[Epidemiology and prevention of heat-related adverse health effects on elderly people]. / Epidemiologie und Prävention hitzebedingter Gesundheitsschäden älterer Menschen.

Heat waves increase the morbidity and mortality in Germany, particularly of older patients in need of care. Due to climate change the number of heat waves in Germany will increase threefold by the end of the century. In addition, the proportion of patients at risk will grow due to demographic change. Therefore, the Government and the Federal States have developed recommendations for heat action plans, in which the medical profession should also participate in the prevention of heat-related damage to health. Physicians and their team should first become acquainted with the topic. In addition, they should inform patients at risk and their relatives of the risks and preventive measures. In the summer a critical check of drugs is also needed because medications impair cooling mechanisms in heat waves, the pharmacokinetics can change and unwanted side effects of drugs occur more frequently. Lastly, due to their central position in the healthcare system, physicians should participate in the coordination of a good nursing care and intensification of social contacts during heat waves.

Model development to study strategies of younger and older adults getting up from the floor.

BACKGROUND: Long lies after a fall remain a public health challenge. Many successful fall prevention programmes have been developed but only few of them include recovery strategies after a fall. Once better understood, such movement strategies could be implemented into training interventions. AIMS: A model of motion sequences describing successful movement strategies for rising from the floor in different age groups was developed. Possible risk factors for poor rising performance such as flexibility and muscle power were evaluated. METHODS: Fourteen younger subjects between 20 and 50 years of age and 10 healthy older subjects (60+ years) were included. Movement strategies and key components of different rising sequences were determined from video analyses. The temporal parameters of transfers and number of components within the motion sequences were calculated. Possible explanatory variables for differences in rising performance were assessed (leg extension power, flexibility of the knee- and hip joints). RESULTS: Seven different components were identified for the lie-to-stand-walk transfer, labelled as lying, initiation, positioning, supporting, elevation, or stabilisation component followed by standing and/or walking. Median time to rise was significantly longer in older subjects (older 5.7s vs. younger 3.7s; p < 0.001), and leg extension power (left p = 0.002, right p = 0.013) and knee flexibility (left p = 0.019, right p = 0.025) were significantly lower. The number of components for rising was correlated with hip flexibility (r = 0.514) and maximal power (r = 0.582). The time to rise was correlated with minimal goniometric knee angle of the less flexible leg (r = 0.527) and maximal leg extension power (r = 0.725). CONCLUSIONS: A motion sequence model containing seven different components identified by individual key-frames could be established. Age-related differences in rising strategies and performance were identified.

Validity of linear encoder measurement of sit-to-stand performance power in older people.

OBJECTIVE: To investigate construct validity of linear encoder measurement of sit-to-stand performance power in older people by showing associations with relevant functional performance and physiological parameters. DESIGN: Cross-sectional study. SETTING: Movement laboratory of a geriatric rehabilitation clinic. PARTICIPANTS: Eighty-eight community-dwelling, cognitively unimpaired older women (mean age 78 years). MAIN OUTCOME MEASURES: Sit-to-stand performance power and leg power were assessed using a linear encoder and the Nottingham Power Rig, respectively. Gait speed was measured on an instrumented walkway. Maximum quadriceps and hand grip strength were assessed using dynamometers. Mid-thigh muscle cross-sectional area of both legs was measured using magnetic resonance imaging. RESULTS: Associations of sit-to-stand performance power with power assessed by the Nottingham Power Rig, maximum gait speed and muscle cross-sectional area were r=0.646, r=0.536 and r=0.514, respectively. A linear regression model explained 50% of the variance in sit-to-stand performance power including muscle cross-sectional area (p=0.001), maximum gait speed (p=0.002), and power assessed by the Nottingham Power Rig (p=0.006). CONCLUSIONS: Construct validity of linear encoder measurement of sit-to-stand power was shown at functional level and morphological level for older women. This measure could be used in routine clinical practice as well as in large-scale studies. CLINICAL TRIAL REGISTRATION NUMBER: DRKS00003622.

The association between the home environment and physical activity in community-dwelling older adults.

