Intra and Inter-Device Reliabilities of the Instrumented Timed-Up and Go Test Using Smartphones in Young Adult Population.

The Timed-Up and Go (TUG) test is widely utilized by healthcare professionals for assessing fall risk and mobility due to its practicality. Currently, test results are based solely on execution time, but integrating technological devices into the test can provide additional information to enhance result accuracy. This study aimed to assess the reliability of smartphone-based instrumented TUG (iTUG) parameters. We conducted evaluations of intra- and inter-device reliabilities, hypothesizing that iTUG parameters would be replicable across all experiments. A total of 30 individuals participated in Experiment A to assess intra-device reliability, while Experiment B involved 15 individuals to evaluate inter-device reliability. The smartphone was securely attached to participants' bodies at the lumbar spine level between the L3 and L5 vertebrae. In Experiment A, subjects performed the TUG test three times using the same device, with a 5 min interval between each trial. Experiment B required participants to perform three trials using different devices, with the same time interval between trials. Comparing stopwatch and smartphone measurements in Experiment A, no significant differences in test duration were found between the two devices. A perfect correlation and Bland-Altman analysis indicated good agreement between devices. Intra-device reliability analysis in Experiment A revealed significant reliability in nine out of eleven variables, with four variables showing excellent reliability and five showing moderate to high reliability. In Experiment B, inter-device reliability was observed among different smartphone devices, with nine out of eleven variables demonstrating significant reliability. Notable differences were found in angular velocity peak at the first and second turns between specific devices, emphasizing the importance of considering device variations in inertial measurements. Hence, smartphone inertial sensors present a valid, applicable, and feasible alternative for TUG assessment.

Smartphone-based evaluation of static balance and mobility in long-lasting COVID-19 patients.

Background: SARS-CoV-2 infection can lead to a variety of persistent sequelae, collectively known as long COVID-19. Deficits in postural balance have been reported in patients several months after COVID-19 infection. The purpose of this study was to evaluate the static balance and balance of individuals with long COVID-19 using inertial sensors in smartphones. Methods: A total of 73 participants were included in this study, of which 41 had long COVID-19 and 32 served as controls. All participants in the long COVID-19 group reported physical complaints for at least 7 months after SARS-CoV-2 infection. Participants were evaluated using a built-in inertial sensor of a smartphone attached to the low back, which recorded inertial signals during a static balance and mobility task (timed up and go test). The parameters of static balance and mobility obtained from both groups were compared. Results: The groups were matched for age and BMI. Of the 41 participants in the long COVID-19 group, 22 reported balance impairment and 33 had impaired balance in the Sharpened Romberg test. Static balance assessment revealed that the long COVID-19 group had greater postural instability with both eyes open and closed than the control group. In the TUG test, the long COVID-19 group showed greater acceleration during the sit-to-stand transition compared to the control group. Conclusion: The smartphone was feasible to identify losses in the balance motor control and mobility of patients with long-lasting symptomatic COVID-19 even after several months or years. Attention to the balance impairment experienced by these patients could help prevent falls and improve their quality of life, and the use of the smartphone can expand this monitoring for a broader population.

Wearable Inertial Sensor Approach for Postural Adjustment Assessments during Predictable Perturbations in Sport.

INTRODUCTION: Evidence supports the importance of efficient postural control to improve performance in sports. This involves the use of strategies such as anticipatory posture adjustments and compensatory adjustments. Technology makes analysis and assessments in sports cheaper, while being valid and reliable compared to the gold-standard assessment equipment. OBJECTIVES: This article aimed to test the validity and reliability of signals extracted from the sensor's accelerometer (Metamotion C), by comparing it to the data obtained from the gold-standard equipment (a three-dimensional video-motion-capture system). DESIGN: Observational, cross-sectional study. METHODS: We exposed 20 healthy young standing people to the pendulum impact paradigm, which consisted of predictable anteroposterior disturbances applied at the shoulder level. In order to measure this, we observed the acceleration of the center of mass in the anticipatory and compensatory phase of the disturbance and compared the signals of the two devices (Metamotion C and a motion-capture system). RESULTS: The validation results showed the significant linear correlation of all variables with a moderate to large correlation of r ≥ 0.5 between the devices. In contrast, the reliability results between sessions obtained by filming were all significant and above 0.75, indicating excellent reliability. The APAonset variable had a reasonable to high intra-class correlation in the anticipatory phase. In the compensatory phase, the CPAtime variable showed an excellent correlation. CONCLUSIONS: Metamotion C proved reasonably valid and highly reliable in measuring the center of mass acceleration compared to the camera system in both the anticipatory and compensatory phases.

