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RESUMEN La estabilidad de la pelvis y el tronco, dada por la actividad de los músculos de la región, representa un factor importante para la correcta ejecución de la técnica deportiva y la prevención de lesiones en lanzadores paralímpicos. El objetivo de este estudio fue analizar a través de electromiografía de superficie, la actividad muscular del recto abdominal, oblicuo externo del abdomen y erector de la columna, vientres longuísimo e iliocostal, durante el lanzamiento de bala desde silla, en 4 atletas paralímpicos (2 con lesión en miembros inferiores y 2 con lesión medular). La electromiografía evidenció variaciones en los patrones de activación, el tiempo de ejecución y la amplitud de la señal, acorde a la condición de discapacidad y el grado de afectación del tronco. Esto permitió tener un panorama más real de las acciones musculares durante el gesto deportivo y la detección de opciones de mejora para los deportistas.
ABSTRACT The stability of the pelvis and trunk, given by the activity of the muscles in the region, represents an important factor for the correct execution of the sports technique and the prevention of injuries in Paralympic throwers. The objective of this study was to analyze, through surface electromyography the muscular activity of the rectus abdominis, external oblique of the abdomen and erector spinae, longuissimus and iliocostal bellies, during the shot put from a chair; in 4 Paralympic athletes (2 with lower limb injury and 2 with spinal cord injury). Electromyography showed variations in activation patterns, execution time and amplitude of the signal, according to the disability condition and the degree of trunk involvement. This allowed to have a more realistic panorama of the muscular actions during the sport gesture and the detection of improvement options for the athletes.
RESUMO A estabilidade da pélvis e do tronco, dada pela actividade dos músculos da região, representa um factor importante para a correcta execução da técnica desportiva e a prevenção de lesões nos lançadores paraolímpicos. O objectivo deste estudo foi analisar; através da electromiografía de superfície, a actividade muscular do recto abdominal, oblíquo externo do abdómen e erector da coluna vertebral, barriga muito comprida e iliocostal, durante o tiroteio em 4 atletas paraolímpicos (2 com lesão nos membros inferiores e 2 com lesão na medula espinal). A electromiografía mostrou variações nos padrões de activação, tempo de execução e amplitude do sinal, de acordo com a condição de incapacidade e o grau de envolvimento do tronco. Isto permitiu-nos ter uma imagem mais real das acções musculares durante o gesto desportivo e a detecção de opções de melhoria para os atletas.
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Objective To explore the characteristics of trunk muscle activity in persons with Parkinson's disease (PD) in search of better treatments for abnormal posture.Methods Ninety persons with PD of different severity and 8 normal controls were studied using surface electromyography (sEMG).A sixteen-lead sEMG instrument was used to collect sEMG amplitudes from the bilateral thoracic erector spinae,lumbar erector spinae,external oblique and rectus abdominis muscles when the subjects were lying,standing and walking.Results Compared with the control group,a significant increase was observed in the sEMG amplitude of the lumbar erector spinal muscle [(18.56±14.57) μV] and rectus abdominis muscles [(24.00±18.80)μV] of the PD group when lying.Significant relative increases in (P＜0.05),of the external oblique muscles were observed [(27.87± 11.49)μV] when standing (P＜0.05),and in the thoracic erector spinae muscle [(58.74±29.69)μV] and external oblique muscles [(59.01± 25.20) μV] increased when walking (P＜0.05).Compared with the control group,the sEMG activity of the external oblique muscles was significantly elevated in PD patients at Hoehn and Yahr stage 1 to 1.5 when walking.One or more of the trunk muscle groups showed significantly greater activity in the PD patients in Hoehn and Yahr stage 2 or 3 in all three positions.Conclusions The sEMG activities of the extensor and flexor muscles increase simultaneously in PD patients.More trunk muscles are involved in PD patients with higher H-Y grades.These findings provide a neurophysiological basis for the customizaton of rehabilitation therapy for patients with Parkinson's disease and for the precise selection of muscles for botulinum toxin injection.