UNLABELLED: Physical activity (PA) decreases with increasing age despite the fact that PA exerts beneficial effects on many age-related diseases and conditions. Consequently, there is an interest in modifiable factors that may influence PA among older persons. The purpose of this study was to examine the association between PA and the home environment in well-functioning older community-dwelling persons. METHOD: This study used a person-environment (P-E) fit perspective to the home environment, operationalized by means of assessment of functional limitations in 81 community-dwelling persons (median age 79 years) as well as environmental barriers in their home environments and the nearby exterior surroundings. The interaction between functional limitations and environmental barriers generated a score expressing the magnitude of P-E fit problems in their home environment. PA was rated with a questionnaire covering household-related and recreational activities. RESULTS: We found a significant association between PA and the magnitude of P-E fit problems that explained 3.9 % of the variance of PA. The number of environmental barriers per se was not significantly associated with PA, while functional limitations explained 6.8 % of the variance of PA. CONCLUSION: In well-functioning older persons living in the community environmental aspects of housing demonstrated a weak association with PA.

Geriatric rehabilitation after hip fracture. Role of body-fixed sensor measurements of physical activity.

BACKGROUND: The demand for geriatric rehabilitation will drastically increase over the next years. It will be increasingly important to demonstrate the efficacy and effectiveness of geriatric rehabilitation. One component is the use of objective and valid assessment procedures. These should be understandable to patients, relevant for goal attainment, and able to document change. A number of currently used physical capacity measures have floor effects. The use of body-fixed sensor technology for monitoring physical activity is a possible supplement for the assessment during geriatric rehabilitation to overcome floor effects and directly monitor improvement of mobility as a component of geriatric rehabilitation in many patients. METHODS: The observational study with a pre-post design examined 65 consecutive geriatric hip fracture inpatients. Measurements were performed on admission and 2 weeks later. The capacity measures included gait speed, chair rise time, a balance test, 2-Minute-Walk test and the Timed-Up-and-Go test. Physical activity was measured over 9 h using body-fixed sensor technology and expressed as cumulated walking and walking plus standing (time on feet). RESULTS: Body-fixed sensors allowed direct measurement of physical activity in all patients available for testing. Cumulated walking and standing (time on feet) increased from a median 83.6 to 102.6 min. Cumulated walking increased from a median 7.0 to 16.3 min. The comparison with the physical capacity measures demonstrated a modest to fair correlation (rs = 0.455 and 0.653). This indicates that physical capacity measures are not the same construct as physical activity. CONCLUSION: Body-fixed sensor-based assessment of physical activity was feasible even in geriatric patients with severe mobility problems and decreased the number of patients with missing data both on admission and 2 weeks later. Body-fixed sensor data documented change in activity level.

Fall detection with body-worn sensors : a systematic review.

BACKGROUND AND AIMS: Falls among older people remain a major public health challenge. Body-worn sensors are needed to improve the understanding of the underlying mechanisms and kinematics of falls. The aim of this systematic review is to assemble, extract and critically discuss the information available in published studies, as well as the characteristics of these investigations (fall documentation and technical characteristics). METHODS: The searching of publically accessible electronic literature databases for articles on fall detection with body-worn sensors identified a collection of 96 records (33 journal articles, 60 conference proceedings and 3 project reports) published between 1998 and 2012. These publications were analysed by two independent expert reviewers. Information was extracted into a custom-built data form and processed using SPSS (SPSS Inc., Chicago, IL, USA). RESULTS: The main findings were the lack of agreement between the methodology and documentation protocols (study, fall reporting and technical characteristics) used in the studies, as well as a substantial lack of real-world fall recordings. A methodological pitfall identified in most articles was the lack of an established fall definition. The types of sensors and their technical specifications varied considerably between studies. CONCLUSION: Limited methodological agreement between sensor-based fall detection studies using body-worn sensors was identified. Published evidence-based support for commercially available fall detection devices is still lacking. A worldwide research group consensus is needed to address fundamental issues such as incident verification, the establishment of guidelines for fall reporting and the development of a common fall definition.

Automated approach for quantifying the repeated sit-to-stand using one body fixed sensor in young and older adults.

