Real-world data capture of daily limb loading using force-sensing insoles: Feasibility and lessons learned.

Force-sensing insoles are wearable technology that offer an innovative way to measure loading outside of laboratory settings. Few studies, however, have utilized insoles to measure daily loading in real-world settings. This is an ancillary study of a randomized controlled trial examining the effect of weight loss alone, weight loss plus weighted vest, or weight loss plus resistance training on bone health in older adults. The purpose of this ancillary study was to determine the feasibility of using force-sensing insoles to collect daily limb loading metrics, including peak force, impulse, and loading rate. Forty-four participants completed a baseline visit of three, 2-minute walking trials while wearing force-sensing insoles. During month two of the intervention, 37 participants wore insoles for 4 days for 8 waking hours each day. At 6-month follow-up, participants completed three, two-minute walking trials and a satisfaction questionnaire. Criteria for success in feasibility was defined as: a) > 60 % recruitment rate; b) > 80 % adherence rate; c) > 75 % of usable data, and d) > 75 % participant satisfaction. A 77.3 % recruitment rate was achieved, with 44 participants enrolled. Participants wore their insoles an average of 7.4 hours per day, and insoles recorded an average of 5.5 hours per day. Peak force, impulse, and loading rate collected at baseline and follow-up were 100 % usable. During the real-world settings, 87.8 % of data was deemed usable with an average of 1200 min/participant. Lastly, average satisfaction was 80.5 %. These results suggest that force-sensing insoles appears to be feasible to capture real-world limb loading in older adults.

Age and beta amyloid deposition impact gait speed, stride length, and gait smoothness while transitioning from an even to an uneven walking surface in older adults.

BACKGROUND: Capturing a measure of movement quality during a complex walking task may indicate the earliest signs of detrimental changes to the brain due to beta amyloid (Aß) deposition and be a potential differentiator of older adults at elevated and low risk of developing Alzheimer's disease. This study aimed to determine: 1) age-related differences in gait speed, stride length, and gait smoothness while transitioning from an even to an uneven walking surface, by comparing young adults (YA) and older adults (OA), and 2) if gait speed, stride length, and gait smoothness in OA while transitioning from an even to an uneven walking surface is influenced by the amount of Aß deposition present in an OA's brain. METHODS: Participants included 56 OA (>70 years of age) and 29 YA (25-35 years of age). In OA, Aß deposition in the brain was quantified by PET imaging. All participants completed a series of cognitive assessments, a functional mobility assessment, and self-report questionnaires. Then participants performed two sets of walking trials on a custom-built walkway containing a mixture of even and uneven surface sections, including three trials with a grass uneven surface and three trials with a rocks uneven surface. Gait data were recorded using a wireless inertial measurement unit system. Stride length, gait speed, and gait smoothness (i.e., log dimensionless lumbar jerk) in the anteroposterior (AP), mediolateral (ML), and vertical (VT) directions were calculated for each stride. Outcomes were retained for five stride locations immediately surrounding the surface transition. RESULTS: OA exhibited slower gait (Grass: p < 0.001; Rocks: p = 0.006), shorter strides (Grass: p < 0.001; Rocks: p = 0.008), and smoother gait (Grass AP: p < 0.001; Rocks AP: p = 0.002; Rocks ML: p = 0.02) than YA, but they also exhibited greater reductions in gait speed and stride length than YA while transitioning to the uneven grass and rocks surfaces. Within the OA group, those with greater Aß deposition exhibited decreases in smoothness with age (Grass AP: p = 0.02; Rocks AP: p = 0.03; Grass ML: p = 0.04; Rocks ML: p = 0.03), while those with lower Aß deposition exhibited increasing smoothness with age (Grass AP: p = 0.01; Rocks AP: p = 0.02; Grass ML: p = 0.08; Rocks ML: p = 0.07). Better functional mobility was associated with less smooth gait (Grass ML: p = 0.02; Rocks ML: p = 0.05) and with less variable gait smoothness (Grass and Rocks AP: both p = 0.04) in the OA group. CONCLUSION: These results suggest that, relative to YA, OA may be adopting more cautious, compensatory gait strategies to maintain smoothness when approaching surface transitions. However, OA with greater Aß deposition may have limited ability to adopt compensatory gait strategies to increase the smoothness of their walking as they get older because of neuropathological changes altering the sensory integration process and causing worse dynamic balance (i.e., jerkier gait). Functional mobility, in addition to age and Aß deposition, may be an important factor of whether or not an OA chooses to employ compensatory strategies to prioritize smoothness while walking and what type of compensatory strategy an OA chooses.

