Effect of Timing and Coordination Training on Mobility and Physical Activity Among Community-Dwelling Older Adults: A Randomized Clinical Trial.

Importance: Standard exercise interventions targeting underlying physiologic system impairments have limited success in improving walking. Augmenting standard interventions with timing and coordination training, which incorporates the principles of motor learning and integrates multiple systems, may be more successful. Objective: To determine whether a standard strength and endurance program incorporating timing and coordination training (standard-plus) improves gait speed more than strength and endurance training alone. Design, Setting, and Participants: The Program to Improve Mobility in Aging (PRIMA) study was an assessor-blinded, randomized, 2-group intervention trial that included a 12-week intervention and 24-week follow-up period. The trial was conducted at a university research clinic from 2016 to 2020. Participants included 249 community-dwelling older adults (aged ≥65 years) with gait speed between 0.60 and 1.20 m/s. Statistical analysis was performed from December 2020 to March 2021. Interventions: Participants were randomized to standard strength and endurance (n = 125) or standard-plus, including timing and coordination training (n = 124), 50 to 60 minutes, twice a week for 12 weeks. Main Outcomes and Measures: Primary outcome of gait speed and secondary outcomes representing components of the intervention (leg strength and power, 6-minute walk test, chair sit-and-reach test, and figure of 8 walk test) and activity and participation (Late Life Function and Disability Instrument and daily physical activity measured by accelerometry) were measured at 12, 24, and 36 weeks. Results: Among 249 randomized participants, 163 (65.5%) were female, 22 (8.8%) were Black, 219 (88.0%) were White; mean (SD) age was 77.4 (6.6) years; mean (SD) gait speed was 1.07 (0.16) m/s; and 244 (98.0%) completed the intervention. The 2 groups did not have significantly different improvements in gait speed or secondary outcomes representing the components of the intervention at any time point. For gait speed, individuals in the standard-plus group had a mean (SD) improvement of 0.079 (0.135) m/s over 12 weeks, 0.065 m/s (0.141) over 24 weeks, and 0.059 (0.150) m/s over 36 weeks; individuals in the standard group improved gait speed by 0.081 (0.124) m/s over 12 weeks, 0.051 (0.129) m/s over 24 weeks, and 0.065 (0.148) m/s over 36 weeks. Conclusions and Relevance: This randomized clinical trial found no difference in gait speed change between the standard and standard-plus intervention groups, and both groups showed sustained improvements in mobility 24 weeks after the intervention. Trial Registration: ClinicalTrials.gov Identifier: NCT02663778.

Potential long-term impact of "On The Move" group-exercise program on falls and healthcare utilization in older adults: an exploratory analysis of a randomized controlled trial.

BACKGROUND: Wellness program participation may reduce the risk of falling, emergency department-use, and hospitalization among older adults. "On the Move" (OTM), a community-based group exercise program focused on the timing and coordination of walking, improved mobility in older adults, but its impact on falls, emergency department-use, and hospitalizations remains unclear. The aim of this preliminary study was to investigate the potential long-term effects that OTM may have on downstream, tertiary outcomes. METHODS: We conducted a secondary analysis of a cluster-randomized, single-blind intervention trial, which compared two community-based, group exercise programs: OTM and a seated exercise program on strength, endurance, and flexibility (i.e. 'usual-care'). Program classes met for 50 min/session, 2 sessions/week, for 12 weeks. Older adults (≥65 years), with the ability to ambulate independently at ≥0.60 m/s were recruited. Self-reported incidence of falls, emergency department visitation, and hospitalization were assessed using automated monthly phone calls for the year following intervention completion. Participants with ≥1 completed phone call were included in the analyses. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were calculated (reference = usual-care). RESULTS: Participants (n = 248) were similar on baseline characteristics and number of monthly phone calls completed. Participants in the seated exercise program attended an average of 2.9 more classes (p = .017). Of note, all results were not statistically significant (i.e. 95% CI overlapped a null value of 1.0). However, point estimates suggest OTM participation resulted in a decreased incidence rate of hospitalization compared to usual-care (IRR = 0.88; 95% CI = 0.59-1.32), and the estimates strengthened when controlling for between-group differences in attendance (adjusted IRR = 0.82; 95% CI = 0.56-1.21). Falls and emergency department visit incidence rates were initially greater for OTM participants, but decreased after controlling for attendance (adjusted IRR = 1.08; 95% CI = 0.72-1.62 and adjusted IRR = 0.96; 95% CI = 0.55-1.66, respectively). CONCLUSION: Compared to a community-based seated group exercise program, participation in OTM may result in a reduced risk of hospitalization. When OTM is adhered to, the risk for falling and hospitalizations are attenuated. However, definitive conclusions cannot be made. Nevertheless, it appears that a larger randomized trial, designed to specifically evaluate the impact of OTM on these downstream health outcomes is warranted. TRIAL REGISTRATION: Clinical trials.gov (NCT01986647; prospectively registered on November 18, 2013).