Much is known about the sit-to-stand (STS) and its biomechanics. Currently, however, there is little opportunity for instrumented quantification of the STS as part of screening or diagnosis in clinical practice. The objectives of the present study were to describe the feasibility of using an automated approach for quantifying the STS using one sensor location and to start testing the discriminative validity of this approach by comparing older and younger adults. 15 older subjects recruited from a residential care home and 16 young adults performed 5 repeated sit-to-stand and stand-to-sit movements. They were instrumented with a small and lightweight measurement system (DynaPort(®)) containing 1 triaxial seismic accelerometer and 3 uniaxial gyroscopes fixed in a belt around the waist. Durations of the (sub-)phases of the STS were analyzed and maximum angular velocities were determined. All successful STS cycles were automatically detected without any errors. The STS duration in the older adults was significantly longer and more variable in all phases (i.e., sit-to-stand, standing, stand-to-sit and sitting) compared to the young adults. Older adults also exhibited lower trunk flexion angular velocity. The results of this first fully automated analysis of instrumented repeated STS movements demonstrate that several STS parameters can be identified that provide a basis for a more precise, quantitative study of STS performance in clinical practice.

Assessment of adaptive walking performance.

Although mostly negative aspects are reported to be associated with gait variability, irregular walking is needed when walking performance has to be adapted to specific environmental conditions. The aim of this study was to evaluate the test-retest reliability and discriminative ability of a measure to assess adaptive walking performance and to identify parameters associated with test performance in young and elderly subjects. Eighteen older (mean age 78.1 years) and 19 young women (mean age 30.8 years) were instructed to walk as precisely as possible over a defined course targeting 26 arbitrarily positioned rectangle boxes fixed on an instrumented walk way with embedded pressure sensors. ICC(1,1) of 0.79 demonstrated sufficient reliability in the cohort of older women. Targeting was significantly worse (or deviation was larger) in older women than in young women (mean 3.20cm versus 2.27cm, p=0.005). Mean gait speed of the older women was higher during the test (0.50m/s versus 0.40m/s, p=0.020), but not during unconstrained walking (1.15m/s versus 1.50m/s, p<0.001). The deviation measure classified 78% of the subjects into correct age group (sensitivity 67%, specificity 90%, p=0.003). Adaptive walking performance was associated with parameters describing physical performance as well as with cognitive executive function. This study shows that this test of adaptive walking performance is a reliable measure of irregular walking with ability to discriminate between young and older subjects. Our results suggest that older persons might try to camouflage their lack of accuracy during adaptive walking by higher gait speed.

Validation of seat-off and seat-on in repeated sit-to-stand movements using a single-body-fixed sensor.

The identification of chair rise phases is a prerequisite for quantifying sit-to-stand movements. The aim of this study is to validate seat-off and seat-on detection using a single-body-fixed sensor against detection based on chair switches. A single sensor system with three accelerometers and three gyroscopes was fixed around the waist. Synchronized on-off switches were placed under the chair. Thirteen older adults were recruited from a residential care home and fifteen young adults were recruited among college students. Subjects were asked to complete two sets of five trials each. Six features of the trunk movement during seat-off and seat-on were calculated automatically, and a model was developed to predict the moment of seat-off and seat-on transitions. The predictions were validated with leave-one-out cross-validation. Feature extraction failed in two trials (0.7%). For the optimal combination of seat-off predictors, cross-validation yielded a mean error of 0 ms and a mean absolute error of 51 ms. For the best seat-on predictor, cross-validation yielded a mean error of -3 ms and a mean absolute error of 127 ms. The results of this study demonstrate that seat-off and seat-on in repeated sit-to-stand movements can be detected semi-automatically in young and older adults using a one-body-fixed sensor system with an accuracy of 51 and 127 ms, respectively. The use of the ambulatory instrumentation is feasible for non-technically trained personnel. This is an important step in the development of an automated method for the quantification of sit-to-stand movements in clinical practice.

Physical activity of moderately impaired elderly stroke patients during rehabilitation.