The Dynamic Interplay of Objective and Subjective Balance and Subsequent Task Performance: Implications for Fall Risk in Older Adults.

INTRODUCTION: Falls occur in daily life when an activity results in a loss of balance that is too great to recover from. Our purpose in this study was to examine how fall risk differentiates the dynamic interplay of objective and subjective balance on a given day and subsequent task performance on that day. METHODS: For 30 consecutive days, following a baseline fall risk assessment, 41 older adults (56% female, Age M = 75.22, SD = 6.75) self-assessed balance and task performance using a smartphone. The Activity-specific Balance Confidence scale measured subjective balance. Postural sway and chair-stand performance were measured within a smartphone using accelerometry. Data were analyzed using multilevel random coefficient models. RESULTS: Tests of heterogeneity in level one residuals showed day-to-day variability in balance confidence and postural sway to be greater in individuals with higher fall risk at baseline. Baseline fall risk differentiated how the interplay of balance confidence and postural sway on a given day related to chair-stand performance on that day. For those with higher fall risk, on days that balance confidence was higher, greater postural sway was followed by greater chair-stand performance. CONCLUSION: Findings indicate that older adults, especially those with higher fall risk, may be unaware of subtle fluctuations in balance, which could lead to engaging in activities that exceed the capacity to maintain balance at that moment. Fall prevention efforts should address older adults' understanding of and responses to fluctuations of physical function in daily life.

Factors associated with falls in older adults: A secondary analysis of a 12-month randomized controlled trial.

PURPOSE: While identifying older adults at risk for falls is important, fall prediction models have had limited success, in part because of a poor understanding of which physical function measures to include. The purpose of this secondary analysis was to determine physical function measures that are associated with future falls in older adults. METHODS: In a 12-month trial comparing Vitamin D3 supplementation versus placebo on neuromuscular function, 124 older adults completed physical function measures at baseline, including the Short Physical Performance Battery (SPPB), Timed Up and Go, tests of leg strength and power, standing balance on a force plate with firm and foam surfaces, and walking over an instrumented walkway. Falls were recorded with monthly diaries over 12 months and categorized as no falls vs. one or more falls. Univariate and multivariable logistic regression adjusting for demographics, treatment assignment, depression, and prescription medications were conducted to examine the association between each physical function measure and future falls. Models were additionally adjusted for fall history. RESULTS: 61 participants sustained one or more falls. In univariate analysis, white race, depression, fall history, SPPB, and postural stability on foam were significantly associated with future falls. In multivariable analysis, fall history (OR (95% CI): 3.20 (1.42-7.43)), SPPB (0.80 (0.62-1.01)), and postural stability on foam (3.01 (1.18, 8.45)) were each significantly associated with future falls. After adjusting for fall history, only postural stability on foam was significantly associated with falls. CONCLUSIONS: When developing fall prediction models, fall history, the SPPB, and postural stability when standing on foam should be considered.

Mobile Technology for Falls Prevention in Older Adults.

Falls are the leading cause of accidental death in older adults that result from a complex interplay of risk factors. Recently, the need for person-centered approach utilizing personalization, prediction, prevention, and participation, known as the P4 model, in fall prevention has been highlighted. Features of mobile technology make it a suitable technological infrastructure to employ such an approach. This narrative review aims to review the evidence for using mobile technology for personalized fall risk assessment and prevention since 2017 in older adults. We aim to identify lessons learned and future directions for using mobile technology as a fall risk assessment and prevention tool. Articles were searched in PubMed and Web of Science with search terms related to older adults, mobile technology, and falls prevention. A total of 23 articles were included. Articles were identified as those examining aspects of the P4 model including prediction (measurement of fall risk), personalization (usability), prevention, and participation. Mobile technology appears to be comparable to gold-standard technology in measuring well-known fall risk factors including static and dynamic balance. Seven applications were developed to measure different fall risk factors and tested for personalization, and/or participation aspects, and 4 were integrated into a falls prevention program. Mobile health technology offers an innovative solution to provide tailored fall risk screening, prediction, and participation. Future studies should incorporate multiple, objective fall risk measures and implement them in community settings to determine if mobile technology can offer tailored and scalable interventions.

