant coding for each category.

Participants

Exercise professionals (kinesiologists and exercise therapists) (N=18).

Interventions

Not applicable.

Main Outcome Measures

Not applicable.

Results

All participants felt that technology could enhance their practice by supporting programming, communication, and/or information management. Potential barriers to technology integration related primarily to the need to accommodate the broad range of complex health conditions present among clients, which would impact (1) their ability to engage with the technology and (2) relevance of technology-derived outcomes. Specific concerns related to individuals with significant cognitive and/or functional impairment. Solutions to these barriers emphasized the need for flexible technology and appropriate normative data to maximize the potential for uptake.

Conclusions

The participating exercise professionals working in a retirement and long-term care setting saw technology as a potentially effective addition to current clinical practice. To increase the likelihood for clinical uptake, technology must be maximize flexibility in order to accommodate a wide range of physical and cognitive abilities and meet specific needs related to setting and job responsibilities. The findings emphasize the need for continuous dialogue between technology producers and end users for successful development and implementation.

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.

A feasibility study towards instrumentation of the Sport Concussion Assessment Tool (iSCAT)

The Sports Concussion Assessment Tool (SCAT) is a pen and paper-based evaluation tool for use by healthcare professionals in the acute evaluation of suspected concussion. Here we present a feasibility study towards instrumented SCAT (iSCAT). Traditionally, a healthcare professional subjectively counts errors according to SCAT marking criteria matrix. It is hypothesized that an instrumented version of the test will be more accurate while providing additional digital-based parameters to better inform player management. The feasibility study focuses on the SCAT physical functioning tasks only: double leg stance, single-leg stance, tandem stance and tandem gait. Amateur university rugby players underwent iSCAT testing and data were recorded with 8 inertial units attached at different anatomical locations. Video data were gathered simultaneously as reference. An iSCAT algorithm was used to detect errors and quantify additional concussion-based time and frequency domain parameters to assess participant stability during balance and gait tasks. Future work aims to instrument other SCAT features such as hand-eye coordination while deploying methods within a large concussion project.

The feasibility and validity of a wearable sensor system to assess the stability of high-functioning lower-limb prosthesis users

Introduction

Lower-limb prosthesis users (LLPUs) experience increased fall risk due to gait and balance impairments. Clinical outcome measures are useful for measuring balance impairment and fall risk screening but suffer from limited resolution and ceiling effects. Recent advances in wearable sensors that can measure different components of gait stability may address these limitations. This study assessed feasibility and construct validity of a wearable sensor system (APDM Mobility Lab) to measure postural control and gait stability.

Materials and Methods

Lower-limb prosthesis users (n=22) and able-bodied controls (n=24) completed an Instrumented Stand-and-Walk Test (ISAW) while wearing the wearable sensors. Known-groups analysis (prosthesis versus controls) and convergence analysis (Prosthetic Limb Users Survey of Mobility [PLUS-M] and Activity-specific Balance Confidence [ABC] Scale) were performed on 20 stability-related measures.

Results

The system was applied without complications; however missing anticipatory postural adjustment data points for nine subjects affected the analysis. Of the 20 analyzed measures output by the sensors, only three significantly differed (p≤.05) between cohorts, and two demonstrated statistically significant correlations with the self-report measures.

Conclusions

The results of this study suggest the clinical feasibility but only partial construct validity of the wearable sensor system in conjunction with the ISAW test to measure LLPU stability and balance. The sample consisted of high-functioning LLPUs, so further research should evaluate a more representative sample with additional outcome measures and tasks.

Fifteen Years of Wireless Sensors for Balance Assessment in Neurological Disorders

Balance impairment is a major mechanism behind falling along with environmental hazards. Under physiological conditions, ageing leads to a progressive decline in balance control per se. Moreover, various neurological disorders further increase the risk of falls by deteriorating specific nervous system functions contributing to balance. Over the last 15 years, significant advancements in technology have provided wearable solutions for balance evaluation and the management of postural instability in patients with neurological disorders. This narrative review aims to address the topic of balance and wireless sensors in several neurological disorders, including Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, stroke, and other neurodegenerative and acute clinical syndromes. The review discusses the physiological and pathophysiological bases of balance in neurological disorders as well as the traditional and innovative instruments currently available for balance assessment. The technical and clinical perspectives of wearable technologies, as well as current challenges in the field of teleneurology, are also examined.

