Gleichgewichtsfähigkeit als zentraler Aspekt funktioneller Mobilität: Entwicklung und Validierung eines zielgruppenspezifischen, alltagsbezogenen Assessmentparadigmas für junge Senioren

Mobilität ist eine wichtige Voraussetzung für Gesundheit, Wohlbefinden und Unabhängigkeit. Um diese möglichst lange beizubehalten und ein gesundes, selbstständiges Leben zu ermöglichen, wird in den letzten Jahren zunehmend gefordert, mit der Erkennung und Behandlung von Mobilitäts- und Gleichgewichtseinschränkungen frühzeitig vor dem Auftreten von deutlichen Einschränkungen oder gar Stürzen zu beginnen. Deshalb sind Assessments nötig, über die beginnende subtile Mobilitäts- und Gleichgewichtseinschränkungen bereits in der speziellen Zielgruppe der noch fitten jungen Senioren zwischen 60 und 70 Jahren erfasst werden können. Bisherige Übersichtsarbeiten zeigten allerdings, dass ein Großteil der bisher verwendeten Assessments für diese Zielgruppe keine Herausforderung darstellt. Aus diesem Grund sind die Entwicklung und Validierung von anspruchsvollen Assessments notwendig, wodurch die Personen an die Grenzen ihrer motorischen Leistungsfähigkeit gebracht werden. In vorangegangenen Studien zeigte sich die Community Balance & Mobility Scale (CBM)bereits als ein vielversprechendes, anspruchsvolles Instrument zur Erfassung der Gleichgewichtsfähigkeit und funktionellen Mobilität bei jüngeren Senioren. Bisher war aber keine deutschsprachige Version dieser Skala verfügbar. Deshalb wurde in Manuskript I die CBM nach den internationalen ‚Recommendations for the Cross-Cultural Adaptation of Health Status Measures‘ aus dem Englischen ins Deutsche (G-CBM) übersetzt und anschließend validiert. Es zeigte sich eine sehr gute Intra- (ICC3,k = 0,998; p < 0,001) und Intertester-Reliabilität (ICC2,k = 0,996; p < 0,001) sowie eine moderate bis hohe Konstruktvalidität (ρ = 0,32-0,85; p < 0,001). Im Vergleich zu anderen Instrumenten traten keine Deckeneffekte auf, was auf die spezielle Eignung der G-CBM bei jungen Senioren hinweist. Insgesamt zeigte sich die G-CBM als reliables und valides Instrument zur Messung beginnender Gleichgewichtseinschränkungen bei jungen Senioren, das nun für den Einsatz im deutschsprachigen Raum verfügbar ist. Ein weiteres entscheidendes Kriterium für den Einsatz eines Assessments ist dessen Durchführbarkeit im Hinblick auf die benötigte Zeit und das zur Verfügung stehende Material. Für die Durchführung der CBM werden zwischen 20 und 30 Minuten benötigt. Dies ist für ihren Einsatz in der täglichen Praxis zu lang. Zudem wurden sowohl bei der Validierung der G-CBM als auch in anderen vorangegangenen Studien mögliche Redundanzen innerhalb der CBM identifiziert, was sich durch eine sehr hohe interne Konsistenz (α > 0,90) zeigte. Um die benötigte Zeit und die Redundanzen zu minimieren, wurde in Manuskript II eine verkürzte Version der CBM, die sog. s-CBM, entwickelt und anhand anderer etablierter Erhebungsinstrumente der Mobilität und Gleichgewichtsfähigkeit validiert. Über eine explorative Faktorenanalyse wurde eine um mehr als 60 % reduzierte Version entwickelt, die anstelle von 13 Aufgaben nur noch vier Aufgaben umfasst und in etwa 10 Minuten durchzuführen ist. Im Hinblick auf die Gütekriterien Konstruktvalidität, diskriminative Validität und das