Treadmill training with virtual reality to enhance gait and cognitive function among people with multiple sclerosis: a randomized controlled trial.

BACKGROUND: Motor and cognitive impairments impact the everyday functioning of people with MS (pwMS). The present randomized controlled trial (RCT) evaluated the benefits of a combined motor-cognitive virtual reality training program on key motor and cognitive symptoms and related outcomes in pwMS. METHODS: In a single-blinded, two-arm RCT, 124 pwMS were randomized into a treadmill training with virtual reality (TT + VR) group or a treadmill training alone (TT) (active-control) group. Both groups received three training sessions per week for 6 weeks. Dual-tasking gait speed and cognitive processing speed (Symbol Digit Modalities Test, SDMT, score) were the primary outcomes. Secondary outcomes included additional tests of cognitive function, mobility, and patient-reported questionnaires. These were measured before, after, and 3 months after training. RESULTS: Gait speed improved (p < 0.005) in both groups, similarly, by about 10 cm/s. The TT + VR group (n = 53 analyzed per-protocol) showed a clinically meaningful improvement of 4.4 points (95% CI 1.9-6.8, p = 0.001) in SDMT, compared to an improvement of only 0.8 points in the TT (n = 51 analyzed per-protocol) group (95% CI 0.9-2.5 points, p = 0.358) (group X time interaction effect p = 0.027). Furthermore, TT + VR group-specific improvements were seen in depressive symptoms (lowered by 31%, p = 0.003), attention (17%, p < 0.001), and verbal fluency (11.6% increase, p = 0.002). DISCUSSION: These findings suggest that both TT and TT + VR improve usual and dual-task gait in pwMS. Nonetheless, a multi-modal approach based on VR positively impacts multiple aspects of cognitive function and mental health, more than seen after treadmill-treading alone. Trial registered at ClinicalTrials.Gov NCT02427997.

Estimating heterogeneity of physical function treatment response to caloric restriction among older adults with obesity.

Clinical trials conventionally test aggregate mean differences and assume homogeneous variances across treatment groups. However, significant response heterogeneity may exist. The purpose of this study was to model treatment response variability using gait speed change among older adults participating in caloric restriction (CR) trials. Eight randomized controlled trials (RCTs) with five- or six-month assessments were pooled, including 749 participants randomized to CR and 594 participants randomized to non-CR (NoCR). Statistical models compared means and variances by CR assignment and exercise assignment or select subgroups, testing for treatment differences and interactions for mean changes and standard deviations. Continuous equivalents of dichotomized variables were also fit. Models used a Bayesian framework, and posterior estimates were presented as means and 95% Bayesian credible intervals (BCI). At baseline, participants were 67.7 (SD = 5.4) years, 69.8% female, and 79.2% white, with a BMI of 33.9 (4.4) kg/m2. CR participants reduced body mass [CR: -7.7 (5.8) kg vs. NoCR: -0.9 (3.5) kg] and increased gait speed [CR: +0.10 (0.16) m/s vs. NoCR: +0.07 (0.15) m/s] more than NoCR participants. There were no treatment differences in gait speed change standard deviations [CR-NoCR: -0.002 m/s (95% BCI: -0.013, 0.009)]. Significant mean interactions between CR and exercise assignment [0.037 m/s (95% BCI: 0.004, 0.070)], BMI [0.034 m/s (95% BCI: 0.003, 0.066)], and IL-6 [0.041 m/s (95% BCI: 0.009, 0.073)] were observed, while variance interactions were observed between CR and exercise assignment [-0.458 m/s (95% BCI: -0.783, -0.138)], age [-0.557 m/s (95% BCI: -0.900, -0.221)], and gait speed [-0.530 m/s (95% BCI: -1.018, -0.062)] subgroups. Caloric restriction plus exercise yielded the greatest gait speed benefit among older adults with obesity. High BMI and IL-6 subgroups also improved gait speed in response to CR. Results provide a novel statistical framework for identifying treatment heterogeneity in RCTs.