A Scoping Review of Physical Performance Outcome Measures Used in Exercise Interventions for Older Adults With Alzheimer Disease and Related Dementias

BACKGROUND AND PURPOSE

There is growing evidence that exercise interventions can mitigate functional decline and reduce fall risk in older adults with Alzheimer disease and related dementias (ADRD). Although physical performance outcome measures have been successfully used in older adults without cognitive impairment, additional research is needed regarding their use with individuals who have ADRD, and who may have difficulty following instructions regarding performance of these measures. The purpose of this scoping review was to identify commonly used physical performance outcome measures, for exercise interventions, that are responsive and reliable in older adults with ADRD. Ultimately, we aimed to provide recommendations regarding the use of outcome measures for individuals with ADRD across several domains of physical performance.

METHODS

A scoping review was conducted to broadly assess physical performance outcome measures used in exercise interventions for older adults with ADRD. Exercise intervention studies that included at least 1 measure of physical performance were included. All physical performance outcome measures were abstracted, coded, and categorized into 5 domains of physical performance: fitness, functional mobility, gait, balance, and strength. Criteria for recommendations were based on (1) the frequency of use, (2) responsiveness, and (3) reliability. Frequency was determined by the number of studies that used the outcome measure per physical performance domain. Responsiveness was assessed via calculated effect size of the outcome measures across studies within physical performance domains. Reliability was evaluated via published studies of psychometric properties.

RESULTS AND DISCUSSION

A total of 20 physical performance outcome measures were extracted from 48 articles that met study inclusion criteria. The most frequently used outcome measures were the 6-minute walk test, Timed Up and Go, repeated chair stand tests, short-distance gait speed, the Berg Balance Scale, and isometric strength measures. These outcome measures demonstrated a small, medium, or large effect in at least 50% of the exercise intervention studies. Good to excellent reliability was reported in samples of older adults with mild to moderate dementia. Fitness, functional mobility, gait, balance, and strength represent important domains of physical performance for older adults. The 6-minute walk test, Timed Up and Go, repeated chair stand tests, short-distance gait speed, Berg Balance Scale, and isometric strength are recommended as commonly used and reliable physical performance outcome measures for exercise interventions in older adults with mild to moderate ADRD. Further research is needed on optimal measures for individuals with severe ADRD.

CONCLUSIONS

The results of this review will aid clinicians and researchers in selecting reliable measures to evaluate physical performance outcomes in response to exercise interventions in older adults with ADRD.

Are cost-effective technologies feasible to measure gait in older adults? A systematic review of evidence-based literature

BACKGROUND

Unrestricted by time and place, innovative technologies seem to provide cost-effective solutions for gait assessment in older adults.

OBJECTIVE

The objective of this study is to provide an overview of gait assessment for older adults by investigating critical gait characteristics of older adults, discussing advantages and disadvantages of the current gait assessment technologies, as well as device applicability.

METHODS

The Preferred Reporting Item for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed during the review. Inclusion criteria were: (1) Sample consisting of adults older than 60 years; (2) qualitative, quantitative, or mixed-method researches using one or more specific gait assessment technologies; and (3) publication in English between 2000 and 2018.

RESULTS

In total, twenty-one studies were included. Gait speed, stride length, frequency, acceleration root mean square, step-to-step consistency, autocorrelation, harmonic ratio were reported in the existing literatures to be associated with falls. The enrolled studies address the use of pedometer, wearable accelerometer-based devices, Kinect, Nintendo Wii Balance Board as cost-effective gait assessment technologies.

CONCLUSIONS

Gait parameters and assessment approaches for older adults are diverse. Cost-effective technologies such as a wearable accelerometer-based device, Kinect, and the Nintendo Wii Balance Board provide potential alternatives for gait assessment with acceptable validity and reliability compared with sophisticated devices. The popularity and development of cost-effective devices have made large-scale data collection for gait assessment possible in the daily environment. Further study could involve older adults and their family members/caregivers in use of these technologies to design elderly-friendly products.

