Clinimetric evaluation of inertial motion sensors of the cervical spine in patients with pediatric neurological motor disorders: validity, reliability and behavior patterns

Para los profesionales sanitarios es de gran importancia la obtención de datos clínicos válidos y fiables, para establecer unos objetivos de tratamiento adecuados a las necesidades específicas de cada paciente y para poder valorar su efectividad. Los sensores inerciales de movimiento (IMU) representan un gran avance para medir la cinemática de los segmentos corporales, aplicable al ámbito sanitario, y muestran una buena fiabilidad en la medición del Rango de movimiento articular (ROM) en humanos y la columna cervical en adultos. Por otro lado, un problema común en la Parálisis Cerebral (PC) es la demora o déficit en el Control Cefálico (CC), considerado un hito motor básico, que condiciona el desarrollo y adquisición progresiva de los niveles motrices. Además, el CC se encarga de garantizar una adecuada y segura alimentación, así como, permitir desarrollar adaptaciones posturales para relacionarse, adaptarse al entorno y sus exigencias. Así, esta tesis doctoral se propone como un estudio de las propiedades métricas, en términos de validez y fiabilidad, de los IMU, como herramienta de medida del ROM y el CC en sujetos con PC. Para ello, se analiza la movilidad cervical determinada sincrónicamente con el instrumento Cervical Range of Motion (CROM) y con IMU, así como se describe el diseño y desarrollo de una nueva prueba para la evaluación del ROM y el CC cervical en la población infantil con PC. En ambos casos, además del análisis de un grupo de sujetos con PC, se ha estudiado una muestra de sujetos control. Frente a este contexto, en la primera publicación, se abordó como objetivo principal determinar las propiedades clinimétricas en términos de validez y fiabilidad de los IMU en la medición del ROM cervical en niños con PC. Para ello se diseñó un protocolo de evaluación, una hoja informativa junto con un consentimiento informado y un documento para el registro de los datos. Se emplearon un IMU y un dispositivo CROM de forma simultánea. El ROM cervical se midió mediante la realización de 3 repeticiones de cada movimiento cervical, que se reprodujeron pasados 5 minutos para valorar la fiabilidad intradía. De igual forma, la medición se repitió a los 3-5 días para la estimación de la fiabilidad interdías. Los datos se anotaron en la hoja de registro, se tomaron los valores máximos y se procedió a su análisis estadístico e interpretación. Con objeto de evaluar la validez concurrente se aplicó el coeficiente de correlación de Pearson, la prueba t pareada y se construyeron gráficos de Bland-Altman para cada ROM. Asimismo, para analizar la fiabilidad relativa se determinó calculando el Coeficiente de Correlación Intraclase (CCI) para la fiabilidad intra e interdía. Y, por último, para la fiabilidad absoluta se calculó el error estándar de medida (SEM) y el cambio mínimo detectable (MDC). Por otra parte, herramientas como las escalas y pruebas que habitualmente se utilizan para la valoración funcional de los sujetos con PC, suelen ser subjetivas y en ocasiones difíciles de aplicar en población infantil. Su desarrollo en la práctica asistencial también depende de la destreza y experiencia de cada examinador. Para tratar de ofrecer una herramienta, que potencialmente presente datos de calidad más objetivos, en un segundo artículo, se diseña una nueva prueba para determinar la postura cervical y su control motor en la población infantil con PC, basada en la tecnología inercial, con un enfoque de suficiente validez y fiabilidad para analizar el movimiento humano, con bajo coste económico, gran versatilidad, portabilidad y capacidad para adaptarse a la morfología corporal. Primero se realizó una revisión de la literatura y dos pruebas de concepto, hasta lograr la versión final de la prueba. Posteriormente, se llevó a cabo un estudio de medición clínica que evaluó su validez de constructo y de contenido, así como la fiabilidad interdías. Durante el protocolo, se empleó una silla estable que se adaptó a las características antropométricas de cada individuo, una mesa y un ordenador. Fue utilizado un IMU colocado en la frente con una cinta flexible y ajustable. El sensor capturó los movimientos en los tres planos, mientras el sujeto observaba un vídeo durante 2 minutos. Para el registro y procesamiento de los datos brutos, se conectó vía bluetooth el sensor con la aplicación móvil iUCOTRACK ©. Se repitió la prueba a los 3-5 días, siguiendo el mismo protocolo, con objetivo de estudio de la fiabilidad. Para obtener un mejor feed-back de los datos obtenidos, además de las características del movimiento, en términos de longitud del desplazamiento, velocidad y aceleración, se diseñó una elipse con los movimientos cefálicos en los planos sagital