Assigning UPDRS Scores in the Leg Agility Task of Parkinsonians: Can It Be Done through BSN-based Kinematic Variables?

In this paper, by characterizing the Leg Agility (LA) task, which contributes to the evaluation of the degree of severity of the Parkinson's Disease (PD), through kinematic variables (including the angular amplitude and speed of thighs' motion), we investigate the link between these variables and Unified Parkinson's Disease Rating Scale (UPDRS) scores. Our investigation relies on the use of a few body-worn wireless inertial nodes and represents a first step in the design of a portable system, amenable to be integrated in Internet of Things (IoT) scenarios, for automatic detection of the degree of severity (in terms of UPDRS score) of PD. The experimental investigation is carried out considering 24 PD patients.Comment: 10 page

Mechanical lifting energy consumption in work activities designed by means of the "revised NIOSH lifting equation"\u80\u9d

The aims of the present work were: to calculate lifting energy consumption (LEC) in work activities designed to have a growing lifting index (LI) by means of revised NIOSH lifting equation; to evaluate the relationship between LEC and forces at the L5-S1 joint. The kinematic and kinetic data of 20 workers were recorded during the execution of lifting tasks in three conditions. We computed kinetic, potential and mechanical energy and the corresponding LEC by considering three different centers of mass of: 1) the load (CoML); 2) the multi-segment upper body model and load together (CoMUpp+L); 3) the whole body and load together (CoMTot). We also estimated compression and shear forces. Results shows that LEC calculated for CoMUpp+L and CoMTot grew significantly with the LI and that all the lifting condition pairs are discriminated. The correlation analysis highlighted a relationship between LEC and forces that determine injuries at the L5-S1 joint

Comparison of a New Inertial Sensor Based System with an Optoelectronic Motion Capture System for Motion Analysis of Healthy Human Wrist Joints

This study aims to compare a new inertial measurement unit based system with the highly accurate but complex laboratory gold standard, an optoelectronic motion capture system. Inertial measurement units are sensors based on accelerometers, gyroscopes, and/or magnetometers. Ten healthy subjects were recorded while performing flexion-extension and radial-ulnar deviation movements of their right wrist using inertial sensors and skin markers. Maximum range of motion during these trials and mean absolute difference between the systems were calculated. A difference of 10° ± 5° for flexion-extension and 2° ± 1° for radial-ulnar deviation was found between the two systems with absolute range of motion values of 126° and 50° in the respective axes. A Wilcoxon rank sum test resulted in a no statistical differences between the systems with p-values of 0.24 and 0.62. The observed results are even more precise than reports from previous studies, where differences between 14° and 27° for flexion-extension and differences between 6° and 17° for radial-ulnar deviation were found. Effortless and fast applicability, good precision, and low inter-observer variability make inertial measurement unit based systems applicable to clinical settings

VALIDATION OF AN INERTIAL MEASUREMENT UNIT BASED ESTIMATION OF TRUNK MOTION IN SIT-SKIING: A PILOT STUDY

Sagittal plane trunk movement is important for producing propulsive force when sit-skiing. We aimed to validate the use of inertial measurement units for measuring sagittal plane trunk movements during sit-skiing in the field. Able-bodied participants (n=4) performed 30 seconds of sit-skiing in a kneeling position on a treadmill while one AdMos IMU sensor (on the upper back) and 4 reflective markers on the trunk recorded kinematics. A secondary validation was performed with 4 sensors and markers attached to a rigid body, which was rotated to mimic the trunk during sit-skiing. For the rigid body, the root mean square error wa

Upper Limb Portable Motion Analysis System Based on Inertial Technology for Neurorehabilitation Purpose

Here an inertial sensor-based monitoring system for measuring and analyzing upper limb movements is presented. The final goal is the integration of this motion-tracking device within a portable rehabilitation system for brain injury patients. A set of four inertial sensors mounted on a special garment worn by the patient provides the quaternions representing the patient upper limb’s orientation in space. A kinematic model is built to estimate 3D upper limb motion for accurate therapeutic evaluation. The human upper limb is represented as a kinematic chain of rigid bodies with three joints and six degrees of freedom. Validation of the system has been performed by co-registration of movements with a commercial optoelectronic tracking system. Successful results are shown that exhibit a high correlation among signals provided by both devices and obtained at the Institut Guttmann Neurorehabilitation Hospital

Validity and reliability of NOTCH® inertial sensors for measuring elbow joint angle during tennis forehand at different sampling frequencies

