In modified couple stress analysis of Timoshenko micro-beams, three geometrical parameters, including the deflection, rotation and slope are appeared as the natural boundary conditions in the variational formulation. This leads to appearance of more natural parameters at each section and increase in computational cost of numerical investigations. In this study, a new idea is proposed for revising the boundary conditions, and based on primary kinematical considerations in the classical Timoshenko beam theory, the slope is discarded from the boundary conditions. Then a modified form of governing equations is proposed for deriving the weak form. Based on this consideration, several numerical problems are investigated as the case studies and the results of proposed model are compared with exact analytical solutions and available data from the experimental investigations. According to the obtained results, the present model provides accurate results and can be reliably used for one-dimensional microstructural analysis with various loading and support conditions.