y transversal, evaluando su área y sus dimensiones anteroposterior y lateral, como variables principales. Para evaluar el estado funcional de los niños con PC, se aplicó la GMFM-88 y la PEDI. La validez de constructo se estimó determinando la capacidad discriminante del nuevo test e identificando asociaciones entre las medidas funcionales y los resultados de la nueva prueba. Para ello, se aplicaron la prueba t de Student no pareada, una curva de características operativas del receptor (ROC, en sus siglas en inglés) y el test U de Mann- Whitney para comparar subgrupos de sujetos con PC. Para la validez concurrente en el grupo PC, se calculó el coeficiente de correlación de Pearson entre los datos sociodemográficos y los resultados obtenidos el primer día, y los dominios y puntuaciones totales de las escalas GMFM- 88 y PEDI. Para la obtención de la fiabilidad relativa se determinó el CCI en el test-retest en ambos grupos. Y, por último, se evaluó la fiabilidad absoluta con el cálculo del SEM y el MDC. Los resultados obtenidos en la primera publicación mostraron altas correlaciones entre el CROM y el IMU y en ambos grupos (PC y controles), salvo en el plano trasversal. Por otra parte, los gráficos de Bland-Altman indicaron un sesgo por debajo de 5° entre ambos sistemas de medición, menos en la rotación en el grupo PC que fue de 8,2°. Los CCI fueron superiores a 0,8 entre métodos y grupos. En la fiabilidad absoluta, el SEM obtuvo valores inferiores a 8,5° y el MDC valores superiores a 20° en el movimiento rotacional en la medición entredías. En la segunda publicación, la nueva prueba para determinar la postura cervical y su control motor en niños con PC mostró una alta capacidad discriminante en el área de la elipse (Área Bajo la Curva = 0.8) y en ambas dimensiones. Las variables de la nueva prueba se asociaron de moderada a fuerte con las medidas funcionales. Los CCI fueron superiores a 0,8 para los individuos del grupo PC. El SEM para ambos grupos fue aceptablemente bajo, en los movimientos angulares por debajo de 4° para ambos grupos, y en las variables de la elipse fue mayor en el grupo PC. La gran variabilidad entre individuos reveló un MDC alto, principalmente en el grupo con PC. Concluimos que los resultados obtenidos en ambas publicaciones sugieren que los IMU son válidos y fiables para medir el ROM, así como para evaluar la postura y el control motor de la columna cervical en los niños con PC. Si bien la aplicabilidad de los hallazgos, del protocolo y de la nueva prueba se limita a muestras y procedimientos similares. Por consiguiente, se plantea la necesidad de estudios futuros con el fin de estandarizar los procedimientos y determinar datos normativos del ROM cervical en diferentes poblaciones.For healthcare professionals, obtaining valid and reliable clinical data is of great importance in order to establish treatment goals suited to the individual needs of each patient and to be able to assess their effectiveness. Inertial motion sensors (IMU) represent a breakthrough in the measurement of the kinematics of body segments, applicable to the healthcare setting, and show good reliability in measuring joint range of motion (ROM) in humans and the cervical spine in adults. A common problem in Cerebral Palsy (CP) is the delay or deficit in head control (HC), considered a basic motor milestone, which conditions the development and progressive acquisition of motor levels. In addition, HC is responsible for ensuring adequate and safe feeding, as well as enabling the development of postural adaptations to interact with others and adapt to the environment and its demands. Thus, this doctoral thesis proposes a study of the metric properties, in terms of validity and reliability, of the IMU, as a tool for measuring ROM and HC in subjects with CP. For this reason, it aims to analyze the cervical mobility determined synchronously with the Cervical Range of Motion (CROM) instrument and with IMU, in addition to describing the design and development of a new test for the evaluation of Range of Motion (ROM) and cervical HC in children with CP. In both cases, in addition to the analysis of a group of subjects with CP, a sample of control patients have been studied. In this context, the main objective of the first publication was to determine the clinimetric properties in terms of validity and reliability of the IMU in the measurement of cervical ROM in children with CP. For this purpose an evaluation protocol was designed, together with an information sheet, an informed consent form and a form for data recording. The IMU and a CROM device were used simultaneously. Cervical ROM was measured by performing 3 repetitions of each cervical movement, which were reproduced after 5 minutes to assess intraday reliability. Similarly, the measurement procedure was repeated after 3-5 days to estimate interday