Program to improve mobility in aging (PRIMA) study: Methods and rationale of a task-oriented motor learning exercise program.

Walking difficulty is a common and costly problem in older adults. A potentially important yet unaddressed strategy to enhance walking ability through exercise intervention is to add a timing and coordination component in gait training (i.e. task specific timing and coordination exercise intervention) to the usual strength, endurance, and flexibility training. We describe the methods and rationale of a randomized single-blind, physical therapist supervised, exercise intervention trial to compare the effects of a standard strength, endurance, and flexibility program to a standard plus timing and coordination program in community-dwelling older adults walking slower than the desired gait speed of 1.2 m/s. Exercise sessions are twice weekly for 12 weeks. Participants are assessed at baseline, 12 weeks (post intervention), 24 weeks and 36 weeks. The primary outcome is gait speed, secondary outcomes represent components of the interventions (strength, endurance, flexibility, timing and coordination), and tertiary outcomes are measure of activity and participation (Late Life Function and Disability Instrument and physical activity). The findings of this trial will (1) establish if a standard-plus task specific timing and coordination program is superior to a standard strength and endurance program in improving mobility, activity and participation and (2) determine if the improvements are sustained over time. The information derived from this project will provide valuable insight into the prevention and management of walking difficulty, which is so common in older Americans.

Randomized Controlled Trial of Exercise to Improve Walking Energetics in Older Adults.

BACKGROUND AND OBJECTIVES: Mobility limitation is common and has been linked to high energetic requirements of daily activities, including walking. The study objective was to determine whether two separate forms of exercise could reduce the energy cost of walking and secondary outcomes related to activity and participation domains among older adults with mobility limitation. RESEARCH DESIGN AND METHODS: Community-dwelling older adults with self-reported mobility limitation (n = 72) were randomized to 12 weeks of twice-weekly, group-based, instructor-led timing and coordination, aerobic walking, or stretching and relaxation (active control) programs. The primary outcome was the energy cost of walking (mL O2/kg/m), assessed by a 5-minute treadmill walking test (0.8 m/s). Secondary outcomes were fatigability, physical activity, endurance, physical function, and life-space. Baseline-adjusted ANCOVAs were used to determine mean differences between exercise and control groups at 12 and 24 weeks. RESULTS: Exercise session attendance was high: 86% for timing and coordination, 81% for aerobic walking, and 90% for stretching and relaxation. At 12 weeks, timing and coordination reduced the mean energy cost of walking by 15% versus stretching and relaxation (p = .008). Among those with high baseline cost, timing and coordination reduced mean energy cost by 20% versus stretching and relaxation (p = .055). Reductions were sustained at 24 weeks. Aerobic walking had no effect on the energy cost of walking at 12 or 24 weeks. At 12 weeks, there was a trend toward faster gait speed (by 0.1 m/s) in timing and coordination versus stretching and relaxation (p = .074). Fatigability, physical activity, endurance, physical function, and life-space did not change with timing and coordination or aerobic walking versus stretching and relaxation at 12 or 24 weeks. DISCUSSION AND IMPLICATIONS: Twelve weeks of timing and coordination, but not aerobic walking, reduced the energy cost of walking among older adults with mobility limitation, particularly among those with high baseline energy cost; reductions in energy cost were sustained following training cessation. Timing and coordination also led to a trend toward faster gait speed.

Effectiveness of a Timing and Coordination Group Exercise Program to Improve Mobility in Community-Dwelling Older Adults: A Randomized Clinical Trial.