Portable and low-cost motion capture systems are gaining importance for biomechanical analysis. The aim was to determine the concurrent validity and reliability of the NOTCH® inertial sensors to measure the elbow angle during tennis forehand at different sampling frequencies (100, 250 and 500 Hz), using an optical capture system with sub-millimetre accuracy as a reference. 15 competitive players performed forehands wearing NOTCH and an upper body marker-set and the signals from both systems were adjusted and synchronized. The error magnitude was tolerable (5-10◦) for all joint-axis and sampling frequencies, increasing significantly at 100 Hz for the flexion–extension and pronation-supination angles (p = 0.002 and 0.023; Cohen d > 0.8). Concordance correlation coefficient was very large (0.7–0.9) in all cases. The within-subject error variation between the test–retest did not show significant differences (p > 0.05). NOTCH® is a valid, reliable and portable alternative to measure elbow angles during tennis forehand

RunScribe Sacral Gait Lab™ Validation for Measuring Pelvic Kinematics during Human Locomotion at Different Speeds

Optoelectronic motion capture systems are considered the gold standard for measuring walking and running kinematics parameters. However, these systems prerequisites are not feasible for practitioners as they entail a laboratory environment and time to process and calculate the data. Therefore, this study aims to evaluate the validity of the three-sensor RunScribe Sacral Gait Lab™ inertial measurement unit (IMU) in measuring pelvic kinematics in terms of vertical oscillation, tilt, obliquity, rotational range of motion, and the maximum angular rates during walking and running on a treadmill. Pelvic kinematic parameters were measured simultaneously using an eight-camera motion analysis system (Qualisys Medical AB, GÖTEBORG, Sweden) and the three-sensor RunScribe Sacral Gait Lab™ (Scribe Lab. Inc. San Francisco, CA, USA) in a sample of 16 healthy young adults. An acceptable level of agreement was considered if the following criteria were met: low bias and SEE ( 0.90), and good reliability (ICC > 0.81). The results obtained reveal that the three-sensor RunScribe Sacral Gait Lab™ IMU did not reach the validity criteria established for any of the variables and velocities tested. The results obtained therefore show significant differences between the systems for the pelvic kinematic parameters measured during both walking and runningThe State Research Agency (SRA)The European Regional Development Fund (ERDF) with the project EDUSPORT (REF: PID2020-115600RB-C21

Biomechanical determinant factors in tennis forehand drive

The forehand drive in tennis is considered essential in the performance of athletes. Despite several studies in biomechanics, there are unexplored issues and methodologies that may contribute to a better understanding of the key factors in performance and greater efficiency to capture kinematic data contributing to a positive impact for tennis players. Therefore, the first study aimed to compare the contribution of the upper limb to racket speed among intermediate and experienced tennis players. The results showed that what differentiate the two groups is the contribution of the shoulder to the racket head velocity. In order to use the same method with elite athletes in real situation with a simpler methodology, the second study aimed to validate an inertial measurement unit system. The results of this study demonstrated a high degree of confidence to collect kinematic data in the forehand drive. After this validation, in the third study we determined the contribution of the upper limbs to the racket head velocity in elite players, in the field. The results showed some differences when compared to previous studies using the same methodology, these differences may be related to the level of the players or the type of the stroke. Finally, the fourth study aimed to determine the moments of force of the dominant upper limb between a forehand in a quasi-static stance and a dynamic frontal weight transfer stance forehand. The results showed a higher load on the joints during the forehand in quasi-static stance. We can conclude that the results obtained during the various studies may contribute to a greater knowledge of coaches to help athletes to achieve a better performance in the forehand drive, as well as health professionals to understand which techniques may be associated with a higher load on the joints.O batimento de direita no ténis é considerado decisivo na performance dos atletas. Apesar de vários estudos ao nível da biomecânica, existem questões e metodologias inexploradas que poderão contribuir para uma melhor compressão de fatores chave na performance dos tenistas. O primeiro estudo teve como objetivo comparar a contribuição do membro superior para velocidade da raquete entre jogadores de nível intermédio e experientes. Os resultados demonstraram que o que diferencia os dois grupos é a contribuição do ombro para a velocidade da cabeça da raquete. Para utilizarmos o mesmo método com atletas de elite em situação real e com uma metodologia menos pesada do ponto de vista da sua preparação, o segundo estudo teve como objetivo validar um sistema de sensores inercias. Os resultados deste estudo demonstraram que podemos recolher com confiança os dados cinemáticos neste movimento através de um sistema de sensores inerciais. Após esta validação, no terceiro estudo determinámos a contribuição dos membros superiores para a velocidade da cabeça da raquete em jogadores de elite, no campo. Os resultados demonstraram algumas diferenças quando comparados com estudos prévios utilizando a mesma metodologia, estas diferenças poderão estar relacionadas com a diferença do nível de jogadores ou o tipo de batimento. Por último, o quarto estudo teve como objetivo determinar os momentos de força do membro superior dominante entre um batimento apoiado e um batimento dinâmico. Os resultados demonstraram uma maior carga nas articulações durante o batimento em apoio. Podemos concluir que os resultados obtidos durante os vários estudos poderão contribuir para um maior conhecimento dos treinadores no sentido de ajudar os atletas a atingir uma melhor performance no batimento de direita, bem como os profissionais de saúde a perceber quais os batimentos que poderão estar associados a uma maior carga nas articulações