The Developments and Iterations of a Mobile Technology-Based Fall Risk Health Application.

Falls are a prevalent and serious health concern across clinical populations. A critical step in falls prevention is identifying modifiable risk factors, but due to time constraints and equipment costs, fall risk screening is rarely performed. Mobile technology offers an innovative approach to provide personalized fall risk screening for clinical populations. To inform future development, this manuscript discusses the development and testing of mobile health fall risk applications for three unique clinical populations [older adults, individuals with Multiple Sclerosis (MS), and wheeled-device users]. We focus on key lessons learned and future directions to improve the field of fall risk mHealth. During the development phase, we first identified fall risk factors specific to each population that are measurable with mobile technology. Second, we determined whether inertial measurement units within smartphones can measure postural control within the target population. Last, we developed the interface of each app with a user-centered design approach with usability testing through iterative semi-structured interviews. We then tested our apps in real-world settings. Our cumulative work demonstrates that mobile technology can be leveraged to provide personalized fall risk screening for different clinical populations. Fall risk apps should be designed and tailored for the targeted group to enhance usefulness and feasibility. In addition, fall risk factors measured with mobile technology should include those that are specific to the population, are measurable with mobile technology, and can accurately measure fall risk. Future work should improve fall risk algorithms and implement mobile technology into fall prevention programs.

Hysteresis and stiffness of the lateral ankle complex in those with chronic ankle instability.

The role of mechanical laxity and viscoelastic tissue properties in chronic ankle instability (CAI) is unclear, but may influence repeated injury. The purpose was to determine if lateral ankle complex stiffness and hysteresis was altered in CAI individuals with and without mechanical laxity, compared to copers and uninjured controls. Thirty-five recreational athletes (19 females, 22.1 ± 2.7 years, 69.7 ± 15.7 kg, 168.4 ± 10.7 cm) were assessed for ankle injury history and self-reported instability. An instrumented arthrometer was applied and laxity, stiffness and hysteresis values were captured. Results from ANOVA tests indicated the CAI with laxity group had lower beginning- (3.2 ± 0.6 N/mm) and end-range stiffness (4.5 ± 0.4 N/mm) than the CAI without laxity group (4.7 ± 0.6; 6.0 ± 0.6 N/mm) and uninjured controls (4.6 ± 1.1; 5.8 ± 0.8 N/mm, p < 0.003). Hysteresis was greater in the CAI with laxity group than without laxity (91.0 ± 17.3 vs 62.8 ± 12.0 dN•mm; p = 0.03). Altered tissue properties in a CAI with laxity group likely indicate diminished ability of the lateral ankle complex to respond to loading. Accurately assessing, then avoiding or restoring tissue impairments after injury, may encourage better patient outcomes.

Frequency and characteristics of falls in people living with and without multiple sclerosis during the COVID-19 pandemic: A cross-sectional online survey.

