RESUMEN
AIM: To identify the clinical features correlating with the presence and severity of scoliosis in girls with Rett syndrome (RTT). METHOD: Seventy-five girls with a clinical and genetically determined diagnosis of RTT participated in this cross-sectional study. Clinical scales administered included the Rett assessment rating scale, the modified Ashworth scale, the Rett syndrome motor evaluation scale, the PainAD, and the scale of evaluation of purposeful hand function. Multivariable analyses, such as ordinal logistic regression and ANCOVA, were used to assess the correlation between these scales and a clinical score of scoliosis. RESULTS: About 60% of patients had scoliosis, in general mild or moderate. The severity of scoliosis correlated with age and important neurological factors such as muscular hypertonus and hyperreflexia, standing, walking (level walking and on stairs), and postural transitions. No association was found with global disease severity, hand function, pain, or type of genetic mutation. INTERPRETATION: Scoliosis is a relevant problem in RTT. It should be carefully monitored along the life span, especially in conjunction with (loco-)motor impairment in these patients.
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Síndrome de Rett , Escoliosis , Femenino , Humanos , Síndrome de Rett/complicaciones , Síndrome de Rett/genética , Síndrome de Rett/diagnóstico , Escoliosis/genética , Escoliosis/complicaciones , Estudios Transversales , Índice de Severidad de la Enfermedad , Caminata , MutaciónRESUMEN
BACKGROUND: Quantitative assessments of activities of daily living (ADL) play an essential role in evaluating the impact of disease and interventions on people's quality of life. Motion capture systems traditionally used for quantitative assessments of postural transitions and movement associated with ADL are limited to the laboratory setting. Wearable accelerometers can remove these limitations and enable easier-to-use, longer-term, and remote functional evaluations. OBJECTIVE: To investigate the validity of a single tri-axial accelerometer mounted on the head for monitoring postural transition and the timed-up-and-go test. METHODS: Two accelerometers with a sampling frequency of 100 Hz were attached to twelve able-bodied study participants' sternum and right mastoid process. We developed algorithms for the functional calibration of accelerometers and the detection of the postural transitions by measuring the head inclination angle and variations of the gravitational components of the accelerometer readout. Participants performed a battery of ADL tests involving a wide variety of postural transitions. The head-mounted accelerometers results were compared with a sternum-mounted accelerometer and validated against a video motion capture system as a gold standard reference. RESULTS AND SIGNIFICANCE: The results indicate that, utilizing our proposed algorithm, a single tri-axial accelerometer mounted on the head can deliver high accuracy (>95 %), sensitivity (>90 %), and specificity (100 %) for detecting both postural transitions and walking events. Together with the small size and unobtrusive placement of the head-mounted accelerometer, these results demonstrate an attractive solution for the reliable assessment of ADLs and clinical evaluations based on functional tests such as the timed-up-and-go test.
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Actividades Cotidianas , Equilibrio Postural , Acelerometría , Algoritmos , Humanos , Calidad de Vida , Estudios de Tiempo y MovimientoRESUMEN
The frequency and quality of sit-to-stand and stand-to-sit postural transitions decrease with age and are highly relevant for fall risk assessment. Accurate classification and characterization of these transitions in daily life of older adults are therefore needed. In this study, we propose to use instrumented shoes for postural transition classification as well as transition duration estimation from insole force signals. In the first part, data were collected with 10 older adults and 10 young participants performing transitions in the laboratory while wearing the instrumented shoes, without arm assistance. A wavelet approach was used to transform the insole force data, and candidate events were selected for transition duration estimation. Transition durations were then validated against a model based on force plate reference. Vertical force estimation was also compared to force plate measurement. In the second part, postural transitions were classified in daily life using the instrumented shoes and validated against a highly accurate wearable system. Transition duration was estimated with an error ranging from 10 to 20% while the error for vertical force estimation was 7%. Postural transition classification was achieved with excellent sensitivity and precision exceeding 90%. In conclusion, the instrumented shoes are suitable for classifying and characterizing postural transitions in daily life conditions of healthy older adults. Graphical abstract "Experimental setup showing instrumented shoes, reference force plate, as well as IMUs used for postural transition classification and duration estimation comparison".