Gait Phases Detection in Elderly using Trunk-MIMU System

The increasing interest towards wearable Magnetic Inertial Measurement Units (MIMUs) for gait analysis is justified by their low invasiveness, confirmed repeatability and complete independence from laboratory constraints. However, some crucial doubts about the identification of a suitable sensor set-up and algorithm in different gait conditions and populations still exist. In this context, the principal aim of the present study was to investigate the effect of different walking conditions on the accuracy of gait phases detection with a trunk-MIMU system. Eleven healthy elderly subjects performed gait trials in four different walking conditions (fast speed, normal speed, slow speed and normal speed with dual-task). A stereophotogrammetric system was adopted as gold standard. The accuracy of the estimation of stance and swing phases was evaluated from the comparison of trunk-MIMU to the stereophotogrammetric system. Mean error values smaller than 0.03 s confirmed the accuracy of the tru nk-MIMU algorithm for an elderly population. Consequently, trunk-MIMU system can be considered suitable for the characterization of gait phases in elderly subjects regardless of walking conditions

Visual perceptual skills and motor performance in gymnastics : the influence of task constraints

Esta dissertação teve como principal objetivo investigar a influência dos constrangimentos da tarefa nos comportamentos visual e motor de ginastas de nível elite. Para recolher dados dos comportamentos visual e motor num contexto ecológico representativo, foi validado um sistema de sensores inerciais para medir os ângulos articulares em 3D, durante uma tarefa gímnica. Três estudos foram realizados. O primeiro estudo investigou o comportamento visual durante a realização de quatro tarefas no mini trampolim e no mini-trampolim com mesa de saltos, aumentando progressivamente o nível de complexidade. O segundo estudo analisou a validade de um sistema de sensores inerciais na medição de ângulos articulares em 3D durante a realização de uma tarefa gímnica, utilizando um sistema optoelectrónico como referência. O estudo final examinou a influência dos constrangimentos da tarefa (presença e ausência da mesa de saltos) nos comportamentos visual e motor de ginastas de elite, durante a fase de corrida para o mini trampolim e mini-trampolim com mesa de saltos. O primeiro estudo sugeriu que os ginastas adaptaram o comportamento visual à complexidade da tarefa. O mini-trampolim foi a área de interesse mais fixada. O segundo estudo mostrou que o sistema de sensores inerciais apresentou boas correlações, erros aceitáveis e que não apresenta diferenças significativas para a maioria das articulações, comparando com o sistema optoelectrónico. O último estudo revelou que a presença da mesa de saltos influenciou o comportamento visual dos ginastas com menor expertise, enquanto que o comportamento motor foi diferentes nas duas tarefas para todos dos ginastas. Estas conclusões sugerem que o sistema de sensores inerciais é válido para fornecer dados cinemáticos aos treinadores e ginastas, e que os constrangimentos da tarefa influenciam o comportamento visual de ginastas de elite de forma distinta, consoante o nível de expertise.The main aim of this dissertation was to investigate the influence of task constraints on gaze and motor behaviours in elite gymnasts. To collect gaze and motor data in an ecological and representative context, an inertial measurement units system to measure 3D joint angles outside the laboratory was validated. To accomplish these goals, three studies were completed. In the first study, gaze behaviour was investigated during the performance of four gymnastics tasks on mini-trampoline and on mini-trampoline with vaulting table, while increasing the level of complexity. The second study analysed the validity of an inertial measurement units system in measuring 3D joint angles during a gymnastics task, using an optoelectronic system as a reference. The final study examined the influence of task constraint (i.e., presence and absence of vaulting table) on gaze and motor behaviours of elite gymnasts, during the approach run phase to the mini-trampoline and mini-trampoline with vaulting table. The first study showed that gymnasts adapted their gaze behaviours according to the level of complexity of the task and that the most fixated area of interest was the mini-trampoline. The second study demonstrated that the inertial measurement units system has very good and acceptable correlations, acceptable errors and no significant differences for the majority of the joint ankles. Finally, the last study revealed that the presence of the vaulting table influenced gaze behaviour only in elite gymnasts (compared to super-elite gymnasts), while different motor behaviours occurred across the two tasks, irrespective of gymnasts’ level of expertise. The findings indicate that the inertial measurement units system is valid to provide kinematics data, and task constraints (i.e., presence and absence of vaulting table) influence gaze behaviours of elite gymnasts differently, across varying levels of expertise