In older adults, physical activity (PA) is promoted for public health preventive effort. It is also a major target in the rehabilitation process. Existing assessment tools in the clinical routine do not include any aspects of PA or participation and are often prone to floor or ceiling effects. The aim of this study was to document the process of rehabilitation by activity monitoring without floor or ceiling effects. Ninety-two stroke patients of a geriatric rehabilitation unit (mean age 82 years, ±6.21 years, 61% women) were included in an observational study to assess physical capacity (balance, chair rise, gait speed) and PA at admission and two weeks thereafter. PA was measured through an ambulatory activity monitor based on accelerometers and gyroscopes and showed no floor or ceiling effects. Floor effects were however documented for measures of physical capacity (admission 5-11%; follow-up 2-9%) and ceiling effects were registered for the balance test (admission 17.4%; follow-up 22.8%). Improvements were documented for measures of physical capacity as well as for PA (all p < 0.001). We conclude that the assessment of PA by activity monitoring is a valuable measure to document objectively the process of rehabilitation without floor or ceiling effects.

Robotic-assisted rehabilitation of proximal humerus fractures in virtual environments: a pilot study.

BACKGROUND AND OBJECTIVE: With the growing incidence of upper arm fractures among older people, innovative treatment strategies will be needed in geriatric rehabilitation. A pilot study was designed to test the feasibility of robotic-assisted rehabilitation after proximal humeral fractures. PATIENTS AND METHODS: Within a sample of 8 older patients (79.5 ± 6.12 years), functional ability, quality and range of movement, self-rated impairment, quality of life, and user satisfaction were measured in an observational pre-/postdesign. During rehabilitation robotic-assisted training was applied. RESULTS: Training motivation and acceptance were high in this sample, showing improvements in functional ability (p = 0.03), quality of movement (p = 0.02), range of motion, self-evaluation (p = 0.01), and quality of life. CONCLUSION: This pilot study highlights the possible implementation of robotic-assisted rehabilitation after proximal humeral fractures in geriatric rehabilitation. The measurement and training protocol was suitable to document progress in rehabilitation.

[Recommendation of an assessment protocol to describe geriatric inpatient rehabilitation of lower limb mobility based on ICF: an interdisciplinary consensus process]. / Empfehlungen für die Durchführung des motorischen Assessments der unteren Extremität zur ICF-basierten Verlaufsbeurteilung der Mobilität in der stationären geriatrischen Rehabilitation: Bericht eines interdisziplinären Konsensusprozesses.

Because of the growing demand of geriatric rehabilitation, objective and clear indication decisions are needed with respect to limited financial resources. The aim of an interdisciplinary consensus group was to critically evaluate the most commonly used tests of functional performance of the lower limbs and to recommend useful tests to document progress of inpatient rehabilitation. Assessment of standing, walking, walking with a dual-task, sit-to-stand transfer, lying-to-sit-to-stand transfer, and stair climbing were recommended to document functional performance of the lower limbs and to describe rehabilitation targets. Future research is needed, because reasonably validated assessment tools do not exist for all of these domains. In addition to a standardized assessment of physical capacity, physical activity and participation with regard to the International Classification of Functioning, Disability, and Health (ICF) context have to be assessed. Body fixed sensors seem to be a promising assessment tool to objectively document progress in rehabilitation.

Development of the Lie-to-Sit-to-Stand-to-Walk Transfer (LSSWT) test for early mobilization in older patients in geriatric rehabilitation.

BACKGROUND: Early discharge from a rehabilitation center is only possible, if patients are able to do basic transfers independently (e.g., get up from bed and walk to the toilet). Against this background, the Lie-to-Sit-to-Stand-to-Walk Transfer (LSSWT) test was developed in order to quantify complex transfer abilities in older adults. This study was to evaluate the reliability and validity of this instrument. MATERIAL AND METHODS: A total of 24 older patients (80.25±8.10 years) of a geriatric rehabilitation unit performed the LSSWT test. Expert ratings were used to measure criterion validity. The Timed Up & Go test (TUG) was administered to assess construct validity. Furthermore, the time score of the LSSWT test was correlated with the Trunk Control Test (TCT), balance performance, the Chair Stand Test (CST) and gait speed. Intra- and interrater reliability were measured, conducting the LSSWT test on consecutive days. RESULTS: The coefficients of correlation between the LSSWT test and the expert ratings as well as the TUG test were r=-0.82 and r=0.83, respectively. Furthermore, the association with the TCT, balance, CST, and gait speed were r=-0.51, r=-0.45, r=0.47, and r=-0.72, respectively. The results of intrarater reliability and interrater reliability were ICC=0.96 and ICC=0.77, respectively. CONCLUSION: The study shows that the LSSWT test is a valid measure for quantifying difficulties in transfer abilities of patients during geriatric rehabilitation. The good correlation between LSSWT test and TUG test indicates good construct validity, but also that the LSSWT test provides additional information. Interrater reliability was moderate; therefore, the training of the supervisors should be re-evaluated. Further research is needed to establish cut-off values for discharge decision and to analyze the use of the LSSWT test in different subgroups.

