Upper limbs cranking for post-stroke rehabilitation: A pilot study on healthy subjects

Since one of the major consequences of stroke is hemiparesis, the rehabilitation of upper limbs is necessary to improve the quality of life. Arm cranking gesture represents an alternative rehabilitation tool, especially if accompanied by a biofeedback involving and motivating patients. The aim of this pilot study was twofold: (1) to evaluate the effect of a visual and virtual biofeedback on arm cranking gesture and (2) to estimate the duration of pull and push phases of the crank cycle. Nine healthy and young subjects were involved in the test and were asked to perform the arm cranking gesture in different conditions. A stereophotogrammetric system was adopted to create a virtual, visual and real time biofeedback of cadence, to measure the real cadence of participants and to estimate push and pull phases durations. Results showed that the biofeedback helped subjects to follow an externally imposed cadence. Furthermore, the pull phase resulted to be slightly longer than the push one, although the angular amplitude of the two phases suggested they were the same

Roturas tendinosas y musculares en el hombro del deportista

El complejo articular del hombro está sometido a solicitaciones mecánicas en la mayoría de las modalidades deportivas; así el 10-15% de los traumatismos sufridos por los atletas afectan a esta articulación (1). La "patología reina" del hombro del deportista es la inestabilidad, por su frecuencia, importantes implicaciones funcionales y tratamiento problemático. Por el contrario, las roturas musculares y tendinosas del hombro son lesiones poco frecuentes en el deportista pero no por ello irrelevantes, pues pueden provocar una gran incapacidad para seguir desempeñando el mismo deporte y al mismo nivel de competición si no se hace un tratamiento correcto, a pesar del cual a veces los resultados no son satisfactorios. Es decir, pueden representar el "principio del fin" de la actividad deportiva. Tibone y cols. (2) en un estudio realizado sobre tratamiento quirúrgico de roturas del manguito de los rotadores en atletas, encuentran que sólo el 32% de los jugadores de baseball profesionales tratados por ellos volvían a jugar en la liga profesional americana después de su lesión

Upper Limbs Musculoskeletal OpenSim Model: Customization and Assessment

Computational modelling is a powerful tool in biomechanical studies. Open-source software OpenSim provides different musculoskeletal models. However, existing upper body models consider only one limb, which could be a limitation in reproducing two-handed tasks. The purpose of this research was to develop a two upper limbs model that can be customized with subject’s anthropometry and muscles properties. The proposed model was composed of thorax, left and right upper limbs. Each limb presents 3 degrees of freedom (shoulder flexion-extension, elbow flexion-extension and prono-supination), 4 flexor and 3 extensor muscles. A preliminary model assessment was done. A subject was asked to execute isometric tests at three elbow angles, holding different loads, while EMG muscle activation was recorded. Simulated and experimental muscles activation were compared considering the right upper limb. Very good results were obtained without external load, whereas differences were observed when increasing the load; but, overall, model performance remained acceptable

Measuring the quality of teacher-child interaction in autistic disorder

The teacher-child relationship fulfils critical functions for the well being of the child, affecting emotive development, academic achievements, behavioral conducts and relationships with peers. The goal of the presented study is to compare the perceptions of the class teacher and of the support teacher concerning their relationship with subjects with autistic spectrum disorders (ASD; N=14; Mean age =90.07 months; SD=19.36) and with children of the control group (4 classmates per every subject of the experimental group, for a total of 56 pupils, Mean age = 80.36 months; SD=18.33). The perception by the teacher of the class, concerning the relationship with children with ASD, is characterized by higher levels of Conflict, and lower levels of Closeness, if compared with perceptions about the relationship with children of the control group (Conflict: t=-3.317; df= 14.931; p<0.01; Closeness: t= 5.638; df = 65; p < 0.001). The perception of the two teachers only correlates with regards to the Conflict dimension (r=0.769; p < 0.01). In reference to the child's adaptive skills only the social skills scale correlates with the Closeness. This is true in the perception of the support teacher (r=0.598; p<0.05). Finally, we take into account how the perception of the relationship relates with the socio-personal and professional data of the teachers and with the social features of the children

Contraction level, but not force direction or wrist position, affects the spatial distribution of motor unit recruitment in the biceps brachii muscle

Purpose: Different motor units (MUs) in the biceps brachii (BB) muscle have been shown to be preferentially recruited during either elbow flexion or supination. Whether these different units reside within different regions is an open issue. In this study, we tested wheter MUs recruited during submaximal isometric tasks of elbow flexion and supination for two contraction levels and with the wrist fixed at two different angles are spatially localized in different BB portions. Methods: The MUs’ firing instants were extracted by decomposing high-density surface electromyograms (EMG), detected from the BB muscle of 12 subjects with a grid of electrodes (4 rows along the BB longitudinal axis, 16 columns medio-laterally). The firing instants were then used to trigger and average single-differential EMGs. The average rectified value was computed separately for each signal and the maximal value along each column in the grid was retained. The center of mass, defined as the weighted mean of the maximal, average rectified value across columns, was then consdiered to assess the medio-lateral changes in the MU surface representation between conditions. Results: Contraction level, but neither wrist position nor force direction (flexion vs. supination), affected the spatial distribution of BB MUs. In particular, higher forces were associated with the recruitment of BB MUs whose action potentials were represented more medially. Conclusion: Although the action potentials of BB MUs were represented locally across the muscle medio-lateral region, dicrimination between elbow flexion or supination seems unlikely from the surface representation of MUs action potentials

Wearable Inertial Devices in Duchenne Muscular Dystrophy: A Scoping Review

In clinical practice and research, innovative digital technologies have been proposed for the characterization of neuromuscular and movement disorders through objective measures. Among these, wearable devices prove to be a suitable solution for tele-monitoring, tele-rehabilitation, and daily activities monitoring. Inertial Measurement Units (IMUs) are low-cost, compact, and easy-to-use wearable devices that evaluate kinematics during different movements. Kinematic variables could support the clinical evaluation of the progression of some neuromuscular diseases and could be used as outcome measures. The current review describes the use of IMUs for the biomechanical assessment of meaningful outcome measures in individuals affected by Duchenne muscular dystrophy (DMD). The PRISMA methodology was used and the search was conducted in different databases (Scopus, Web of Science, PubMed). A total of 23 articles were examined and classified according to year of publication, ambulatory/non-ambulatory subjects, and IMU positioning on human body. The analysis points out the recent regulatory identification of Stride Velocity 95th Centile as a new endpoint in therapeutic DMD trials when measured continuously from a wearable device, while only a few studies proposed the use of IMUs in non-ambulatory patients. Clinical recognition of reliable and accurate outcome measures for the upper body is still a challeng