Augmenting Clinical Outcome Measures of Gait and Balance with a Single Inertial Sensor in Age-Ranged Healthy Adults

Gait and balance impairments are linked with reduced mobility and increased risk of falling. Wearable sensing technologies, such as inertial measurement units (IMUs), may augment clinical assessments by providing continuous, high-resolution data. This study tested and validated the utility of a single IMU to quantify gait and balance features during routine clinical outcome tests, and evaluated changes in sensor-derived measurements with age, sex, height, and weight. Age-ranged, healthy individuals (N = 49, 20-70 years) wore a lower back IMU during the 10 m walk test (10MWT), Timed Up and Go (TUG), and Berg Balance Scale (BBS). Spatiotemporal gait parameters computed from the sensor data were validated against gold standard measures, demonstrating excellent agreement for stance time, step time, gait velocity, and step count (intraclass correlation (ICC) > 0.90). There was good agreement for swing time (ICC = 0.78) and moderate agreement for step length (ICC = 0.68). A total of 184 features were calculated from the acceleration and angular velocity signals across these tests, 36 of which had significant correlations with age. This approach was also demonstrated for an individual with stroke, providing higher resolution information about balance, gait, and mobility than the clinical test scores alone. Leveraging mobility data from wireless, wearable sensors can help clinicians and patients more objectively pinpoint impairments, track progression, and set personalized goals during and after rehabilitation.

Wearable Inertial Sensors to Assess Standing Balance: A Systematic Review

Wearable sensors are de facto revolutionizing the assessment of standing balance. The aim of this work is to review the state-of-the-art literature that adopts this new posturographic paradigm, i.e., to analyse human postural sway through inertial sensors directly worn on the subject body. After a systematic search on PubMed and Scopus databases, two raters evaluated the quality of 73 full-text articles, selecting 47 high-quality contributions. A good inter-rater reliability was obtained (Cohen's kappa = 0.79). This selection of papers was used to summarize the available knowledge on the types of sensors used and their positioning, the data acquisition protocols and the main applications in this field (e.g., "active aging", biofeedback-based rehabilitation for fall prevention, and the management of Parkinson's disease and other balance-related pathologies), as well as the most adopted outcome measures. A critical discussion on the validation of wearable systems against gold standards is also presented.

Postural Dynamics Are Associated With Cognitive Decline in Parkinson's Disease

Early features of Parkinson's disease (PD) include both motor and cognitive changes, suggesting shared common pathways. A common motor dysfunction is postural instability, a known predictor of falls, which have a major impact on quality of life. Understanding mechanisms of postural dynamics in PD and specifically how they relate to cognitive changes is essential for developing effective interventions. The aims of this study were to examine the changes that occur in postural metrics over time and explore the relationship between postural and cognitive dysfunction. The study group consisted of 35 people (66 ± 8years, 12 female, UPDRS III: 22.5 ± 9.6) diagnosed with PD who were recruited as part of the Incidence of Cognitive Impairment in Cohorts with Longitudinal Evaluation—PD Gait (ICICLE-GAIT) study. Postural and cognitive assessments were performed at 18, 36, and 54 months after enrolment. Participants stood still for 120 s, eyes open and arms by their side. Postural dynamics were measured using metrics derived from a single tri-axial accelerometer (Axivity AX3, York, UK) on the lower back. Accelerometry metrics included jerk (derivative of acceleration), root mean square, frequency, and ellipsis (acceleration area). Cognition was evaluated by neuropsychological tests including the Montreal Cognitive Assessment (MoCA) and digit span. There was a significant decrease in accelerometry parameters, greater in the anteroposterior direction, and a decline in cognitive function over time. Accelerometry metrics were positively correlated with lower cognitive function and increased geriatric depression score and negatively associated with a qualitative measure of balance confidence. In conclusion, people with PD showed reduced postural dynamics that may represent a postural safety strategy. Associations with cognitive function and depression, both symptoms that may pre-empt motor symptoms, suggest shared neural pathways. Further studies, involving neuroimaging, may determine how these postural parameters relate to underlying neural and clinical correlates.

Cholinergic Pathway SNPs and Postural Control in 477 Older Adults

Objective: To determine whether single nucleotide polymorphisms (SNPs) of the cholinergic system and quantitative parameters of postural control are associated in healthy older adults. This is a cross-sectional analysis from the TREND study.