Importance: Timing and coordination exercises may be an important addition to community-based health promotion exercise programs to improve walking in older adults. Objective: To compare the effectiveness of the On the Move group exercise program, which focuses on the timing and coordination of movement, with a seated strength, endurance, and flexibility program (usual care) at improving function, disability, and walking ability of older adults. Design, Setting, and Participants: Cluster-randomized, single-blind intervention trial. Thirty-two independent living facilities, senior apartment buildings, and senior community centers were randomized to On the Move (16 sites; 152 participants) or usual care (16 sites; 146 participants). Participants were 65 years or older, able to ambulate independently with a gait speed of at least 0.60 m/s, able to follow 2-step commands, and were medically stable. Interventions: Exercise classes were 50 minutes, twice a week for 12 weeks and had 10 or fewer participants per class. On the Move consisted of warm-up, timing and coordination (stepping and walking patterns), strengthening, and stretching exercises. The usual-care program consisted of warm-up, strength, endurance, and stretching exercises. Main Outcomes and Measures: The primary outcomes were self-report of function and disability (Late Life Function and Disability Instrument) and mobility (6-minute walk distance and gait speed) assessed by blinded individuals. Results: Participants (mean [SD] age, 80.0 [8.1] years) were mostly female (251 [84.2%]) and white (249 [83.6%]) and had a mean (SD) of 2.8 (1.4) chronic conditions. Intervention groups were similar on baseline characteristics. Postintervention, 142 (93.4%) participants in On the Move and 139 (95.2%) participants in usual care completed testing. On the Move had greater mean (SD) improvements than the usual-care group in gait speed (0.05 [0.13] vs -0.01 [0.11] m/s; adjusted difference = 0.05 [0.02] m/s; P = .002) and 6-minute walk distance (20.6 [57.1] vs 4.1 [55.6] m; adjusted difference = 16.7 [7.4] m; P = .03). Attendance was greater in the usual-care program compared with On the Move (95 [65.1%] vs 76 [50.0%] attended ≥20 classes; P = .03). There were no significant differences in any of the other primary or secondary outcomes. Conclusions and Relevance: The On the Move group exercise program was more effective at improving mobility than a usual-care exercise program, despite lower attendance. Additional research examining the impact of the intervention on long-term disability outcomes is needed before recommending routine implementation into clinical practice. Trial Registration: clinicaltrials.gov Identifier: NCT01986647.

Motor sequence learning-induced neural efficiency in functional brain connectivity.

Previous studies have shown the functional neural circuitry differences before and after an explicitly learned motor sequence task, but have not assessed these changes during the process of motor skill learning. Functional magnetic resonance imaging activity was measured while participants (n=13) were asked to tap their fingers to visually presented sequences in blocks that were either the same sequence repeated (learning block) or random sequences (control block). Motor learning was associated with a decrease in brain activity during learning compared to control. Lower brain activation was noted in the posterior parietal association area and bilateral thalamus during the later periods of learning (not during the control). Compared to the control condition, we found the task-related motor learning was associated with decreased connectivity between the putamen and left inferior frontal gyrus and left middle cingulate brain regions. Motor learning was associated with changes in network activity, spatial extent, and connectivity.

Stakeholder involvement in the design of a patient-centered comparative effectiveness trial of the "On the Move" group exercise program in community-dwelling older adults.

BACKGROUND: Group exercise programs for older adults often exclude the timing and coordination of movement. Stakeholder involvement in the research process is strongly encouraged and improves the relevance and adoption of findings. We describe stakeholder involvement in the design of a clinical trial of a group-based exercise program that incorporates timing and coordination of movement into the exercises. METHODS: The study was a cluster randomized, single-blind intervention trial to compare the effects on function, disability and mobility of a standard group exercise program and the "On the Move" group exercise program in older adults residing in independent living facilities and senior apartment buildings, and attending community centers. Exercise classes were twice weekly for 12weeks delivered by study exercise leaders and facility activity staff personnel. OUTCOMES: The primary outcomes function, disability and mobility were assessed at baseline and post-intervention. Function and disability were assessed using the Late Life Function and Disability Instrument, and mobility using the Six-Minute Walk Test and gait speed. STAKEHOLDERS: Patient and provider stakeholders had significant input into the study aims, design, sample, intervention, outcomes and operational considerations. SUMMARY: A community-based exercise program to improve walking can be developed to address both investigator identified missing components in current exercise to improve walking and stakeholder defined needs and interest for the activity program. Involvement of stakeholders substantially improves the relevance of research questions, increases the transparency of research activities and may accelerate the adoption of research into practice.