BACKGROUND: Public health responses to Coronavirus Disease 2019 (COVID-19) including lockdowns may negatively impact physical and mental functioning in clinical populations. People living with multiple sclerosis (MS) may be more susceptible to physical function deterioration while practicing social distancing. Recent reports have suggested that about 50% of people with MS (pwMS) decreased their leisure physical activity during COVID-19, and upwards of 30% reported decreased physical fitness levels. However, the impact of social distancing on adverse health-related outcomes such as falls has not received much scrutiny. Therefore, we explored the frequency and characteristics of falls experienced by people living with and without MS during the COVID-19 pandemic. METHODS: Two-hundred and thirty-nine individuals, including 106 pwMS (median age: 59 years) and 133 people living without MS (median age: 66 years) were recruited for this cross-sectional study. A snowball sampling strategy was used for online recruitment. Participants completed a customized falls questionnaire and the number of falls experienced (if any) during COVID-19 was recorded. Fall-related characteristics such as the timing, locations, activities undertaken before falling and consequences, as well as self-reported physical activity were also recorded. RESULTS: Overall, participants reported 232 falls (1.67 falls/person in pwMS and 0.41 falls/person in non-MS participants). People living with MS (pwMS) had a significantly higher frequency of falls (58.5% vs 21.8%; p< 0.001) and recurrent falls (45.3% vs 9.8%; p< 0.001) compared to non-MS participants. Additionally, pwMS reported a significantly higher proportion of in-home falls (83.9% vs 54.2%; p = 0.004), as well as a higher proportion of overall injuries (44.3% vs 12.5%, p< 0.001), fractures (5.7% vs 0.8%, p = 0.048), and healthcare utilization (9.4% vs 1.6%, p = 0.007) compared to non-MS participants. A similar proportion of pwMS (49.1%) and non-MS participants (52.2%) reported lower physical activity levels during COVID-19. CONCLUSION: This cross-sectional study revealed that pwMS remain at high risk of falls and fall-related outcomes during COVID-19. The high number of falls experienced by pwMS is of clinical concern considering the current strain on the healthcare system. Findings from this study highlight the importance of monitoring falls and the potential for telerehabilitation in persons with MS during COVID-19.

Building on Lessons Learned in a Mobile Intervention to Reduce Pain and Improve Health (MORPH): Protocol for the MORPH-II Trial.

BACKGROUND: Engaging in sufficient levels of physical activity, guarding against sustained sitting, and maintaining a healthy body weight represent important lifestyle strategies for managing older adults' chronic pain. Our first Mobile Health Intervention to Reduce Pain and Improve Health (MORPH) randomized pilot study demonstrated that a partially remote group-mediated diet and daylong activity intervention (ie, a focus on moving often throughout the day) can lead to improved physical function, weight loss, less pain intensity, and fewer minutes of sedentary time. We also identified unique delivery challenges that limited the program's scalability and potential efficacy. OBJECTIVE: The purpose of the MORPH-II randomized pilot study is to refine the MORPH intervention package based on feedback from MORPH and evaluate the feasibility, acceptability, and preliminary efficacy of this revised package prior to conducting a larger clinical trial. METHODS: The MORPH-II study is an iteration on MORPH designed to pilot a refined framework, enhance scalability through fully remote delivery, and increase uptake of the daylong movement protocol through revised education content and additional personalized remote coaching. Older, obese, and low-active adults with chronic multisite pain (n=30) will be randomly assigned to receive a 12-week remote group-mediated physical activity and dietary weight loss intervention followed by a 12-week maintenance period or a control condition. Those in the intervention condition will partake in weekly social cognitive theory-based group meetings via teleconference software plus one-on-one support calls on a tapered schedule. They will also engage with a tablet application paired with a wearable activity monitor and smart scale designed to provide ongoing social and behavioral support throughout the week. Those in the control group will receive only the self-monitoring tools. RESULTS: Recruitment is ongoing as of January 2021. CONCLUSIONS: Findings from MORPH-II will help guide other researchers working to intervene on sedentary behavior through frequent movement in older adults with chronic pain. TRIAL REGISTRATION: ClinicalTrials.gov NCT04655001; https://clinicaltrials.gov/ct2/show/NCT04655001. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/29013.

Incorporating Nutrition, Vests, Education, and Strength Training (INVEST) in Bone Health: Trial Design and Methods.

BACKGROUND: Achievement of 5-10% weight loss (WL) among older adults living with obesity considerably improves prognosis of health-related outcomes; however, concomitant declines in bone mineral density (BMD) limit overall benefit by increasing fracture risk. Declines in mechanical loading contribute to WL-associated BMD loss, with pilot data signaling the addition of external weight replacement (via weighted vest use) during intentional WL mitigates bone loss at weight bearing sites to a similar degree as resistance exercise training (RT). Definitive data in support of weighted vest use as a potential strategy to mitigate WL-associated bone loss in this population are needed. METHODS: In the Incorporating Nutrition, Vests, Education, and Strength Training (INVEST) in Bone Health trial (NCT04076618), 192 older adults (60-85 years) who are overweight (BMI ≥ 27 kg/m2) with at least one obesity-related risk factor or obese (BMI = 30-40 kg/m2) will be randomly assigned to participate in one of three 12-month intervention groups: WL alone, WL + weighted vest use (WL + VEST), or WL + RT. The primary aim is to determine the effects of WL + VEST compared to WL alone and WL + RT on indicators of bone health and subsequent fracture risk. DISCUSSION: Determining effective, translatable strategies that minimize bone loss during intentional WL among older adults holds public health potential. The INVEST in Bone Health trial offers an innovative approach for increasing mechanical stress during intentional WL in the absence of RT. If successful, findings from this study will provide evidence in support of a scalable solution to minimize bone loss during intentional WL among older adults with obesity.