Methods: All participants performed a static postural control task for 30 s on a foam pad in semitandem stance and eyes closed. We analyzed mean power frequency (MPF), area, acceleration, jerk, and velocity from a mobile sensor worn at the lower back using a validated algorithm. Genotypes of four SNPs in genes involved in the cholinergic system (SLC5A7, CHAT, BCHE, CHRNA4) were extracted from the NeuroX chip. All participants present a normal neurological examination and a Minimental state examination score >24.

Results: Four hundred and seventy seven participants were included. Mean age was 69 years, 41% were female. One SNP of the cholinergic pathway was significantly associated with a quantitative postural control parameter. The minor allele of rs6542746 in SLC5A7 was associated with lower MPF (4.04 vs. 4.22 Hz; p = 3.91 × 10^-4). Moreover, the following associations showed trends toward significance: minor allele of rs6542746 in SLC5A7 with higher anteroposterior acceleration (318 vs. 287 mG; p = 0.005), and minor allele of rs3810950 in CHAT with higher mediolateral acceleration [1.77 vs. 1.65 log(mG); p = 0.03] and velocity [1.83 vs. 1.74 log(mm/s); p = 0.019]. Intraindividual occurrence of rs6542746 and rs3810950 minor alleles was dose-dependently related with lower MPF (p = 0.004).

Conclusion: This observational study suggests an influence of SNPs of the cholinergic pathway on postural control in older adults.

Factors associated with poor balance ability in older adults of nine high-altitude communities

INTRODUCTION

Poor balance ability in older adults result in multiple complications. Poor balance ability has not been studied among older adults living at high altitudes. In this study, we analysed factors associated with poor balance ability by using the Functional Reach (FR) among older adults living in nine high-altitude communities.

MATERIAL AND METHODS

Analytical cross-sectional study, carried out in inhabitants aged 60 or over from nine high-altitude Andean communities of Peru during 2013-2016. FR was divided according to the cut-off point of 8 inches (20.32 cm) and two groups were generated: poor balance ability (FR less or equal than 20.32 cm) and good balance ability (greater than 20.32 cm). Additionally, we collected socio-demographic, medical, functional and cognitive assessment information. Poisson regression models were constructed to identify factors associated with poor balance ability. Prevalence ratio (PR) with 95% confidence intervals (95CI%) are presented.

RESULTS

A total of 365 older adults were studied. The average age was 73.0 ± 6.9 years (range: 60-91 years), and 180 (49.3%) participants had poor balance ability. In the adjusted Poisson regression analysis, the factors associated with poor balance ability were: alcohol consumption (PR = 1.35; 95%CI: 1.05-1.73), exhaustion (PR = 2.22; 95%CI: 1.49-3.31), gait speed (PR = 0.67; 95%CI: 0.50-0.90), having had at least one fall in the last year (PR = 2.03; 95%CI: 1.19-3.46), having at least one comorbidity (PR = 1.60; 95%CI: 1.10-2.35) and having two or more comorbidities (PR = 1.61; 95%CI: 1.07-2.42) compared to none.

CONCLUSIONS

Approximately a half of the older adults from these high-altitude communities had poor balance ability. Interventions need to be designed to target these balance issues and prevent adverse events from concurring to these individuals.

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.

Mobility limitations related to reduced pulmonary function among aging people with chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is a major cause of disability. We aimed to analyse the impact of reduced pulmonary function on non-respiratory impairments and mobility activity limitations in an elderly population with COPD and to elucidate which specific limitations on mobility are related to reduced pulmonary function

Methods

Cross-sectional study of 110 patients with COPD, recruited from public and university hospital. The effect of impaired pulmonary function on the risk of non-respiratory impairments and mobility limitations was analysed using validated measures, including: the 6-Minute Walk Test (6MWT), skeletal muscle strength, the Short Physical Performance Battery (SPPB), and self-reported mobility questionnaire. Multivariate analysis was used to control for confounders such as age, sex, height, education, and cigarette smoking.

Results

Greater impairment of pulmonary function was associated with less distance walked during the 6MWT, poorer SPPB scores, and greater risk of self-reported mobility limitations (p<0.05). Lower forced expiratory volume in 1 s was also associated with a greater risk of limitations in carrying items under 10 pounds (4.54 kg), walking alone up and down a flight of stairs, and walking two or three neighbourhood blocks. There was no clear statistical relationship between pulmonary function impairment and skeletal muscle strength.

