Background. The purpose of the present study is to quantitatively describe the relationships between joint angles and muscle architecture of human triceps surae [medial (MG) and lateral (GL) gastrocnemius and soleus (SOL) muscles] after 7 d of « dry » water immersion (DI) with use neuromuscular electrical stimulation (NMES). Methods. Six healthy young men subjects participated in this study. During DI, subjects performed NMES muscle groups of both lower extremities. NMES continued for 6 d, during which daily 5 d on end (from Monday to Friday inclusive) including one day of rest (Saturday). Before and after DI with NMES, а internal architecture (lengths and angles of fascicles, and muscle thickness) of human triceps surae were determined. The triceps surae muscle architecture was measured in vivo by use of B-mode ultrasonography. The ank1e was positioned at 15 dorsiflexion ° ( 15 ) and 0, +15, and +30 p1antar flexion, with the knee set at 90. At each position, longitudina1 u1trasonic...
Aims of research. Investigation of a wave of unloading in a cylindrical network of nonlinear elastic fibers. Given the many options for wave propagation in cylindrical networks, an attempt is made to solve the problem of continuous waves. Methods. The movement of the network in the axial direction is cornsidered. nonlinear elastic fibers; To a basis of a cylindrical system are accepted: an individual vector i r parallel wave of unloading; cylindrical network; to a cylinder axis, j r · an individual vector of a tangent to cross-section section continuous waves of the cylinder, k · an individual vector perpendicular to the previous ones, x is the coordinate in the direction of the axis of the cylinder, y is the length of an arc of the circumference of the cylinder. The problem reduces to a hyperbolic system of equations under appropriate conditions. Since the wave speed increases when the net is stretched, the stretch wave will obviously be discontinuous. In order to study continuous ...