Challenging the motor control of walking: Gait variability during slower and faster pace walking conditions in younger and older adults.

BACKGROUND: Gait variability is a measure of motor control of gait. Little is known about age-related changes in the motor control of gait (gait variability) during challenging walking conditions, such as slower and faster pace walking. OBJECTIVE: The purpose of this study was to examine the impact of challenging walking conditions (slower and faster speeds) on gait variability in younger and older adults. DESIGN: This study was a cross-sectional, observational design. METHODS: Forty younger (mean age=26.6±6.0years) and 111 community-dwelling older adults (mean age=77.3±6.0years), independent in ambulation, were studied. Gait characteristics were collected using a computerized walkway (GaitMat II™). Step length, step width, step time, swing time, stance time and double support time variability were derived as the standard deviation of all steps across the 4 passes. RESULTS: Compared to younger, older adults had a significant change in their gait variability from usual to slower in step width (-0.006±0.003), step time (0.028±0.006), swing time (0.023±0.004), stance time (0.042±0.008), and double support time (0.024±0.005). Changes in gait variability from usual to faster were not significantly different between younger and older adults. LIMITATION: Gait variability was examined during self-selected over-ground walking, where subjects directed to walk "slower", "usual" and "faster". CONCLUSIONS: Walking slowly is more challenging to the motor control of gait and may be more sensitive to age-related declines in gait than usual and faster speed walks.

The test-retest reliability and minimal detectable change of spatial and temporal gait variability during usual over-ground walking for younger and older adults.

Gait variability is a marker of gait performance and future mobility status in older adults. Reliability of gait variability has been examined mainly in community dwelling older adults who are likely to fluctuate over time. The purpose of this study was to compare test-retest reliability and determine minimal detectable change (MDC) of spatial and temporal gait variability in younger and older adults. Forty younger (mean age=26.6 ± 6.0 years) and 46 older adults (mean age=78.1 ± 6.2 years) were included in the study. Gait characteristics were measured twice, approximately 1 week apart, using a computerized walkway (GaitMat II). Participants completed 4 passes on the GaitMat II at their self-selected walking speed. Test-retest reliability was calculated using Intra-class correlation coefficients (ICCs(2,1)), 95% limits of agreement (95% LoA) in conjunction with Bland-Altman plots, relative limits of agreement (LoA%) and standard error of measurement (SEM). The MDC at 90% and 95% level were also calculated. ICCs of gait variability ranged 0.26-0.65 in younger and 0.28-0.74 in older adults. The LoA% and SEM were consistently higher (i.e. less reliable) for all gait variables in older compared to younger adults except SEM for step width. The MDC was consistently larger for all gait variables in older compared to younger adults except step width. ICCs were of limited utility due to restricted ranges in younger adults. Based on absolute reliability measures and MDC, younger had greater test-retest reliability and smaller MDC of spatial and temporal gait variability compared to older adults.

Translation of a Motor Learning Walking Rehabilitation Program Into a Group-Based Exercise Program for Community-Dwelling Older Adults.

BACKGROUND: Traditional exercise programs for older adults, which focus on aerobic and strength training, have had only modest effects on walking. Recently, a motor learning exercise program was shown to have greater effects on walking compared with a traditional exercise program. Translating this novel motor learning exercise program into a group exercise program would allow it to be offered as an evidence-based, community-based program for older adults. OBJECTIVE: To translate a walking rehabilitation program based on motor learning theory from one-on-one to group delivery (On the Move) and evaluate multiple aspects of implementation in older adults with impaired mobility. DESIGN: The translation process involved multiple iterations, including meetings of experts in the field (Phase I), focus groups (Phase II), and implementation of the newly developed program (Phase III). Phase III was based on a one-group model of intervention development for feasibility, safety, potential effects, and acceptability. SETTING: Community sites, including 2 independent living facilities, an apartment building, and a community center. PARTICIPANTS: Adults 65 years of age or older who could ambulate independently and who were medically stable. Thirty-one adults, mean age 82.3 ± 5.6 years, were eligible to participate. METHODS: The group exercise program was held twice a week for 12 weeks. MAIN OUTCOME MEASUREMENTS: Acceptability of the program was determined by retention and adherence rates and a satisfaction survey. Risk was measured by adverse events and questions on perceived challenge and safety. Mobility was assessed pre- and postintervention by gait speed, Figure of 8 Walk Test, and 6-minute walk test. RESULTS: Modifications to the program included adjustments to format/length, music, education, and group interaction. The 12-week program was completed by 24 of 31 entrants (77%). Adherence was high, with participants attending on average 83% of the classes. Safety was excellent, with only 1 subject experiencing a controlled, noninjurious fall. There was preliminary evidence for improved mobility after the intervention: gait speed improved from 0.76 ± 0.21 to 0.81 ± 0.22 m/s, P = .06; Figure of 8 Walk Test from 13.0 ± 3.9 to 12.0 ± 3.9 seconds, P = .07; and 6-minute walk test from 246 ± 75 to 281 ± 67 m, P = .02. CONCLUSIONS: The group-based program was safe and acceptable to older adults with impaired mobility and resulted in potentially clinically meaningful improvements in mobility.

