Kurt Murer

Wearable systems for monitoring mobility-related activities in older people: a systematic review:

Objective: The use of wearable motion-sensing technology offers important advantages over conventional methods for obtaining measures of physical activity and/or physical functioning in aged individuals. This review aims to identify the actual state of applying wearable systems for monitoring mobility-related activity in older populations. In this review we focus on technologies and applications, research designs, feasibility and adherence aspects, and clinical relevance of wearable motion-sensing technology. Data sources: PubMed (MEDLINE since 1990), Ovid (BIOSIS, CINAHL), and Cochrane (Central) and reference lists of all relevant articles were searched. Review methods: Two authors independently reviewed randomized and non-randomized trials on people above 65 years systematically. Quality of selected articles was scored and study results were summarised and discussed. Results: Two hundred and twenty-seven abstracts were considered. After application of inclusion criteria and full text reading, 42 articles were taken into account in a full text review. Twenty of these papers evaluated walking with step counters, other papers used varying accelerometry approaches for obtaining overall activity measures (n = 16), or for monitoring changes in body postures and activity patterns (n = 17). Seven studies explicitly mentioned feasibility and/or adherence aspects. Eight studies presented outcome evaluations of interventions. Eight articles were representing descriptive research designs, three articles were using mixed descriptive and exploratory research designs, 23 articles used exploratory research-type designs, and eight articles used experimental research designs. Conclusion: Although feasible methods for monitoring human mobility are available, evidence-based clinical applications of these methods in older populations are in need of further development.

Reproducibility of an Isokinetic Strength-Testing Protocol of the Knee and Ankle in Older Adults

Background: Muscle power assessed by isokinetic dynamometers has the potential for playing an important role in investigating functional status in older subjects. Researchers and clinicians are interested in the reliability of isokinetic test protocols for the confidential assessment of status, as this affects the interpretation of the results of an intervention program. Objective: The current study investigated the inter- and intrarater reliability of an isokinetic strength-testing protocol of the knee and ankle preceded by a familiarization session. Methods: Twenty-four independently living elderly subjects (6 males, 18 females, mean age 71.2 ± 5.5 years) were assessed 3 times in two test sessions. The main outcomes were the intraclass correlation coefficient, standard error of measurements (SEM) and ratio of limits of agreement (RLOA) for isokinetic knee and ankle contractions, as measured with the Biodex System 3. Results: The intraclass correlation coefficients of the isokinetic variables varied from 0.81 to 0.99 representing ‘good’ to ‘very good’ reliability. Most SEM and RLOA indexes represented acceptable agreement which varied from 6 to 13 and 18 to 37%, respectively. Nonacceptable agreement was found for ankle plantar flexion with SEMs that varied from 14 to 17% and RLOAs from 39 to 48%. Conclusion: The results of this study demonstrate that the Biodex System 3 is a reliable device when used for elderly living independently. The ability of the device to determine a real change in isokinetic ankle and knee contractions is better on a group level than on an individual level. The Biodex System 3 can be employed with confidence in studies to determine the effect of exercise intervention programs on physical activity.

Cognitive and cognitive-motor interventions affecting physical functioning: A systematic review