Auftreten von Deckeneffekten zeigten sich keine nennenswerten Unterschiede zu jenen der CBM. Dadurch kann die s-CBM als valides und praktikables Instrument zur Erfassung beginnender Mobilitäts- und Gleichgewichtseinschränkungen bei jungen Senioren empfohlen werden, das auch für den täglichen Einsatz in der Praxis geeignet ist. Zusätzlich zum Vorhandensein adäquater Assessments unter Laborbedingungen ist es wichtig, den Zusammenhang dieser Assessments und der täglich durchgeführten Aktivität junger Senioren zu kennen, um sowohl alltagsrelevante Erhebungsinstrumente als auch Interventionen entwickeln zu können. Deshalb widmet sich Manuskript III der Untersuchung des Zusammenhangs zwischen der unter Laborbedingungen erfassten Mobilität und Gleichgewichtsfähigkeit (Kapazität), der im alltäglichen Leben durchgeführten körperlichen Aktivität (Performanz) und den vorangegangenen Stürzen junger Senioren. Als Hypothese wurde angenommen, dass in der speziellen Zielgruppe der jungen Senioren die alltägliche Performanz und Stürze von anspruchsvollen Kapazitätsassessments besser abgebildet werden als von weniger anspruchsvollen. Im Labor wurden dafür sowohl weniger anspruchsvolle Assessments wie die Erfassung der habituellen Ganggeschwindigkeit und der Timed Up-and-Go Test als auch anspruchsvolle Kapazitätsassessments wie die Erfassung der schnellen Ganggeschwindigkeit oder die Community Balance & Mobility Scale eingesetzt. Die Durchführung der anspruchsvollen Assessments erfolgte unter Zeit- und/oder Präzisionsdruck. Die Performanz wurde über sieben Tage hinweg mithilfe am Körper getragener Sensoren erfasst. Über validierte Algorithmen wurde der prozentuale Anteil der Sitzzeit, der leicht aktiven Zeit und der moderat-anstrengend aktiven Zeit extrahiert. Der Zusammenhang zwischen Kapazität, Performanz und den vorangegangenen Stürzen wurde mittels Korrelations-, Regressions- und Receiver Operating Characteristics-Analysen untersucht. Die Kapazitätsassessments zeigten schwache bis moderate Zusammenhänge mit der Performanz und Stürzen, die anspruchsvollen jedoch stärkere (r = 0,10-0,31; p < 0,001-0,461) als die weniger anspruchsvollen (r = 0,06-0,22; p = 0,012-0,181). Die anspruchsvollen Kapazitätsassessments erklärten in drei von vier Regressionsmodellen einen signifikanten Anteil der Varianz der Performanz und Stürze (2,5-8,6 %) und unterschieden am besten zwischen hoher/geringer Performanz und Stürzern/Nicht-Stürzern (AUC = 0,59-0,70). Diese Ergebnisse bestätigen die Hypothese, dass die anspruchsvollen Erhebungsinstrumente die Performanz und Stürze junger Senioren besser widerspiegeln als einfache und bestätigen die Wichtigkeit des Einsatzes dieser Erhebungsinstrumente in dieser Zielgruppe. Nach dem Kenntnisstand der Autorin wurde in dieser Arbeit erstmalig ein zielgruppenspezifisches, alltagsbezogenes Assessmentparadigma für die Gleichgewichtsfähigkeit und funktionelle Mobilität entwickelt, das einen Beitrag dazu leistet, beginnende Mobilitäts- und Gleichgewichtseinschränkungen in der speziellen Zielgruppe der jungen Senioren zu erfassen und deren Zusammenhang mit Performanz und Stürzen widerzuspiegeln. Die Arbeit bildet damit die Grundlage für die Entwicklung von präventiven Interventionen zum Erhalt der Kapazität und Performanz von jungen Senioren