Effects of Three Types of Exercise Interventions on Healthy Old Adults' Gait Speed: A Systematic Review and Meta-Analysis.

BACKGROUND: Habitual walking speed predicts many clinical conditions later in life, but it declines with age. However, which particular exercise intervention can minimize the age-related gait speed loss is unclear. PURPOSE: Our objective was to determine the effects of strength, power, coordination, and multimodal exercise training on healthy old adults' habitual and fast gait speed. METHODS: We performed a computerized systematic literature search in PubMed and Web of Knowledge from January 1984 up to December 2014. Search terms included 'Resistance training', 'power training', 'coordination training', 'multimodal training', and 'gait speed (outcome term). Inclusion criteria were articles available in full text, publication period over past 30 years, human species, journal articles, clinical trials, randomized controlled trials, English as publication language, and subject age ≥65 years. The methodological quality of all eligible intervention studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. We computed weighted average standardized mean differences of the intervention-induced adaptations in gait speed using a random-effects model and tested for overall and individual intervention effects relative to no-exercise controls. RESULTS: A total of 42 studies (mean PEDro score of 5.0 ± 1.2) were included in the analyses (2495 healthy old adults; age 74.2 years [64.4-82.7]; body mass 69.9 ± 4.9 kg, height 1.64 ± 0.05 m, body mass index 26.4 ± 1.9 kg/m2, and gait speed 1.22 ± 0.18 m/s). The search identified only one power training study, therefore the subsequent analyses focused only on the effects of resistance, coordination, and multimodal training on gait speed. The three types of intervention improved gait speed in the three experimental groups combined (n = 1297) by 0.10 m/s (±0.12) or 8.4% (±9.7), with a large effect size (ES) of 0.84. Resistance (24 studies; n = 613; 0.11 m/s; 9.3%; ES: 0.84), coordination (eight studies, n = 198; 0.09 m/s; 7.6%; ES: 0.76), and multimodal training (19 studies; n = 486; 0.09 m/s; 8.4%, ES: 0.86) increased gait speed statistically and similarly. CONCLUSIONS: Commonly used exercise interventions can functionally and clinically increase habitual and fast gait speed and help slow the loss of gait speed or delay its onset.

Improving motor control in walking: a randomized clinical trial in older adults with subclinical walking difficulty.

OBJECTIVE: To test the proposed mechanism of action of a task-specific motor learning intervention by examining its effect on measures of the motor control of gait. DESIGN: Single-blinded randomized clinical trial. SETTING: University research laboratory. PARTICIPANTS: Adults (N=40) aged ≥65 years with gait speed >1.0m/s and impaired motor skill (figure-of-8 walk time >8s). INTERVENTIONS: The 2 interventions included a task-oriented motor learning and a standard exercise program; both interventions included strength training. Both lasted 12 weeks, with twice-weekly, 1-hour, physical therapist-supervised sessions. MAIN OUTCOME MEASURES: Two measures of the motor control of gait, gait variability and smoothness of walking, were assessed pre- and postintervention by assessors masked to the treatment arm. RESULTS: Of 40 randomized subjects, 38 completed the trial (mean age ± SD, 77.1±6.0y). The motor learning group improved more than the standard group in double-support time variability (.13m/s vs .05m/s; adjusted difference [AD]=.006, P=.03). Smoothness of walking in the anteroposterior direction improved more in the motor learning than standard group for all conditions (usual: AD=.53, P=.05; narrow: AD=.56, P=.01; dual task: AD=.57, P=.04). Smoothness of walking in the vertical direction also improved more in the motor learning than standard group for the narrow-path (AD=.71, P=.01) and dual-task (AD=.89, P=.01) conditions. CONCLUSIONS: Among older adults with subclinical walking difficulty, there is initial evidence that task-oriented motor learning exercise results in gains in the motor control of walking, while standard exercise does not. Task-oriented motor learning exercise is a promising intervention for improving timing and coordination deficits related to mobility difficulties in older adults, and needs to be evaluated in a definitive larger trial.