BackgroundSeveral types of cognitive or combined cognitive-motor intervention types that might influence physical functions have been proposed in the past: training of dual-tasking abilities, and improving cognitive function through behavioral interventions or the use of computer games. The objective of this systematic review was to examine the literature regarding the use of cognitive and cognitive-motor interventions to improve physical functioning in older adults or people with neurological impairments that are similar to cognitive impairments seen in aging. The aim was to identify potentially promising methods that might be used in future intervention type studies for older adults.MethodsA systematic search was conducted for the Medline/Premedline, PsycINFO, CINAHL and EMBASE databases. The search was focused on older adults over the age of 65. To increase the number of articles for review, we also included those discussing adult patients with neurological impairments due to trauma, as these cognitive impairments are similar to those seen in the aging population. The search was restricted to English, German and French language literature without any limitation of publication date or restriction by study design. Cognitive or cognitive-motor interventions were defined as dual-tasking, virtual reality exercise, cognitive exercise, or a combination of these.Results28 articles met our inclusion criteria. Three articles used an isolated cognitive rehabilitation intervention, seven articles used a dual-task intervention and 19 applied a computerized intervention. There is evidence to suggest that cognitive or motor-cognitive methods positively affects physical functioning, such as postural control, walking abilities and general functions of the upper and lower extremities, respectively. The majority of the included studies resulted in improvements of the assessed functional outcome measures.ConclusionsThe current evidence on the effectiveness of cognitive or motor-cognitive interventions to improve physical functioning in older adults or people with neurological impairments is limited. The heterogeneity of the studies published so far does not allow defining the training methodology with the greatest effectiveness. This review nevertheless provides important foundational information in order to encourage further development of novel cognitive or cognitive-motor interventions, preferably with a randomized control design. Future research that aims to examine the relation between improvements in cognitive skills and the translation to better performance on selected physical tasks should explicitly take the relation between the cognitive and physical skills into account.

Concurrent validity of a trunk tri-axial accelerometer system for gait analysis in older adults

The aim of this study was (1) to determine the concurrent validity of a trunk tri-axial accelerometer system (DynaPort) with the GAITRite system for spatio-temporal gait parameters at preferred, slow and fast self-selected walking speed that were recorded for averaged and individual step data in an older adult population and (2) to compare the levels of agreement for averaged step data from different walking distances and individual step data. The levels of agreement between the two systems for averaged step data was excellent for walking speed, cadence, step duration and step length (intraclass correlation coefficients (ICCs) between 0.99 and 1.00, ratios limits of agreement (RLOA) between 0.7% and 3.3%), moderate for variability of step duration (ICCs between 0.88 and 0.98 and RLOAs between 19% and 34%) and low for variability of step length (ICCs between 0.24 and 0.33 and RLOAs between 73% and 87%). The levels of agreement for individual step duration and step length were moderate with ICCs between 0.81 and 0.89 and with RLOAs between 9% and 13%. Comparing RLOAs from averaged step data across the different walking distances and individual step data, the RLOAs decreased with increased number of steps. The results of this study demonstrate that the DynaPort system, which allows measurements in real life conditions, is a highly valid tool for assessment of spatio-temporal gait parameters for averaged step data across a walkway length of approximately 20m in independent living elderly. Gait variability measures and individual step data need to be viewed with caution because of the moderate to low levels of agreement between the two systems.

A cognitive-motor intervention using a dance video game to enhance foot placement accuracy and gait under dual task conditions in older adults: a randomized controlled trial

BackgroundComputer-based interventions have demonstrated consistent positive effects on various physical abilities in older adults. This study aims to compare two training groups that achieve similar amounts of strength and balance exercise where one group receives an intervention that includes additional dance video gaming. The aim is to investigate the different effects of the training programs on physical and psychological parameters in older adults.MethodsThirty-one participants (mean age ± SD: 86.2 ± 4.6 years), residents of two Swiss hostels for the aged, were randomly assigned to either the dance group (n = 15) or the control group (n = 16). The dance group absolved a twelve-week cognitive-motor exercise program twice weekly that comprised progressive strength and balance training supplemented with additional dance video gaming. The control group performed only the strength and balance exercises during this period. Outcome measures were foot placement accuracy, gait performance under single and dual task conditions, and falls efficacy.ResultsAfter the intervention between-group comparison revealed significant differences for gait velocity (U = 26, P = .041, r = .45) and for single support time (U = 24, P = .029, r = .48) during the fast walking dual task condition in favor of the dance group. No significant between-group differences were observed either in the foot placement accuracy test or in falls efficacy.ConclusionsThere was a significant interaction in favor of the dance video game group for improvements in step time. Significant improved fast walking performance under dual task conditions (velocity, double support time, step length) was observed for the dance video game group only. These findings suggest that in older adults a cognitive-motor intervention may result in more improved gait under dual task conditions in comparison to a traditional strength and balance exercise program.Trial registrationThis trial has been registered under ISRCTN05350123 (http://www.controlled-trials.com)