Comparison of acceleration signals of simulated and real-world backward falls.

Most of the knowledge on falls of older persons has been obtained from oral reports that might be biased in many ways. Fall simulations are widely used to gain insight into circumstances of falls, but the results, at least concerning fall detection, are not convincing. Variation of acceleration and maximum jerk of 5 real-world backward falls of 4 older persons (mean age 68.8 years) were compared to the corresponding signals of simulated backward falls by 18 healthy students. Students were instructed to "fall to the back as if you were a frail old person" during experiment 1. In experiment 2, students were instructed not to fall, if possible, when released from a backward lean. Data acquisition was performed using a tri-axial acceleration sensor. In experiment 1, there was significantly more variation within the acceleration signals and maximum jerk was higher in the real-world falls, compared to the fall simulation. Conversely, all values of acceleration and jerk were higher for the fall simulations, compared to real-world falls in experiment 2. The present findings demonstrate differences between real-world falls and fall simulations. If fall simulations are used, their limitations should be noted and the protocol should be adapted to better match real-world falls.

Evaluation of an ergonomically modified bed to enhance mobilization in geriatric rehabilitation. A pilot study.

The number of older patients with decreased capacity to independently perform a sit-to-stand transfer will increase during the next decade. It was hypothesized that an ergonomically modified bed prototype would either allow patients to stand up from the prototype independently or with reduced impact on the lower extremities. Standing up from the prototype was examined by force plate measurements in 30 patients of a geriatric rehabilitation hospital (median age 83.5 years). Nine of the patients were not able to stand up from the bed without arm rests, but were able to stand up with the help of arm rests. In those 21 patients, able to stand up even without arm rests, the use of arm rests caused a lower maximum vertical ground reaction force (p=0.03). No differences in quality concerning using or not using the armrests were documented neither for the time to stand up nor for symmetry of ground reaction force. In summary, the study shows that an ergonomically modified bed adds increased independency during the sit-to-stand transfer in selected patients. The reduction of peak vertical ground reaction force by using arm rests could be beneficial for certain patient groups.

Improvement of balance after audio-biofeedback. A 6-week intervention study in patients with progressive supranuclear palsy.

Progressive supranuclear palsy (PSP) is a neurodegenerative disease with no sufficient treatment options to date. The most devastating symptom is the loss of balance with consecutive falls. Based on the observation that postural control improved in patients with vestibular dysfunction after audio-biofeedback training, we tested the effects of this training in PSP patients. Eight PSP patients were included into an uncontrolled 6-week intervention trial. The focus of the training was the improvement of posture and dynamic balance by using audio-biofeedback. The device was well accepted. No adverse events occurred. A significant improvement in the Berg Balance Scale was observed (T2 vs. T1, p=0.016), which remained significant at the 4-week follow-up (T3 vs. T1, p=0.008). Significant improvement of the Parkinson's disease questionnaire was demonstrated. No significant changes were found in the Timed Up-and-Go Test, the Five Chair Rise Test, and in specific clinical scales. To our knowledge, the present study is the first to demonstrate that audio-biofeedback training with PSP patients is associated with improvements of balance and psychosocial aspects.

Distance to achieve steady state walking speed in frail elderly persons.