Callosal hyperintensities and gait speed gain from two types of mobility interventions in older adults.

OBJECTIVE: To assess whether the volume of callosal hyperintensities in the genu and splenium of older adults with mobility impairment is differentially associated with the degree of gain in gait speed after 2 types of gait interventions. DESIGN: Single-blind randomized controlled trial of 2 types of gait exercises in older adults. SETTING: Research center in an academic institution. PARTICIPANTS: Ambulatory adults (N=44) aged ≥65 years with a slow and variable gait. INTERVENTION: Twelve-week physical therapist-guided trial of a conventional walking, endurance, balance, and strength (WEBS) intervention (n=20) versus a timing and coordination of gait (TC) intervention (n=22). MAIN OUTCOME MEASURE: Gain in gait speed after the intervention and its relation to callosal hyperintensities in the genu and splenium of the corpus callosum. RESULTS: Gait speed improved in both the WEBS group (mean change, 0.16m/s) and the TC group (mean change, 0.21m/s; both P<.05). The volume of white matter hypertintensities (WMHs) in the genu was differentially associated with gait speed gain (group × genual WMH interaction, P=.05). Greater genual WMH volume was related to a smaller gait speed gain in the WEBS group (P=.01) but not in the TC (P=.10) group. Splenial WMH volume was not differentially associated with gait speed gain (interaction, P=.90). CONCLUSIONS: Callosal hyperintensities differentially influence gait speed gain by the type of gait rehabilitation. Mobility impaired older adults with genual hyperintensities may benefit from a rehabilitation program focused on motor skill learning rather than on strength and endurance training.

The impact of testing protocol on recorded gait speed.

BACKGROUND: Gait speed predicts disability, cognitive decline, hospitalization, nursing home admission and mortality. Although gait speed is often measured in clinical practice and research, testing protocols vary widely and their impact on recorded gait speed has yet to be explored. OBJECTIVES: Our purpose is to describe and compare gait speeds obtained from different testing protocols in the same individuals. DESIGN: Cross-sectional. SETTING: University research setting. Participants Subjects were 104 community-dwelling older adults who could ambulate household distances independently (mean age = 77.2 ± 6.1). MEASUREMENTS: Gait speed was recorded over 4m using the protocols: (1) standing start, usual pace over ground, (2) walking start, usual pace over ground with an optokinetic device, (3) walking start, usual pace over ground with a stop watch (4) walking start, usual pace on a computerized walkway, and (5) walking start, fast pace on a computerized walkway. A linear mixed model and pairwise comparisons was used to compare gait speeds within individuals across different protocols. RESULTS: Mean ± SD gait speed for each condition was: standing start, usual pace over ground 0.97 ± 0.23 m/s; walking start, usual pace over ground 1.14 ± 0.2 5m/s; walking start, usual pace on walkway 1.01 ± 0.26 m/s; and walking start, fast pace on walkway 1.31 ± 0.34 m/s. On average, the determined gait speed was 0.17 m/s faster during the walking compared to the standing start (p < .001), 0.07 m/s slower on the computerized walkway compared to over ground (p < .001), and 0.25 m/s faster during the fast pace compared to the usual pace walk (p < .001). CONCLUSION: Starting protocol (standing vs. walking), testing surface (over ground vs. computerized walkway), and walking pace (usual vs. fast) impact recorded gait speed in older adults. Care should be taken when comparing gait speeds from studies with different testing protocols.

The Test-Retest Reliability of Indirect Calorimetry Measures of Energy Expenditure During Overground Walking in Older Adults With Mobility Limitations.