A Motor Learning Approach to Reducing Fall-Related Injuries.

Falls are the leading cause of injury related death in older adults. In this piece, a motor learning lens is applied to falls, and falls are viewed as three interdependent phases: 1) destabilization, 2) descent, and 3) impact. This review examines how movements can be performed in the descent and impact phases to potentially reduce fall-related injuries. The evidence that movements performed during the descent and impact phases are voluntary motor skills that can be learned by older adults is reviewed. Data from young adult and older adult studies suggest that safe landing strategies can reduce impact force, are voluntary, and are learnable. In conclusion, safe landing strategies may provide a complimentary approach to reduce fall-related injuries.

Smartphone accelerometry to assess postural control in individuals with multiple sclerosis.

BACKGROUND: Falls are a major health concern for people with Multiple Sclerosis (pwMS), and impaired postural control is an important predictor of falls. Lab-based technology to measure posture is precise but expensive, and clinical tests may not capture underlying impairments. An alternative solution is to leverage smartphone accelerometry as it is affordable, ubiquitous, and portable. RESEARCH QUESTION: Can smartphone accelerometry measure postural control compared to a force plate and research grade accelerometer in pwMS, and can smartphone accelerometry discriminate between assisted device and non-assisted device users? METHODS: 27 pwMS (12 assisted device users, 15 non-assisted device users) stood on a force plate while holding a smartphone with an attached research grade accelerometer against their chest. Participants performed two, 30 s trials of: eyes open, eyes closed, semi-tandem, tandem, and single leg. Acceleration and center of pressure were extracted, and Root Mean Square (RMS) and 95 % confidence ellipse were calculated. Spearman's correlations were performed, and receiving operating characteristic (ROC) curves and the Area Under the Curve (AUC) were calculated. RESULTS: There were moderate to high correlations between the smartphone and accelerometer for RMS (ρ = 0.85 - 1.0; p = 0.001 - <0.001) and 95 % area ellipse (ρ = 0.92 - 0.99; p = <0.001). There were weak to moderate correlations between the smartphone and force plate for RMS (ρ = 0.38 - 0.92; p = 0.06 - <0.001) and 95 % area ellipse (ρ = 0.69 - 0.90 p = 0.002 - <0.001). To discriminate between assisted device usage, ROC curves for smartphone outputs were constructed, the AUC was high and statistically significant (p < 0.001 - 0.02). SIGNIFICANCE: There is potential to leverage smartphone accelerometery to measure postural control in pwMS. These finding provide preliminary results to support the development of a mobile health application to measure fall risk for pwMS.

A wearable sensor identifies alterations in community ambulation in multiple sclerosis: contributors to real-world gait quality and physical activity.

People with multiple sclerosis (pwMS) often suffer from gait impairments. These changes in gait have been well studied in laboratory and clinical settings. A thorough investigation of gait alterations during community ambulation and their contributing factors, however, is lacking. The aim of the present study was to evaluate community ambulation and physical activity in pwMS and healthy controls and to compare in-lab gait to community ambulation. To this end, 104 subjects were studied: 44 pwMS and 60 healthy controls (whose age was similar to the controls). The subjects wore a tri-axial, lower back accelerometer during usual-walking and dual-task walking in the lab and during community ambulation (1 week) to evaluate the amount, type, and quality of activity. The results showed that during community ambulation, pwMS took fewer steps and walked more slowly, with greater asymmetry, and larger stride-to-stride variability, compared to the healthy controls (p < 0.001). Gait speed during most of community ambulation was significantly lower than the in-lab usual-walking value and similar to the in-lab dual-tasking value. Significant group (pwMS /controls)-by-walking condition (in-lab/community ambulation) interactions were observed (e.g., gait speed). Greater disability was associated with fewer steps and reduced gait speed during community ambulation. In contrast, physical fatigue was correlated with sedentary activity, but was not related to any of the measures of community ambulation gait quality including gait speed. This disparity suggests that more than one mechanism contributes to community ambulation and physical activity in pwMS. Together, these findings demonstrate that during community ambulation, pwMS have marked gait alterations in multiple gait features, reminiscent of dual-task walking measured in the laboratory. Disease-related factors associated with these changes might be targets of rehabilitation.