This study aims to determine the length of the gait initiation phase before achieving steady state walking in frail older people. Based on body fixed sensors, habitual walking was analysed in 116 community-dwelling older persons (mean age 83.1 years, 84% women). The start of steady state walking was identified using an algorithm taking into account speeds from consecutive strides. On average, participants reached a walking speed of 0.66 m/s after an acceleration phase of 1.43 m (89% after 2.47 m). When spatio-temporal variables were calculated from 4, 6, 8, 10, or 20 consecutive stride cycles after achieving steady state, similar values were observed for mean gait speed and stride length. The variability of these factors differed depending on the number of gait cycles. Assessments of steady state gait in frail elderly people should therefore exclude the first 2.5m of walking. If gait variability is to be assessed, it is recommended that more than 20 stride cycles be used.

Effectiveness of physical training on motor performance and fall prevention in cognitively impaired older persons: a systematic review.

OBJECTIVE: To determine whether older cognitively impaired people benefit from physical training with regard to motor performance or fall risk reduction and to critically evaluate the methodologic approach in identified randomized controlled intervention trials. DESIGN: Published randomized controlled intervention trials from 1966 through 2004 were identified in PubMed, CINAHL, Gerolit, and the Cochrane Central Register of Controlled Trials according to predefined inclusion criteria and evaluated by two independent reviewers using a modified rating system for randomized controlled intervention trials developed by the Cochrane Library. RESULTS: There were 11 randomized controlled intervention trials that met the predefined inclusion criteria. There was a large heterogeneity regarding methodology, sample size, type of intervention, study outcomes, and analyses. We found conflicting evidence regarding the effect of physical training on motor performance and falls in older people with cognitive impairment. However, a considerable number of the studies had methodologic limitations, which hampered the evaluation of the effectiveness of training. CONCLUSIONS: The randomized controlled intervention trials showed only limited effectiveness of physical training in patients with cognitive impairment. More studies with adequate sample size, sensitive and validated measurements, and higher specificity for the types of intervention targeting subgroups of patients with different degrees of cognitive impairment are required to give evidence-based recommendations.

Gait analysis and WOMAC are complementary in assessing functional outcome in total hip replacement.

OBJECTIVE: To investigate the correlation between objective and subjective evaluation of patients with total hip replacement. DESIGN: Prospective preliminary trial comparing the Western Ontario and McMaster University questionnaire (WOMAC) and gait analysis preoperatively and three months postoperatively. SETTING: A German academic orthopaedic centre specializing in total hip replacement surgery. SUBJECTS: Seventeen patients (median age 70 years) with hip osteoarthritis. INTERVENTION: All patients had had a primary unilateral total hip replacement. MAIN MEASURES: WOMAC questionnaire to assess self-perceived health status and gait analysis to determine objective gait parameters. RESULTS: Performance of walking as well as subjective judgement of health status improved following surgery (gait speed P = 0.0222; stride length P = 0.038; stance phase ratio P = 0.0466; WOMAC P < 0.0001). However, the correlation between gait parameters and WOMAC was poor (r = -0.27 or less). Correlation between changes of walking parameters and WOMAC was bad to good (r = 0.01 to r = -0.72). CONCLUSION: The WOMAC questionnaire might not reflect walking performance. The addition of gait analysis is recommended to gain objective information about the quality of gait.

Evaluation of a fall detector based on accelerometers: a pilot study.

As falls and fall-related injuries remain a major challenge in the public health domain, reliable and immediate detection of falls is important so that adequate medical support can be delivered. Available home alarm systems are placed on the hip, but have several shortcomings. A fall detector based on accelerometers and placed at head level was developed, as well as an algorithm able to distinguish between activities of daily living and simulated falls. Accelerometers were integrated into a hearing-aid housing, which was fixed behind the ear. The sensitivity of the fall detection was assessed by investigation into the acceleration patterns of the head of a young volunteer during intentional falls. The specificity was assessed by investigation into activities of daily living of the same volunteer. In addition, a healthy elderly woman (83 years) wore the sensor during the day. Three trigger thresholds were identified so that a fall could be recognised: the sum-vector of acceleration in the xy-plane higher than 2 g; the sum-vector of velocity of all spatial components right before the impact higher than 0.7 m s(-1); and the sum-vector of acceleration of all spatial components higher than 6 g. The algorithm was able to discriminate activities of daily living from intentional falls. Thus high sensitivity and specificity of the algorithm could be demonstrated that was better than in other fall detectors worn at the hip or wrist at the same stage of development.