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Introduction: This work presents the development of a novel robotic knee exoskeleton controlled by motion intention based on sEMG, which uses admittance control to assist people with reduced mobility and improve their locomotion. Clinical research remark that these devices working in constant interaction with the neuromuscular and skeletal human system improves functional compensation and rehabilitation. Hence, the users become an active part of the training/rehabilitation, facilitating their involvement and improving their neural plasticity. For recognition of the lower-limb motion intention and discrimination of knee movements, sEMG from both lower-limb and trunk are used, which implies a new approach to control robotic assistive devices. Methods A control system that includes a stage for human-motion intention recognition (HMIR), based on techniques to classify motion classes related to knee joint were developed. For translation of the user's intention to a desired state for the robotic knee exoskeleton, the system also includes a finite state machine and admittance, velocity and trajectory controllers with a function that allows stopping the movement according to the users intention. Results The proposed HMIR showed an accuracy between 76% to 83% for lower-limb muscles, and 71% to 77% for trunk muscles to classify motor classes of lower-limb movements. Experimental results of the controller showed that the admittance controller proposed here offers knee support in 50% of the gait cycle and assists correctly the motion classes. Conclusion The robotic knee exoskeleton introduced here is an alternative method to empower knee movements using sEMG signals from lower-limb and trunk muscles.
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Objective To correlate the isokinetic strength of stroke survivors' trunk flexors and extensors with the kinematic parameters of their gait.Methods Thirty stroke survivors and 30 healthy counterparts formed an observation group and a control group.The strength of everyone's trunk flexors and extensors was measured isokinetically,including the flexor peak torque (FPT),extensor peak torque (EPT) and the ratio of the two (F/E).The test velocities were 30°/s,60°/s and 90°/s.And the kinematic parameters of their gait,including the step length,stride,velocity,frequency,width and cycle time were measured using a 3D gait analysis system,as well as the percentage of stance phase,swing phase,double support phase and single support phase.Results No significant differences were found between the average FPT,EPT or F/E of the two groups at any of the three test velocities.At the 30°/s test velocity the average FPT,EPT and F/E of the observation group were all positively correlated with the average step length,stride,velocity,steps/min,width and cycle time,as well as with the stance phase,swing phase,double support phase and single support phase percentages.The strongest correlation was between F/E and velocity (r=0.57),followed by frequency (r=0.54).Conclusion litating the walking ability of stroke survivors and correcting their gait should focus on strengthening the trunk muscles and optimizing their coordination.
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Although the trunk segment shows well-coordinated movements in concert with the arms and legs during bipedal walking, little is understood about the neural mechanisms controlling the trunk muscles in response to sudden tactile sensations in the foot during walking. This study examined the cutaneous reflexes (CR) to shed light on the neural mechanisms underlying the regulation of the trunk muscles during walking and standing. Eleven healthy men participated in the study. Electromyographic (EMG) activities were recorded in the trapezius (TRAP), erector spinae (ES), and rectus abdominis (RA) muscles. To elicit CR, non-noxious electrical stimulation of the sural nerve at the ipsilateral lateral malleolus was applied during treadmill walking and tonic contraction of the test muscles during standing. During walking, cutaneous nerve stimulation in the foot gave rise to facilitatory CR in all the muscles, and the amplitude of the CR was strongly modulated in a phase-dependent manner. The amplitude of the background EMG and the amplitude of the CR showed a highly significant correlation in all the muscle tested during standing. However, this was true only in the ES during walking. In the RA, the inhibitory CR during standing changed to a facilitatory one during walking. In addition, reflex ratios were significantly larger during walking than standing. These findings suggest that common neural mechanisms in limb muscles could function in the TRAP and RA, however, in the ES disparate neural mechanisms play a crucial role in modulating cutaneous reflexes during walking and standing.
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The purpose of this study was to examine the effects of aquatic exercise training on the trunk muscles function and activities of daily living in abdominal obese women. Nineteen abdominal obese (abdominal circumference: 90 cm or more) and fifteen age-matched non-obese women were recruited as participants in this study. The aquatic exercise training (60 min/day, three days/week for 8 weeks) based on abdominal twists for activating the trunk muscle function. Physical parameters, biochemical characteristics, arteriosclerotic parameters and activities of daily living scores were assessed before and after the training period. In both groups showed abdominal circumference, percent of body fat, blood pressure and lower extremity muscle strength increased significantly after aquatic exercising training. In particular, endurance capacity of abdominal and back muscles increased significantly and activities of daily living scores were significantly improved in the obese group. Moreover, the improvement in the strength of lower extremities and improvement in the activities of daily living scores, such as climbing and descending stairs, in the obese group tended to be higher than non-obese women. Additionally, in abdominal obese group, the amount of the reduction of abdominal circumference was significantly associated with that of the increase in the strength of lower extremities. Taken together, these findings suggest the possibilities that the present aquatic exercise training based on trunk muscle exercise improving the function of trunk and lower extremity muscles with reduction in the abdominal obesity, contributing to improve activities of daily living in abdominal obese women.