Validity and Reliability of Smartphone App for Evaluating Postural Adjustments during Step Initiation.

The evaluation of anticipatory postural adjustments (APAs) requires high-cost and complex handling systems, only available at research laboratories. New alternative methods are being developed in this field, on the other hand, to solve this issue and allow applicability in clinic, sport and hospital environments. The objective of this study was to validate an app for mobile devices to measure the APAs during gait initiation by comparing the signals obtained from cell phones using the Momentum app with measurements made by a kinematic system. The center-of-mass accelerations of a total of 20 healthy subjects were measured by the above app, which read the inertial sensors of the smartphones, and by kinematics, with a reflective marker positioned on their lumbar spine. The subjects took a step forward after hearing a command from an experimenter. The variables of the anticipatory phase, prior to the heel-off and the step phase, were measured. In the anticipatory phase, the linear correlation of all variables measured by the two measurement techniques was significant and indicated a high correlation between the devices (APAonset: r = 0.95, p < 0.0001; APAamp: r = 0.71, p = 0.003, and PEAKtime: r = 0.95, p < 0.0001). The linear correlation between the two measurement techniques for the step phase variables measured by ques was also significant (STEPinterval: r = 0.56, p = 0.008; STEPpeak1: r = 0.79, p < 0.0001; and STEPpeak2: r = 0.64, p < 0.0001). The Bland−Altman graphs indicated agreement between instruments with similar behavior as well as subjects within confidence limits and low dispersion. Thus, using the Momentum cell phone application is valid for the assessment of APAs during gait initiation compared to the gold standard instrument (kinematics), proving to be a useful, less complex, and less costly alternative for the assessment of healthy individuals.

Hand Resting Tremor Assessment of Healthy and Patients With Parkinson's Disease: An Exploratory Machine Learning Study.

The aim of this study is comparing the accuracies of machine learning algorithms to classify data concerning healthy subjects and patients with Parkinson's Disease (PD), toward different time window lengths and a number of features. Thirty-two healthy subjects and eighteen patients with PD took part on this study. The study obtained inertial recordings by using an accelerometer and a gyroscope assessing both hands of the subjects during hand resting state. We extracted time and temporal frequency domain features to feed seven machine learning algorithms: k-nearest-neighbors (kNN); logistic regression; support vector classifier (SVC); linear discriminant analysis; random forest; decision tree; and gaussian Naïve Bayes. The accuracy of the classifiers was compared using different numbers of extracted features (i.e., 272, 190, 136, 82, and 27) from different time window lengths (i.e., 1, 5, 10, and 15 s). The inertial recordings were characterized by oscillatory waveforms that, especially in patients with PD, peaked in a frequency range between 3 and 8 Hz. Outcomes showed that the most important features were the mean frequency, linear prediction coefficients, power ratio, power density skew, and kurtosis. We observed that accuracies calculated in the testing phase were higher than in the training phase. Comparing the testing accuracies, we found significant interactions among time window length and the type of classifier (p < 0.05). The study found significant effects on estimated accuracies, according to their type of algorithm, time window length, and their interaction. kNN presented the highest accuracy, while SVC showed the worst results. kNN feeding by features extracted from 1 and 5 s were the combination with more frequently highest accuracies. Classification using few features led to similar decision of the algorithms. Moreover, performance increased significantly according to the number of features used, reaching a plateau around 136. Finally, the results of this study suggested that kNN was the best algorithm to classify hand resting tremor in patients with PD.