Motor Learning in People with Multiple Sclerosis: A Systematic Review and Meta-analysis.

OBJECTIVE: To systematically review and quantitatively synthesize the existing evidence of motor learning in persons with multiple sclerosis (PwMS). DATA SOURCES: PubMed, Cumulative Index to Nursing and Allied Health Literature, and Web of Science were searched using the following terms: multiple sclerosis, task learning, motor learning, skill learning, performance learning. STUDY SELECTION: Studies had to include PwMS with a main outcome being motor learning, be published in peer-reviewed journals, and be written in English. The search yielded 68 results, and the inclusion criteria were met by 17 studies. DATA EXTRACTION: Basic descriptors of each study, study protocol, and motor learning measures were extracted. The Grading of Recommendations Assessment, Development, and Evaluation approach revealed the quality of evidence was low with a high risk of bias. Meta-analysis was conducted to determine the difference in implicit and explicit learning in PwMS and controls without multiple sclerosis. DATA SYNTHESIS: Studies scored on average 15.9 of 18 for quality assessment. PwMS were able to learn functional mobility and upper limb manipulation motor skills as indicated by short-term acquisition, transfer, and retention. Implicit learning conditions from the meta-analysis showed that PwMS were able to learn at a similar rate to controls without multiple sclerosis (P<.001), yet explicit learning conditions did not display a significant rate of learning (P=.133). CONCLUSIONS: While this review indicated that PwMS are capable of motor learning, several knowledge gaps still exist. Future research should focus on using higher-quality evidence to understand motor learning in PwMS and translate the findings to rehabilitation and activities of daily living.

Fall Risk Prediction in Multiple Sclerosis Using Postural Sway Measures: A Machine Learning Approach.

Numerous postural sway metrics have been shown to be sensitive to balance impairment and fall risk in individuals with MS. Yet, there are no guidelines concerning the most appropriate postural sway metrics to monitor impairment. This investigation implemented a machine learning approach to assess the accuracy and feature importance of various postural sway metrics to differentiate individuals with MS from healthy controls as a function of physiological fall risk. 153 participants (50 controls and 103 individuals with MS) underwent a static posturography assessment and a physiological fall risk assessment. Participants were further classified into four subgroups based on fall risk: controls, low-risk MS (n = 34), moderate-risk MS (n = 27), high-risk MS (n = 42). Twenty common sway metrics were derived following standard procedures and subsequently used to train a machine learning algorithm (random forest - RF, with 10-fold cross validation) to predict individuals' fall risk grouping. The sway-metric based RF classifier had high accuracy in discriminating controls from MS individuals (>86%). Sway sample entropy was identified as the strongest feature for classification of low-risk MS individuals from healthy controls. Whereas for all other comparisons, mediolateral sway amplitude was identified as the strongest predictor for fall risk groupings.

Gait variability is altered in cancer survivors with self-reported neuropathy.