In vivo load measurements with instrumented implants

Aquatic exercises are widely used for rehabilitation or preventive therapies in order to enable mobilization and muscle strengthening while minimizing joint loading of the lower limb. The load reducing effect of water due to buoyancy is a main advantage compared to exercises on land. However, also drag forces have to be considered that act opposite to the relative motion of the body segments and require higher muscle activity. Due to these opposing effects on joint loading, the load-reducing effect during aquatic exercises remains unknown. The aim of this study was to quantify the joint loads during various aquatic exercises and to determine the load reducing effect of water. Instrumented knee and hip implants with telemetric data transfer were used to measure the resultant joint contact forces in 12 elderly subjects (6x hip, 6x knee) in vivo. Different dynamic, weight-bearing and non-weight-bearing activities were performed by the subjects on land and in chest-high water. Non-weight-bearing hip and knee flexion/extension was performed at different velocities and with additional Aquafins. Joint forces during aquatic exercises ranged between 32 and 396% body weight (BW). Highest forces occurred during dynamic activities, followed by weight-bearing and slow non-weight-bearing activities. Compared to the same activities on land, joint forces were reduced by 36–55% in water with absolute reductions being greater than 100%BW during weight-bearing and dynamic activities. During non-weight-bearing activities, high movement velocities and additional Aquafins increased the joint forces by up to 59% and resulted in joint forces of up to 301%BW. This study confirms the load reducing effect of water during weight-bearing and dynamic exercises. Nevertheless, high drag forces result in increased joint contact forces and indicate greater muscle activity. By the choice of activity, movement velocity and additional resistive devices joint forces can be modulated individually in the course of rehabilitation or preventive therapies

Inter-rater reliability, sensitivity to change and responsiveness of the orthopaedic Wolf-Motor-Function-Test as functional capacity measure before and after rehabilitation in patients with proximal humeral fractures

Background: The incidence of proximal humeral fractures (PHF) increased by more than 30% over the last decade, which is accompanied by an increased number of operations. However, the evidence on operative vs. non-operative treatment and post-operative treatments is limited and mostly based on expert opinion. It is mandatory to objectively assess functional capacity to compare different treatments. Clinical tools should be valid, reliable and sensitive to change assessing functional capacity after PHFs. This study aimed to analyse inter-rater reliability of the videotaped Wolf-Motor-Function-Test-Orthopaedic (WMFT-O) and the association between the clinical WMFT-O and the Disability of the Arm, Shoulder and Hand (DASH) and to determine the sensitivity to change of the WMFT-O and the DASH to measure functional capacity before and after rehabilitation in PHF patients. Methods: Fifty-six patients (61.7 ± 14.7 years) after surgical treatment of PHF were assessed using the WMFT-O at two different time points. To determine inter-rater reliability, the videotaped WMFT-O was evaluated through three blinded raters. Inter-rater agreement was determined by Fleiss’ Kappa statistics. Pearson correlation coefficients were calculated to assess the association between the clinical WMFT-O and the video rating as well as the DASH. Sensitivity to change and responsiveness were analysed for the WMFT-O and the DASH in a subsample of forty patients (53.8 ± 1.4 years) who were assessed before and after a three week robotic-assisted training intervention. Results: Inter-rater agreement was indicated by Fleiss’ Kappa values ranging from 0.33–0.66 for functional capacity and from 0.27–0.54 for quality of movement. The correlation between the clinical WMFT-O and the video rating was higher than 0.77. The correlation between the clinical WMFT-O and the DASH was weak. Sensitivity to change was high for the WMFT-O and the DASH and responsiveness was given. In comparison to the DASH, the sensitivity to change of the WMFT-O was higher. Conclusion: The overall results indicate that the WMFT-O is a reliable, sensitive and responsive instrument to measure more objectively functional change over time in rehabilitation after PHF. Furthermore, it has been shown that video assessment is eligible for studies to ensure a full blinding of raters. Trial registration: Clinicaltrials.gov, NCT03100201. Registered on 28 March 2017. The trial was retrospectively registered

Concurrent validity and reliability of the Community Balance and Mobility scale in young-older adults

