Decreasing balance ability in older adults increases the risk of falls. According to the literature, two balance strategies are revealed, ankle strategy and hip strategy. The aim of this paper is to study the postural stability of the one leg stance on the frontal plane and verify the strategy used in older adults. A hypothesis about two different patterns in hip strategy is made and experiments were conducted with 80 healthy elderly subjects. The posture is captured by Waseda Bioinstrumentation -4 Rev Inertial Measurement Unit (WB-4R IMU). The preliminary analysis shows the dominant pattern is moving the upper body in a lateral direction when losing balance on frontal plane.