Conclusions

Impaired pulmonary function was associated with the 6MWT score and limitations on performance-based and self-reported mobility activities, but not with skeletal muscle strength among elderly COPD patients.

Increased neuromuscular consistency in gait and balance after partnered, dance-based rehabilitation in Parkinson's disease

Here we examined changes in muscle coordination associated with improved motor performance after partnered, dance-based rehabilitation in individuals with mild to moderate idiopathic Parkinson's disease. Using motor module (a.k.a. muscle synergy) analysis, we identified changes in the modular control of overground walking and standing reactive balance that accompanied clinically meaningful improvements in behavioral measures of balance, gait, and disease symptoms after 3 wk of daily Adapted Tango classes. In contrast to previous studies that revealed a positive association between motor module number and motor performance, none of the six participants in this pilot study increased motor module number despite improvements in behavioral measures of balance and gait performance. Instead, motor modules were more consistently recruited and distinctly organized immediately after rehabilitation, suggesting more reliable motor output. Furthermore, the pool of motor modules shared between walking and reactive balance increased after rehabilitation, suggesting greater generalizability of motor module function across tasks. Our work is the first to show that motor module distinctness, consistency, and generalizability are more sensitive to improvements in gait and balance function after short-term rehabilitation than motor module number. Moreover, as similar differences in motor module distinctness, consistency, and generalizability have been demonstrated previously in healthy young adults with and without long-term motor training, our work suggests commonalities in the structure of muscle coordination associated with differences in motor performance across the spectrum from motor impairment to expertise.NEW & NOTEWORTHY We demonstrate changes in neuromuscular control of gait and balance in individuals with Parkinson's disease after short-term, dance-based rehabilitation. Our work is the first to show that motor module distinctness, consistency, and generalizability across gait and balance are more sensitive than motor module number to improvements in motor performance following short-term rehabilitation. Our results indicate commonalities in muscle coordination improvements associated with motor skill reacquisition due to rehabilitation and motor skill acquisition in healthy individuals.

Effectiveness of Aquatic Therapy vs Land-based Therapy for Balance and Pain in Women with Fibromyalgia: a study protocol for a randomised controlled trial

BACKGROUND

Fibromyalgia is a disease with an increasing incidence. It impairs the quality of life of patients and decreases their functional capacity. Aquatic therapy has already been used for managing the symptoms of this syndrome. However, aquatic therapy has only recently been introduced as a treatment modality for improving proprioception in fibromyalgia. The main objective of this study is to determine the effectiveness of two physiotherapy protocols, one in and one out of water, for improving balance and decreasing pain in women with fibromyalgia.

METHODS/DESIGN

The study protocol will be a single-blind randomised controlled trial. Forty women diagnosed with fibromyalgia will be randomly assigned into 2 groups: Aquatic Therapy (n = 20) or Land-based Therapy (n = 20). Both interventions include 60-min therapy sessions, structured into 4 sections: Warm-up, Proprioceptive Exercises, Stretching and Relaxation. These sessions will be carried out 3 times a week for 3 months. Primary outcomes are balance (static and dynamic) and pain (intensity and threshold). Secondary outcomes include functional balance, quality of life, quality of sleep, fatigue, self-confidence in balance and physical ability. Outcome measures will be evaluated at baseline, at the end of the 3-month intervention period, and 6-weeks post-treatment. Statistical analysis will be carried out using the SPSS 21.0 program for Windows and a significance level of p ≤ 0.05 will be used for all tests.

DISCUSSION

This study protocol details two physiotherapy interventions in women with fibromyalgia to improve balance and decrease pain: aquatic therapy and land-based therapy. In current literature there is a lack of methodological rigour and a limited number of studies that describe physiotherapy protocols to manage fibromyalgia symptoms. High-quality scientific works are required to highlight physiotherapy as one of the most recommended treatment options for this syndrome.

TRIAL REGISTRATION

Date of publication in ClinicalTrials.gov: 18/02/2016. ClinicalTrials.gov Identifier: NCT02695875 .