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Equilibrio Postural/fisiología , Zapatos , Adulto , Anciano , Fenómenos Biomecánicos , Femenino , Humanos , MasculinoRESUMEN
Despite its medical relevance, accurate recognition of sedentary (sitting and lying) and dynamic activities (e.g. standing and walking) remains challenging using a single wearable device. Currently, trunk-worn wearable systems can differentiate sitting from standing with moderate success, as activity classifiers often rely on inertial signals at the transition period (e.g. from sitting to standing) which contains limited information. Discriminating sitting from standing thus requires additional sources of information such as elevation change. The aim of this study is to demonstrate the suitability of barometric pressure, providing an absolute estimate of elevation, for evaluating sitting and standing periods during daily activities. Three sensors were evaluated in both calm laboratory conditions and a pilot study involving seven healthy subjects performing 322 sitting and standing transitions, both indoor and outdoor, in real-world conditions. The MS5611-BA01 barometric pressure sensor (Measurement Specialties, USA) demonstrated superior performance to counterparts. It discriminates actual sitting and standing transitions from stationary postures with 99.5% accuracy and is also capable to completely dissociate Sit-to-Stand from Stand-to-Sit transitions.
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Acelerometría/instrumentación , Presión Atmosférica , Monitoreo Ambulatorio/instrumentación , Movimiento/fisiología , Postura/fisiología , Actividades Cotidianas , Adulto , Ambiente , Femenino , Humanos , Masculino , Proyectos Piloto , Caminata/fisiologíaRESUMEN
INTRODUCTION: Falls in hospitals and residential care facilities commonly occur near the bed. The aim of this study was to investigate the accuracy of a continuously wearable, batteryless, low power and low cost monitoring device (Wearable Wireless Identification and Sensing Platform) with a single kinematic sensor capable of real-time monitoring to automatically detect bed entry and exit events. MATERIALS AND METHODS: Three dimensional acceleration readings and the strength of the transmitted signal from the WISP was interpreted to identify bed exit events and sensitivity, specificity and Receiving Operator Curves (ROC) were determined. RESULTS: The sensor located over sternum method performed best with sensitivity and specificity values of 92.8% and 97.5% respectively for detecting bed entry and values of 90.4% and 93.80% respectively for bed exit. On the other hand, the sensor-on-mattress algorithm achieved sensitivity and specificity values of 84.2% and 97.4% respectively for bed entry and 79% and 97.4% for bed exit detection. CONCLUSION: The WISP located over the sternum method is the preferred method to detect bed entry and exit. However, further work in frail older people is required to confirm the performance of this method.
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Aceleración , Accidentes por Caídas/prevención & control , Algoritmos , Equilibrio Postural/fisiología , Dispositivo de Identificación por Radiofrecuencia/economía , Anciano , Lechos , Costos y Análisis de Costo , Diseño de Equipo , Humanos , Curva ROCRESUMEN
The five-times-sit-to-stand test (FTSS) is an established assessment of lower limb strength, balance dysfunction and falls risk. Clinically, the time taken to complete the task is recorded with longer times indicating increased falls risk. Quantifying the movement using tri-axial accelerometers may provide a more objective and potentially more accurate falls risk estimate. 39 older adults, 19 with a history of falls, performed four repetitions of the FTSS in their homes. A tri-axial accelerometer was attached to the lateral thigh and used to identify each sit-stand-sit phase and sit-stand and stand-sit transitions. A second tri-axial accelerometer, attached to the sternum, captured torso acceleration. The mean and variation of the root-mean-squared amplitude, jerk and spectral edge frequency of the acceleration during each section of the assessment were examined. The test-retest reliability of each feature was examined using intra-class correlation analysis, ICC(2,k). A model was developed to classify participants according to falls status. Only features with ICC>0.7 were considered during feature selection. Sequential forward feature selection within leave-one-out cross-validation resulted in a model including four reliable accelerometer-derived features, providing 74.4% classification accuracy, 80.0% specificity and 68.7% sensitivity. An alternative model using FTSS time alone resulted in significantly reduced classification performance. Results suggest that the described methodology could provide a robust and accurate falls risk assessment.