reliability. The results were recorded on the recording sheet, the largest results were selected and were statistically analyzed and interpreted. In order to assess concurrent validity, the Pearson correlation coefficient, paired t-test and Bland-Altman plots were drawn for each ROM. Likewise, to analyze relative reliability, this was determined by calculating the Intraclass Correlation Coefficient (ICC) for intra- and inter-day reliability. Finally, for achieve absolute reliability, the standard error of measurement (SEM) and the minimum detectable change (MDC) were calculated. In addition, tools such as scales and tests commonly used for the functional assessment of patients with CP are usually subjective and sometimes difficult to apply in children. Their development in healthcare practice also depends on the skill and experience of each examiner. In order to provide a tool that shows more objective results, in a second scientific article, a new procedure has been designed to determine cervical posture and its motor control in children with CP, based on inertial technology, with an approach of sufficient validity and reliability to analyze human movement, with a low cost, great versatility, portability and capacity to adapt to body morphology. First, a literature review and two proofs of concept were carried out to obtain the final version of the test. Subsequently, a clinical measurement study was performed to evaluate its construct and content efficacy, and its inter-day reliability. During the protocol, a fixed chair adapted to the anthropometric characteristics of each patient, a table, and a computer were used. Furthermore, an IMU was placed on the forehead with a flexible and adjustable strap. The sensor captured movements in all three planes, while the subject watched a video for two minutes. For the registration and processing of raw data, the sensor was connected via bluetooth with the iUCOTRACK mobile app ©. The test was repeated at 3-5 days, following the same protocol, with the aim of studying reliability. To obtain a better feed-back of the data obtained, in addition to the characteristics of the movement, in terms of displacement length, speed and acceleration, an ellipse was designed with the head movements in the sagittal and transverse planes, evaluating its area and its anteroposterior and lateral dimensions, as main variables. To assess the functional status of children with CP GMFM-88 and PEDI were applied. Construct validity was estimated by determining the discriminant capacity of the new test and identifying associations between the functional measures and the results of the new test. For this purpose, the unpaired Student t-test, a receiver operating characteristic (ROC) and the Mann- Whitney U-test were applied to compare subgroups of subjects with CP. For concurrent validity in the CP group, the Pearson's correlation coefficient was calculated between the sociodemographic data and the results obtained on the first day, and the total domains and scores of the GMFM-88 and PEDI scales. To obtain the relative reliability, the ICC was determined in the test-retest in both groups. Finally, absolute reliability was assessed by calculating the SEM and the MDC. The results obtained in the first publication showed high correlations between CROM and IMU and in both groups (CP and controls), except in the transverse plane. Furthermore, the Bland- Altman charts indicated a bias below 5 degrees between the two measurement systems, except for rotation in the CP group which was 8.2°. The ICC were higher than 0.8 between methods and groups. Regarding absolute reliability, the SEM achieved values less than 8.5 degrees and the MDC obtained values greater than 20° in rotational motion in the interday measurement. In the second publication, the new test to determine cervical posture and motor control in children with CP showed a high discriminatory capacity in the ellipse area (Area Under the Curve 0.8) and in both dimensions. The variables of the new test were moderately to strongly associated with the functional measures. The ICCs were greater than 0.8 for individuals in the CP group. The SEM for both groups was acceptably low, in angular movements below 4° for both groups, whereas in the ellipse variables it was higher in the CP group. The great variability between individuals revealed a high MDC, mainly in the CP group. In conclusion, the results obtained in both publications suggest that IMU is valid and reliable for measuring ROM, as well as for the assessment of the posture and motor control of the cervical spine in children with CP. However, the applicability of the findings, the protocol and these findings are limited to similar samples and procedures. Therefore, future studies are needed to standardize procedures and determine normative cervical ROM data in different populations

