RESUMEN
BACKGROUND: The main position of the working population is becoming sitting. Immobile prolonged sedentary time may cause negative effects including reduced intervertebral discs nutrition. Main ways of mitigating them are regular position changes and exercising. OBJECTIVE: To evaluate influence of the short term training on unstable training machine on balance control and trunk muscles activity in patients with lower back pain. METHODS: Participants (n=16) experiencing lower back pain were trained on an unstable sculling machine "Rehabili". Their balance tested by (Biodex Balance System) and rectus abdominis, externus oblique, transverse abdominis, multifidus and erector spine muscles activity (measured by surface electromyography) while sitting and standing with usual and aligned body postures both before and after six weeks of training (three 15 minutes sessions per week) were compared in between. RESULTS: Balance control improved after the training program. Besides, more symmetrical activation of both sides rectus and transversus abdominis muscles, as well as increased transversus abdominis muscle activation of 19% (p< 0.05), were observed. CONCLUSIONS: Six weeks short sessions training on unstable training machine improved balance control and increased trunk muscles activity especially in aligned body posture when standing or sitting on unstable surface.
Asunto(s)
Diseño de Equipo , Ejercicio Físico , Músculo Esquelético/fisiología , Equilibrio Postural/fisiología , Extremidad Superior/fisiología , Adolescente , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Proyectos Piloto , Adulto JovenRESUMEN
Training equipment used by professional sportsmen has a great impact on their sport performance. Most universal exercisers may help only to improve the general physical condition due to the specific kinematics and peculiar resistance generated by their loading units. Training of effective techniques and learning of psychomotor skills are possible only when exercisers conform to the movements and resistance typical for particular sports kinematically and dynamically. Methodology of developing a magnetorheological resistive exercise device for generating the desired law of passive resistance force and its application in a lever-type rowing machine are described in the paper. The structural parameters of a controllable hydraulic cylinder type device were found by means of the computational fluid dynamics simulation performed by ANSYS CFX software. Parameters describing the magnetorheological fluid as non-Newtonian were determined by combining numerical and experimental research of the resistance force generated by the original magnetorheological damper. A structural scheme of the device control system was developed and the variation of the strength of magnetic field that affects the magnetorheological fluid circulating in the device was determined, ensuring a variation of the resistance force on the oar handle adequate for the resistance that occurs during a real boat rowing stroke.
Asunto(s)
Entrenamiento de Fuerza/instrumentación , Fenómenos Biomecánicos , Biología Computacional , Diseño de Equipo , Análisis de Elementos Finitos , Humanos , Imagenología Tridimensional , Fenómenos Magnéticos , Entrenamiento de Fuerza/estadística & datos numéricos , Reología , DeportesRESUMEN
A multifunctional device to transfer graphical or text information for blind or visually impaired is presented. The prototype using tactile perception has been designed where information displayed on the screen of electronic device (mobile phone, PC) is transferred by oscillating needle, touching the fingertip. Having the aim to define optimal parameters of the fingertip excitation by needle, the computational analysis of different excitation modes has been carried out. A 3D solid computational finite element model of the skin segment, comprising four main fingertip skin layers (stratum corneum, epidermis, dermis and hypodermis) was built by using ANSYS Workbench FEA software. Harmonic analysis of its stress-strain state under excitation with different frequency (up to 10000 Hz) and harmonic force (0.01 N), acting outer stratum corneum layer in normal direction at one, two or three points has been performed. The influence of the mode of dynamic loading of skin was evaluated (in terms of the tactile signal level) on the basis of the normal and shear elastic strain in dermis, where mechanoreceptors are placed. It is shown that the tactile perception of information, delivered by three vibrating pins, may be influenced by configuration of excitation points (their number and phase of loading) and the frequency of excitation.