Background: With the growing number of young-older adults (baby-boomers), there is an increasing demand for assessment tools specific for this population, which are able to detect subtle balance and mobility deficits. Various balance and mobility tests already exist, but suffer from ceiling effects in higher functioning older adults. A reliable and valid challenging balance and mobility test is critical to determine a young-older adult’s balance and mobility performance and to timely initiate preventive interventions. The aim was to evaluate the concurrent validity, inter- and intrarater reliability, internal consistency, and ceiling effects of a challenging balance and mobility scale, the Community Balance and Mobility Scale (CBM), in young-older adults aged 60 to 70 years. Methods: Fifty-one participants aged 66.4 ± 2.7 years (range, 60–70 years) were assessed with the CBM. The Fullerton Advanced Balance scale (FAB), 3-Meter Tandem Walk (3MTW), 8-level balance scale, Timed-Up-and-Go (TUG), and 7-m habitual gait speed were used to estimate concurrent validity, examined by Spearman correlation coefficient (ρ). Inter- and intrarater reliability were calculated as Intra-class-correlations (ICC), and internal consistency by Cronbach alpha and item-total correlations (ρ). Ceiling effects were determined by obtaining the percentage of participants reaching the highest possible score. Results: The CBM significantly correlated with the FAB (ρ = 0.75; p &lt; .001), 3MTW errors (ρ = − 0.61; p &lt; .001), 3MTW time (ρ = − 0.35; p = .05), the 8-level balance scale (ρ = 0.35; p &lt; .05), the TUG (ρ = − 0.42; p &lt; .01), and 7-m habitual gait speed (ρ = 0.46, p &lt; .001). Inter- (ICC2,k = 0.97), intrarater reliability (ICC3,k = 1.00) were excellent, and internal consistency (α = 0.88; ρ = 0.28–0.81) was good to satisfactory. The CBM did not show ceiling effects in contrast to other scales. Conclusions: Concurrent validity of the CBM was good when compared to the FAB and moderate to good when compared to other measures of balance and mobility. Based on this study, the CBM can be recommended to measure balance and mobility performance in the specific population of young-older adults. Trial registration Trial number: ISRCTN37750605 . (Registered on 21/04/2016)

Specific Motor and Cognitive Performances Predict Falls during Ward-Based Geriatric Rehabilitation in Patients with Dementia

The aim of this study was to identify in-hospital fall risk factors specific for multimorbid hospitalized geriatric patients with dementia (PwD) during hospitalization. Geriatric inpatients during ward-based rehabilitation (n = 102; 79.4% females; 82.82 (6.19) years of age; 20.26 (5.53) days of stay) were included in a comprehensive fall risk assessment combining established clinical measures, comprehensive cognitive testing including detailed cognitive sub-performances, and various instrumented motor capacity measures as well as prospective fall registration. A combination of unpaired t-tests, Mann-Whitney-U tests, and Chi-square tests between patients with ("in-hospital fallers") and without an in-hospital fall ("in-hospital non-fallers"), univariate and multivariate regression analysis were used to explore the best set of independent correlates and to evaluate their predictive power. In-hospital fallers (n = 19; 18.63%) showed significantly lower verbal fluency and higher postural sway (p < 0.01 to 0.05). While established clinical measures failed in discriminative as well as predictive validity, specific cognitive sub-performances (verbal fluency, constructional praxis, p = 0.01 to 0.05) as well as specific instrumented balance parameters (sway area, sway path, and medio-lateral displacement, p < 0.01 to 0.03) significantly discriminated between fallers and non-fallers. Medio-lateral displacement and visuospatial ability were identified in multivariate regression as predictors of in-hospital falls and an index combining both variables yielded an accuracy of 85.1% for fall prediction. Results suggest that specific cognitive sub-performances and instrumented balance parameters show good discriminative validity and were specifically sensitive to predict falls during hospitalization in a multimorbid patient group with dementia and an overall high risk of falling. A sensitive clinical fall risk assessment strategy developed for this specific target group should include an index of selected balance parameters and specific variables of cognitive sub-performances.publishe

Wearable Motion Sensors in Older Adults : On the Cutting Edge of Health and Mobility Research

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Towards Using the Instrumented Timed Up-and-Go Test for Screening of Sensory System Performance for Balance Control in Older Adults