The purpose of this study was to assess the relative and absolute reliability of metabolic measures of energy expenditure and gait speed during overground walking in older adults with mobility limitations. Thirty-three (mean age [SD] = 76.4 [6.6] years; 66% female) older adults with slow gait participated. Measures of energy expenditure and gait speed were recorded during two 6-min bouts of overground walking (1 week apart) at a self-selected "usual" walking pace. The relative reliability for all variables was excellent: ICC = .81-.91. Mean differences for five of the six outcome variables was less than or equal to the respected SEM, while all six mean differences fell below the calculated MDC95. Clinicians and researchers can be confident that metabolic measures of energy expenditure and gait speed in older adults with slow walking speeds can be reliably assessed during overground walking, providing an alternative to traditional treadmill assessments.

Aging, motor skill, and the energy cost of walking: implications for the prevention and treatment of mobility decline in older persons.

BACKGROUND: Age-associated neural changes profoundly affect the biomechanics and energetics of walking, increase energy cost, and require novel approaches to exercise that focus on motor learning theory. METHODS: We present a conceptual framework for motor skill in walking, its effect on the energy cost of walking, and the influence of the aging brain. RESULTS: Motor learning theory and practice can be incorporated into interventions to promote skilled, energy efficient walking in older people. CONCLUSIONS: An extensive literature on motor skill and motor learning, derived from neuroscience, sports medicine, and neurorehabilitation, can be applied to problems of walking in late life.

Interventions to Improve Walking in Older Adults.

Interventions to improve walking in older adults have historically been multifactorial (i.e. strengthening, endurance and flexibility programs) focusing on improving the underlying impairments. These impairment-based programs have resulted in only modest improvements in walking. In older adults, walking is slow, less stable, inefficient, and the timing and coordination of stepping with postures and phases of gait is poor. We argue the timing and coordination problems are evidence of the loss of motor skill in walking. Taking a lesson from the sports world and from neurorehabilitation, task-oriented motor learning exercise is an essential component of training to improve motor skill and may be a beneficial approach to improving walking in older adults. In this article we: 1) briefly review the current literature regarding impairment-based interventions for improving mobility, 2) discuss why the results have been only modest, and 3) suggest an alternative approach to intervention (i.e. task oriented motor learning).

What is the relation between fear of falling and physical activity in older adults?

OBJECTIVE: To describe the association between fear of falling (FOF) and total daily activity in older adults. DESIGN: Cross-sectional observational study. SETTING: Ambulatory clinical research training center. PARTICIPANTS: Community-dwelling older adults aged ≥64 years (N=78), who were independent in ambulation with or without an assistive device. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: FOF was defined by self-reported fear ratings using the Survey of Activities and Fear of Falling in the Elderly and self-reported fear status determined by response to the following question: Are you afraid of falling? Physical function was assessed using the Late Life Function and Disability Instrument. Physical activity was recorded using an accelerometer worn on the waist for 7 consecutive days, and mean daily counts of activity per minute were averaged over the 7-day period. RESULTS: Fear ratings were related to total daily activity (r=-.26, P=.02). The relation was not as strong as the relation of function and physical activity (r=.45, P<.001). When stratified by exercise status or functional status, fear was no longer related to total daily activity. Physical function explained 19% of the variance in physical activity, whereas the addition of fear status did not add to the explained variance in physical activity. CONCLUSIONS: FOF is related to total daily physical activity; however, FOF was not independently associated with physical activity when accounting for physical function. Some FOF may be reported as a limitation in function.

Walking smoothness is associated with self-reported function after accounting for gait speed.

BACKGROUND: Gait speed has shown to be an indicator of functional status in older adults; however, there may be aspects of physical function not represented by speed but by the quality of movement. The purpose of this study was to determine the relations between walking smoothness, an indicator of the quality of movement based on trunk accelerations, and physical function. METHODS: Thirty older adults (mean age, 77.7±5.1 years) participated. Usual gait speed was measured using an instrumented walkway. Walking smoothness was quantified by harmonic ratios derived from anteroposterior, vertical, and mediolateral trunk accelerations recorded during overground walking. Self-reported physical function was recorded using the function subscales of the Late-Life Function and Disability Instrument. RESULTS: Anteroposterior smoothness was positively associated with all function components of the Late-Life Function and Disability Instrument, whereas mediolateral smoothness exhibited negative associations. Adjusting for gait speed, anteroposterior smoothness remained associated with the overall and lower extremity function subscales, whereas mediolateral smoothness remained associated with only the advanced lower extremity subscale. CONCLUSION: These findings indicate that walking smoothness, particularly the smoothness of forward progression, represents aspects of the motor control of walking important for physical function not represented by gait speed alone.