In this study, we examined the effect of the SOA- plate on strain and displacement in the proximal, femur, using 9 fresh cadaver femora instrumented with six strain gauges along the medial and lateral conices. Before and after experimentally created two-part and four-part fractures. Strain patterns and screw motion were compared. With previously obtained values for a sliding hip screw and the Richards screw device, the biomechanical characteristics of the three devices were loaded to 1800N. Experimental results showed, thehe other inter fixation device in the treatment of unstable intertrochanteric fractures (P<0.01).