Background: Decreasing performance of the sensory systems&#8217; for balance control, including the visual, somatosensory and vestibular system, is associated with increased fall risk in older adults. A smartphone-based version of the Timed Up-and-Go (mTUG) may allow screening sensory balance impairments through mTUG subphases. The association between mTUG subphases and sensory system performance is examined. Methods: Functional mobility of forty-one community-dwelling older adults (&gt;55 years) was measured using a validated mTUG. Duration of mTUG and its subphases &#8216;sit-to-walk&#8217;, &#8216;walking&#8217;, &#8216;turning&#8217;, &#8216;turn-to-sit&#8217; and &#8216;sit-down&#8217; were extracted. Sensory systems&#8217; performance was quantified by validated posturography during standing (30 s) under different conditions. Visual, somatosensory and vestibular control ratios (CR) were calculated from posturography and correlated with mTUG subphases. Results: Vestibular CR correlated with mTUG total time (r = 0.54; p &lt; 0.01), subphases &#8216;walking&#8217; (r = 0.56; p &lt; 0.01), and &#8216;turning&#8217; (r = 0.43; p = 0.01). Somatosensory CR correlated with mTUG total time (r = 0.52; p = 0.01), subphases &#8216;walking&#8217; (r = 0.52; p &lt; 0.01) and &#8216;turning&#8217; (r = 0.44; p &lt; 0.01). Conclusions: Supporting the proposed approach, results indicate an association between specific mTUG subphases and sensory system performance. mTUG subphases &#8216;walking&#8217; and &#8216;turning&#8217; may allow screening for sensory system deterioration. This is a first step towards an objective, detailed and expeditious balance control assessment, however needing validation in a larger study

The effects of unexpected mechanical perturbations during treadmill walking on spatiotemporal gait parameters, and the dynamic stability measures by which to quantify postural response - Fig 1

<p>(A) A schematic drawing of the experimental setup. Forward and backward perturbations were induced by acceleration and deceleration of the treadmill’s belt. Left and right perturbations were induced by moving the treadmill surface in the ML-direction. Reflective markers were placed at specific anatomical locations in accordance with the plug-in-gait marker set. (B) MoS-AP was defined as the AP distance between the XCoM-AP and the anterior boundary of the BoS, defined by the leading toe marker (either RTOE or LTOE for the right and the left foot, respectively). MoS-ML was defined as the ML distance between the XCoM-ML and the lateral boundary of the BoS, defined by the ankle marker (RANKL and LANKL for the right and the left foot, respectively).</p

The effects of unexpected mechanical perturbations during treadmill walking on spatiotemporal gait parameters, and the dynamic stability measures by which to quantify postural response

<div><p>Most falls occur after a loss of balance following an unexpected perturbation such as a slip or a trip. Greater understanding of how humans control and maintain stability during perturbed walking may help to develop appropriate fall prevention programs. The aim of this study was to examine changes in spatiotemporal gait and stability parameters in response to sudden mechanical perturbations in medio-lateral (ML) and anterior-posterior (AP) direction during treadmill walking. Moreover, we aimed to evaluate which parameters are most representative to quantify postural recovery responses. Ten healthy adults (mean = 26.4, SD = 4.1 years) walked on a treadmill that provided unexpected discrete ML and AP surface horizontal perturbations. Participants walked under no perturbation (normal walking), and under left, right, forward, and backward sudden mechanical perturbation conditions. Gait parameters were computed including stride length (SL), step width (SW), and cadence, as well as dynamic stability in AP- (MoS-AP) and ML- (MoS-ML) directions. Gait and stability parameters were quantified by means, variability, and extreme values. Overall, participants walked with a shorter stride length, a wider step width, and a higher cadence during perturbed walking, but despite this, the effect of perturbations on means of SW and MoS-ML was not statistically significant. These effects were found to be significantly greater when the perturbations were applied toward the ML-direction. Variabilities, as well as extremes of gait-related parameters, showed strong responses to the perturbations. The higher variability as a response to perturbations might be an indicator of instability and fall risk, on the same note, an adaptation strategy and beneficial to recover balance. Parameters identified in this study may represent useful indicators of locomotor adaptation to successfully compensate sudden mechanical perturbation during walking. The potential association of the extracted parameters with fall risk needs to be determined in fall-prone populations.</p></div

Difference of means, variability, and extremes of spatiotemporal gait parameters during perturbed walking conditions relative to normal walking.

<p>Difference of means of (A) stride length, (B) step width, and (C) cadence. Difference of variability of (D) stride length, (E) step width, and (F) cadence. Difference of 10th percentile of (G) stride length, (H) step width, and (I) cadence. Difference of 90th percentile of (J) stride length, (K) step width, and (L) cadence. <i>d</i> indicates Cohen’s <i>d</i> statistic effect size. Error bars indicate confidence intervals. (*) indicates statistically significant differences from Normal walking.</p