FIELD: medical engineering. SUBSTANCE: device has base, fixing member and working parts. The fixing member has vertical half-ring, threaded rest rod, threaded axial rod having cantilever with internal thread. Hinged unit having outer strips with holes put on over the axial rod is attached to the free portion of the axial rod, strips are fixed by means of locking nuts. The rods have two nuts each. Control scale with pointer for determining unit rotating angle is attached to the half-ring. The working part has horizontal half-ring with a rod attached to it by means of coupling fixing member. Cross-strip with cantilever and axial rod inserted into it is attached to its upper end. Movable roller is fixed on one rod end and screw is fixed on the other end. EFFECT: high accuracy in determining instability degree by means of modeling. 3 cl, 5 dwg
