Abstract: Objective To analyze the latency of posture evoked response of normal lower limb muscle in different stimulations and explore its influencing factors. Methods The normal lower limb was induced to produce postural evoked response by the dynamic posturography through two kinds of perturbations, the supporting surface rotation stimulation （Toes-up and Toes-down） and the horizontal perturbation stimulation （Forward and Backward）. The latencies of tibialis anterior muscle and gastrocnemius muscle were recorded by surface electromyography acquisition system. The differences of the left and right limb, gender and height on the latency of postural evoked response were analyzed. Results （1） Under the Toes-up and Backward perturbation, the latency of tibialis anterior muscle was longer than gastrocnemius muscle; under the Toes-down and Forward perturbation, the latency of gastrocnemius muscle was longer than tibialis anterior muscle. （2） The latencies of left limb and right limb had no significant difference. （3） The latency in male was longer than that in female. （4） The latency gradually increased with the increase of height. Conclusion In the postural evoked response, different perturbations, gender and height have significant impacts on the latency of posture evoked response of lower limb muscle. However, the effect of height and gender should be not considered referring to the same individual.

Key words: forensic medicine, evoked potentials, muscle, skeletal, dynamic posturography