Reproducibility of spatio-temporal gait parameters under different conditions in older adults using a trunk tri-axial accelerometer system

The aim of this study was to determine intra- and interrater reliability of spatio-temporal gait parameters on different walking surfaces and under dual task conditions in an older adult population using a trunk tri-axial accelerometer (DynaPort((MiniMod)) system. Twenty-three independent living, older subjects (8 males, 15 females) aged 73.4+/-4.3 years walked three times at their preferred walking speed in two test sessions under four different conditions over 24 m (gymnasium floor versus soft foam rubber walkway, with both normal and dual task walking conditions). Inter- and intrarater reliability was assessed. Subsequently intraclass correlation coefficients (ICC), coefficients of variation (CV) and ratios limits of agreement (RLOA) were calculated. The reliability of walking speed, cadence, step duration and step length was excellent with high ICCs and small CVs and RLOAs. ICCs of gait variability ranged from 0.12 to 0.88. The corresponding CVs ranged from 12% to 34% and RLOAs from 35% to 93% and appeared relatively large. The results of this study demonstrate that walking speed, cadence, step duration and step length under more challenging conditions can be reliably measured in independent living older adults using the DynaPort(MiniMod) system. Gait variability measures need to be viewed with caution and further research in older populations is needed to determine the value of these parameters derived from this measurement system.

The effect of a cognitive-motor intervention on voluntary step execution under single and dual task conditions in older adults: a randomized controlled pilot study

Background This randomized controlled pilot study aimed to explore whether a cognitive-motor exercise program that combines traditional physical exercise with dance video gaming can improve the voluntary stepping responses of older adults under attention demanding dual task conditions. Methods Elderly subjects received twice weekly cognitive-motor exercise that included progressive strength and balance training supplemented by dance video gaming for 12 weeks (intervention group). The control group received no specific intervention. Voluntary step execution under single and dual task conditions was recorded at baseline and post intervention (Week 12). Results After intervention between-group comparison revealed significant differences for initiation time of forward steps under dual task conditions (U = 9, P = 0.034, r = 0.55) and backward steps under dual task conditions (U = 10, P = 0.045, r = 0.52) in favor of the intervention group, showing altered stepping levels in the intervention group compared to the control group. Conclusion A cognitive-motor intervention based on strength and balance exercises with additional dance video gaming is able to improve voluntary step execution under both single and dual task conditions in older adults.

Effect of additional functional exercises on balance in elderly people

Objective: To evaluate the additional effect of functional exercises on balance and lower extremity function among hostel-dwelling elderly people partaking in strength,training. Design: A randomized two-group parallel controlled trial. Setting: A senior resident’s hostel in Switzerland. Participants: Thirty-two individuals randomized to either strength or strength and functional exercise groups. Interventions: Both groups received machine-driven strength training for 45 min, twice weekly, for 12 weeks. The strength and functional exercises group received an additional 30 min of functional exercise training, once weekly. Main outcome measures: Tinetti test, balance tests and a physical performance test. Assessments were performed before and after the intervention. Results: Improvements for the balance test depended on the type of training (significant interaction effects [F(1,20)= 6.7; P = 0.018]). This test improved from 11.3 ∓ 11.7 to 17 ∓ 11.2 (P = 0.009) in the combined training group (n = 12) and remained from 7.3 ∓ 9.5 to 6.9 ∓ 9.2 unchanged (P = 0.821) in the strength training group (n = 13). A significant difference between groups following training was observed (P = 0.031). The Tinetti balance score and the chair stand test of the physical performance assessment improved from 14.3 ∓ 1.9 to 15.3 ∓ 1.1 (P = 0.026) and 1.8 ∓ 1.2 to 2.8 ∓ 1.1 (P = 0.012) respectively in the combined training group only. Conclusions: Our findings suggest that twice-weekly lower extremity strength training of 12 weeks’ duration in hostel-dwelling elderly people only improves task-specific balance performance and lower extremity physical function when additional functional exercises are added.