Spatial variability in threshold temperatures of heat wave mortality: impact assessment on prevention plans

Spain’s current heat wave prevention plans are activated according to administrative areas. This study analyses the determination of threshold temperatures for triggering prevention-plan activation by reference to isoclimatic areas, and describes the public health benefits. We subdivided the study area – the Madrid Autonomous Region (MAR) – into three, distinct, isoclimatic areas: ‘North’, ‘Central’ and ‘South’, and grouped daily natural-cause mortality (ICD-10: A00-R99) in towns of over 10,000 inhabitants (2000–2009 period) accordingly. Using these three areas rather than the MAR as a whole would have resulted in a possible decrease in mortality of 73 persons (38– 108) in the North area, and in aborting unnecessary activation of the plan 153 times in the Central area and 417 times in the South area. Our results indicate that extrapolating this methodology would bring benefits associated with a reduction in attributable mortality and improved effectiveness of public health interventions.This study was funded by a ‘Miguel Servet type 1’ grant (SEPY 1037/14), as well as a Health Research Fund grant (Fondo de Investigaciones Sanitarias/FIS Project ENPY1133/16 from the Carlos III Institute of Health

Design, Validity, and Reliability of a New Test, Based on an Inertial Measurement Unit System, for Measuring Cervical Posture and Motor Control in Children with Cerebral Palsy

Objective: The aim of this study was to design and propose a new test based on inertial measurement unit (IMU) technology, for measuring cervical posture and motor control in children with cerebral palsy (CP) and to evaluate its validity and reliability. Methods: Twenty-four individuals with CP (4–14 years) and 24 gender- and age-matched controls were evaluated with a new test based on IMU technology to identify and measure any movement in the three spatial planes while the individual is seated watching a two-minute video. An ellipse was obtained encompassing 95% of the flexion/extension and rotation movements in the sagittal and transversal planes. The protocol was repeated on two occasions separated by 3 to 5 days. Construct and concurrent validity were assessed by determining the discriminant capacity of the new test and by identifying associations between functional measures and the new test outcomes. Relative reliability was determined using the intraclass correlation coefficient (ICC) for test–retest data. Absolute reliability was obtained by the standard error of measurement (SEM) and the Minimum Detectable Change at a 90% confidence level (MDC90). Results: The discriminant capacity of the area and both dimensions of the new test was high (Area Under the Curve ≈ 0.8), and consistent multiple regression models were identified to explain functional measures with new test results and sociodemographic data. A consistent trend of ICCs higher than 0.8 was identified for CP individuals. Finally, the SEM can be considered low in both groups, although the high variability among individuals determined some high MDC90 values, mainly in the CP group. Conclusions: The new test, based on IMU data, is valid and reliable for evaluating posture and motor control in children with CP

Concurrent Validity and Reliability of an Inertial Measurement Unit for the Assessment of Craniocervical Range of Motion in Subjects with Cerebral Palsy

Objective: This study aimed to determine the validity and reliability of Inertial Measurement Units (IMUs) for the assessment of craniocervical range of motion (ROM) in patients with cerebral palsy (CP). Methods: twenty-three subjects with CP and 23 controls, aged between 4 and 14 years, were evaluated on two occasions, separated by 3 to 5 days. An IMU and a Cervical Range of Motion device (CROM) were used to assess craniocervical ROM in the three spatial planes. Validity was assessed by comparing IMU and CROM data using the Pearson correlation coefficient, the paired t-test and Bland–Altman plots. Intra-day and inter-day relative reliability were determined using the Intraclass Correlation Coefficient (ICC). The Standard Error of Measurement (SEM) and the Minimum Detectable Change at a 90% confidence level (MDC90) were obtained for absolute reliability. Results: High correlations were detected between methods in both groups on the sagittal and frontal planes (r > 0.9), although this was reduced in the case of the transverse plane. Bland–Altman plots indicated bias below 5º, although for the range of cervical rotation in the CP group, this was 8.2º. The distance between the limits of agreement was over 23.5º in both groups, except for the range of flexion-extension in the control group. ICCs were higher than 0.8 for both comparisons and groups, except for inter-day comparisons of rotational range in the CP group. Absolute reliability showed high variability, with most SEM below 8.5º, although with worse inter-day results, mainly in CP subjects, with the MDC90 of rotational range achieving more than 20º. Conclusions: IMU application is highly correlated with CROM for the assessment of craniocervical movement in CP and healthy subjects; however, both methods are not interchangeable. The IMU error of measurement can be considered clinically acceptable; however, caution should be taken when this is used as a reference measure for interventions

Umbrales de definición de ola de frío e impacto sobre la mortalidad en España. Necesidad de Planes de prevención

Ponencia presentada en: XXXIV Jornadas Científicas de la AME y el XVII Encuentro Hispano Luso de Meteorología celebrado en Teruel, del 29 de febrero al 2 de marzo de 2016

Determinación de umbrales de definición de ola de calor e impacto sobre la mortalidad en España