Estudo ergonômico de mototaxistas / Ergonomic study of motocabs

Objetivo: analisar se a atitude postural de mototaxistas em sua atividade profissional é um fatorde risco para o advento de doenças ocupacionais. Método: pesquisa do tipo transversal,realizada no Laboratório de Mecanoterapia do Centro de Ciências Biológicas e da Saúde doEstado do Pará. Aplicou-se um questionário a 30 profissionais do município de Santarém,indagando sobre os seus possíveis sinais e sintomas osteomioarticulares. Em seguida, foramrealizados 30 fotogramas do perfil da amostra em seu posto de serviço e analisados de formacomputadorizada utilizando o software Corel Draw 12 para mensurar ângulos anatômicos paraelaboração de um perfil de atitude postural durante a atividade laboral. O perfil observado foicomparado com parâmetros da postura de conforto ergonomicamente correta, obtendo-se umindicativo do quanto essa se desvia da postura sentada adequada. Os desvios observados foramcorrelacionados com as queixas detectadas no questionário para a elaboração das devidasconclusões. Resultados: a postura adotada pelos mototaxistas durante o trabalho difere da,ergonomicamente, recomendada para trabalhadores que adotam a postura sentada em suaatividade. Este achado pode estar intimamente relacionado com o alto índice de queixa de dor(80%) e parestesias (36,66%) relatadas pela casuística estudada. Conclusão: a atitude posturaldo profissional mototaxista em função de uma má ergonomia associada a outros fatoresinerentes a sua atividade laboral pode trazer risco a saúde deste profissional.

Objective: To evaluate if the attitude of postural motocab's in his professional activity is a riskfactor for the emergence of occupational disease. Method: research type of transversal,performed in Mecanotherapy Laboratory of Biological Science and Health Center of StateUniversity of Pará. Was applied a closed questionnaire to 30 professionals in the city ofSantarem, inquiring about the possible signs and musculoskeletal symptoms. Then, 30 frameswere made of the sample profile in his service station, these frames were analyzed usingcomputer software Corel draw 12 to measure anatomic angles to prepare a profile of posturalattitude during the work activity. The profile was observed compared with parameters ofcomfort ergonomically correct posture of obtaining an indication of how much it deviates fromthe proper sitting posture. The deviations were correlated with the complaints identified in thequestionnaire for the preparation of appropriate conclusions. Results: the posture adopted bymotocab's during work differs from the ergonomically recommended for workers who adopt asitting posture in its activity. This finding may be closely related to the high rate of complaintsof pain (80%) and paresthesia (36.66%) reported by the sample. Conclusion: the attitude of theprofessional motocab's posture due to a poor ergonomics associated with other factors inherentin their work activities can risk the health of these professionals

Efeito da aplicação do frio na sensação de posicionamento articular do tornozelo / Effect of the cold application on the joint position sense of ankle

Objetivo: investigar como as modalidades crioterapêuticas de bolsa de gelo (BG) e imersão em água gelada (IAG) influenciam na capacidade proprioceptiva de percepção de posicionamento articular de sujeitos saudáveis. Método: pesquisa observacional e analítica, realizada no Laboratório de Mecanoterapia do Centro de Ciências Biológicas e da Saúde da Universidade do Estado do Pará. Foi verificada a angulação articular do tornozelo de 15 indivíduos saudáveis, registrada pela fotogrametria em três posicionamentos da articulação do tornozelo: flexão máxima (FM), extensão máxima (EM) e a metade da amplitude entre FM e EM (1/2FE). Os posicionamentos articulares foram alcançados de forma ativa e sem ajuda visual. O registro foi realizado antes e depois da aplicação de duas modalidades crioterapêuticas, BG e IAG, na região do tornozelo, onde a temperatura da superfície da pele se manteve entre 5°C e 10°C durante 20 minutos. Aplicou-se o Teste t pareado, para analisar se houve alguma alteração dos ângulos mensurados após os protocolos crioterapêuticos. A sensibilidade tátil da pele foi aferida pelo estesiômetro antes e após os protocolos de aplicação do frio. Resultados: houve alteração da sensibilidade tátil cutânea de todos os indivíduos em ambos os protocolos, porém após o protocolo de IAG, 27% tiveram sensibilidade anormal ao teste estesiométrico e 73% mantiveram-se na faixa normal, enquanto que após o protocolo de BG apenas 7% tiveram sensibilidade anormal e 93% mantiveram-se com a sensibilidade preservada. Verificou-se alteração significativa no valor do ângulo articular de 1/2FE após o protocolo de BG e para EM após ambos os protocolos. Considerações finais: a aplicação da BG foi mais efetiva em alterar a sensação de posicionamento da articulação do tornozelo que a IAG. (AU)