Quantification of everyday motor function in a geriatric population

This pilot study evaluated variability in physical activities and the correlations between walking, two types of postural transitions, and falls efficacy with an ambulatory activity monitor. An 11-subject convenience sample wore the monitor for 2 consecutive days; in addition, 7 subjects carried the monitor on 1 day of the following week. Demographic characteristics of the sample were age: mean +/- standard deviation [SD] = 87.8 +/- 2.5 yr, body mass index: mean +/- SD = 25.3 +/- 2.1 kg/m(2), and Mini-Mental State Examination score: mean +/- SD = 27.5 +/- 2.0. Analyzed movements were sit-to-stand (SiSt) and stand-to-sit postural transitions, dynamic activity (walking), and static behavior (sitting, standing, lying). Significant correlations were found for the SiSt transition duration (TD) between days (intraclass correlation coefficient = 0.78). No differences were found between the durations of sitting (p = 0.8), lying (p = 0.72), standing (p = 0.06), and walking (p = 0.6). These parameters showed highly variable correlation coefficients. A significant correlation was observed between falls efficacy and SiSt measures (r = 0.84, p < 0.01, df = 9). We reliably determined the SiSt TD after subjects wore the monitor for 1 day in the home environment. Poor correlations between 2 consecutive measurement days for dynamic and static activity underline the necessity of recording further days to assess physical activity levels in the geriatric population.

The effect of a foot gymnastic exercise programme on gait performance in older adults: A randomised controlled trial

Background. Aged-related loss of ankle dorsiflexion range of motion (ROM) and toe plantarflexor strength play an important role in gait performance. Further, conventional strength, balance and gait training can significantly improve the lower extremity muscle power and functional abilities of older individuals. It remains unclear, however, whether training effects can be enhanced by augmenting ankle ROM and toe plantarflexor strength complementary to training. Objective. This study investigated the effect of physical exercise combined with foot gymnastics on the gait performance in older adults. Methods. Fifty-six independent living, older adults aged 66–91 years were randomly assigned to either foot gymnastics group (FG; n = 28) or training group (TG; n = 28). Further, 14 subjects were integrated as a control group (CG; n = 14) (no exercise). The FG and TG completed the same training program consisting of aerobic exercises, progressive resistance strength training and stretching exercises twice per week for 12 weeks, whereas the FG performed additional foot gymnastic exercises at the end of the training session and a 10-min foot gymnastics home-program daily. Assessments included the Falls Efficacy Scale – International (FES-I), Expanded Timed Get-up-and-Go test (ETGUG), gait analysis and muscle power measurements of the knee and ankle joint at pre- and post-training. Results. No significant change in FES-I score occurred in either group. The FG showed a significant improvement of ankle ROM. There were significant time × group interactions in walking speed, step length, in several muscle power measurements and in ETGUG. The positive effects of gait parameters ranged between 1 and 11% and between 2 and 12%, of muscle power between 14 and 34% and 14 and 46% and of ETGUG were 10 and 8% for the FG and TG, respectively. The FG and TG did not differ significantly in their improvements. The CG showed a trend to deteriorations between 0 and −6% for gait parameters, between −4 and −14% for muscle power and 0% for ETGUG. Conclusions. The results of this study provide evidence of significant improvements in gait performance, muscle power and ETGUG after a conventional training program in independent living, older adults. However, there is no additional effect on physical performance after foot gymnastic exercises.