BACKGROUND: Falls are prevalent among cancer survivors, and neuropathy, a side effect from chemotherapy treatment, is thought to contribute to falls. While falls commonly occur during walking, there is limited information about gait function in cancer survivors with neuropathy. RESEARCH QUESTION: What is the difference between gait speed and gait variability in cancer survivors with and without self-reported neuropathy and healthy controls? METHODS: Seventeen cancer survivors and 12 healthy individuals [age: 53.5 (11.8), gender: 10 females] participated in a single testing session. Cancer survivors were grouped into neuropathy [n = 9; age: 61.9 (6.1); gender: 8 females] and no neuropathy [n = 8; age: 50.75 (14.1); gender: 7 females] based on the self-reported FACT/GOG Neurotoxicity subscale questionnaire. All participants completed two walking trials at their comfortable pace across a 6 m pressure sensitive walkway. A one-way ANOVA with Tukey's post-hoc analysis and effect sizes were used to detect differences in gait speed, step length variability, and step width variability between groups. RESULTS: Although there were no group differences in gait speed, a significant main effect was found for step length variability (p =  0.03, η2 = 0.24) between groups. Step length variability was significantly less in cancer survivors with neuropathy than healthy controls (p = 0.05, d = 1.30). There was a significant main effect for step width variability between groups (p = 0.05, η2 = 0.20). Cancer survivors with neuropathy had significantly greater step width variability than healthy controls (p = 0.04, d = 1.04). SIGNIFICANCE: Cancer survivors with neuropathy display greater step width variability and less step length variability than healthy controls. Gait variability may be a more sensitive marker than gait speed to track mobility in cancer survivors with neuropathy symptoms. Assessing and treating gait function in cancer survivors with neuropathy symptoms may improve everyday ambulation.

Balance and Gait Alterations Observed More Than 2 Weeks After Concussion: A Systematic Review and Meta-Analysis.

OBJECTIVE: The aim of the study was to systematically review and quantitatively synthesize the existing evidence of balance and gait alterations lasting more than 2 wks after concussion in adults. DESIGN: A systematic review was conducted through PubMed, CINAHL, SPORTDiscus, and Web of Science. Investigations must include adult participants with at least one concussion, were measured for 14 days after injury, and reported balance or gait measures. Balance error scoring system scores, center of pressure sway area and displacement, and gait velocity were extracted for the meta-analysis. RESULTS: Twenty-two studies were included. Balance alterations were observed for 2 wks after concussion when participants were tested with eyes closed, for longer durations of time, and with nonlinear regulatory statistics. The meta-analysis of center of pressure sway area with no visual feedback indicated that concussed individuals had greater sway area (P < 0.001). Various gait alterations were also observed, which may indicate that concussed individuals adopt a conservative gait strategy. The meta-analysis revealed that concussed participants walked 0.12 m/sec (P < 0.001) and 0.06 m/sec (P = 0.023) slower in single and dual-task conditions, respectively. CONCLUSIONS: Subtle balance and gait alterations were observed after 2 wks after a concussion. Understanding these alterations may allow clinicians to improve concussion diagnosis and prevent subsequent injury.

Smartphone technology can measure postural stability and discriminate fall risk in older adults.

BACKGROUND: Falls are the leading cause of injury related death in older adults. Impaired postural stability is a predictor of falls but is seldom objectively assessed in clinical or home settings. Embedded accelerometers within smartphones offer potential to objectively measure postural stability. The purpose of this study was to determine if a smartphone embedded accelerometer can measure static postural stability and distinguish older adults at high levels of fall risk. METHODS: Thirty older adults (age: 65.9 ± 8.8) underwent seven balance tests while standing on a force plate and holding a smartphone against their chest in a standardized order. Participants also completed the Physiological Profile Assessment to assess their fall risk. Center of pressure (COP) parameters from the force plate including velocity in the anterioposterior (AP) and mediolateral (ML) directions and 95% confidence ellipse were derived. Maximum acceleration and root mean square (RMS) in ML, AP and vertical axes were derived from the smartphone. Spearman rank-order correlations between force plate and smartphone measures were conducted, and receiver operating characteristic (ROC) and the area under the curves (AUC) were constructed to distinguish between low and high fall risk. RESULTS: There were moderate to strong significant correlations between measures derived from the force plate and measures derived from the smartphone during challenging balance conditions (ρ = 0.42-0.81; p < 0.01-0.05). The AUC for ROC plots were significant for all COP measures during challenging balance conditions (p < 0.01-0.05). The AUC for ROC plots were significant for RMS vertical and AP during challenging balance conditions (p = 0.01-0.04). SIGNIFICANCE: This study provides evidence that a smartphone is a valid measure of postural stability and capable of distinguishing fall risk stratification in older adults. There is potential for smartphones to offer objective, fall risk assessments for older adults.