Ponencia presentada en: XXXIV Jornadas Científicas de la AME y el XVII Encuentro Hispano Luso de Meteorología celebrado en Teruel, del 29 de febrero al 2 de marzo de 2016

Perceived distress in assisted gait with a four-wheeled rollator under stress induction conditions

In assisted ambulation, the user’s psychological comfort has a significant impact not only on acceptability of mobility aids but also on overall gait performance. Specifically, in the case of rollators, negative states such as distress may result in balance loss, inefficient manoeuvres, and an increased risk of falling. This paper presents a pilot study to investigate the effect of distress on rollator assisted navigation. To achieve this goal, a novel test protocol is proposed to assess distress while walking with a rollator, using the Self-Assessment Manikin (SAM) questionnaire. First, the participant completes a standardised visual stress induction test and fills in a SAM questionnaire on the dimensions of arousal and valence, to establish personal benchmarks. Then, they complete a course consisting of four navigation tasks with different levels of difficulty that affect the rollator manoeuvrability, filling in a SAM questionnaire after each task. An experiment including 25 healthy volunteers has been completed. Our preliminary results show that stressors like uneven or sloping surfaces increase perceived stress, whereas the shape of the trajectory does not significantly affect stress. The ultimate purpose of this work is to validate a performance-oriented protocol to investigate the dynamics of stress response in assisted walk and to train automatic stress detection systems.The work was supported by the Ministerio de Ciencia e Innovación [RTI2018-096701-B-C22]; Ministerio de Ciencia, Innovación y Universidades [RTI2018-096701-B-C21 (SAVIA:]; Ministerio de Ciencia, Innovación y Universidades [RTI2018-096701-B-C21]; Universidad de Málaga [E3-PROYECTOS DE PRUEBA DE CONCEPTO (E3/02/18)].Peer ReviewedPostprint (published version

Paravertebral Muscle Mechanical Properties and Spinal Range of Motion in Patients with Acute Neck or Low Back Pain: A Case-Control Study

Our aims were to identify potential differences in muscle mechanical properties (MMPs) of cervical and lumbar tissues and in spinal range of motion (ROM) between patients with acute low back pain (LBP) or acute neck pain (NP) and healthy controls, and to identify if ROMs and MMPs are able to identify subjects among the three groups. Clinical variables (pain, disability, fear of movement, kinesiophobia, quality of life), MMPs and ROMs were obtained in 33 subjects with acute LBP, 33 with acute NP, and 33 healthy control subjects. Between-groups differences and explanatory models to discriminate groups depending on MMPs and ROMs were calculated. The results showed that cervical tone was higher in patients with acute NP than in controls, while cervical decrement was higher in both spinal pain groups. Patients with acute NP showed reduced cervical flexion when compared to acute LBP and control groups, and also cervical rotation, but just against controls. Furthermore, lumbar flexion was reduced in patients with acute LBP when compared to those with acute NP. Cervical decrement was able to discriminate spinal pain individuals from controls in a multinominal regression (R2: Cox–Snell estimation = 0.533; Nagelkerke estimation = 0.600). Lumbar flexion differentiated patients with acute LBP and controls, whereas cervical flexion differentiated patients with acute NP and controls. This study supports a tendency of the affectation of other spinal regions when only one is affected

Influence of Spinal Movements Associated with Physical Evaluation on Muscle Mechanical Properties of the Lumbar Paraspinal in Subjects with Acute Low Back Pain

This research aimed to identify changes in muscle mechanical properties (MMPs) when a standardized sequence of movements is performed and to determine the influence of acute low back pain (LBP) and age on the MMPs. Socio-demographic, clinical variables and MMPs were collected in 33 patients with LBP and 33 healthy controls. A 2 × 2 × 2 (group × age × time) analysis of variance (ANOVA) mixed model was used to determine the effect of the study factors on the different MMPs. There were no significant triple interactions. After the movements, tone and stiffness increased 0.37 Hz and 22.75 N/m, respectively, in subjects <35 years, independent of their clinical status. Relaxation showed differences by age in healthy subjects and creep in LBP subjects. Furthermore, elasticity was higher in <35 years (p < 0.001) without the influence of any other factor. In conclusion, sequenced movements can modify tone and stiffness as a function of age, while age-associated changes in viscoelastic characteristics depends on pain but not on movements. The MMPs should be assessed, not only at the beginning of the physical examination at rest, but also along the patient’s follow-up, depending on their pain and age, in a clinical setting