Clinical evaluation during walker-assisted gait is the first step to assess the evolution of a patient during rehabilitation and to identify his needs and difficulties. Advances in robotics made it possible to integrate a gait analysis tool on a walker to enrich the existing rehabilitation tests with new sets of objective gait parameters. This paper focuses on the legs detection method to estimate legs position during an assisted walk and the detection of gait events. In this paper, a walker is equipped with a laser range sensor (LRF) and encoders to analyze the spatiotemporal parameters of the walker users. Preliminary results obtained on ten subjects show that relevant data using a LRF can be extracted for gait analysis with a small error.